Apparatus and method for preparing cooling water on demand

Abstract

The present invention relates to a solution of industrial water, a solution of water treated with a cationic ion exchanger, a solution of demineralized water, a solution of Mg 2+ and Ca 2+ The present invention relates to a cooling water preparation method for reproducing a target cooling water by using at least two aqueous solutions selected from among aqueous solutions containing ions. The present invention also relates to a casting method using cooling water obtained by the preparation method, and a casting device (100) including the preparation device.

Description

[Technical field]

[0001] The present invention relates to a method for preparing cooling water for cooling products during metallurgical processing operations, in particular for casting applications of cast parts, for example in a casting process of products, preferably products made of aluminum alloys. The present invention also relates to a casting device comprising a device for preparing cooling water. [Background technology]

[0002] It is known from the prior art (Gildemeister D., Light Metals 2014, pp. 885-891) that the composition of cooling water intended for metallurgical processing methods can have an influence on the cooling process. In particular, the use of cooling water with an uncontrolled and / or unadapted composition during the formation of plates in semi-continuous casting can produce negative effects on the formation of the plates, such as cracks, breaks, excessive bending of the plate legs, expansion that can block the casting process or induce leakage of liquid metal, etc. The influence of each parameter constituting the cooling water is not yet fully known, but on the other hand, it has already been demonstrated that alkalinity (characterized by P-alkalinity (TA) and total alkalinity (TAC)), hardness (characterized for example by hardness (TH)), pH, conductivity or turbidity have an influence on the heat transfer.

[0003] There is therefore a need to be able to vary the cooling water parameters to study their effects and to be able to use optimized water depending on the case. Indeed, it is necessary to be able to control the quality of the water at the start of semi-continuous casting and to be able to use cooling water different from the water available at the industrial site.

[0004] Moreover, before carrying out a metallurgical processing method on an industrial scale, cooling tests are often carried out by means of simulations or actual tests to determine the cooling conditions adapted to a given industrial water. However, once determined, these cooling conditions are generally not transferable for all industrial waters, which makes it difficult to transfer metallurgical processing processes from one industrial site to another. Moreover, since the test means for determining the cooling conditions are not systematically present at the production site, it seems that a solution could be to carry out these tests at a site separate and remote from the production site. However, this solution requires that water from the production site is available at this other site in sufficient quantities. The major problem with such a cooling water supply is the large volume required, which involves obvious logistical and cost problems. Moreover, changes in the composition of the cooling water may occur during transportation.

[0005] Therefore, there is a need to have available on demand cooling water that is a faithful replica of the cooling water that will subsequently be used at the production site for the tests carried out during the determination of cooling conditions. Alternatively, there is also a need to have available foundry cooling water with a specific composition that allows having a constant thermal efficiency over time, especially during the start-up transient phase. However, this problem is difficult to solve, since the composition of the water is not easy to control and modify, especially when it concerns the concentration of dissolved CaSO4 and MgCO4 salts. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Gildemeister D., Light Metals 2014, pp. 885-891 Summary of the Invention [Problem to be solved by the invention]

[0007] The object of the present invention is to propose a solution which answers all or part of the aforementioned problems. [Means for solving the problem]

[0008] This object is achieved in a method for the preparation of cooling water for cooling products during metallurgical processing operations, in particular for the application of semi-continuous casting of cast products, by implementing a method comprising the following steps: - analyzing the composition of the target cooling water to determine a target final composition (cfc). The analysis result is substantially identical to the target final composition (cfc). According to the invention, the term "substantially" must be understood as being capable of generating an approximation of at least one useful parameter. In fact, the analysis step makes it possible to determine at least one useful parameter selected from the group comprising calcium concentration (THCa), magnesium concentration (THMg), total alkalinity (TAC), P-alkalinity (TA), hardness (TH), chloride ion concentration (CCl), sulfate ion concentration (CS), bromide ion concentration (CBr), sodium ion concentration (CNa) and pH. The target composition (cfc) can therefore be identical to the analysis result or equal to + / - 10%, preferably + / - 5%, of the analysis result. - providing at least one first aqueous solution characterized by a first composition and at least one second aqueous solution different from the first aqueous solution and characterized by a second composition, said first aqueous solution and said second aqueous solution having: Industrial water solutions, A solution of water treated with a cationic ion exchanger, Demineralized water solution, Mg 2+ and Ca 2+ An aqueous solution containing ions, A step selected from the group consisting of: a first mixing step in which a first volume of a first aqueous solution and a second volume of a second aqueous solution are mixed to produce a mixture volume of a mixture solution which forms the whole or part of the cooling water and which is characterized by a mixture composition, said first volume of the first aqueous solution and said second volume of the second aqueous solution being determined by a calculation step (E7) depending on said first composition and said second composition, a mixing stage, wherein each of the first composition (c1), the second composition (c2), the mixture composition (cm1) and the target final composition (cfc) is defined by at least one useful parameter selected from the group consisting of calcium concentration (THCa), magnesium concentration (THMg), total alkalinity (TAC), P-alkalinity (TA), hardness (TH), chloride ion concentration (CCl), sulfate ion concentration (CS), bromide ion concentration (CBr), sodium ion concentration (CNa) and pH; - a calculation step (E7), in which a first volume (V1) of the first aqueous solution and a second volume (V2) of the second aqueous solution are determined depending on said at least one useful parameter defining a first composition (c1), said at least one useful parameter defining a second composition (c2) and such that said at least one useful parameter defining a mixture composition (cm1) approaches said at least one useful parameter defining a target final composition (cfc).

[0009] By industrial water is meant industrial water having a conductivity of 2000 μS / cm or less, preferably between 100 μS / cm and 2000 μS / cm. Preferably, the hardness of industrial water is 80° F or less, preferably 50° F or less. By industrial water is meant water used for industrial purposes, as opposed to domestic water and agricultural water.

[0010] By water solution treated with a cationic ion exchanger is meant a solution having a conductivity of 100 μS / cm or more, being decarbonated water with TH≦TAC+3°f or displaced water with TH≦3°f, where TH and TAC are the hardness and P alkalinity, respectively, of the water solution treated with the cationic ion exchanger under consideration, expressed in French hardness.

[0011] By demineralized water solution is meant a solution with a conductivity of 100 μS / cm or less. Demineralized water is defined as a solution that does not contain any dissolved ions (e.g. Ca 2+ or HCO3 - Demineralized water is water that no longer contains any dissolved inorganic substances (such as aluminum hydroxide (Al(OH)3) or iron(III) hydroxide (Fe(OH)3), dissolved silica (Si(OH)4), etc.) and is completely free of dissolved neutral inorganic substances (such as aluminum hydroxide (Al(OH)3) or iron(III) hydroxide (Fe(OH)3), dissolved silica (Si(OH)4), etc.). Demineralized water has a hardness of 1°F or less.

[0012] "Mg 2+ and Ca 2+ By "aqueous solution containing ions" is meant a solution whose conductivity is 20 μS / cm or more and whose hardness TH is greater than 50° F. Preferably, Mg 2+ and Ca 2+ The hardness TH of an aqueous solution containing ions is at least 5 times greater than the hardness of an industrial water solution. 2+ and Ca 2+ "An aqueous solution containing Mg ions" refers to 2+ and Ca 2+ The ion concentrations of industrial water, water treated with cationic ion exchangers, and desalted water are 2+ and Ca 2+ It means a solution with a higher ion concentration than that of Mg 2+ and Ca 2+ By using an aqueous solution containing Mg ions, it becomes possible to more easily and on demand produce cooling water with a composition close to the target final composition. 2+ and Ca 2+ The use of aqueous solutions containing ions is highly advantageous when water with harder properties than available industrial water is required, or to stabilize the composition of the water in relation to seasonal variations.

[0013] The measures described above make it possible to propose a method for the preparation of cooling water having a composition close to the target final composition.

[0014] The preparation method may further comprise one or more of the following features, considered separately or in combination:

[0015] According to one embodiment, the providing step comprises providing a third or fourth aqueous solution selected to be different from each other and from the first and second aqueous solutions, said third or fourth aqueous solutions being: - Industrial water solutions, - a solution of water treated with a cationic ion exchanger, - a solution of demineralized water, - Mg 2+ and Ca 2+ an aqueous solution containing ions, is selected from the group consisting of:

[0016] In this case, the first mixing step includes mixing the third and / or fourth aqueous solution with the first and second aqueous solutions, and it is therefore appreciated that the mixing step of a first volume of the first aqueous solution with a second volume of the second aqueous solution is not limiting and may include mixing of three or more different aqueous solution volumes.

[0017] According to one embodiment, the cooling water is obtained by mixing four aqueous solution volumes, each of which is a solution of industrial water, a solution of water treated with a cationic ion exchanger, a solution of demineralized water and a solution of Mg 2+ and Ca 2+ It is derived from an aqueous solution containing ions.

[0018] According to one embodiment, the target final composition corresponds to the composition of cooling water available at an industrial production site, for example a part production site in a foundry.

[0019] According to one embodiment, the calculation step is carried out by a calculation unit configured to calculate a first volume of the first aqueous solution and a second volume of the second aqueous solution, so as to minimize the difference between said at least one useful parameter defining the mixture composition and said at least one useful parameter defining the target final composition. Advantageously, the calculation unit thus allows a priority selection to be made on the accuracy of one useful parameter in relation to the other useful parameters. In this way, the preparation method can be carried out in cases where there is no unique or exact mathematical solution for the preparation of cooling water having a composition close to the target final composition.

[0020] According to one embodiment, each of the first composition, the second composition, the mixture composition and the target final composition is defined by a plurality of useful parameters, and the calculation step can be performed by weighting each useful parameter of the plurality of useful parameters by a weighting factor.

[0021] According to one embodiment, the mixing step comprises: - a step of controlling the mixture composition, in which an intermediate value of said at least one useful parameter defining the mixture composition is determined so as to calculate an initial deviation between said intermediate value and a target value of said at least one useful parameter defining a target final composition, - if the initial deviation is greater than the threshold deviation, the mixing stage is performed by mixing the volume of solution of industrial water, the volume of solution of water treated with a cationic ion exchanger, the volume of solution of demineralized water, Mg 2+ and Ca 2+A second mixing step is included in which at least one correction factor selected from the group consisting of a volume of an aqueous solution containing ions, a mass of a salt and a mass of a pH adjuster is mixed into the mixture solution to produce a corrected mixture volume of the corrected mixture solution characterized by a corrected mixture composition defined by at least one useful parameter, said at least one correction factor being selected in such a way that a corrected deviation between the corrected value of said at least one useful parameter defining the corrected mixture composition and said target value is smaller than an initial deviation.

[0022] According to an embodiment, the second mixing step is performed as long as the corrected deviation is greater than a threshold deviation. According to an embodiment, the control step comprises determining the corrected deviation. According to an embodiment, the threshold deviation may be equal to 10% of the target value.

[0023] According to one embodiment, at least one of the first and second mixing steps is carried out to maintain the corrected mixture solution at a temperature between 10°C and 35°C, preferably between 12°C and 30°C.

[0024] According to one embodiment, the preparation method further comprises a step of providing at least one additional element selected from the group comprising salts and pH adjusters, and the first mixing step further comprises mixing the additional element mass, said additional element mass being determined according to the first composition and the second composition and the target final composition.

[0025] According to one embodiment, the salts and pH adjusters include sodium chloride NaCl, sodium bicarbonate NaHCO3, sodium carbonate Na2CO3, calcium chloride CaCl2, magnesium sulfate MgSO4, magnesium chloride MgCl2, and sodium bromide NaBr.

