58results about "Phosphoric acid" patented technology

This invention discloses a dynamic defoaming device for a stirring system, belonging to the technical field of wet-process phosphoric acid production equipment. It includes a reaction tank, a stirring shaft, stirring blades, a three-phase feeder, a liquid overflow port, an overflow depth adjuster, an interface foam separator, a secondary foam separator, and a foam overflow port. The overflow depth adjuster is located on the inner wall of the reaction tank, with its upper end connected to the liquid overflow port and its lower end adjustablely positioned in the middle of the reaction tank. The interface foam separator is located within the reaction tank and matches the material liquid level. The secondary foam separator is located in the upper part of the reaction tank and maintains a set interval from the interface foam separator, forming a static foam space. This invention achieves efficient and thorough foam removal and precise separation of liquid and solid materials, effectively improving the purity of phosphoric acid products, production efficiency, and equipment operational stability.

The invention relates to a method for high-value utilization of waste lithium iron phosphate battery lithium extraction slag, and belongs to the technical field of waste lithium ion battery resource utilization. The method comprises the following steps: S1, mixing the lithium iron phosphate lithium extraction slag with a low-concentration sulfuric acid solution in proportion, carrying out countercurrent washing, carrying out solid-liquid separation, carrying out acid dissolution on a solid, carrying out gradient recycling on a washing solution, and carrying out resin adsorption and reverse osmosis treatment on a high-impurity washing solution for recycling; s2, reacting the pretreated solid with medium-concentration sulfuric acid, reducing a dissolved solution by using iron powder, then carrying out solid-liquid separation to obtain a first batch of ferrous sulfate heptahydrate, adding concentrated sulfuric acid into mother liquor, carrying out secondary crystallization, then carrying out solid-liquid separation, and recrystallizing the obtained solid by using washing wastewater to obtain a second batch of ferrous sulfate heptahydrate; s3, recovering sulfuric acid by adopting a membrane treatment method, and recovering phosphoric acid from residual mother liquor by adopting an extraction method; or directly treating the lithium iron phosphate waste residue. According to the method, efficient separation and recovery of iron and phosphorus resources and full-component high-value utilization of the lithium iron phosphate lithium extraction slag are realized.

The invention relates to a process for obtaining phosphoric acid from phosphate-containing ash from waste incineration plants, in particular from sewage sludge ash from sewage sludge incineration plants. Pure phosphoric acid, especially purified phosphoric acid, is obtained in several steps. Calcium sulfate, which is used, for example, as a building material, and acidic metal salt solutions, which can be used again for precipitation in wastewater treatment plants, are also produced. In the improved process according to the invention, turbidity or precipitation occurring in the filtrates, supernatants, and eluates is reduced or removed in at least one turbidity separation step.

The disclosure relates to a continuous process for obtaining phosphoric acid and calcium sulphate dihydrate from apatite, and sulphuric acid using hydrochloric acid as an intermediate attacking agent, comprising the steps: Leaching (101) apatite (11) with an aqueous solution of hydrochloric acid (12,13) to solubilize phosphorus compounds contained in the apatite, thereby obtaining a solution (15) containing phosphate (H3PO4) and calcium chloride (CaCl2); extracting (103) said solution (15) with organic solvent (16), yielding an organic extract (17) loaded with phosphate ions, and an aqueous raffinate (21) containing calcium chloride and residual impurities; re-extracting the phosphate ions from the organic extract (17) with water (18), thus yielding an aqueous extract (19) of phosphoric acid, and an unloaded organic phase substantially free of phosphoric acid, reacting (107) the raffinate (21) containing calcium chloride with sulphuric acid (26) to cause precipitation of calcium ions in the raffinate as calcium sulphate dihydrate and to recover chloride ions in the raffinate in the form of hydrochloric acid (12), wherein the reaction of the raffinate (21) containing calcium chloride with sulphuric acid (26) involves intermittent agitation of the raffinate, filtering off (108) precipitated calcium sulphate dihydrate (27) from the previous step (107) and washing it with water, recycling (112) the recovered hydrochloric acid (12) to the step (101) of the leaching apatite.

Provided is a method for producing a phosphate capable of easily producing a target phosphate. This method for producing a phosphate includes: an acid leaching step (S1) of leaching a component contained in a starting material containing phosphorus into an acid to obtain a phosphorus-containing liquid; and a precipitation formation step (S2) of adding an alkali to the phosphorus-containing liquid to obtain a precipitate containing a phosphate, wherein in the precipitation formation step (S2), the pH of the phosphorus-containing liquid is adjusted according to the temperature of the phosphorus-containing liquid.

