Method for removing organic matter impurities in wet metallurgy feed liquid

Abstract

The invention relates to a method for removing organic matter impurities in wet metallurgy feed liquid. The method comprises a dynamic crystal filtration process and an advanced oxidation process, and the dynamic crystal filtration process is carried out in a dynamic crystal filtration device and comprises an adsorbent coating section, a filtration adsorption section and a backwashing section. According to the method, the dynamic crystal filtration process and the advanced oxidation process are combined, and efficient and deep removal of the organic matter impurities in the hydrometallurgy feed liquid is achieved.

Description

Technical Field

[0001] The invention belongs to the field of chemical technology, and in particular relates to a method for removing organic impurities in hydrometallurgical liquid. Background Art

[0002] With the rapid development of the lithium battery industry, the purity requirements for the production of nickel sulfate and cobalt sulfate are constantly increasing. Organic matter (expressed as total organic carbon, TOC) in nickel sulfate and cobalt sulfate products is a common impurity.

[0003] The main sources of organic impurities include, but are not limited to, various organic components in the extractant that remain in the solution during the extraction process, and the derived organic molecules after long-term changes. In lithium-powered battery recycling, organic impurities also include organic components extracted or decomposed from battery materials and electrolytes. In addition, in the production process, most of the feed liquid circulates for a long time in the production process, and only a small part of the feed liquid is discharged through an open circuit or enters the next production section, resulting in the feed liquid in different process steps, temperature changes, and other long-term circulation processes. The organic impurities undergo complex decomposition and changes, making the impurity composition and removal mechanism complex and the removal efficiency low.

[0004] Organic impurities can affect the purity of the final product and reduce its quality. In the context of the recent rapid development of the new energy industry, downstream users have higher and higher requirements for raw materials. Controlling the proportion of organic impurities is one of the key indicators to ensure product value and competitiveness. In addition, in specific applications such as electroplating nickel, organic impurities can make the nickel coating brittle and crack, which has a direct impact on its use.

[0005] At present, the removal of organic impurities in nickel sulfate and cobalt sulfate products mainly involves adsorbing organic matter in the feed liquid to reduce the content of organic matter in the solution. Common adsorption materials include activated carbon or resin. However, there are problems or limitations with such adsorption materials or processes.

[0006] Conventional resin tower adsorption process, due to the high concentration of salt in the feed liquid, will greatly reduce the adsorption efficiency of the resin, and the regeneration efficiency of the adsorbed resin will be affected under high salt conditions, resulting in a short process operation cycle, frequent regeneration, high regeneration cost, and greatly reduced overall process effect and cost.

[0007] There are two application methods for conventional activated carbon adsorption tower processes. The most common method is to fill the activated carbon particles in the adsorption tower, and the liquid to be treated flows from the top of the tower through the activated carbon layer and out of the bottom of the tower, and the organic impurities are adsorbed in the process. This method can only use granular activated carbon with larger particle size. When the activated carbon particles are too small, the flow channel between the particles will be narrow, and the flow pressure will be too high, so that the liquid cannot flow smoothly (or ultra-high pressure is required to flow through, making energy consumption and equipment materials unfeasible). Usually in applications in similar scenarios, the size of activated carbon particles is generally 12-40 mesh.

[0008] When dealing with organic matter in hydrometallurgical liquid, large-particle activated carbon has obvious disadvantages compared with small-particle activated carbon. First, hydrometallurgical liquid often contains high oily substances due to the use of extractants. Oily substances will be adsorbed on the surface of activated carbon particles, blocking the channel from the surface of activated carbon to the adsorption points inside the activated carbon, resulting in a significant reduction in the adsorption capacity of activated carbon. If fine-particle activated carbon is used, the surface area of ​​carbon particles can be greatly increased, the adsorption capacity for oily substances can be increased, and the loss of adsorption points blocked inside carbon particles can be reduced, thereby significantly increasing the adsorption capacity. Secondly, studies have shown that the adsorption rate of activated carbon will increase significantly as the particle size decreases. For example, using the Constant Diffusivity model of activated carbon adsorption, theoretically, when 380 micron (equivalent to about 40 mesh) activated carbon particles need 1 hour to achieve adsorption equilibrium, 38 micron activated carbon particles can reach adsorption equilibrium in only 36 seconds. Therefore, the use of ultra-fine powdered activated carbon can greatly improve both the adsorption rate and adsorption capacity.

[0009] Another application of activated carbon is to mix activated carbon with liquid for adsorption, such as adding activated carbon into a mixing and stirring tank, and then separating the liquid from the activated carbon after mixed adsorption. This application method can use smaller particles of activated carbon. However, the adsorption efficiency of mixed adsorption (or static adsorption) is lower than that of adsorption tower (or dynamic adsorption). Any adsorption process must follow its relevant thermodynamic laws, which can be summarized by adsorption isotherms, such as Figure 1 As shown. In this thermodynamic relationship, when adsorption is in equilibrium, the adsorption density (or adsorption capacity, i.e., the amount of pollutants adsorbed by a unit mass of adsorption material) of the adsorbent material is related to the concentration of the adsorbate in the solution at equilibrium. In the mixed adsorption (static adsorption) process, the equilibrium concentration is equal to the effluent concentration. When the treatment requirements are high, the equilibrium concentration (effluent concentration) is very low, and the adsorption density of the activated carbon is also low. In the dynamic adsorption process, the activated carbon will be in equilibrium with the influent concentration, and the adsorption capacity will be greatly improved. Dynamic adsorption has obvious advantages over static adsorption in terms of adsorption capacity and adsorption efficiency.

[0010] In addition, activated carbon adsorption generally works better for non-polar, hydrophobic, and long-chain organic matter, but tends to have poor adsorption effects on highly polar and short-chain organic matter. Such small-molecule organic matter can be removed through other means, such as advanced oxidation processes. From the perspective of molecular structure, small molecules are more easily completely degraded and oxidized than large molecules. Therefore, combining multiple processes and using different processes to remove specific components will more effectively improve the removal of organic impurities in the feed liquid.