[0026] According to one embodiment, the additional element mass is diluted in an aqueous solution during a dilution step prior to the first mixing step. For example, the additional element mass can be diluted in a portion of a solution of demineralized water.

[0027] According to one embodiment, the solution of water treated with a cationic ion exchanger is decarbonated water obtained by the following steps: - providing a cation exchanger comprising a weak cation resin, the cation exchanger being characterized in that the weak cation resin is enriched in calcium divalent cations, Ca 2+ or magnesium divalent cation Mg 2+ The weak cation resin is capable of capturing calcium divalent cation Ca 2+ or magnesium divalent cation Mg 2+ configuring the filling configurations to vary between forming a stockpile of; - a charging step with a weak cation resin, during which part of the industrial water solution is circulated through the cation exchanger, causing it to vary from a regenerated configuration to a charged configuration; - a degassing step in which the water leaving the cation exchanger is degassed so as to obtain decarbonated water.

[0028] According to one embodiment, the weak cation resin contains calcium divalent cations, Ca, bound to carbonate or bicarbonate ions. 2+ or magnesium divalent cation Mg 2+ can be captured.

[0029] In this case, the degassing step comprises degassing the water loaded with dissolved carbonic acid (derived from calcium and magnesium carbonates and bicarbonates) leaving the cation exchanger. According to one embodiment, the degassing step is carried out naturally by leaving the water leaving the cation exchanger in open air. According to one embodiment, the degassing step is carried out in a degassing tower.

[0030] According to one embodiment, the degassing step is carried out by subjecting the water leaving the cation exchanger to a continuous cascade, or by mixing, stirring, bubbling, or by using a fluidized degassing tower with countercurrent injection of air.

[0031] According to one embodiment, the solution of water treated with a cationic ion exchanger is displaced water obtained by the following steps: - providing a cation exchanger comprising a strong cation resin, the cation exchanger being characterized in that the strong cation resin is a calcium divalent cation, Ca 2+ or magnesium divalent cation Mg 2+ The regeneration structure can capture the divalent cation Ca of calcium, and the strong cation resin can capture the divalent cation Ca of calcium. 2+ or the divalent cation of magnesium, Mg 2+ configuring the filling configurations to vary between forming a stockpile of; - A part of the industrial water solution is circulated through the cation exchanger to change the cation exchanger from the regenerated configuration to the packed configuration and to remove Ca 2+ and Mg 2+ A step of loading with a strong cationic resin in such a way as to obtain cation-free displaced water.

[0032] According to one embodiment, the strong cation resin contains calcium divalent cations, Ca, bound to carbonate or bicarbonate ions. 2+ or magnesium divalent cation Mg 2+ can be captured.

[0033] The use of strong cationic resins to obtain a solution of water treated with cationic ion exchangers is advantageous when the industrial water solution contains little calcium carbonate and has a low alkalinity. Regeneration mode with salt (softener type) or regeneration mode with dilute strong acid (H3O + When using a regeneration mode with salts such as NaCl or Na2SO4, the substituted water can also be called "soft water". Soft water is water in which the cations are completely replaced by Ca 2+ and Mg 2+ The cation is Na + When using the dilute strong acid regeneration mode, the replacement water is "hydronium ion H3O +This water can also be called "water in which all cations have been replaced by hydronium ions H3O + By Ca 2+ and Mg 2+ It is water that has replaced the cations.

[0034] According to one embodiment, the loading step with a weak or strong cation resin comprises a loading level detection step, in which measurements are made of the variations in pH or another parameter of the water present at the outlet of the cation exchanger in order to constantly deduce the loading level of the cation exchanger (e.g. for future cycles).

[0035] According to one embodiment, the demineralized water solution is obtained by a desalination step in which a part of the decarbonated water solution or of the replacement water solution is desalinated by reverse osmosis or by an ion exchange process on a desalination resin so as to obtain a demineralized water solution. The desalination process conventionally comprises (depending on the composition of the water and in particular its alkalinity) a replacement operation on a strong cation resin, degassing and a replacement operation of the anions on one or two anion resins. Preferably, when using replacement water obtained by a regeneration technique with dilute strong acids, the replacement step on a cation resin is not necessary to obtain the demineralized water.

[0036] According to one embodiment, Mg 2+ and Ca 2+ The aqueous solution containing ions is Mg 2+ and Ca 2+ The Mg was captured by weak or strong cation resins to produce an aqueous solution containing ions. 2+ and Ca 2+ The ions are obtained during an elution step in which a strong acid is circulated through the cation exchanger in such a way that they dissolve.

[0037] According to one embodiment, the elution step is carried out with the addition of Mg to optimize the amount of acid used and to optimize the regeneration of the cation exchanger. 2+ and Ca 2+ A measuring step is included in which the pH of an aqueous solution containing ions is measured.

[0038] According to one embodiment, the amount of strong acid added during the elution step is defined in relation to a certain volume of weak or strong cation resin to be treated. Such an amount of strong acid can, for example, form part of the technical data of the cation resin used, said technical data specifying the volume and concentration of strong acid required to regenerate said cation resin.

[0039] According to one embodiment, Mg 2+ and Ca 2+ The aqueous solution containing ions is obtained by taking a partial amount of the solution obtained during the elution step. For example, such a partial amount may correspond to the amount of water produced at the beginning of the elution step. In this case, the remainder of the water produced during the elution step, which is necessary for the regeneration of the cation exchanger, is then treated and discharged. In this way, the Mg content in the solution obtained during the elution step is reduced when the weak or strong cation resin is completely regenerated. 2+ and Ca 2+ It is possible to control and limit the excess of strong acid with an aqueous solution containing ions. According to one embodiment, the strong acid is hydrochloric acid or sulfuric acid, preferably diluted in water at a ratio of 2 to 10%. When the strong acid is sulfuric acid, the Mg obtained in the elution step is 2+ and Ca 2+ The ion-containing aqueous solution contains dissolved salts of CaSO4 and MgSO4.

[0040] According to one embodiment, the elution step is carried out after a loading step with a weak cation resin or after a loading step with a strong cation resin, it being therefore understood that the elution step and then the loading step make it possible to alternate the cation exchanger between a regeneration configuration and a loading configuration.

[0041] According to one embodiment, the preparation method further comprises a second analysis step in which at least one useful parameter of the industrial water solution selected from the group comprising calcium concentration, magnesium concentration, total alkalinity, P-alkalinity, hardness and pH is measured.

[0042] According to one embodiment, the second analysis step is carried out on the solution of water treated with a cationic ion exchanger, or on the solution of demineralized water, or on the solution of Mg 2+ and Ca 2+ It can be carried out to determine useful parameters for aqueous solutions containing ions.

[0043] The aforementioned measures allow the selection of one or more aqueous solutions having a composition more suitable to serve as a base for producing a mixture solution having a mixture composition approaching the target final composition. The object of the present invention can also be achieved by the use of a cooling water obtained by the above-mentioned preparation method and characterized by said target final composition, for cooling products in metallurgical processing steps such as casting, quenching or hot rolling.

[0044] The object of the invention can also be achieved by carrying out a method for casting a product, preferably made of an aluminium alloy, comprising the following steps: - (a) preparing a liquid metal bath, preferably made of an aluminium alloy containing, in weight percent, 0-6.0 Cu; 0-8 Mg; 0-12 Si; 0-12 Zn, each of the other components being up to 3 and totaling up to 10, the balance being aluminium; - (b) casting said liquid metal, preferably by vertical semi-continuous casting, such that during the initial casting phase a first cooling water is used, characterized by a first mixture composition obtained by the above-mentioned preparation method.

[0045] The casting method according to the invention comprises the preparation method defined above.

[0046] The first cooling water characterized by a first mixture composition is - analyzing a target cooling water composition to determine a target final composition; - providing at least one first aqueous solution characterized by a first composition and at least one second aqueous solution different from the first aqueous solution and characterized by a second composition, said first aqueous solution and said second aqueous solution having: Industrial water solutions, A solution of water treated with a cationic ion exchanger, Demineralized water solution, Mg 2+ and Ca 2+ an aqueous solution containing ions, and - a first mixing step in which a first volume of a first aqueous solution and a second volume of a second aqueous solution are mixed to produce a mixture volume of a mixture solution constituting all or part of the cooling water and characterized by a mixture composition, the first volume of the first aqueous solution and the second volume of the second aqueous solution being determined as a function of the first composition and the second composition, Each of the first composition (c1), the second composition (c2), the mixture composition (cm1) and the target final composition (cfc) is defined by at least one useful parameter selected from the group including calcium concentration (THCa), magnesium concentration (THMg), total alkalinity (TAC), P-alkalinity (TA), hardness (TH), chloride ion concentration (CCl), sulfate ion concentration (CS), bromide ion concentration (CBr), sodium ion concentration (CNa) and pH; - a calculation step (E7) in which a first volume (V1) of the first aqueous solution and a second volume (V2) of the second aqueous solution are determined depending on said at least one useful parameter defining a first composition (c1), said at least one useful parameter defining a second composition (c2) and such that said at least one useful parameter defining a mixture composition (cm1) approaches said at least one useful parameter defining a target final composition (cfc); The compound is obtained by a preparation method comprising the steps of:

[0047] The preparation method may further have one or more of the features presented above.

[0048] The casting method may further comprise one or more of the following characteristics, considered separately or in combination:

[0049] According to one embodiment, the casting method comprises, at the completion of the start-up casting phase, a steady-state casting phase, characterized in that during the steady-state casting phase a second cooling water is used, characterized by a second composition different from the first cooling water. Optionally, this second cooling water is obtained by a conditioning method. Optionally, this second composition is a second mixture composition obtained by a preparation method. According to another embodiment, the second cooling water is not obtained by the preparation method of the invention and may be a solution of industrial water.

[0050] Finally, an object of the present invention is to provide a casting apparatus including a cooling water preparation device, said preparation device comprising a mixing unit adapted to contain a first aqueous solution characterized by a first composition and a second aqueous solution different from the first aqueous solution and characterized by a second composition, said first and second aqueous solutions being: - Industrial water solutions, - a solution of water treated with a cationic ion exchanger, - a solution of demineralized water, - Mg 2+ and Ca 2+ An aqueous solution containing ions, is selected from the group consisting of It can also be achieved by implementing a casting apparatus including a mixing unit configured to mix a first volume of the first aqueous solution and a second volume of the second aqueous solution to produce a mixture volume of a mixture solution constituting all or a portion of a cooling water and characterized by a mixture composition, wherein the first volume of the first aqueous solution and the second volume of the second aqueous solution are determined as a function of the first composition and the second composition, and such that the mixture composition approaches a predetermined target final composition.

[0051] The casting apparatus may further comprise one or more of the following features, considered separately or in any combination:

[0052] According to one embodiment, the mixing unit is configured to mix two or more volumes of aqueous solution.

[0053] According to one embodiment, the preparation device comprises: - a first tank configured to contain a solution of industrial water; - a second tank configured to receive the solution of water treated with the cationic ion exchanger; - a third tank configured to contain a solution of demineralized water; - Mg 2+ and Ca 2+ a fourth tank configured to contain an aqueous solution containing ions; The at least one tank is selected from the group consisting of:

[0054] According to one embodiment, the use of the first tank, the second tank, the third tank and the fourth tank can be replaced by a continuous line mixing method, which means the possibility of performing the mixing of the aqueous solutions directly in the piping, the replenishment equipment system or by inserting a small volume static mixer or mixing reactor.