The application discloses a kind of phosphoric acid extraction semi-water-two water alternate crystallization system and method, belong to the technical field of wet-process phosphoric acid production, the system is by the reaction tank unit of series connection and semi-water and two water reaction tank alternate arrangement, with the sulfuric acid dilution mixed heat exchanger group connected with reaction tank, simple heat exchanger group is arranged between tank to realize heat transfer.Construction.The method includes: material is temperature-adjusted after passing through sulfuric acid dilution mixed heat exchanger, in turn into the reaction tank sequence of alternate arrangement, heat circulation is carried out in adjacent tank by simple heat exchanger, under the control of PLC in 75~85 DEG C and 88~95 DEG C interval, realize the alternate crystallization of semi-water-two water calcium sulfate.The application replaces traditional flash evaporation external discharge with heat internal circulation between tank, solves the technical problems of high steam energy consumption, low phosphorus recovery rate, insufficient phosphoric acid concentration and high upgrading cost of stock device in traditional process, and has the comprehensive advantages of energy saving, yield, low-cost transformation and phosphogypsum resource.

The invention discloses a dechlorination method of a wet-process phosphoric acid process, and belongs to the technical field of dechlorination of wet-process phosphoric acid. The method comprises the following steps: adding ground phosphorite into a reaction tank A, carrying out decomposition reaction on the phosphorite and high-temperature slurry to obtain slurry a, pumping the slurry a into a reaction tank B, adding concentrated sulfuric acid and a sodium persulfate solution, activating sodium persulfate in the inherent high temperature, strong acid and Fe2 environment, carrying out oxidation dechlorination reaction, and carrying out solid-liquid separation to obtain low-chlorine phosphoric acid and phosphogypsum; finally, the reaction tank B is connected with a tail gas washing system, water is used for circulating washing, then alkali liquor is used for countercurrent washing, and the pollution discharge standard is met. The oxidation dechlorination process is integrated in the wet-process phosphoric acid production process for the first time, chloride ions are efficiently oxidized into chlorine to be removed by utilizing the strong oxidizing property of sodium persulfate, the dechlorination rate can reach 95% or above, the chlorine content in phosphoric acid is remarkably reduced, equipment corrosion is relieved, the product quality is improved, and the method is simple in process, low in energy consumption, low in cost, green, environmentally friendly and suitable for industrial production. The method is suitable for industrial application.

There is provided a method for producing ferrous sulphate and phosphoric acid comprising treating ferrous phosphate with sulphuric acid for obtaining ferrous sulphate and phosphoric acid. Additionally, there is provided a use of sulphuric acid for treating ferrous phosphate for obtaining ferrous sulphate and phosphoric acid.

The present invention relates to a method for combined recovery of phosphate and nitrogen from sewage sludge. The core objective of the present invention is to recover phosphorus from sewage sludge ash and convert phosphorus into NP fertilizer diammonium phosphate using steam from sewage sludge drying and nitrogen from liquid manure.

The application discloses a method for preparing phosphoric acid by high-temperature solid-state reaction of phosphate rock and ammonium sulfate. The method for preparing phosphoric acid is to use phosphate rock and ammonium sulfate as raw materials and adopt high-temperature solid-state reaction to prepare pure phosphoric acid. Compared with a traditional process, the whole process flow is simple and convenient to operate. Compared with other thermal methods, the energy consumption of the method is lower, the recycling of ammonium sulfate is realized, the process cost is reduced to a certain extent, and the utilization and conversion of medium and low grade phosphate rock are realized.

The present invention concerns a process for producing a phosphate containing product from a phosphate source (P0), the process comprising the following steps: feeding a reactor with a raw material (PC1) comprising at least 10 wt.% P2O5, and at least 0.7 wt.% CaO, in a digestion step (D1), adding to the raw material (PC1) a digestion liquor (L) comprising H2SO4 to yield a digested suspension (PC2), in a separation step (S1), separating the digested suspension (PC2) into an aqueous phosphate rich solution (P1) a calcium rich first solid cake (C1). Characterized in that, the digestion liquor (L) is added to the at least one raw material (PC1) in amounts such that 0.80 < SO4 / Ca < 1.7.