[0011] However, in hydrometallurgy, the use of advanced oxidation is also limited. Commonly used technologies such as ozone oxidation generally need to be used with a catalyst, otherwise there will be problems with high efficiency and low cost, and it will not have practical application significance. Common ozone catalysts are mostly metal-based catalysts, which may dissolve metal ions after long-term use and bring new impurities to the feed liquid. Other oxidants such as hydrogen peroxide have the same problem, and catalysts (ferrous ions, etc.) will bring new impurities to the feed liquid. Ultraviolet catalysis can promote the generation of hydroxyl radicals in ozone and hydrogen peroxide, but the use of ultraviolet light is also limited by high costs.

[0012] Peroxone is a catalytic oxidation method that uses a certain ratio of ozone and hydrogen peroxide to simultaneously add ozone and hydrogen peroxide to improve the efficiency of advanced oxidation. This process has not been used in the treatment of liquid containing organic impurities in hydrometallurgy. Summary of the invention

[0013] Problem that the invention aims to solve

[0014] There is still an urgent need to develop a method for removing organic impurities from hydrometallurgical slurries that has a high adsorption rate and adsorption capacity of activated carbon, but does not have disadvantages such as high overflow pressure, and has a high organic impurity removal rate.

[0015] Solutions for solving problems

[0016] The present invention provides a method for removing organic impurities in hydrometallurgical liquid, which solves the above-mentioned problem by combining a dynamic crystal filtration process and an advanced oxidation process.

[0017] Specifically, the present invention solves the problem of the present invention through the following solutions.

[0018] [1] A method for removing organic impurities from a hydrometallurgical liquid, comprising the following steps:

[0019] (1) Dynamic crystal filtration process

[0020] The dynamic crystal filtration process is carried out in a dynamic crystal filtration device, which includes one or more dynamic crystal filtration elements, and the dynamic crystal filtration element includes a tubular filter housing and one or more filter tubes located inside the filter housing, and the tube wall of the filter tube is made of porous material; there is a gap between the inner wall of the filter housing and the outer wall of the filter tube for material flow;

[0021] The dynamic crystal filtration process includes an adsorbent coating section, a filtration adsorption section, and a backwashing section;

[0022] In the adsorbent coating section, the adsorbent is coated on the inner side of the tube wall of the filter tube;

[0023] In the filtration and adsorption section, the hydrometallurgical liquid to be treated enters the interior of the filter tube, contacts the adsorbent coated on the inner side of the tube wall of the filter tube, and flows through the filter tube in a dead-end filtration or cross-flow filtration manner to obtain a liquid treated by dynamic crystallization filtration;

[0024] In the backwashing section, the adsorbent coated on the inner tube wall of the filter tube is washed with the backwash material, so that the adsorbent is separated from the tube wall of the filter tube and discharged out of the dynamic crystal filtration device together with the backwash material;

[0025] and

[0026] (2) Advanced Oxidation Process

[0027] In the advanced oxidation process, ozone-containing gas and hydrogen peroxide are mixed with the feed liquid treated by dynamic crystallization filtration and reacted to obtain a treated feed liquid.

[0028] [2] The method according to [1], wherein the hydrometallurgical liquid contains nickel sulfate or cobalt sulfate, preferably a liquid containing nickel sulfate or cobalt sulfate produced in a hydrometallurgical process for producing nickel sulfate or cobalt sulfate.

[0029] [3] The method according to [1], wherein the adsorbent is one or more selected from carbon-based adsorption materials, resin adsorption materials or plant-based shell materials;

[0030] Preferably, the adsorbent is activated carbon;

[0031] Preferably, the tube wall of the filter tube is made of a flexible porous material;

[0032] Preferably, in the dynamic crystal filtration process, the adsorbent coating section, the filtration adsorption section and the backwashing section are cyclically repeated in sequence.

[0033] [4] The method according to any one of [1] to [3], wherein the advanced oxidation step is carried out in a continuous flow reaction tower, wherein the feed liquid treated by dynamic crystallization is continuously flowed into the reaction tower from the upper part of the reaction tower; the ozone-containing gas is continuously transported into the reaction tower through an aeration device from the lower part of the reaction tower, and continuously leaves from the top of the reaction tower after the reaction; hydrogen peroxide is continuously flowed into the reaction tower from the top of the reaction tower; the ozone-containing gas and hydrogen peroxide are mixed and reacted with the feed liquid treated by dynamic crystallization in the reaction tower to finally obtain a treated feed liquid, which continuously flows out from the bottom of the reaction tower;

[0034] Preferably, the surface load of the feed liquid of the reaction tower is 4 to 24 m 3 / m 2 -h, the reaction tower height is 2 to 4 meters;

[0035] Preferably, based on the liquid treated by dynamic crystallization, the ozone dosage is 100-1000 mg / L; the hydrogen peroxide dosage is 20-240 mg / L.

[0036] [5] The method according to any one of [1] to [3], wherein the advanced oxidation process is carried out in a sequencing batch reactor, wherein the feed liquid treated by dynamic crystallization is fed into the reactor from the upper feed port of the reactor, and then the ozone-containing gas and hydrogen peroxide are continuously fed into the reactor simultaneously, so that the ozone-containing gas and hydrogen peroxide are mixed with the feed liquid treated by dynamic crystallization and react; after the reaction is completed, the feeding of the ozone-containing gas and hydrogen peroxide is stopped, and the treated feed liquid in the reactor is discharged from the bottom of the reactor;

[0037] The ozone-containing gas is fed into the reactor through an aeration device disposed at the bottom of the reactor, and hydrogen peroxide is fed into the reactor through a hydrogen peroxide feed port at the bottom of the reactor;

[0038] Preferably, the reaction time is 30 to 60 min;

[0039] Preferably, the hydrogen peroxide feed port is set at a position 1 to 5 cm away from the top of the ozone aeration device;

[0040] Preferably, the reactor height is 2 to 4 meters;

[0041] Preferably, based on the liquid treated by dynamic crystallization, the ozone dosage is 100-1000 mg / L; the hydrogen peroxide dosage is 20-240 mg / L;

[0042] Preferably, the ozone-containing gas flow rate is designed to be 0.017 to 0.42 L / min based on the treatment of each liter of liquid treated by dynamic crystallization.