[0055] According to one embodiment, the mixing unit is further configured to accommodate at least one additional element selected from the group including salts and pH adjusters and to mix a mass of the additional element with the solution of the mixture, the mass of the additional element being determined according to the first composition, the second composition and the target final composition.

[0056] According to one embodiment, the preparation device further comprises an additional element storage unit configured to store said at least one additional element.

[0057] In one embodiment, the casting apparatus further comprises a calculation unit configured to determine a first volume of the first aqueous solution and a second volume of the second aqueous solution as a function of useful parameters defining the first composition, useful parameters defining the second composition, and in a manner such that the useful parameters defining the mixture composition approach the useful parameters defining the target final composition.

[0058] According to one embodiment, the casting apparatus further comprises a cation exchanger comprising an active material, said cation exchanger being calcium divalent cation Ca 2+ or magnesium divalent cation Mg 2+ is bound to the active material, and the active material is a calcium divalent cation, Ca 2+ or magnesium divalent cation Mg 2+ and a regenerated configuration capable of capturing cations, said cation exchanger comprising a means for allowing connection to a mixing unit. According to one embodiment, the cation exchanger comprises a weak cation resin. According to one embodiment, the cation exchanger comprises a strong cation resin.

[0059] According to one embodiment, the cation exchanger comprises means allowing it to be connected to at least one tank, such as a first tank, a second tank, a third tank or a fourth tank.

[0060] According to one embodiment, the casting apparatus further comprises a reverse osmosis apparatus or an ion exchanger with desalting resin, said reverse osmosis apparatus or said ion exchanger comprising means making it possible to connect it to a mixing unit and a cation exchanger.

[0061] According to one embodiment, the reverse osmosis device or the ion exchanger in the desalination resin comprises means allowing it to be connected to at least one tank, such as a first tank, a second tank, a third tank or a fourth tank.

[0062] According to one embodiment, the preparation device comprises a strong acid supply device, said strong acid supply device being configured to be coupled to the cation exchanger.

[0063] According to one embodiment, the casting apparatus further comprises an analysis unit configured to measure at least one useful parameter selected from the group comprising calcium concentration, magnesium concentration, total alkalinity, P-alkalinity, hardness, and pH.

[0064] According to one embodiment, the mixing unit includes a temperature control system including a temperature sensor configured to measure a mixture temperature corresponding to a temperature of the mixture solution, said temperature control system being configured to maintain the mixture temperature between 10°C and 35°C, preferably between 12°C and 30°C.

[0065] According to one embodiment, the temperature control system comprises heating means configured to heat the mixing unit when the mixture temperature is below 10°C, preferably below 12°C.

[0066] According to one embodiment, the temperature control system comprises cooling means configured to cool the mixing unit when the mixture temperature is above 35°C, preferably above 30°C.

[0067] Other aspects, objects, advantages and features of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, given by way of non-limiting example, and with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0068] [Figure 1] 1 is a schematic diagram of a casting apparatus including a preparation device according to a particular embodiment of the present invention; [Diagram 2] FIG. 1 is a schematic representation of some elements of a casting device allowing the preparation of an aqueous solution according to a particular embodiment of the invention. [Diagram 3] FIG. 1 is a schematic diagram of the steps of the preparation method according to a particular embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0069] In the figures and in the following parts of the specification, the same reference numbers represent identical or similar elements. Moreover, different elements are not drawn to scale in order to prioritize clarity of the figures. Moreover, different embodiments and variants are not mutually exclusive and can be combined with each other.

[0070] As illustrated in figures 1 to 3, the present invention relates to a method for the preparation of cooling water 1 for cooling products during metallurgical processing operations, in particular for casting applications of cast parts. The present invention also relates to the use of cooling water 1 obtained by this preparation method for cooling products in metallurgical processing steps such as casting, quenching or hot rolling.

[0071] Unlike continuous casting, where the concept of the start-up step does not prevail with regard to the quality of the final product, since it is possible to cut off parts of the product with defects, it is important to control the cooling during the start-up phase of the product obtained by semi-continuous casting, otherwise there is a risk that its production will be impossible. In semi-continuous casting, the difficulty is in successfully transitioning from the zero speed at the beginning of the product formation to a steady speed. We refer to the start-up phase. This transition is manifested in the form of a deformation of the root of the plate, known to those skilled in the art as camber. If this deformation is too great, as occurs when the root is cooled too strongly, the camber can produce what those skilled in the art call "sink marks", which can sometimes degenerate into "warping", i.e., the jamming of the plate in its mold. Camber associated with unsuitable cooling conditions can lead to root fractures or root cracks, which are less catastrophic. These fractures or cracks are completely harmful, since they can propagate in the steady state and thus cause the product to be scrapped, or if not, and at least, prevent the plate from being hot-rolled without sawing the root to restore the integrity of the product. Finally, camber that does not cause any casting scrap may nevertheless manifest itself in variations in the product cross section and prevent the product from being rolled without sawing off the root.

[0072] The skilled person knows how to implement adapted casting conditions to minimize the appearance of these defects. However, it is important that the conditions found are reproducible from casting to casting. The inventors have discovered that it is especially important to obtain cooling water that is reproducible during all start-up phases with the aim of guaranteeing the same thermal efficiency. The inventors have solved this problem by proposing a cooling water preparation method that makes it possible to produce the target cooling water on demand.

[0073] For example, the target cooling water may correspond to industrial water available at a site where the casting method is to be carried out on a large scale, where this site is different from the production site where the preparation of the cooling water is intended to be carried out. For example, the target cooling water may correspond to industrial water available during certain periods of the year. This is the case, for example, when the industrial water of the site is taken from a river and its composition changes according to the seasonality of summer and winter. It may be advantageous to select the same industrial water to be always available, regardless of the season. The target cooling water may be water that is considered suitable for the start of casting due to its advantage of being energy efficient.

[0074] Figure 1 shows - (a) preparing a liquid metal bath, preferably made of an aluminium alloy containing, by weight, 0-6.0 Cu, 0-8 Mg, 0-12 Si, 0-12 Zn, not more than 3 each and not more than 10 total other elements, the balance being aluminium; - (b) casting said liquid metal, preferably by vertical semi-continuous casting, so that during the initial solidification phase a first cooling water 1a is used, characterized by a first mixture composition cma, which is obtained by the preparation method according to the invention, as described in more detail below; The present invention relates to a method for casting a product, preferably made of an aluminum alloy, comprising:

[0075] Preferably, aluminum alloys of the AA1xxx or AA2xxx or AA3xxx or AA4xxx or AA5xxx or AA6xxx or AA7xxx series are cast.

[0076] As non-limiting examples, examples of AA1xxx series aluminum alloys to be used in the methods described herein may include AA1100, AA1100A, AA1200, AA1200A, AA1300, AA1110, AA1120, AA1230, AA1230A, AA1235, AA1435, AA1145, AA1345, AA1445, AA1150, AA1350, AA1350A, AA1450, AA1370, AA1275, AA1185, AA1285, AA1385, AA1188, AA1190, AA1290, AA1193, AA1198, or AA1199.

[0077] Non-limiting examples of AA2xxx series aluminum alloys to be used in the methods described herein include AA2001, AA2002, AA2004, AA2005, AA2006, AA2007, AA2007A, AA2007B, AA2008, AA2009, AA2010, AA2011, AA2011A, AA2111, AA2111A, AA2111B, AA2012, AA2013, AA2014, AA2014A, AA2214, AA2015, AA2016, AA2017, AA2017A, AA2117, AA2018, AA2218, AA2618, AA2618A, AA2219, AA2319, AA2419, AA2420, AA2421, AA2422, AA2423, AA2424, AA2425, AA2426, AA2427, AA2428, AA2429, AA2430, AA2431, AA2432, AA2433, AA2434, AA2435, AA2436, AA2437, AA2438, AA2439, AA2440, AA2441, AA2442, AA2443, AA2444, AA2445, AA2446, AA2447, AA2448, AA2449, AA2450, AA2451, AA2452, AA2453, AA2454, AA24 AA2124, AA2224, AA2224A, AA2324, AA2424, AA2524, AA2624, AA2724, AA2824, AA2025, AA2026, AA2027, AA2028, AA2 028A, AA2028B, AA2028C, AA2029, AA2030, AA2031, AA2032, AA2034, AA2036, AA2037, AA2038, AA2039, AA2139, AA204 AA2097, AA2197, AA2297, AA2397, AA2098, AA2198, AA2099, or AA2199.

[0078] Non-limiting examples of AA3xxx series aluminum alloys to be used in the methods described herein may include AA3002, AA3102, AA3003, AA3103, AA3103A, AA3103B, AA3203, AA3403, AA3004, AA3004A, AA3104, AA3204, AA3304, AA3005, AA3005A, AA3105A, AA3105B, AA3007, AA3107, AA3207, AA3207A, AA3307, AA3009, AA3010, AA3110, AA3011, AA3012, AA3012A, AA3013, AA3014, AA3015, AA3016, AA3026, AA30, AA30, AA30, or AA3065.

[0079] Non-limiting examples of AA4xxx series aluminum alloys to be used in the methods described herein may include AA4004, AA4104, AA4006, AA4007, AA4008, AA4009, AA4010, AA4013, AA4014, AA4015, AA4015A, AA4115, AA4016, AA4017, AA AA4019, AA4020, AA4021, AA4026, AA4032, AA4043, AA4043A, AA4143, AA4343, AA4643, AA4943, AA4044, AA4045, AA4145, AA4145A, AA4046, AA4047, AA4047A or AA44.

[0080] Non-limiting examples of AA5xxx series aluminum alloys to be used in the methods described herein include AA5182, AA5183, AA5005, AA5005A, AA5205, AA5305, AA5505, AA5605, AA5006, AA5106, AA5010, AA5110, AA5110A, AA5210, AA5310, AA5016, AA5017, AA5018, AA5018A, AA5019, AA5019A. , AA5119, AA5119A, AA5021, AA5022, AA5023, AA5024, AA5026, AA5027, AA5028, AA5040, AA5140, AA5041, AA5042, AA5043 , AA5049, AA5149, AA5249, AA5349, AA5449, AA5449A, AA5050, AA5050A, AA5050C, AA5150, AA5051, AA5051A, AA5151, AA52 51, AA5251A, AA5351, AA5451, AA5052, AA5252, AA5352, AA5154, AA5154A, AA5154B, AA5154C, AA5254, AA5354, AA5454, A A5554, AA5654, AA5654A, AA5754, AA5854, AA5954, AA5056, AA5356, AA5356A, AA5456, AA5456A, AA5456B, AA5556, AA555 AA5183, AA5283A, AA5283, AA5283A, AA5283B, AA5383, AA5483, AA5086, AA5186, AA5087, AA5187, or AA5088.