A method for preparing phosphoric acid from ferrophosphorus slag comprises the following steps that the ferrophosphorus slag is placed in first alkali liquor for a first reaction to obtain first reaction liquid, and solid-liquid separation is conducted on the first reaction liquid to obtain iron-containing slag and phosphorus-containing alkali leaching liquid; a transformation agent is added into the phosphorus-containing alkaline leaching solution for a second reaction to obtain a second reaction solution, and the second reaction solution is subjected to solid-liquid separation to obtain phosphate and a second alkaline solution; adding an acid solution into the phosphate to carry out a third reaction so as to obtain insoluble salt and crude phosphoric acid; and adding an extracting agent into the crude phosphoric acid to obtain phosphoric acid. According to the method for preparing the phosphoric acid from the ferrophosphorus slag, the technical problems that in the prior art, the preparation cost of the phosphoric acid is high, the recovery rate of ferrophosphorus in the ferrophosphorus slag is not high, and the environment is prone to pollution are solved.

This invention discloses a coating agent for kiln-process phosphoric acid production and its preparation method, belonging to the technical field of kiln-process phosphoric acid coating agents. The coating agent is composed of β-gypsum powder, coal powder, and residue from the kiln-process phosphoric acid reaction. First, each raw material is ground to below 75 micrometers. Then, β-gypsum powder and coal powder are mixed at a C:S mass ratio ≥4, and the residue from the kiln-process phosphoric acid reaction is added simultaneously, with the residue accounting for 70% to 80% of the total mass of the coating agent. The above materials are then uniformly mixed to complete the preparation of the coating agent for the kiln-process phosphoric acid production. When using, process water is added to coat the kiln-process phosphoric acid pellets. The coating agent of this invention can effectively prevent oxygen oxidation of the fixed carbon in the pellets and prevent the pellets from sticking together and forming rings.

The invention relates to a method for producing phosphoric acid, a monovalent cation sulfate and calcium carbonate, comprising a first treatment of a phosphate source with an inorganic acid solution, a second treatment for obtaining calcium sulfate, recovery of phosphoric acid and calcium sulfate to be treated in a treatment with a monovalent cation carbonate solution, and recovery of calcium carbonate and a monovalent cation sulfate.

Provided is a new method for producing phosphoric acid. A method for producing phosphoric acid according to the present disclosure comprises the following steps. Step S20: A step for treating, with an acid, a raw material containing calcium phosphate to obtain an acid extracted solution. Step S30: A step for mixing the obtained acid extracted solution with a base to obtain a calcium phosphate precipitate. Step S40: A step for mixing the obtained calcium phosphate precipitate with an acid and / or a salt thereof and forming a hardly soluble calcium salt.

The present invention relates to an improved process for recovering phosphoric acid from sewage sludge ash, said process comprising a leaching step; a conversion step for converting metal phosphates to phosphoric acid; solvent extraction of phosphoric acid from the leach solution using an organic solvent; a washing step for removing sulfuric acid; and stripping of the phosphoric acid to obtain an aqueous solution containing phosphoric acid.

The application discloses a crystal form regulator and application thereof in phosphogypsum byproduct of wet-process phosphoric acid, and belongs to the technical field of phosphorus chemical industry.The crystal form regulator is composed of a compound capable of forming aluminum-fluorine complex anions and iron-fluorine complex anions under acidic conditions.The crystal form regulator provided by the application can remove 100% of calcium ions in acidolysis liquid, and can also obtain phosphogypsum with good crystal morphology, and solves the problem that calcium ions in acidolysis liquid after decomposition of phosphate rock by nitric acid or hydrochloric acid cannot be completely precipitated and crystallized from the acid liquid.

A method of producing ammonium phosphates from at least one mineral containing phosphate and an element which is calcium, magnesium, iron, or aluminum. The method includes contacting the at least one mineral (or a combination of them) with a cation exchanger for a time and at a temperature sufficient to yield phosphoric acid from the mineral.

This invention discloses a method for treating wastewater from ferric phosphate production, belonging to the technical field of wastewater treatment. The wastewater from ferric phosphate production includes wash water and reaction mother liquor generated during the iron / iron red process for producing ferric phosphate. The treatment method includes the following steps: (1) a phosphoric acid purification and recovery process, including: pre-treating the wash water sequentially, the pre-treatment including filtration, cooling, resin adsorption, and ultrafiltration to obtain ultrafiltrate; and recovering phosphoric acid from the ultrafiltrate to obtain recycled phosphoric acid and a first clear liquid; (2) a recycled product water preparation process, including: adjusting the pH of the first clear liquid with alkali to obtain raw water; and concentrating a first mixture including raw water and makeup water to obtain impurity concentrate and recycled product water; (3) a deep purification and discharge process, including: purifying a second mixture including impurity concentrate, reaction mother liquor, and resin regeneration liquid to obtain compliant product water.