[0043] [6] The method according to any one of [1] to [3], wherein in the adsorbent coating section, an adsorbent slurry is transported to the interior of the filter tube, and a cross-flow filtration operation is performed to allow the adsorbent to adhere to the inner side of the tube wall of the filter tube, wherein the adsorbent slurry comprises an adsorbent and a treated feed liquid;

[0044] Preferably, the adsorbent is in granular form with a particle size of 0.05 to 500 microns; preferably 12 to 200 microns;

[0045] Preferably, the coating amount of the adsorbent is 20 to 1920 g / m 2 ; preferably 240~960g / m 2 ;

[0046] Preferably, in the cross-flow filtration operation, the flux through the tube wall of the filter tube is 30 to 800 LMH; preferably 200 to 400 LMH;

[0047] Preferably, the flow rate of the adsorbent slurry entering the filter tube is 0.5 to 5 cm / s;

[0048] Preferably, the content of the adsorbent in the adsorbent slurry is 5 to 50 g / L;

[0049] Preferably, the cross-flow filtration operation time is 1 to 60 minutes; preferably 3 to 30 minutes.

[0050] [7] The method according to any one of [1] to [3], wherein in the filtration and adsorption stage, the flow rate permeating the tube wall per unit area of ​​the filter tube is 20 to 800 LMH; preferably 100 to 200 LMH;

[0051] Preferably, in the case of cross-flow filtration, the ratio of the cross-flow flow rate to the effluent flow rate is 0.5:1 to 5:1.

[0052] [8] The method according to any one of [1] to [3], wherein the backwashing section comprises (a) upwashing, (b) backwashing and (c) downwashing operations in sequence, wherein:

[0053] (a) Upwashing is to allow the backwash material to enter the interior of the filter tube from the lower end of the filter tube, cross-flow wash and flow out from the upper end of the filter tube;

[0054] (b) backwashing is to allow the backwash material to enter the gap between the inner wall of the filter housing and the outer wall of the filter tube, and flow through the tube wall of the filter tube to the interior of the filter tube;

[0055] (c) Downwashing is to allow the backwash material to enter the interior of the filter tube from the upper end of the filter tube, cross-flow wash and flow out from the lower end of the filter tube;

[0056] Preferably, the backwash material is treated liquid;

[0057] Preferably, during (a) the upwash operation, the flow rate of the backwash material entering the interior of the filter tube is 10 to 40 cm / s; preferably 15 to 30 cm / s; (a) the duration of the upwash operation is 5 to 30 s; preferably 5 to 10 s;

[0058] Preferably, (b) during the backwashing operation, the flux of the backwash material passing through the wall of the filter tube to the interior of the filter tube is 2000-6000LMH; preferably 3000-4000LMH; (b) the duration of the backwashing operation is 5-30s; preferably 5-10s;

[0059] Preferably, (c) during the downwash operation, the flow rate of the backwash material entering the interior of the filter tube is 10 to 40 cm / s; preferably 15 to 30 cm / s; (c) the duration of the downwash operation is 5 to 30 s; preferably 5 to 10 s;

[0060] Preferably, the operations of (a) up-punching, (b) back-punching and (c) down-punching are performed once in sequence, or repeated 2 to 5 times in a cycle, preferably 2 to 3 times.

[0061] [9] The method according to any one of [1] to [3], wherein in the advanced oxidation step, the concentration of ozone in the ozone-containing gas is 50 to 250 g / m 3 ; The concentration of hydrogen peroxide in hydrogen peroxide is 0.1 to 33% by mass; The molar feed ratio of hydrogen peroxide to ozone (H2O2:O3) is 0.28:1 to 0.76:1.

[0062]

[10] The method according to any one of [1] to [3], wherein the backwashing section further comprises a post-backwashing material processing operation, wherein the post-backwashing material is a mixture of the backwashing material and the adsorbent obtained by (a) upwashing, (b) backwashing and (c) downwashing operations, and the post-backwashing material processing operation comprises solid-liquid separation of the post-backwashing material,

[0063] Preferably, the solid-liquid separation is performed by plate and frame separation or centrifugal separation;

[0064] Preferably, when the backwash material is a treated liquid, the liquid obtained by solid-liquid separation is used as the liquid to be treated in the filtration and adsorption section.

[0065] Effects of the Invention

[0066] The method of the present invention combines a dynamic crystal filtration process with an advanced oxidation process to achieve efficient and deep removal of organic impurities in hydrometallurgical liquid.

[0067] The method of the present invention adopts a dynamic crystal filtration process to remove low-polarity long-carbon chain organic matter that is easily adsorbed and removed. The adsorption process combines the high-efficiency adsorption form of dynamic adsorption with the high adsorption performance of micron- to nano-scale adsorption materials, thereby significantly improving the adsorption capacity and adsorption rate. In addition, after adsorption saturation, the adsorption layer can be automatically eluted and re-coated to circulate, thereby avoiding the problems of manpower for filling and removing carbon, shutdown and production in the adsorption process of the existing process, and improving production efficiency. In the advanced oxidation process, high-polarity, short-carbon chain organic matter that is not easily adsorbed is further removed by degradation.

[0068] The method of the present invention can achieve deep removal of organic impurities, and at the same time, no impurities are introduced into the feed liquid or the feed liquid is diluted during the process, which can fully meet the special requirements of metallurgical and chemical production. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 Schematic diagram of the relationship between mixed adsorption and dynamic adsorption and adsorption isotherms.

[0070] Figure 2 The schematic diagram of an advanced oxidation process using a continuous flow reaction tower in one embodiment of the present invention.

[0071] Figure 3 FIG. 1 is a schematic diagram of an advanced oxidation process using a sequencing batch mixing reactor according to an embodiment of the present invention.

[0072] Figure 4 and Figure 5 Schematic diagram of a dynamic crystal filtration device used in one embodiment of the present invention.