[0081] Non-limiting examples of AA6xxx series aluminum alloys to be used in the methods described herein include AA6101, AA6101A, AA6101B, AA6201, AA6201A, AA6401, AA6501, AA6002, AA6003, AA6103, AA6005, AA6005A, AA6005B, AA6005C, AA6105, AA6205, AA6305, AA6006, AA6106, AA6206 , AA6306, AA6008, AA6009, AA6010, AA6110, AA6110A, AA6011, AA6111, AA6012, AA6012A, AA6013, AA6113, AA6014, AA6 015, AA6016, AA6016A, AA6116, AA6018, AA6019, AA6020, AA6021, AA6022, AA6023, AA6024, AA6025, AA6026, AA6027, A A6028, AA6031, AA6032, AA6033, AA6040, AA6041, AA6042, AA6043, AA6151, AA6351, AA6351A, AA6451, AA6951, AA605 3, AA6055, AA6056, AA6156, AA6060, AA6160, AA6260, AA6360, AA6460, AA6460B, AA6560, AA6660, AA6061, AA6061A, AA AA6061, AA6361, AA6162, AA6262, AA6262A, AA6063, AA6063A, AA6463, AA6463A, AA6763, AA6963, AA6064, AA6064A, AA6065, AA6066, AA6068, AA6069, AA6070, AA6081, AA6181, AA6181A, AA6082, AA6082A, AA6182, AA6091 or AA6092.

[0082] Non-limiting examples of AA7xxx series aluminum alloys to be used in the methods described herein include AA7011, AA7019, AA7020, AA7021, AA7039, AA7072, AA7075, AA7085, AA7108, AA7108A, AA7015, AA7017, AA7018, AA7019A, AA7024, AA7025, AA7026, AA7027, AA7028, AA7029, AA7030, AA7031, AA7032, AA7033, AA7034, AA7035, AA7036, AA7037, AA7038, AA7039A, AA7039, AA7040, AA7041, AA7042, AA7043, AA7044, AA7045, AA7046, AA7047, AA7048, AA7049, AA7050, AA7051, AA7052, AA7053, AA7054, AA7055, AA7056, AA7057, AA7058, AA7059, AA7060, AA7061, AA7062, AA7063, AA7064, AA7065, AA7066, AA7067, AA7068, AA7069, AA7070, AA7071, AA7072, AA7075, AA7085, AA7108, AA7108A, AA7015, 025, AA7028, AA7030, AA7031, AA7033, AA7035, AA7035A, AA7046, AA7046A, AA7003, AA7004, AA7 005, AA7009, AA7010, AA7011, AA7012, AA7014, AA7016, AA7116, AA7122, AA7023, AA7026, AA7029 , AA7129, AA7229, AA7032, AA7033, AA7034, AA7036, AA7136, AA7037, AA7040, AA7140, AA7041, A A7049, AA7049A, AA7l49, 7204, AA7249, AA7349, AA7449, AA7050, AA7050A, AA7150, AA7250, AA70 55, AA7155, AA7255, AA7056, AA7060, AA7064, AA7065, AA7068, AA7168, AA7175, AA7475, AA7076, AA7178, AA7278, AA7278A, AA7081, AA7181, AA7185, AA7090, AA7093, AA7095 or AA7099.

[0083] As shown in the non-limiting example of FIG. 1, the casting method can include a steady-state phase c at the completion of the casting start phase, characterized in that a second cooling water is used during the casting steady-state phase c. The second cooling water 1b is characterized by a second target final composition cfb. For example, this second cooling water 1b can also be obtained by the preparation method described in more detail below. Alternatively, the second cooling water 1b can correspond to a solution 3 of industrial water.

[0084] 1-3 show a non-limiting example of a preparation method according to one particular embodiment of the present invention.

[0085] The preparation method comprises a first analysis step E1 of the target cooling water 1 composition. This analysis step allows the determination of the target final composition cfc. Generally, according to the invention, the determination of the composition corresponds to the determination of at least one useful parameter selected from the group comprising the calcium concentration THCa, the magnesium concentration THMg, the total alkalinity TAC, the P-alkalinity TA, the hardness TH, the chloride ion concentration CCl, the sulfate ion concentration CS, the bromide ion concentration CBr, the sodium ion concentration CNa and the pH.

[0086] Thus, the target final composition cfc determined by the first analysis step E1 makes it possible to define at least one target useful parameter puc selected from the group comprising the calcium concentration THCa, the magnesium concentration THMg, the total alkalinity TAC, the P-alkalinity TA, the hardness TH, the chloride ion concentration CCl, the sulfate ion concentration CS, the bromide ion concentration CBr, the sodium ion concentration CNa and the pH.

[0087] The preparation method comprises a step E6 of providing at least one first aqueous solution characterized by a first composition c1 and at least one second aqueous solution different from the first aqueous solution and characterized by a second composition c2, said first aqueous solution and said second aqueous solution being: - Industrial water solution 3, - a solution of water treated with a cationic ion exchanger 5, - solution of demineralized water 7, - Mg 2+ and Ca 2+ 9. Aqueous solutions containing ions; The method also includes a step selected from the group consisting of:

[0088] As in the case of the target final composition cfc, the first composition c1 and the second composition c2 have a calcium concentration THCa, a magnesium concentration THMg, a total alkalinity TAC, and a P alkalinity TA , hardness TH, chloride ion concentration CCl, sulfate ion concentration CS, bromide ion concentration CBr, sodium ion concentration CNa and pH.

[0089] The at least one defined useful parameter pu1 and pu2 is of the same nature as the useful parameter puc of said at least one target. The compositions c1 and c2 are different.

[0090] Preferably, the industrial water solution 3 is characterized by a conductivity between 100 μS / cm and 2000 μS / cm.

[0091] Preferably, the cationic ion exchanger treated water solution 5 is decarbonated water, preferably decarbonated water having a conductivity of 100 μS / cm or more and a hardness TH in French hardness (°f) units such that TH≦TAC+3°f and a total alkalinity TAC in French hardness (°f) units. Preferably, the cationic ion exchanger treated water solution 5 is permuted water, preferably having a conductivity of 100 μS / cm or more and a hardness TH in French hardness (°f) units such that TH≦3°f.

[0092] Preferably, the demineralized water 7 has a conductivity of less than 100 μS / cm.

[0093] Preferably, Mg 2+ and Ca 2+ The aqueous solution containing the ions has a conductivity of 20 μS / cm or greater and a hardness TH in French hardness (°f) units such that TH≧50°f.

[0094] According to the present invention, in one embodiment, the first aqueous solution and the second aqueous solution are both a solution of industrial water or a solution of water treated with a cationic ion exchanger or a solution of Mg 2+ and Ca 2+ It may be an aqueous solution containing ions, yet the compositions c1 and c2 are different.

[0095] FIG. 2 illustrates in more detail the various means by which the four solutions mentioned above can be obtained.

[0096] The solution 3 of industrial water corresponds, for example, to the water present at the industrial site where the preparation method object of the present invention is carried out. It is possible that this industrial site is a different site from the industrial site where the target cooling water is available. For example, the target cooling water may correspond to the industrial water available on the site where the casting method is carried out on a large scale. The solution 3 of industrial water may itself correspond to the industrial water present on the industrial site for the development of the casting method. The solution 3 of industrial water may be obtained from pumping in an aquifer and then treated by various steps such as iron removal, and / or filtration, and / or redox stabilization, so as to be stable and usable for the industrial needs of the site.

[0097] The industrial water solution 3 may come from a water tank allowing recycling of the water by cooling (eg using a cooling tower or a cold generating unit).

[0098] It may therefore be advantageous for the preparation method to comprise a second analysis step E2 in which at least one useful parameter of said industrial water solution 3 is measured, selected from the group comprising calcium concentration THCa, magnesium concentration THMg, total alkalinity TAC, P-alkalinity TA, hardness TH, chloride ion concentration CCl, sulfate ion concentration CS, bromide ion concentration CBr, sodium ion concentration CNa and pH. The useful parameter analyzed in analysis step E2 is of the same nature as said at least one target useful parameter puc. "Of the same nature" means that when hardness TH is selected to define the target final composition cfc, the hardness TH of the industrial water 3 is determined.

[0099] Such a second analysis step E2 can be carried out to determine at least one useful parameter of the solution 5 of water treated with a cationic ion exchanger and / or to determine at least one useful parameter of the solution 7 of demineralized water and / or to determine the Mg 2+and Ca 2+ It is also possible to determine at least one useful parameter of the aqueous solution 9 containing ions. It is thus possible to select the aqueous solution or solutions having the most suitable composition to serve as a basis for the preparation of a mixture solution having a mixture composition cm1 approaching the target final composition cfc.

[0100] In the remainder of this specification, when reference is made to "aqueous solutions", this includes solutions of industrial water 3, water treated with cationic ion exchangers 5, demineralized water 7 and Mg 2+ and Ca 2+ The group consisting of aqueous solutions 9 containing ions is included.

[0101] The cationic ion exchanger treated aqueous solution 5 can be obtained by two methods which are explained below.

[0102] According to a first non-limiting variant, the aqueous solution 5 treated with a cationic ion exchanger comprises: a step E30 of providing a cation exchanger 20 comprising a weak cation resin 21, said cation exchanger 20 being characterized in that said weak cation resin 21 is a weak cation exchanger containing calcium divalent cations Ca 2+ or magnesium divalent cation Mg 2+ The weak cation resin 21 is capable of capturing calcium divalent cation Ca 2+ or magnesium divalent cation Mg 2+ a step E30 configured to vary between the filling configurations constituting a reserve of; a filling step E32 with a weak cation resin, in which part of the industrial water solution 3 circulates in the cation exchanger 20, causing said cation exchanger to go from the regenerated configuration to the filled configuration; a degassing step E34 in which the water leaving the cation exchanger 20 is degassed so as to obtain decarbonated water; This is the decarbonated water obtained according to the procedure.

[0103] The degassing step E34 can be carried out naturally, for example by leaving the water leaving the cation exchanger 20 in the open air. Alternatively, the degassing step E34 can be carried out in a degassing tower 24. According to a third possibility, the degassing step E34 can be carried out by subjecting the water leaving the cation exchanger 20 to a continuous cascade, or by mixing, stirring, bubbling or by using a bleed-through degassing tower 24 with countercurrent injection of air.

[0104] Preferably, the decarbonated water has a conductivity of 100 μS / cm or more and a hardness TH in French hardness (°f) units and a total alkalinity TAC in French hardness (°f) units such that TH≦TAC+3°f.

[0105] According to a second non-limiting variant, the aqueous solution 5 treated with a cationic ion exchanger contains: a step E31 of providing a cation exchanger 20 comprising a strong cation resin 23, said cation exchanger 20 being characterized in that said strong cation resin 23 is composed of calcium divalent cations Ca 2+ or magnesium divalent cation Mg 2+ The strong cationic resin 23 is capable of capturing calcium divalent cations Ca 2+ or magnesium divalent cation Mg 2+ a step E31 configured to vary between the filling configurations constituting a reserve of; a step E33 of filling with a strong cation exchange resin in such a way that a part of the solution 3 of industrial water is circulated in the cation exchanger 20 in order to change said cation exchanger from the regenerated configuration to the filled configuration and to obtain replacement water; The displaced water is obtained according to the following:

[0106] According to one embodiment, the filling steps E32, E33 include a filling level detection step in which measurements are made of the variations in pH or another parameter of the water present at the outlet of the cation exchanger 20, and thus the filling level of the cation exchanger 20 is constantly deduced therefrom (e.g. for future cycles).

[0107] Preferably, the displaced water has a conductivity of 100 μS / cm or greater and a hardness TH in French hardness (°f) units such that TH≦3°f.

[0108] If the industrial water solution 3 contains little calcareous matter, it is advantageous to obtain a cationic ion-exchanged water solution 5 by means of a cation exchanger 20 using active material of a strong cationic resin 23 .