The disclosure relates to a continuous process for obtaining phosphoric acid and calcium sulphate dihydrate from apatite, and sulphuric acid using hydrochloric acid as an intermediate attacking agent, comprising the steps: Leaching (101) apatite (11) with an aqueous solution of hydrochloric acid (12,13) to solubilize phosphorus compounds contained in the apatite, thereby obtaining a solution (15) containing phosphate (H3PO4) and calcium chloride (CaCl2); extracting (103) said solution (15) with organic solvent (16), yielding an organic extract (17) loaded with phosphate ions, and an aqueous raffinate (21) containing calcium chloride and residual impurities; re-extracting the phosphate ions from the organic extract (17) with water (18), thus yielding an aqueous extract (19) of phosphoric acid, and an unloaded organic phase substantially free of phosphoric acid, reacting (107) the raffinate (21) containing calcium chloride with sulphuric acid (26) to cause precipitation of calcium ions in the raffinate as calcium sulphate dihydrate and to recover chloride ions in the raffinate in the form of hydrochloric acid (12), filtering off (108) precipitated calcium sulphate dihydrate (27) from the previous step (107) and washing it with water, dividing (113) the remaining hydrochloric acid (12) aqueous solution into a primary stream (12a) and a secondary stream (12b); and recycling (112) the primary stream (12a) of the aqueous solution of hydrochloric acid (12) to the step (101) of the leaching apatite, and at least partially removing the secondary stream (12b) from the process.

The invention relates to a method for recovering phosphoric acid from phosphate-containing ash from waste incinerators, in particular from sewage sludge ash from sewage sludge incinerators. In said method, pure phosphoric acid, in particular purified phosphoric acid, is recovered in multiple steps. Further products produced are calcium sulphate, which is used as a construction material, for example, and acidic metal salt solutions, which can be reused for precipitation in sewage treatment plants. In the improved method according to the invention, turbidity or precipitation occurring in the filtrates, supernatants and eluates is reduced or removed in at least one turbidity separation step.

The disclosure relates to a continuous process for obtaining phosphoric acid and calcium sulphate dihydrate from apatite, and sulphuric acid using hydrochloric acid as an intermediate attacking agent, comprising the steps: Leaching (101) apatite (11) with an aqueous solution of hydrochloric acid (12,13) to solubilize phosphorus compounds contained in the apatite, thereby obtaining a solution (15) containing phosphate (H3PO4) and calcium chloride (CaCl2); extracting (103) said solution (15) with organic solvent (16), yielding an organic extract (17) loaded with phosphate ions, and an aqueous raffinate (21) containing calcium chloride and residual impurities; re-extracting the phosphate ions from the organic extract (17) with water (18), thus yielding an aqueous extract (19) of phosphoric acid, and an unloaded organic phase substantially free of phosphoric acid, reacting (107) the raffinate (21) containing calcium chloride with sulphuric acid (26) having a concentration of 1-12.5 M to cause precipitation of calcium ions in the raffinate as calcium sulphate dihydrate and to recover chloride ions in the raffinate in the form of hydrochloric acid (12), filtering off (108) precipitated calcium sulphate dihydrate (27) from the previous step (107) and washing it with water, recycling (112) the recovered hydrochloric acid (12) to the step (101) of the leaching apatite.

The present disclosure provides a novel method for producing phosphoric acid. A method for producing phosphoric acid according to the present disclosure includes the following steps. And step S20, carrying out acid treatment on the raw material containing calcium phosphate to obtain an acid extracting solution. And S30, mixing the obtained acid extracting solution with alkali to obtain calcium phosphate precipitate. And S40, mixing the obtained calcium phosphate precipitate with acid and / or salt thereof, and forming insoluble calcium salt.

The objective of the present invention is to provide a method for preparing cremation crystals, the method using phosphoric acid extracted from cremated remains as a catalyst in the heat treatment of ashes so that transparent cremation crystals can be prepared only with components of skeletal remains derived from a single individual, and using only skeletal remains of a single individual through the control of the classification ratio of raw bone powder and phosphorus-extracted bone powder, and the like, so that the amount of phosphorus in the crystals is controlled, thereby enabling cremation crystals transparency to be controlled, and thus aesthetic requirements of consumers are satisfied and use as various kinds of jewelry is also facilitated.