[0073] Figure 6 The process flow diagram of one embodiment of the present invention is shown in FIG. DETAILED DESCRIPTION

[0074] The following is a detailed description of the present invention. The technical features described below are described based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples.

[0075] <Terms and Definitions>

[0076] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints A and B.

[0077] In the present specification, a numerical range expressed using "above" or "below" means a numerical range including the number.

[0078] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0079] In this specification, the use of "optionally" or "optional" indicates that certain substances, components, execution steps, application conditions and other factors are used or not used.

[0080] In this specification, the unit names used are all international standard unit names, and unless otherwise stated, the "%" used indicates weight or mass percentage.

[0081] In this specification, the references to "preferred embodiments", "embodiments", etc., mean that the specific elements (e.g., features, structures, properties and / or characteristics) described in connection with the embodiments are included in at least one embodiment described herein, and may or may not exist in other embodiments. In addition, it should be understood that the elements may be combined in various embodiments in any suitable manner.

[0082] <Method for removing organic impurities from hydrometallurgical liquid>

[0083] An object of the present invention is to provide a method for removing organic impurities from hydrometallurgical liquid, which comprises the following steps:

[0084] (1) Dynamic crystal filtration process

[0085] The dynamic crystal filtration process is carried out in a dynamic crystal filtration device, which includes one or more dynamic crystal filtration elements, and the dynamic crystal filtration element includes a tubular filter housing and one or more filter tubes located inside the filter housing, and the tube wall of the filter tube is made of porous material; there is a gap between the inner wall of the filter housing and the outer wall of the filter tube for material flow;

[0086] The dynamic crystal filtration process includes an adsorbent coating section, a filtration adsorption section, and a backwashing section;

[0087] In the adsorbent coating section, the adsorbent is coated on the inner side of the tube wall of the filter tube;

[0088] In the filtration and adsorption section, the hydrometallurgical liquid to be treated enters the interior of the filter tube, contacts with the adsorbent coated on the inner tube wall of the filter tube, and flows through the filter tube in a dead-end filtration or cross-flow filtration manner to obtain a liquid treated by dynamic crystallization filtration;

[0089] In the backwashing section, the adsorbent coated on the inner tube wall of the filter tube is washed with the backwash material, so that the adsorbent is separated from the tube wall of the filter tube and discharged out of the dynamic crystal filtration device together with the backwash material;

[0090] and

[0091] (2) Advanced Oxidation Process

[0092] In the advanced oxidation process, ozone and hydrogen peroxide are mixed with the feed liquid treated by dynamic crystallization filtration and reacted to obtain a treated feed liquid.

[0093] The hydrometallurgical liquid treated by the present invention has the characteristics of high salt and the use of an extractant in the upstream process. The hydrometallurgical liquid to be treated by the method of the present invention can remove organic impurities therein. Therefore, the method of the present invention is suitable for occasions where the end product needs to be high in purity and low in organic content.

[0094] Preferably, the content of organic impurities in the treated liquid obtained by the method of the present invention is 60 mg / L or less, preferably 55 mg / L or less, and more preferably 50 mg / L or less.

[0095] In some embodiments, the hydrometallurgical feed liquid comprises nickel sulfate and / or cobalt sulfate, and is preferably a feed liquid containing nickel sulfate or cobalt sulfate produced in a hydrometallurgical process for producing nickel sulfate or cobalt sulfate.

[0096] Each aspect of the method of the present invention is described in detail below.

[0097] Dynamic crystal filtration process

[0098] In the method of the present invention, the dynamic crystal filtration process includes an adsorbent coating section, a filtration adsorption section and a backwashing section.

[0099] In some embodiments, the adsorbent coating section, the filtration adsorption section, and the backwashing section are cyclically repeated.

[0100] In the method of the present invention, each stage of the dynamic crystallization process can be carried out at a temperature of, for example, 10 to 60°C, preferably 20 to 50°C.

[0101] In the method of the present invention, the process can be carried out by automated equipment, which greatly reduces the manpower and time required for manual carbon filling and carbon removal in traditional processes.

[0102] In the method of the present invention, the dynamic crystallization process has no particular restrictions on the pH of the liquid to be treated, and can be carried out under conventional hydrometallurgical conditions, such as the pH conditions for hydrometallurgical production of nickel sulfate and cobalt sulfate.

[0103] Dynamic crystal filtration device

[0104] In the present invention, the dynamic crystal filtration process is carried out in a dynamic crystal filtration device, which includes one or more dynamic crystal filtration elements. The dynamic crystal filtration element includes a tubular filter housing and one or more filter tubes located inside the filter housing. The tube wall of the filter tube is composed of a porous material; there is a gap between the inner wall of the filter housing and the outer wall of the filter tube for material flow.

[0105] The dynamic crystal filtration device that can be used in the present invention is described in CN 117776323 A, for example.

[0106] In some embodiments, plate-shaped positioning parts are provided at both ends of the filter housing, and the plane direction of the plate-shaped positioning parts is substantially parallel to the cross section of the filter housing. The positioning parts are provided with openings, which are connected to the interior of the filter tube to allow materials inside the filter tube to enter and exit. The filter housing is also provided with openings to allow materials in the gap between the inner wall of the filter housing and the outer wall of the filter tube to enter and exit.

[0107] In some embodiments, the porous material is a flexible porous material.

[0108] In some embodiments, the pore size of the porous material is preferably 0.01-5 μm. The pore size of the porous material within the above range is conducive to enabling the adsorbent to be coated on the wall of the filter tube.

[0109] In a preferred embodiment, the dynamic crystal filtration device is a liquid treatment device described in patent document CN110304701A. Specifically, Figure 4 , Figure 5 As shown, it includes: a filter body 100 and a filter tube 200; a liquid flow cavity is arranged in the filter body 100, and the filter tube 200 is arranged in the liquid flow cavity. A first liquid inlet and outlet 140 is arranged on the filter body 100, and the filter tube 200 is connected with the first liquid inlet and outlet 140; a second liquid inlet and outlet 150 is arranged on the filter body 100.