[0109] The demineralized water solution can be obtained by any method known in the prior art. According to the principles of the present invention, in a preferred embodiment, the demineralized water solution 7 can be obtained by a desalination step E41 in which a part of the decarbonated or displaced water solution is desalted by reverse osmosis 27 or an ion exchange process on a series of desalting resins (cation / anion) 25 to obtain a demineralized water solution 7.

[0110] According to one embodiment, the demineralized water solution 7 is converted to hydronium ions HO by a strong cation resin. + A filling step E33 in which the cation is replaced by H3O + A part of the water in which the cations have been replaced by β-phenylenediamine can be obtained by a desalting step E41 on the resin 25, in which the water is simply treated with a series of anion resins 25. Before passing through the anion resin 25, a preliminary degassing may be carried out.

[0111] Preferably, the demineralized water 7 has a conductivity of less than 100 μS / cm.

[0112] Finally, Mg 2+ and Ca 2+ The aqueous solution 9 containing ions is Mg 2+ and Ca 2+ The Mg ions are captured by the weak cation resin 21 or the strong cation resin 23 to produce an aqueous solution 9 containing Mg ions. 2+ and Ca 2+The strong acid 11 is obtained during the elution step E43 in which it is circulated in the cation exchanger 20 so that the ions dissolve. Typically, the strong acid 11 is hydrochloric acid or sulfuric acid, preferably diluted in water at a concentration of 2 to 10%. In the particular case in which the strong acid 11 is sulfuric acid, the Mg ions obtained during the elution step E43 are 2+ and Ca 2+ The aqueous solution 9 containing ions also contains dissolved salts of CaSO4 and MgSO4. These salts are highly advantageous to obtain, since they avoid the use of additional elements containing sulfur. In fact, Mg 2+ and Ca 2+ This aqueous solution 9 containing ions contains the salts CaSO4 and MgSO4 and is obtained directly from industrial water and acid. Thus, on the one hand, the procurement of salts such as calcium sulfate (CaSO4) or magnesium sulfate (MgSO4) is avoided. On the other hand, it is particularly known that calcium sulfate, usually called "plaster" in common parlance, has an extremely low solubility in water, making its dissolution complex and difficult.

[0113] Advantageously, the elution step E43 is carried out after the loading steps E32, E33, it being therefore fully understood that the elution step E43 and the loading steps E32, E33 make it possible to alternately vary the cation exchanger 20 between a regenerated configuration and a loaded configuration.

[0114] According to one embodiment, the elution step E43 comprises the step of: 2+ and Ca 2+ It may include a measuring step E45 in which the pH of the aqueous solution 9 containing ions is measured.

[0115] In fact, the elution step E43 is carried out by circulation of a strong acid in the cation exchanger 20, so that Mg 2+ and Ca 2+ It is possible to find traces of strong acid 11 in an aqueous solution 9 containing ions, which may affect its pH.

[0116] Therefore, Mg 2+ and Ca 2+In order to better control the composition of the aqueous solution 9 containing ions, it is preferable to ensure the absence of strong acid 11 in this solution. To avoid this, it is possible to envisage defining the amount of strong acid 11 added during the elution step E43 in relation to the volume of weak cation resin 21 or strong cation resin 23 to be treated.

[0117] Such an amount of strong acid 11 may, for example, form part of the technical data of the cationic resin 21, 23 used, which data specify the volume and concentration of strong acid 11 required to regenerate said cationic resin 21, 23. In this way, the amount of Mg, when the weak cationic resin 21 or the strong cationic resin 23 is completely regenerated, is calculated. 2+ and Ca 2+ It is possible to prevent mixing of an aqueous solution 9 containing ions with a strong acid 11 .

[0118] Alternatively, the measurement step E45 can be carried out by measuring a parameter other than pH, for example measuring the conductivity, in this way making it possible to know and control any accidental surplus of strong acid 11 during the elution step E43.

[0119] Preferably, Mg 2+ and Ca 2+ The aqueous solution containing the ions has a conductivity of 20 μS / cm or greater and a hardness TH in French hardness (°f) units such that TH≧50°f.

[0120] With reference to Fig. 1, the preparation method may further comprise a step E51 of providing at least one additional element selected from the group comprising salt 13 and pH adjuster 15. The salt 13 and pH adjuster 15 may in particular comprise sodium chloride NaCl, sodium bicarbonate NaHCO3, sodium carbonate Na2CO3, calcium chloride CaCl2, magnesium sulfate MgSO4, magnesium chloride MgCl2 and sodium bromide NaBr. A mass marked "m" of the additional element may then be diluted in an aqueous solution during a dilution step E53 to form an additional solution. For example, an additional element of mass m may be diluted in a portion of solution 7 of demineralized water. If several additional elements are added, it is possible to achieve several additional solutions, each corresponding to a diluted additional element. In this case, several masses mj corresponding to each additional element j are diluted in the aqueous solution.

[0121] Referring again to the supplying step E6, it is fully understood that this supplying step E6 of the first and second aqueous solutions is not limiting and can also include the supplying of three or more different aqueous solution volumes. Thus, the supplying step E6 can include the supplying of a third or fourth aqueous solution selected to be different from each other and different from the first and second aqueous solutions, said third or fourth aqueous solutions being: - Industrial water solution 3, - a solution of water treated with a cationic ion exchanger 5, - solution of demineralized water 7, - Mg 2+ and Ca 2+ 9. Aqueous solutions containing ions; is selected from the group consisting of:

[0122] The preparation method can then include a calculation step E7 in which a first volume V1 of the first aqueous solution and a second volume V2 of the second aqueous solution are determined depending on said at least one useful parameter pu1 defining a first composition c1 and said at least one useful parameter pu2 defining a second composition c2. If salt 13 and pH adjuster 15 are provided during step E51, the calculation step E7 also aims to determine the mass m of an additional element depending on the first composition c1, the second composition c2 and the target final composition cfc. As noted above, the determination of the first volume V1 of the first aqueous solution and the second volume V2 of the second aqueous solution is not limiting and the calculation step E7 can also include the determination of a third volume V3 of a third aqueous solution characterized by a third composition c3 and a fourth volume V4 of a fourth aqueous solution characterized by a fourth composition c4.

[0123] These volumes V1, V2, V3 and V4 of aqueous solution and this mass m are for mixing during a mixing stage P3 described below so as to produce a mixture volume Vm1 of a solution of the mixture characterized by a mixture composition cm1 which may also be defined by at least one useful parameter pum1 selected from the group including calcium concentration THCa, magnesium concentration THMg, total alkalinity TAC, P-alkalinity TA, hardness TH, chloride ion concentration CCl, sulfate ion concentration CS, bromide ion concentration CBr, sodium ion concentration CNa and pH.

[0124] The calculation step E7 thus aims to determine the aqueous solution volumes V1, V2, V3 and V4 and the mass m such that said at least one useful parameter pum1 defining the mixture composition cm1 approaches said at least one useful parameter puc defining the target final composition cfc. It is therefore fully understood that, depending on the calculation step, the volumes V1, V2, V3 or V4 may be zero and the mass m may also be zero.

[0125] For example, according to a first non-limiting variant, calculation step E7 makes it possible to determine a first volume V1 of a first aqueous solution determined by at least one first useful parameter pu1 of the same nature as the at least one target useful parameter puc and a second volume V2 of a second aqueous solution determined by at least one second useful parameter pu2 of the same nature as the at least one target useful parameter puc.

[0126] The calculation step may consist of solving the following simultaneous equations: pu1×V1+pu2×V2=puc×Vm1 Vm1=V1+V2

[0127] If several target useful parameters puc are determined for a target final composition cfc, the described calculation method consists of solving as many simultaneous equations as there are target useful parameters determined.

[0128] In this case, it is advantageous to use a calculation unit 30 .

[0129] According to an embodiment, the calculation step E7 is carried out by a calculation unit 30 configured to calculate the first volume V1 of the first aqueous solution and the second volume V2 of the second aqueous solution in such a way as to minimize the difference between said at least one useful parameter defining the mixture composition cm1 and said at least one useful parameter defining the target final composition cfc. When the target final composition cfc is defined by several parameters, sometimes there is no solution for V1 and V2 that allows to solve the simultaneous equations. Advantageously, the calculation unit 30 allows to perform a priority selection on the accuracy of one useful parameter in relation to the other useful parameters. In this way, the preparation method can be carried out when there is no unique or exact mathematical solution for the preparation of cooling water 1 having a composition close to the target final composition cfc.

[0130] According to one embodiment, each of the first composition c1, the second composition c2, the mixture composition cm1 and the target final composition cfc is defined by a plurality of useful parameters, and the calculation step E7 can then be performed by weighting each useful parameter of said plurality of useful parameters by a weighting coefficient.

[0131] According to one embodiment, the calculation step E7 may be carried out by comparing each useful parameter with another useful parameter of the same type. For example, according to another non-limiting variant, the calculation step E7 makes it possible to determine the first volume V1 of the first aqueous solution and the second volume V2 of the second aqueous solution by comparing the total alkalinity TAC of the first aqueous solution, the total alkalinity TAC of the second aqueous solution and the total alkalinity TAC of the cooling water 1. Thus, each useful parameter can be compared with another useful parameter of the same type during the calculation step E7.

[0132] Finally, the preparation method includes a mixing stage P3, which includes a first mixing step E8 in which a first volume V1 of the first aqueous solution and a second volume V2 of the second aqueous solution are mixed to produce a mixture volume Vm1 of a mixture solution characterized by a mixture composition cm1, which mixture solution then constitutes all or part of the cooling water 1.

[0133] It is well understood that said first volume V1 of the first aqueous solution and said second volume V2 of the second aqueous solution are determined during calculation step E7 in response to said first composition c1 and said second composition c2 and such that the mixture composition cm1 approaches a predetermined target final composition cfc.

[0134] As in the supply step E6, the mixing stage P3 is not limited to a first volume V1 of the first aqueous solution and a second volume V2 of the second aqueous solution, but may also comprise the mixing of three or more different aqueous solution volumes. For example, the supply step E6 may comprise the mixing of the first and second aqueous solutions with a third and / or a fourth aqueous solution. Moreover, the first mixing step E8 may itself also comprise the mixing of a mass m of an additional element, which is also determined during the calculation step E7. Thus, according to a particular embodiment, the solution 3 of industrial water, the solution 5 of water treated with a cationic ion exchanger, the solution 7 of demineralized water and the solution 8 of Mg 2+ and Ca 2+ The cooling water 1 can be obtained by mixing four aqueous solution volumes V1, V2, V3, V4 each originating from an aqueous solution 9 containing ions and a mass m of an additional element.

[0135] The mixing stage P3 can then include a control step E9 of the mixture composition cm1, such that an intermediate value of said at least one useful parameter defining the mixture composition cm1 is determined and an initial deviation between the target value of said at least one useful parameter defining the target final composition cfc and said intermediate value is calculated. The control step E9 thus makes it possible to determine the deviation between the useful parameters of the mixture composition cm1 and the corresponding useful parameters of the target final composition cfc. In other words, the control step E9 makes it possible to quantify whether the mixture composition cm1 is close enough to the target final composition cfc or not.

[0136] If the initial deviation is greater than a threshold deviation, i.e. if the mixture composition cm1 is too far from the target final composition cfc, the mixing stage can include a second mixing step E10 in which at least one correction factor is mixed into the mixture solution so as to produce a corrected mixture volume Vm2 of the corrected mixture solution characterized by a corrected mixture composition cm2 defined by at least one useful parameter. The correction factors are the volume of solution 3 of industrial water, the volume of solution 5 of water treated with a cationic ion exchanger, the volume of solution 7 of demineralized water, the volume of Mg 2+ and Ca 2+is selected from the group consisting of the volume of the aqueous solution 9 containing ions, the mass m1 of the salt 13, and the mass m2 of the pH adjuster 15.