The present invention relates to a method for recovering iodine from a solution of phosphoric acid, the method comprising the following steps: a) providing a solution of phosphoric acid comprising dissolved iodine, the concentration of iodine in the solution being at least 30 ppm; b) oxidizing the solution of phosphoric acid so as to convert the dissolved iodine into volatile iodine; c) blowing air to carry the volatile iodine from the oxidized solution resulting from step b) into an absorption column; d) in the absorption column, absorbing the volatile iodine in a solution comprising an absorbent; e) concentrating the solution resulting from step d) via reverse osmosis, liquid-liquid extraction or chemical precipitation; f) precipitating and recovering crystals of diiodine or an iodine salt.

The production device comprises a primary impurity removal module, a phosphoric acid solution generation module, an arsenic removal module and a blending module which are connected in sequence, the primary impurity removal module comprises a yellow phosphorus tank, a primary filter and an impurity removal tank which are connected in sequence; the phosphoric acid solution generation module comprises a combustion tower; the arsenic removal module comprises an arsenic removal tank and an ultrafiltration system; the blending module comprises a phosphoric acid dilution tank; a secondary filter is arranged between the primary impurity removal module and the phosphoric acid solution generation module; a three-stage filter is arranged between the phosphoric acid solution generation module and the arsenic removal module; and the electronic-grade phosphoric acid is discharged through the four-stage filter. The device can effectively remove impurities of front-end raw materials, middle-end reaction liquid and rear-end products, and the yield of phosphoric acid reaches 95% or above.

This invention provides a method for preparing crude desulfurized hemihydrate phosphoric acid in a hemihydrate wet phosphoric acid process. This invention utilizes CaO in the decomposition tank and SO4 in the crystal growth tank. 2‑ The slurry from both tanks is fed together into the coarse desulfurization reaction tank for mixing and reaction to achieve desulfurization, further simplifying the desulfurization slurry filtration step. Furthermore, vacuum flash evaporation is used to cool the desulfurized slurry before it enters the vacuum filtration system, avoiding excessive scaling within the system. Fluorine generated during vacuum flash evaporation and vacuum filtration is recovered. This invention achieves desulfurization without the need for external desulfurizing agents, reducing the cost of coarse desulfurization reagents and shortening the coarse desulfurization process. It also avoids the P2O5 waste caused by adding phosphate concentrate in traditional coarse desulfurization processes. This invention offers a simple desulfurization process, low cost, and methods to reduce the frequency of cleaning the slurry vacuum filtration system and increase system operating rate.

The disclosure relates to a method for purifying yellow phosphorus including bringing yellow phosphorus and wood-based activated carbon into contact with each other. The disclosure also relates to a method for producing high-purity phosphoric acid including generating a gas of phosphorus pentoxide by burning yellow phosphorus obtained by the purifying method and then hydrating the gas.

The present application relates to the technical field of water treatment, and discloses a chemical flocculation process for deep phosphorus removal of phosphorus-containing wastewater, which comprises the following steps: synchronously feeding the phosphorus-containing wastewater and a polyaluminum chloride solution into a high-frequency shearing reaction zone, adjusting the shearing rate and the hydraulic retention time, adding hydrogen ions according to the alkalinity of the wastewater to maintain the pH at 4.5-5.5, so as to form a multi-core hydroxyl complex; introducing the fluid into a secondary reaction zone, inducing the pH transition and homogeneous nucleation by jetting an alkaline regulator, and using the generated primary microflocs to capture phosphate to form a phosphorus-rich complex; and separating and collecting the precipitate. The present application changes the phosphorus removal mechanism from physical entrapment to chemical coordination bonding by interfering with the hydrolysis path of aluminum salt, simultaneously improves the phosphorus grade of the precipitate during deep phosphorus removal, and makes the precipitate have the secondary mineral resource recovery value, so as to achieve the resource comprehensive utilization of the wastewater treatment process.

A method for reducing formation of scale in phosphoric acid production is provided herein. Phosphate-containing ore is combined with an acid to form an acidic slurry and the acidic slurry is processed to form an acidic stream. The method includes providing a scale inhibitor including an inorganic phosphate. The method further includes combining the scale inhibitor and at least one of the phosphate-containing ore, the acidic slurry, or the acidic stream, to reduce the formation of scale. A system for phosphoric acid production exhibiting a reduced formation of scale is also provided herein. The system includes a substrate having a surface in contact with at least one of the phosphate-containing ore, the acidic slurry formed from the phosphate-containing ore and the acid, or the acidic stream formed from the acidic slurry. The system including the scale inhibitor exhibits a reduced formation of scale on the surface.