[0110] Preferably, the filter body 100 includes a filter housing 110 and two positioning parts 120; the filter housing 110 is provided with the liquid flow cavity, the filter tube 200 is provided in the filter housing 110, the two positioning parts 120 are provided at both ends of the filter housing 110, and the two positioning parts 120 are connected to both ends of the filter tube 200; the first liquid inlet and outlet 140 is provided in two, the two first liquid inlet and outlet 140 are provided on the two positioning parts 120 in a one-to-one correspondence, and the second liquid inlet and outlet 150 is provided on the side wall of the filter housing 110. Preferably, the positioning part 120 includes a positioning plate 122; the positioning plate 122 is provided in the filter housing 110, the positioning plate 122 is provided with a filter fixing hole, and the filter tube 200 extends into the filter fixing hole to fix the filter tube 200.

[0111] Adsorbent

[0112] Preferably, the adsorbent used in the method of the present invention is in granular form, with a particle size of 0.05 to 500 microns, preferably 12 to 200 microns.

[0113] In the method of the present invention, by utilizing the dynamic crystal filtration process, the use of micron-sized adsorbents is allowed, and the thickness of the adsorbent coating is low, so the filtration resistance is low. In addition, dynamic adsorption is achieved when using micron-sized adsorbents, which has the characteristics of high adsorption capacity and adsorption rate.

[0114] The adsorbent used in the method of the present invention is one or more selected from carbon-based adsorption materials, resin adsorption materials or plant-based shell materials. Among them, the carbon-based adsorption material is a material mainly composed of carbon elements, including but not limited to activated carbon and modified activated carbon, etc.; the plant-based shell material refers to a material directly processed from plant raw materials (such as walnut shells), which can be a porous fibrous material, etc.

[0115] Preferably, the adsorbent is activated carbon.

[0116] Adsorbent coating section

[0117] In the adsorbent coating section, the adsorbent is coated on the inner side of the tube wall of the filter tube.

[0118] In some embodiments, in the adsorbent coating section, adsorbent slurry is transported to the interior of the filter tube, and a cross-flow filtration operation is performed to allow the adsorbent to adhere to the inner tube wall of the filter tube, wherein the adsorbent slurry contains adsorbent and treated feed liquid.

[0119] By using treated liquid (hydrometallurgical liquid from which organic impurities have been removed) as the liquid medium in the adsorbent slurry, it is possible to avoid introducing other components during the process. The treated liquid used to prepare the adsorbent slurry may come from the method of the present invention (in the stable operation stage of the process), or may be a treated liquid obtained by treating the to-be-treated liquid of the method of the present invention by a conventional method for removing organic impurities (for example, in the start-up stage of the process).

[0120] Preferably, based on the area of ​​the filter tube wall, the coating amount of the adsorbent is 20 to 1920 g / m 2 , preferably 140 to 1200 g / m 2 , more preferably 240 to 960 g / m 2 .

[0121] Preferably, in the cross-flow filtration operation of the adsorbent coating section, the flux penetrating the tube wall of the filter tube is 30 to 800 LMH, preferably 100 to 600 LMH; more preferably 200 to 400 LMH.

[0122] Preferably, the flow rate of the adsorbent slurry entering the filter tube is 0.5-5 cm / s.

[0123] Preferably, the content of the adsorbent in the adsorbent slurry is 5 to 50 g / L.

[0124] Preferably, the cross-flow filtration operation time of the adsorbent coating section is 1 to 60 minutes; preferably 3 to 30 minutes.

[0125] Preferably, the thickness of the adsorbent coating is 0.1 to 2 mm.

[0126] Filtration and adsorption section

[0127] In the filtration and adsorption section, the hydrometallurgical liquid to be treated enters the interior of the filter tube, contacts the adsorbent coated on the inner side of the tube wall of the filter tube, and flows through the filter tube in a dead-end filtration or cross-flow filtration manner to obtain a liquid treated by dynamic crystallization filtration.

[0128] Preferably, in the filtration and adsorption section, the flow rate permeating the tube wall of the filtration tube per unit area is 20 to 800 LMH, preferably 50 to 400 LMH; more preferably 100 to 200 LMH.

[0129] Preferably, in the case of cross-flow filtration, the ratio of the cross-flow flow rate to the effluent flow rate may be 0.5:1 to 5:1.

[0130] Backwash Section

[0131] In the backwashing section, the adsorbent coated on the inner tube wall of the filter tube is washed with a backwash material to separate the adsorbent from the tube wall of the filter tube.

[0132] In a specific embodiment, the backwashing section includes (a) upwashing, (b) backwashing and (c) downwashing operations in sequence, wherein:

[0133] (a) Upwashing is to allow the backwash material to enter the interior of the filter tube from the lower end of the filter tube, cross-flow wash and flow out from the upper end of the filter tube;

[0134] (b) backwashing is to allow the backwash material to enter the gap between the inner wall of the filter housing and the outer wall of the filter tube, and flow through the tube wall of the filter tube to the interior of the filter tube;

[0135] (c) Downwashing is to allow the backwash material to enter the interior of the filter tube from the upper end of the filter tube, cross-flow flush, and flow out from the lower end of the filter tube.

[0136] Preferably, the backwash material is treated liquid. By using treated liquid (hydrometallurgical liquid from which organic impurities have been removed) as the backwash material, the overall liquid discharge of the method of the present invention can be reduced, or even zero liquid discharge can be achieved in the entire method.

[0137] The treated liquid used as backwash material can come from the method of the present invention (process stable operation stage), or can be the treated liquid obtained by treating the to-be-treated liquid of the method of the present invention by a conventional method for removing organic impurities (process start-up stage).

[0138] Preferably, in (a) the upwash operation, the flow rate of the backwash material entering the interior of the filter tube is 10 to 40 cm / s, preferably 15 to 30 cm / s.

[0139] Preferably, the duration of the upward punching operation (a) is 5 to 30 seconds, preferably 5 to 10 seconds.