[0137] Naturally, the correction factor is selected such that the corrected deviation between the corrected value of said at least one useful parameter defining the corrected mixture composition cm2 and said target value is smaller than the initial deviation.

[0138] According to one embodiment, it can be envisaged that the control step E9 comprises the determination of a corrected deviation and that the second mixing step E10 is carried out iteratively as long as the corrected deviation is greater than a threshold deviation, which may for example be equal to 10% or 5% or 3% of the target value.

[0139] In general, it can also be envisaged that at least one of the first mixing step E8 and the second mixing step E10 is carried out so as to maintain the corrected mixture solution at a temperature between 10°C and 35°C, preferably between 12°C and 30°C.

[0140] The measures described above make it possible to propose a method for preparing cooling water 1 having a composition close to the target final composition cfc. Moreover, advantageously, Mg 2+ and Ca 2+ The use of an aqueous solution 9 containing ions allows for easier and on-demand production of cooling water 1 having a composition close to the target final composition cfc.

[0141] According to the present invention, Mg 2+ and Ca 2+ The aqueous solution containing ions is Mg 2+ and Ca 2+ The ion concentration of industrial water solutions, water solutions treated with cationic ion exchangers, or demineralized water solutions is 2+ and Ca 2+ It is higher than the ion concentration.

[0142] As indicated above, the preparation and casting methods can be carried out via a casting apparatus 100 which is the subject of the present invention.

[0143] The casting installation depicted in FIG. 1 comprises a preparation device 50 for the cooling water 1. The preparation device 50 in particular comprises: - a first tank 33 adapted to contain a solution 3 of industrial water; - a second tank 35 adapted to receive a solution 5 of water treated with a cationic ion exchanger; - a third tank 37 adapted to contain a solution 7 of demineralised water; - Mg 2+ and Ca 2+ a fourth tank 39 configured to contain an aqueous solution 9 containing ions; The tank may include at least one tank selected from among:

[0144] The embodiment of FIG. 1 has a preparation apparatus 50 that includes four tanks.

[0145] According to an embodiment not shown, the use of the first tank 33, the second tank 35, the third tank 37 and the fourth tank 39 can be replaced by a continuous line mixing method, which refers to the possibility of mixing the aqueous solutions directly in the piping or refilling device system.

[0146] The casting apparatus 100 may further include a cation exchanger 20 (FIG. 2) containing an active material, said cation exchanger 20 being calcium divalent cation Ca 2+ or magnesium divalent cation Mg 2+ is bound to the active material, and the active material is a calcium divalent cation, Ca 2+ or magnesium divalent cation Mg 2+The cation exchanger 20 is configured to vary between a regenerated configuration capable of capturing cations, said cation exchanger 20 comprising means allowing the connection of the cation exchanger 20 to a mixing unit 31, not shown. The active material can comprise a weak cation resin 21 or a strong cation resin 23. As illustrated in FIG. 2, the cation exchanger 20 is contained in a preparation device 50. Simply to be able to carry out the preparation method, the cation exchanger 20 can comprise means allowing the connection of the cation exchanger 20 to at least one tank, for example the first tank 33, the second tank 35, the third tank 37 or the fourth tank 39. These means can comprise, for example, pipes allowing the transfer of fluids towards and out of the cation exchanger 20.

[0147] The casting apparatus 100 comprises a reverse osmosis device 27 or an ion exchanger with desalting resin 25, said reverse osmosis device 27 or said ion exchanger may comprise means allowing it to be connected to a mixing unit 31 and a cation exchanger 20, not shown. Generally, the reverse osmosis device 27 or said ion exchanger with desalting resin 25 comprises means allowing it to be connected to at least one tank, for example the first tank 33, the second tank 35, the third tank 37 or the fourth tank 39. In the variant illustrated in FIG. 2, the reverse osmosis device 27 comprises means allowing it to be fluidly connected to the second tank 35 and the third tank 37.

[0148] The preparation device 50 may include a strong acid supply device 41 configured to be connected to the cation exchanger 20 and an additional element storage unit 32 configured to store at least one additional element selected from the group including a salt 13 and a pH adjuster 15.

[0149] Referring again to FIG. 1, the first tank 33 , the second tank 35 , the third tank 37 , the fourth tank, and the storage unit 32 are fluidly connected to the mixing unit 31 .

[0150] The mixing unit 31 is configured to receive a first aqueous solution characterized by a first composition c1 and a second aqueous solution different from the first aqueous solution characterized by a second composition c2, said first aqueous solution and said second aqueous solution being: - Industrial water solution 3 - a solution of water treated with a cationic ion exchanger 5, - solution of demineralized water 7, - Mg 2+ and Ca 2+ 9. Aqueous solutions containing ions; is selected from the group consisting of:

[0151] Moreover, the mixing unit 31 is configured to mix a first volume V1 of the first aqueous solution and a second volume V2 of the second aqueous solution to produce a mixture volume Vm1 of a mixture solution constituting all or part of the cooling water 1 and characterized by a mixture composition cm1.

[0152] The first volume V1 of the first aqueous solution and the second volume V2 of the second aqueous solution are determined according to the first composition c1 and the second composition c2 and such that the mixture composition cm1 approaches a predetermined target final composition cfc. As depicted in Fig. 1, the mixing unit 31 may be configured to mix three or more aqueous solution volumes. The mixing unit 31 is further configured to accommodate and mix a mass m of an additional element with the mixture solution, the mass m of the additional element being determined according to the first composition c1, the second composition c2 and the target final composition cfc.

[0153] According to a particular embodiment, the mixing unit 31 includes a temperature control system 61 including a temperature sensor 63 configured to measure a mixture temperature corresponding to a temperature of the mixture solution. In this case, the temperature control system 61 is configured to maintain the mixture temperature between 10°C and 35°C, preferably between 12°C and 30°C. The temperature control system 61 may include a heating means 65 configured to heat the mixing unit 31 when the mixture temperature is below 10°C or below 12°C. The temperature control system 61 may also include a cooling means 67 configured to cool the mixing unit 31 when the mixture temperature is above 35°C or above 30°C.

[0154] Furthermore, the casting apparatus 100 can advantageously include an analysis unit 60 configured to measure at least one useful parameter selected from the group including calcium concentration THCa, magnesium concentration THMg, total alkalinity TAC, P-alkalinity TA, hardness TH, and pH.

[0155] The analytical unit 60 may in particular be used to carry out a first analytical step E1 and a second analytical step E2 of the preparation method.

[0156] Finally, the casting apparatus 100 may include a calculation unit 30 configured to determine a first volume V1 of the first aqueous solution and a second volume V2 of the second aqueous solution depending on useful parameters defining the first composition c1, useful parameters defining the second composition c2, and in such a way that useful parameters defining the mixture composition cm1 approach useful parameters defining the target final composition cfc. Generally, the calculation unit may perform the calculation step E7 according to the embodiments described above and below.

[0157] The preparation method and its implementation in the casting apparatus 100 can be better understood based on the following examples, which are provided as non-limiting examples. EXAMPLES

[0158] Example 1: In this embodiment, cooling water 1 is prepared according to a target industrial water. Table 1 below lists the composition of the industrial water solution 3 obtained during the first analysis step E1 and the second analysis step E2, which may for example correspond to the first composition c1, and the target final composition cfc.

[0159] [Table 1]

[0160] In this embodiment, an industrial water solution 3 characterized by a composition c1 has high hardness, high alkalinity and high chloride ion content. This industrial water solution 3 can be stored in a first tank 33.

[0161] A portion of the industrial water solution 3 can then be subjected to a charging step E32 as it circulates through a cation exchanger containing a weak cation resin 21 (resin RESINEX KW-H, manufactured by Jacobi Carbons, Sweden). During this charging step E32, the industrial water solution 3 is charged to a volume of 5 ml 3 / h and then circulates through a degassing device during a degassing step E34, which comprises a countercurrent airflow tower located above a second tank 35. In this second tank, a solution 5 of water treated with a cationic ion exchanger is thus obtained, which is now decarbonated water having, in this example, a second composition c2.

[0162] The second tank 35 may include means allowing this tank to be fluidly connected to a reverse osmosis device 27 so that the third tank 37 may be replenished with desalinated water. According to this embodiment, the reverse osmosis device 27 includes nine membranes and operates with a purge rate of 25%. This reverse osmosis device 27 is operated at a rate of 1 m 3 / h~2m 3 / h of demineralized water solution 7 can be produced.

[0163] The demineralized water solution now exhibits composition c3 stored in the third tank 37.

[0164] If the weak resin 21 of the cation exchanger 20 is sufficiently filled during the filling step E32, the elution step E43 is carried out by eluting MgCl2 having a fourth composition c4, a part of which is stored in a fourth tank 39. 2+ and Ca 2+ It is carried out so as to produce an aqueous solution 9 containing ions. For example, the elution step E43 can be carried out when the loading percentage of the weak resin 21 is between 60% and 90% of saturation in relation to the theoretical saturation calculated for the cation exchanger.

[0165] According to one embodiment, the elution step E43 comprises the following steps: - a thinning step in which industrial water 3 is introduced countercurrently, typically at least 5 m 3 / h water flow rate is used to lift the resin particles and make it possible to remove accumulated impurities, - an elution step with a 4% sulfuric acid solution, which is itself prepared by diluting a 20% commercial sulfuric acid solution with demineralized water using a metering pump. This step is carried out using Mg 2+ and Ca 2+ This makes it possible to produce an aqueous solution 9 containing ions. - Mg 2+ and Ca 2+ a slow rinse step with demineralized water 7 (piston flow of liquid) to circulate a portion of the aqueous solution 9 containing ions towards the tank 39; and - A fast rinsing step with a solution 7 of demineralized water (turbulent flow of liquid), consisting in rapidly removing any traces of acid 11 that may still be present.

[0166] In the particular case of this embodiment, the use of a weak cationic resin 21 makes it possible to obtain a relatively low acidity effluent which is simply neutralized by passing it over a granular bed of calcium carbonate. All water not used for the production of foundry water (1, 1a or 1b), the residue, the part of the unused acid solution, the rinse liquid are considered as acid effluent.

[0167] As previously indicated, the industrial water solution 3 has a first composition c1 determined during the analytical step E2. This first composition c1 of the industrial water solution 3 may be sufficiently stable over time so as not to require a supplementary second analytical step E2.

[0168] In the particular case of this first embodiment, since the first composition c1 is known, the second, third and fourth compositions c2, c3 and c4 can be deduced in the following manner.

[0169] The cationic ion exchanger treated aqueous solution 5 is obtained by decarbonation on a weak cation resin 21. The cations Na bound to strong acid salts (sulfates and chlorides) are + (Sodium), Ca 2+ (Calcium) and Mg 2+ The cations retained by the cation exchanger 20 (Mg bound to carbonate and bicarbonate) are not retained and, like all anions (carbonate, bicarbonate), are found again in the cationic ion exchanger treated aqueous solution 5 by passing through the cation exchanger 20. 2+ and Ca 2+ ) is retained on the weak cation resin 21, and hydronium ions HO + (Ca 2+ Per ion or Mg 2+ 2 H3O per ion + ions). In this case, the second composition c2 of calcium and magnesium ions is therefore calculated from the total hardness TH according to the following formula: TH (of the second composition c2) = TH (of the first composition c1) - TAC (of the first composition c1).

[0170] Therefore, we get TH = 3.1°f (41.1-38.0).

[0171] The calcium (THCa) and magnesium (THMg) values ​​are calculated assuming that they maintain the same ratio as in the industrial water solution (here THCa / THMg=5). Therefore, calculate the THCa and THMg in the cationic ion exchanger treated water solution 5 by solving equations (1) and (2): (1) THCa / THMg=5 (2) THCa+THMg=TH=3.1

[0172] Then, by solving this simultaneous equation, the values ​​in Table 2 below are obtained (THMg=0.5°f and THCa=2.6°f, rounded values).

[0173] The TAC obtained after the deaerator was measured at the outlet of the deaerator at 0.5°F. This value is stable and is not measured with each mix.

[0174] A solution of demineralized water having a third composition c3 is produced by desalination of a solution 5 of water treated with a cationic ion exchanger during a desalination step E41. It is possible to analyze the third composition c3 during a third analysis step consisting of measuring the conductivity of the solution. This third analysis step makes it possible to determine that the main ions have a concentration of less than 5 mg / L, with the exception of sodium and chloride (approximately 5 mg / L).

[0175] Mg 2+ and Ca 2+ The fourth composition c4 of the aqueous solution 9 containing ions depends on the acid concentration 11 used for the regeneration of the weak cation resin 21.

[0176] For this example, we consider an elution yield of the used cation exchanger estimated at 0.98. The value of 0.98 corresponds to the elution yield of the used cation exchanger. The calcium and magnesium ion concentrations (based on which the TH is calculated) then correspond to 0.98 times the sulfuric acid concentration (in molar or °F) at the start of the elution step E43. This sulfuric acid concentration can be controlled by measuring the acid and water flow rates and by in-line measurement of the conductivity. It can be envisaged to only store the eluate within the limits of the capacity of the fourth tank 39 and at the start of the elution step E43. Thus, according to this protocol, the Mg 2+ and Ca 2+ The aqueous solution 9 containing ions is Mg 2+ and Ca 2+ It has a constant fourth composition c4 which can be determined once and for all by carrying out a second analytical step E2 on the aqueous solution 9 containing ions.

[0177] [Table 2]

[0178] The following relationship exists between TH, THCa, THMg and R=THCa / THMg: TH = THCa + THMg THCa=R×TH / (1+R) THMg = TH / (1 + R)

[0179] The step E51 of providing at least one additional element and the dilution step E53 make it possible to form additional solutions of compositions a1, a2, a3, a4 and a5 corresponding to the dilution of the mass m1 of salt or the mass m2 of pH adjuster in the volume of the solution 7 of demineralized water, in such a way as to provide an additional solution of MgSO4 (10%) defined by composition a1, an additional solution of MgCl2 (10%) defined by composition a2, an additional solution of NaHCO3 (8%) defined by composition a3 and an additional solution of NaOH (5%) defined by composition a4. The 20% sulfuric acid solution used to regenerate the cation exchanger 20 is stored in a tank of 3 m3. It can also serve as the additional solution defined by composition a5.

[0180] The chemical compositions of the additional solutions a1, a2, a3, a4 and a5 are written in the same form as the four preceding aqueous solutions, with the parameter TH and the ratio R=THCa / THMg being replaced by THCa and THMg to avoid divergence of the calculations when THCa=0 or THMg=0.

[0181] [Table 3]

[0182] From the available aqueous solutions of compositions c1, c2, c3 and c4, the target final composition cfc and the chemical compositions a1, a2, a3, a4 and a5 of the additional solutions, it is possible to carry out a calculation step E7.

[0183] The mixture composition cm1 of the mixture solution for a volume Vm1 (known) is then represented by the following equation, which varies for each useful parameter of each composition (e.g. THCa, THMg, TAC, sodium, chloride, sulfate). Thus, in this case, six equations are obtained corresponding to six different useful parameters: ci×Vm1=V1×c1i+V2×c2i+V3×c3i+V4×c4i+Va1×a1i+Va2×a2i+Va3×a3i+Va4×a4i+Va5×a5i

[0184] The index i in the above formula refers to the six useful parameters (THCa, THMg, TAC, CNa, CCl, CS) described in this example.

[0185] Vm1=V1+V2+V3+V4+Va1+Va2+Va3+Va4+Va5, where V1, V2, V3 and V4 correspond to the volumes of aqueous solutions of compositions c1, c2, c3 and c4 to be mixed, and Va1, Va2, Va3, Va4 and Va5 correspond to the volumes of additional solutions of compositions a1, a2, a3, a4, a5 to be mixed.

[0186] For this first embodiment, the following parameters Vm1, c1i, c2i, c3i, c4i, a1i, a2i, a3i, a4i, a5i are known: - Vm1 corresponds to the volume of cooling water to be produced. It is also possible to use the flow rate by dividing the volume by time. This parameter is defined by a unique value. For this example, 24 m 3 of cooling water solution is required. This flow rate value is 2.4 m3 if the characteristic time is 10 hours (for example, the time interval between each casting). 3 / h. c1i, c2i, c3i, c4i, a1i, a2i, a3i, a4i, a5i: respectively corresponding to useful parameters of the available aqueous solutions (3, 5, 7, 9) and of the available additional solutions of salt 13 and pH adjuster 15. Optionally, supplementary analytical steps can be carried out to control each useful parameter.

[0187] According to one non-limiting variant, weighting coefficients γi can be used to prioritize one of the useful parameters. In this example, for example, the magnesium concentration THMg is given more importance than the sodium concentration CNa or the sulfate ion concentration CS. The following weighting coefficients γi are therefore selected (Table 4), which make it possible to obtain the following mixture composition cm1:

[0188] [Table 4]

[0189] In this embodiment and within the selected weighting, it is possible to obtain a mixture solution having a mixture composition cm1 equal to the target final composition cfc. However, such a solution is not always mathematically obtainable, taking into account the factors available during the preparation process.

[0190] A calculation step E7 then therefore involves the determination of the volumes to be mixed. In this example, what are unknown are the nine volumes of solutions to be mixed (V1, V2, V3, V4, Va1, Va2, Va3, Va4, Va5). The calculation unit 30 then uses a solver that makes it possible to minimize the sum of the following deviations:

[0191]

number

[0192] To obtain a physically meaningful mathematical solution, conditions at the desired limits are added (i.e., all values ​​are positive and the volumes must not exceed the capacity of the tanks 33, 35, 37, 39) to obtain the volumes of each solution to be added as well as the mixture composition cm1 of the mixture solution.

[0193] Within the framework of this particular example, 24 ml of the mixture solution was obtained by mixing the following volumes: 3 We can obtain the volume Vm1: - V1 (solution 3 of industrial water) = 9.28 m 3 - V2 (solution 5 of water treated with cationic ion exchanger) = 9.10 m 3 - V3 (solution 7 of demineralized water) = 2.64 m 3 - V4(Mg 2+ and Ca 2+ Aqueous solution containing ions 9) = 2.98 m 3 and the following additives: - Va1 (10% MgSO4) = 21.7L - Va2 (10% CaCl2) = 13.3L - Va3, Va4 and Va5 are unused (=0).

[0194] The mixing stage P3 then only comprises a first mixing step E8 by mixing in the mixing unit 31 of calculated volumes corresponding to the different solutions. For example, the first mixing step E8 of the aqueous solutions can be carried out in the order V1, V2, V3, V4 via a magnetic stirrer and then by adding additional solution volumes Va1 and Va2 while maintaining mixing.

[0195] The preparation method can then include a control step E9 in which control of the mixture composition cm1 obtained is performed. This control includes: - Determination of hardness (TH) and total alkalinity (TAC) using color indicator TH and TAC analyzers; - Measuring pH with a pH probe.

[0196] Depending on the result of the control step E9, the pH can then be corrected by adding Javelle water to obtain the desired amount of free chlorine so that the mixture composition cm1 approaches the target final composition cfc.

[0197] Example 2: In this second example, table 5 below describes the composition of a solution of industrial water, which may for example correspond to a first composition c1, and also describes the target final composition cfc. These two compositions are obtained during a first analysis step E1 and a second analysis step E2. In detail, in carrying out the preparation method of this example, the aim is to obtain a cooling water 1 whose useful parameters "hardness and total alkalinity TAC" are lower than the corresponding useful parameters of the target final composition cfc.

[0198] [Table 5]

[0199] According to this embodiment, the preparation device 50 comprises a reverse osmosis device 27 connected to a first tank 33, but does not comprise a cation exchanger 20. Thus, two aqueous solutions characterized by two compositions, namely: a solution 3 of industrial water characterized by a first composition c1; and a solution 7 of demineralized water characterized by a second composition c2, This can only be achieved.

[0200] The reverse osmosis device 27 is replenished with an industrial water solution 3, for example stored in a first tank 33 or directly available on site, which makes it possible to produce a desalinated water solution 7 by a desalting step E41 of a portion of the industrial water solution 3, which is then stored in a third tank 37.

[0201] Advantageously, the industrial water solution 3 serving to produce the demineralized water solution 7 is filtered through a filter with a 5 μm filtering mesh, which makes it possible to avoid membrane fouling (especially at the spacer level) and thus to extend its service life. Advantageously, a polyphosphate-based sequestering agent is continuously injected, which makes it possible to avoid the precipitation of calcium ions in the presence of carbonates in the concentrate loop of the reverse osmosis device 27.

[0202] Within the framework of this embodiment, the solution 3 of industrial water stored in the first tank 33 may have a composition c1 that varies depending, inter alia, on the appliance using this water, the season and the operation of the temperature control system 61. It may therefore be envisaged to carry out one or more analysis steps E2 in order to constantly know a good estimate of the first composition c1 of this solution 3 of stored industrial water.

[0203] Unlike the solution 3 of industrial water, the solution 7 of demineralized water has a substantially constant and known composition c2. It is therefore not necessary to carry out a second analysis step E2 at each desalination step E41. An on-line control of the conductivity is sufficient to ensure good operation of the permeation unit and constant water quality. Table 6 below shows the first and second compositions c1, c2 of the solution 3 of industrial water and the solution 7 of demineralized water.

[0204] [Table 6]

[0205] From the available aqueous solutions and the target final composition cfc, it is possible to carry out the calculation step E7. In this example, it is not possible to use aqueous solutions other than those mentioned above, nor to use additional elements.

[0206] The mixture composition cm1 of the mixture solution for a volume Vm1 (known) is then described by the following equations which vary for each useful parameter of each composition (e.g. THCa, THMg, TAC, sodium, chloride, sulfate). Thus, in this case, six equations are obtained, corresponding to six different useful parameters: ci×Vm1=V1×c1i+V2×c2i

[0207] The index i, Vm1=V1+V2, denotes the six useful parameters (THCa, THMg, TAC, CNa, CCl, CS) described in this example.

[0208] In the case of this first embodiment, the following parameters are known: - Vm1: volume of the solution to be produced - c1i, c2i: these correspond to the useful parameters of the available aqueous solutions (3, 7), respectively.