[0140] Preferably, in the backwashing operation (b), the flux of the backwash material passing through the tube wall of the filter tube to the interior of the filter tube is 2000-6000LMH, preferably 3000-4000LMH.

[0141] Preferably, the duration of the backwash operation (b) is 5 to 30 seconds, more preferably 5 to 10 seconds.

[0142] Preferably, in (c) the downwash operation, the flow rate of the backwash material entering the interior of the filter tube is 10 to 40 cm / s, preferably 15 to 30 cm / s.

[0143] Preferably, the duration of the (c) downstroke operation is 5 to 30 seconds, more preferably 5 to 10 seconds.

[0144] Preferably, in each backwashing section, (a) upwashing, (b) backwashing and (c) downwashing operations are performed once in sequence, or repeated 2 to 5 times in a cycle; preferably 2 to 3 times.

[0145] In some embodiments, the backwash section also includes a post-backwash material processing operation, wherein the post-backwash material is a mixture of backwash material and adsorbent obtained by (a) upwashing, (b) backwashing and (c) downwashing operations, and the post-backwash material processing operation includes solid-liquid separation of the post-backwash material.

[0146] Preferably, the solid-liquid separation is performed by plate and frame separation or centrifugal separation.

[0147] Preferably, when the backwash material is a treated liquid, the liquid obtained by solid-liquid separation is used as the liquid to be treated in the filtration and adsorption section. The liquid obtained by solid-liquid separation is returned to the filtration and adsorption section, and is again subjected to the method of the present invention to remove organic impurities, thereby realizing the recycling of the backwash material.

[0148] The solids obtained from the post-backwash material handling operation may be discharged as waste and / or disposed of.

[0149] In a specific embodiment, the dynamic crystallization process described above Figure 4 and Figure 5 In the dynamic crystal filtration device shown in FIG. 1 , when the adsorbent coating operation is performed, the adsorbent slurry enters the filter tube 200 through the first liquid inlet and outlet 140 to attach the adsorbent to the inner wall of the filter tube 200. When the backwashing operation is performed, the backwash material enters the liquid flow cavity through the second liquid inlet and outlet 150, and the backwash material impacts the tube wall of the filter tube 200, thereby causing the tube wall of the filter tube 200 to be concave, so that the adsorbent on the inner wall of the filter tube 200 falls off.

[0150] Advanced Oxidation Process

[0151] In the advanced oxidation process, ozone-containing gas and hydrogen peroxide are mixed with the feed liquid treated by dynamic crystallization filtration and reacted to obtain a treated feed liquid.

[0152] In the method of the present invention, the advanced oxidation step is performed after the dynamic crystallization step, so that the highly polar short carbon chain organic matter that is difficult to be adsorbed by the adsorbent in the dynamic crystallization step is further removed.

[0153] In the advanced oxidation process of the method of the present invention, only ozone and hydrogen peroxide are used, and the only by-product is water, thereby avoiding the introduction of other components (impurities) into the feed liquid, and also not generating waste mud and waste liquid, and no waste discharge is required.

[0154] Preferably, the ozone-containing gas is prepared using a gas containing oxygen, wherein the oxygen content in the oxygen-containing gas is 20 to 100% by volume, for example, pure oxygen or air.

[0155] Preferably, the concentration of ozone in the gas containing ozone (O3) is 50 to 250 g / m 3 .

[0156] Preferably, the concentration of hydrogen peroxide (the concentration of hydrogen peroxide (H2O2) in hydrogen peroxide) is 0.1 to 33% by mass, preferably 0.15 to 10% by mass.

[0157] Preferably, the molar feed ratio of hydrogen peroxide to ozone (H2O2:O3) is 0.28:1 to 0.76:1.

[0158] Preferably, in the advanced oxidation step, the contact time between the ozone-containing gas and the liquid subjected to the dynamic crystallization filtration treatment is 10 to 60 minutes.

[0159] The advanced oxidation step of the method of the present invention can be carried out in a continuous flow reaction tower or a sequencing batch mixing reactor.

[0160] In some embodiments, the advanced oxidation process is carried out in a continuous flow reaction tower, wherein the feed liquid treated with dynamic crystallization obtained in the dynamic crystallization process continuously flows into the reaction tower from the upper part of the reaction tower; the ozone-containing gas is continuously transported to the reaction tower from the lower part of the reaction tower through an aeration device, and continuously leaves from the top of the reaction tower after contacting and reacting with the feed liquid in the reaction tower; hydrogen peroxide continuously flows into the reaction tower from the top of the reaction tower; the ozone-containing gas and hydrogen peroxide are mixed and reacted with the feed liquid treated with dynamic crystallization in the reaction tower to finally obtain the treated feed liquid, which continuously flows out from the bottom of the reaction tower.

[0161] The aeration device is arranged inside the reaction tower, such as an aeration head, and the distance between the top of the aeration head and the bottom surface of the reactor is 1 to 5 cm.

[0162] Preferably, the ozone-containing gas is prepared using an ozone generator, and the ozone generator is connected to the aeration device.

[0163] Preferably, the (feed liquid) surface load of the reaction tower is 4 to 24 m 3 / m 2 -h, the reaction tower height is 2 to 4 meters.

[0164] Preferably, based on the liquid treated by dynamic crystallization, the ozone dosage is 100-1000 mg / L; the hydrogen peroxide dosage is 20-240 mg / L.

[0165] Preferably, the residence time of the liquid treated by dynamic crystallization filtration in the continuous flow reaction tower is 30 to 60 minutes.

[0166] Preferably, the reaction temperature in the continuous flow reaction tower is 10-60°C, preferably 20-50°C.

[0167] In some embodiments, the advanced oxidation process is carried out in a sequencing batch mixing reactor, wherein the feed liquid treated by dynamic crystallization filtration is fed into the reactor from the upper feed port of the reactor, and then the ozone-containing gas and hydrogen peroxide are continuously fed into the reactor at the same time, so that the ozone-containing gas and hydrogen peroxide are mixed with the feed liquid treated by dynamic crystallization filtration and react; after the reaction is completed, the feeding of the ozone-containing gas and hydrogen peroxide is stopped, and the treated feed liquid in the reactor is discharged from the bottom of the reactor;

[0168] Ozone is fed into the reactor through an aeration device arranged at the lower part of the reactor, and hydrogen peroxide is fed into the reactor through a hydrogen peroxide feed port at the bottom of the reactor.