[0209] According to a non-limiting variant, weighting coefficients γi can be used to prioritize one of the useful parameters. In this example, for example, magnesium concentration THMg and calcium concentration THCa are weighted more than other useful parameters. Therefore, the following weighting coefficients γi are selected, which allow to obtain the following mixture composition cm1 (Table 7):

[0210] [Table 7]

[0211] A calculation step E7 then therefore involves the determination of the volumes to be mixed. In this example, what are unknown are the two volumes V1, V2 of the aqueous solutions to be mixed. The calculation unit 30 then uses a solver that makes it possible to minimize the sum of the following deviations:

[0212]

number

[0213] To obtain a realistic solution, the desired boundary conditions are added, e.g., all values ​​are positive to obtain the volume of each solution to be added as well as the mixture composition cm1 of the mixture solution, and the volume cannot exceed the capacity of the tanks 33, 37.

[0214] In this particular case, it is not possible to obtain the target final composition cfc exactly, taking into account the available aqueous solutions. However, by choosing to mix two parts each of technical solution 3 (V1 = 50% Vm1) and demineralized solution 7 (V2 = 50% Vm1), it is possible to obtain a mixture solution volume Vm1 that complies with the defined targets of the preparation method. [Explanation of symbols]

[0215] 1 Cooling water 3. Industrial water solution 5. Water solution treated with cationic ion exchanger 7. Demineralized water solution 9 mg 2+ and Ca 2+ Aqueous solution containing ions 11 Strong acid 13. Salt 15 pH adjuster 20 Cation Exchanger 21 Weak cationic resin 23 Strong cationic resin 25 Desalting Resin 27 Reverse osmosis equipment 30 Computational Units 31 Mixed Unit 50 Preparation equipment 60 Analysis Units 61 Temperature Control System 63 Temperature Sensor 100 Casting Equipment

Claims

1. A method for preparing cooling water (1) for cooling products during metallurgical processing operations, in particular for the application of semi-continuous casting of cast products, comprising: - a step (E1) of analyzing the target cooling water composition to determine the target final composition (cfc); a step (E6) of supplying at least one first aqueous solution characterized by a first composition (c1) and at least one second aqueous solution different from the first aqueous solution and characterized by a second composition (c2), said first aqueous solution and said second aqueous solution having a solution of industrial water having a hardness of not more than 80° F (French hardness) and a conductivity of not more than 2000 μS / cm (3); ・ T.H. ５ and T.A.C. ５ are the hardness and P-alkalinity of the solution (5) of water treated with the cationic ion exchanger under consideration, expressed in French hardness ° f, respectively, and TH ５ <TAC ５ Decarbonated water such as +3°F or TH ５ A solution of water treated with a cationic ion exchanger having a conductivity of 100 μS / cm or more, the water being a replacement water such as ≦3° f (5); a solution of demineralized water with a conductivity of less than or equal to 100 μS / cm (7), ・Hardness TH ９ Mg with a conductivity of 20 μS / cm or more such that ２＋ and Ca ２＋ An aqueous solution containing ions (9), and a mixing stage (P3) comprising a first mixing step (E8) in which a first volume (V1) of a first aqueous solution and a second volume (V2) of a second aqueous solution are mixed to produce a mixture volume (Vm1) of a mixture solution forming all or part of the cooling water (1) and characterized by a mixture composition (cm1), said first volume (V1) of the first aqueous solution and said second volume (V2) of the second aqueous solution being determined by a calculation step (E7) depending on said first composition (c1) and said second composition (c2), a mixing stage (P3), in which each of the first composition (c1), the second composition (c2), the mixture composition (cm1) and the target final composition (cfc) is defined by at least one useful parameter selected from the group including calcium concentration (THCa), magnesium concentration (THMg), total alkalinity (TAC), P-alkalinity (TA), hardness (TH), chloride ion concentration (CCl), sulfate ion concentration (CS), bromide ion concentration (CBr), sodium ion concentration (CNa) and pH; said calculation step (E7), in which a first volume (V1) of the first aqueous solution and a second volume (V2) of the second aqueous solution are determined depending on said at least one useful parameter defining a first composition (c1), said at least one useful parameter defining a second composition (c2) and such that said at least one useful parameter defining a mixture composition (cm1) approaches said at least one useful parameter defining a target final composition (cfc); A preparation method comprising:

2. 2. The preparation method according to claim 1, wherein the calculation step (E7) is performed by a calculation unit (30) configured to calculate the first volume (V1) of the first aqueous solution and the second volume (V2) of the second aqueous solution so as to minimize the difference between said at least one useful parameter defining the mixture composition (cm1) and said at least one useful parameter defining the target final composition (cfc).

3. 3. The method according to claim 1 or 2, further comprising a step (E51) of providing at least one additional element selected from the group comprising salts (13) and pH adjusters (15), and wherein the first mixing step (E8) further comprises mixing an additional element mass (m), said additional element mass (m) being determined depending on the first composition (c1) and the second composition (c2) and on the target final composition (cfc).

4. The cationic ion exchanger treated aqueous solution (5) - a step (E30) of providing a cation exchanger (20) comprising a weak cation resin (21), said cation exchanger (20) being characterized in that said weak cation resin (21) is a calcium divalent cation Ca ２＋ or magnesium divalent cation Mg ２＋ and the weak cation resin (21) is capable of capturing calcium divalent cation Ca. ２＋ or magnesium divalent cation Mg ２＋ a step (E30) configured to vary between the charging configurations forming a reserve of a charging step (E32) with a weak cation exchanger (20) in which a portion of the industrial water solution (3) circulates, said cation exchanger (20) comprising a weak cation exchanger (21), to cause said cation exchanger to go from a regenerated configuration to a charged configuration; - T.H. ５ and T.A.C. ５ are the hardness and alkalinity of the decarbonated solution expressed in French hardness, respectively, and TH ５ <TAC ５ a degassing step (E34) in which the water leaving the cation exchanger (20) is degassed so as to obtain decarbonated water to +2° f, 4. The method according to claim 1 , wherein the decarbonated water is obtained according to the following formula:

5. The cationic ion exchanger treated aqueous solution (5) - a step (E31) of providing a cation exchanger (20) comprising a strong cation resin (23), said cation exchanger (20) being characterized in that said strong cation resin (23) is a calcium divalent cation Ca ２＋ or magnesium divalent cation Mg ２＋ and the strong cationic resin (23) is capable of capturing calcium divalent cations Ca. ２＋ or magnesium divalent cation Mg ２＋ a step (E31) configured to vary between a filling configuration forming a reserve of A portion of the industrial water solution (3) is circulated in a cation exchanger (20) containing a strong cation resin (23) to change the cation exchanger from a regenerated configuration to a packed configuration and to change the TH ５ and T.A.C. ５ are the hardness and alkalinity of the replacement solution expressed in French hardness, respectively, and TH ５ <TAC ５ a step (E33) of filling with a strong cationic resin in such a way that the displaced water is obtained such that 4. The method according to claim 1 , wherein the water is obtained according to the following formula:

6. 6. Process according to claim 4 or 5, in which a demineralised water solution (7) is obtained by a desalting step (E41), in which a part of the decarbonated water solution or of the displaced water solution is desalted by reverse osmosis or by an ion exchange process on a desalting resin (25) so as to obtain a demineralised water solution (7) with a conductivity of less than or equal to 100 μS / cm.

7. Hardness TH ９ Mg with a conductivity of 20 μS / cm or more such that the ２＋ and Ca ２＋ The Mg is captured by a weak cation resin (21) or a strong cation resin (23) to produce an aqueous solution (9) containing ions. ２＋ and Ca ２＋ During the elution step (E43), in which a strong acid (11) is circulated in the cation exchanger (20) in such a way that the ions dissolve, Mg ２＋ and Ca ２＋ 7. A process according to any one of claims 4 to 6, in which an aqueous solution (9) containing ions is obtained.

8. 8. The process according to claim 7, wherein the strong acid (11) is sulfuric acid.

9. 9. The process according to claim 7 or 8, wherein the elution step (E43) is carried out after the loading step with the weak cationic resin (E32) or after the loading step with the strong cationic resin (E33).

10. 10. Use of the cooling water (1) obtained by the preparation method according to any one of claims 1 to 9 for cooling products in metallurgical processing steps such as casting, quenching or hot rolling.

11. (a) preparing a liquid metal bath, preferably made of an aluminum alloy containing, by weight percent, 0-6.0 Cu, 0-8 Mg, 0-12 Si, 0-12 Zn, up to 3 each and up to 10 total other components, with the balance being aluminum; (b) casting the liquid metal by vertical semi-continuous casting so that during the initial casting phase a first cooling water (1a) is used, characterized by a first mixture composition (cma) obtained by the preparation method according to any one of claims 1 to 9; 1. A method for casting a product, preferably made of an aluminum alloy, comprising:

12. 12. A casting method according to claim 11, comprising a steady-state casting phase (c) at the completion of the start-up casting phase, during which a second cooling water (1b) is used which is characterized by a second composition (cfb) different from the first cooling water (1a), optionally this second cooling water (1b) being obtained by a preparation method according to any one of claims 1 to 9.

13. A casting apparatus (100) including a device (50) for preparing cooling water (1), the device (50) comprising: an analytical unit (60) configured to measure at least one useful parameter selected from the group comprising calcium concentration (THCa), magnesium concentration (THMg), total alkalinity (TAC), P-alkalinity (TA), hardness (TH) and pH; a calculation unit (30) configured to determine a first volume (V1) of the first aqueous solution and a second volume (V2) of the second aqueous solution as a function of useful parameters defining the first composition (c1), useful parameters defining the second composition (c2) and in such a way that the useful parameters defining the mixture composition (cm1) approach the useful parameters defining the target final composition (cfc); a cation exchanger (20) containing an active material, the divalent calcium cation Ca ２＋ or magnesium divalent cation Mg ２＋ is bound to the active material, and the active material is a calcium divalent cation, Ca ２＋ or magnesium divalent cation Mg ２＋ a cation exchanger (20) configured to vary between a regenerated configuration capable of capturing cations of 100% and a regenerated configuration capable of capturing cations of 100% and comprising a means for connecting the cation exchanger (20) to a mixing unit (31), preferably comprising a weak cation resin (21) or a strong cation resin (23); a mixing unit (31) adapted to accommodate a first aqueous solution characterized by a first composition (c1) and a second aqueous solution different from the first aqueous solution and characterized by a second composition (c2), said first aqueous solution and said second aqueous solution being Industrial water solution (3), a solution of water treated with a cationic ion exchanger (5), a solution of demineralized water (7), Mg ２＋ and Ca ２＋ An aqueous solution containing ions (9), is selected from the group consisting of a mixing unit (31) configured to mix a first volume (V1) of the first aqueous solution with a second volume (V2) of the second aqueous solution to produce a mixture volume (Vm1) of a mixture solution that forms the whole or part of the cooling water (1) and is characterized by a mixture composition (cm1), the first volume (V1) of the first aqueous solution and the second volume (V2) of the second aqueous solution being determined in response to the first composition (c1) and the second composition (c2) and in such a way that the mixture composition (cm1) approaches a predetermined target final composition (cfc); A casting apparatus (100) comprising:

14. 14. The casting apparatus (100) of claim 13, further comprising an ion exchanger in a reverse osmosis unit (27) or a desalting resin (25), the ion exchanger in the reverse osmosis unit (27) or the desalting resin (25) comprising means for enabling it to be connected to the mixing unit (31) and the cation exchanger (20).

15. 15. The casting apparatus (100) according to claim 13 or 14, wherein the mixing unit (31) comprises a temperature control system (61) including a temperature sensor (63) configured to measure a mixture temperature corresponding to a temperature of the mixture solution, said temperature control system (61) being configured to maintain the mixture temperature between 10°C and 35°C, preferably between 12°C and 30°C.

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