[0169] Preferably, the reaction time is 30 to 60 minutes.

[0170] Preferably, the reaction temperature is 10-60°C, preferably 20-50°C.

[0171] Preferably, the hydrogen peroxide feed port is arranged at a position 1 to 5 cm away from the top of the ozone aeration device.

[0172] Preferably, the reactor height is 2 to 4 meters.

[0173] Preferably, based on the liquid treated by dynamic crystallization filtration, the ozone dosage is 100-1000 mg / L; the hydrogen peroxide dosage is 20-240 mg / L.

[0174] Preferably, based on the treatment of each liter of liquid subjected to dynamic crystallization filtration, the designed ozone-containing gas flow rate is 0.017 to 0.42 L / min.

[0175] Adsorbent preparation process

[0176] In some embodiments, the method of the present invention further comprises an adsorbent preparation step.

[0177] In the adsorbent preparation process, the adsorbent raw material is physically processed (without changing the chemical properties of the material) to reduce its particle size to the range specified in the present invention.

[0178] Preferably, the physical processing method is grinding, crushing, friction grinding, mechanical pulverization, wherein grinding includes high-energy grinding, low-temperature grinding, wet grinding, etc.

[0179] High-energy ball milling can be performed using a ball mill, such as a planetary ball mill, to cause the adsorbent raw material to collide with the grinding medium material, thereby utilizing centrifugal force and collision to reduce the particle size of the adsorbent raw material.

[0180] The grinding medium material includes but is not limited to stainless steel, hard alloy, metal oxide or ceramic, etc. The particle size of the grinding medium material can be 5 to 50 mm, preferably 10 to 30 mm.

[0181] In some embodiments, the filling rate of the grinding media may be 10 to 60% by volume, preferably 10 to 35% by volume, based on the volume of the grinding chamber (a cavity containing the grinding media and adsorbent raw materials during grinding).

[0182] The main disc speed in the planetary ball mill can be 100-400 rpm, and the planetary disc speed can be 400-800 rpm.

[0183] The ball milling time may be 5 min to 2 h, preferably 30 min to 60 min.

[0184] The particle size of the adsorbent obtained after physical processing is 100 to 1800 meshes.

[0185] The ball milling is preferably carried out in an air atmosphere, but it can also be carried out in an atmosphere without air or filled with an inert gas such as nitrogen.

[0186] Example

[0187] The present invention is further described by enumerating specific embodiments below. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content recorded in the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the present invention equally.

[0188] Preparation of powdered activated carbon

[0189] Take granular activated carbon with a particle size distribution of 40 to 80 mesh and grind it using a Fritsch Pulverisette 4 planetary ball mill. Divide 20 grams of granular activated carbon into two equal parts and add them to two stainless steel grinding boxes of the planetary ball mill. The volume of each grinding box is about 80 ml. Add 25 stainless steel grinding balls with a diameter of 10 mm to each grinding box. During operation, the main disk speed of the planetary ball mill is 400 rpm, and the planetary disk speed where the grinding box is located is 800 rpm. The single grinding time is 30 minutes, and the grinding is repeated twice. The ground activated carbon is then sieved through 200 mesh and 325 mesh sieves to obtain powdered activated carbon with a particle size of 200 to 325 mesh (45 to 74 microns).

[0190] Example 1

[0191] In this embodiment, the cobalt sulfate solution produced in the cobalt sulfate production process is used as the experimental raw material, that is, the solution to be treated, and its TOC content is detected to be 215.4 mg / L.

[0192] (1) Dynamic crystal filtration process

[0193] In this example, a dynamic crystal filtration device for experiment is used, and the effective length of the filter tube is about 14 cm and the effective area is 25 cm. 2 .

[0194] Use the powdered activated carbon obtained above as the crystal filtration material, mix the powdered activated carbon with the liquid after TOC is removed by activated carbon adsorption (TOC is about 80mg / L), and stir to prepare a coating slurry with a solid concentration of about 10g / L. Then use a peristaltic pump to apply the crystal filtration material to the dynamic crystal filtration membrane column device. During coating, a part of the coating slurry flows in from the lower part of the filter tube and flows out from the upper part, without passing through the tube wall (circulating flow). The flow rate of this part in the filter tube is 1.8cm / s; the other part flows out through the tube wall of the filter tube. The flux of this part is 250LMH, and the coating time is 20min. By comparing the changes in the total suspended solids in the coating slurry before and after coating, it is calculated that the coating mass is 2.33g, and the converted coating density is 932g / m 2 With this coating amount, the coating (crystal filter layer) thickness is about 2 mm.

[0195] Then the feed liquid to be treated is pumped into the dynamic crystal filtration membrane column device through a peristaltic pump. Using the dead-end filtration method, the feed liquid entering the membrane column passes through the crystal filtration layer and flows out from the side outlet of the membrane column. The outflowing feed liquid is the treated liquid. The discharge flux is adjusted to 230LMH. Under this flux, the contact time (calculated value) between the feed liquid and the crystal filtration layer during the adsorption process is about 31 seconds, and the filtration adsorption operation time is about 3 hours. About 1.6 liters of treated feed liquid is obtained. During the filtration adsorption separation operation, the operating pressure is always 0KPa.

[0196] After the adsorption separation operation is completed, the dynamic crystal filter membrane column device is backwashed. The backwash liquid is the feed liquid after TOC is removed by activated carbon adsorption (TOC is about 80 mg / L). The backwash peristaltic pump is controlled to make the nozzle flow rate of the filter tube during upwash and downwashing 18 cm / s, and the side flushing flux is 3800 LMH. The upwash time is 7 seconds, the backwash time is 5 seconds, and the downwash time is 5 seconds. Repeat 3 times. By measuring the total suspended solids in the mixed slurry produced by backwashing, the solid mass under backwashing is 2.42g. The backwash efficiency (ratio of backwash mass to coating mass) is 103.86%.

[0197] The TOC test of the treated liquid produced during the experiment showed that the TOC of the treated liquid was 80.8 mg / L, the removal rate was 62.5%, and the activated carbon adsorption capacity was 92.43 mg / g.

[0198] (2) Advanced Oxidation Process

[0199] The advanced oxidation process uses a batch reactor. The reactor has an inner diameter of 140 mm and a height of 200 mm. In the experimental test, the effective height of the feed liquid is 120 mm and the volume is about 1.5 L. An ozone aeration head is installed at the bottom of the device, with a diameter of about 50 mm, and the distance between the top of the aeration head and the bottom surface of the reactor is about 2 cm.

[0200] The ozone generator used in the experiment was used as the ozone source. The air intake volume was 0.15L / min by adjusting the air intake flow rate and equipment power. The ozone concentration measured by the ozone concentration detector was about 100g / m 3 .

[0201] Hydrogen peroxide with a concentration of 0.275wt% (27.5% hydrogen peroxide diluted 100 times before use) was used. The hydrogen peroxide was pumped into the reactor by a peristaltic pump. The hydrogen peroxide inlet pipe was extended into the reactor, about 3cm from the inner bottom surface and about 1cm from the top of the aeration head. The hydrogen peroxide was pumped into the system at a flow rate of about 1.3mL / min.

[0202] Connect the inlet and outlet gas and liquid pipes of the reaction device, and close all the inlet and outlet valves. Pour 1.5L of the treated liquid obtained from the dynamic crystal filtration process into the experimental reaction device, and cover the reactor cover. After that, open the ozone inlet and outlet valves to start introducing ozone. At the same time, open the hydrogen peroxide peristaltic pump and the liquid inlet valve to start adding hydrogen peroxide. At 30min and 60min of reaction, take samples from the middle of the reactor and measure the TOC of the liquid.

[0203] Through measurement, after 30 minutes, the TOC of the feed liquid was 48.2 mg / L, and after 60 minutes, the TOC of the feed liquid was 29.8 mg / L.

[0204] The results of Example 1 show that the method of the present invention has a good TOC removal effect, the TOC content in the product liquid is low, and the adsorption capacity of the activated carbon is high.

[0205] Example 2

[0206] This embodiment uses nickel sulfate solution in the process of producing nickel sulfate as the experimental raw material, that is, the solution to be treated, and its TOC content concentration is 242.54 mg / L.

[0207] (1) Dynamic crystal filtration process

[0208] This example uses a full-size dynamic crystal filtration device, whose filter tube has an effective length of 0.9 m and an effective area of ​​435 cm 2 .

[0209] Use 160-200 mesh powdered activated carbon as the crystal filter material, and use the liquid after TOC removal by activated carbon adsorption (TOC is about 80 mg / L) to prepare a coating slurry with a concentration of 20g / L. By adjusting the peristaltic pump, the flow rate in the filter tube during the coating cycle is controlled to be 2.2cm / s, the flux through the filter tube wall is 300LMH, and the coating time is 60min. By calculating the total suspended solids content of the coating slurry before and after coating, the coating density is 460g / m 2 .

[0210] Take the liquid to be treated and pump it into the full-size dynamic crystal filtration device for adsorption separation in a dead-end filtration mode. Control the flux through the filter tube at 100LMH to obtain about 15 liters of treated liquid. During the filtration adsorption separation operation, the operating pressure is always 0Kpa.

[0211] After the adsorption separation is completed, the liquid after the activated carbon adsorption to remove TOC (TOC is about 80mg / L) is used to backwash the membrane column, and the flow rate of the upper and lower flushes in the filter tube is controlled to be 30cm / s, and the flux through the filter tube during backwashing is controlled to be 4200LMH, the upwash time is 7 seconds, the backwash time is 5 seconds, and the downwash time is 5 seconds. Repeat 3 times to complete the experiment. By measuring the total suspended solids in the mixed slurry produced by backwashing, it is found that the mass of activated carbon under backwashing is about 20.33g. The backwash efficiency is 101.65%.

[0212] The TOC in the treated liquid was measured and found to be 131.09 mg / L, with a removal rate of 46.0%.

[0213] (2) Advanced Oxidation Process

[0214] For the treated liquid obtained in the above dynamic crystal filtration process, a continuous flow experimental reaction device is further used to carry out an ozone + hydrogen peroxide advanced oxidation process to reduce the TOC content.

[0215] The inner diameter of the continuous flow experimental reactor is 25mm and the height is 4m. In the experimental test, the effective height of the liquid is 3.0m and the effective volume is about 1.5L. An ozone aeration head with a diameter of about 10mm is installed at the bottom of the device, and the distance between the top of the aeration head and the bottom surface of the reactor is about 3cm.

[0216] The ozone generator used in the experiment was used as the ozone source. The air intake volume was 0.2L / min by adjusting the air intake flow rate and equipment power. The ozone concentration measured by the ozone concentration detector was about 100g / m 3 .

[0217] Hydrogen peroxide with a concentration of 0.275wt% was used. The hydrogen peroxide was pumped into the reactor by a peristaltic pump. The hydrogen peroxide inlet pipe was inserted into the reactor about 1cm below the liquid level. The hydrogen peroxide was pumped into the system at a flow rate of about 2mL / min.

[0218] The liquid is pumped into the reactor by a peristaltic pump and is pumped out of the reactor from the bottom by a second peristaltic pump. The flow rate of the liquid through the reactor is 1.96 L / h, and the calculated surface load is 4 m 3 / m 2 -h.

[0219] Connect the inlet and outlet gas and liquid inlet and outlet pipes of the reaction device, and close all inlet and outlet valves. Pour 1.5L of the treated liquid obtained in the dynamic crystal filtration process into the experimental reaction device. After that, open the ozone inlet and outlet valves, start to introduce ozone, and at the same time, open the liquid and hydrogen peroxide peristaltic pumps and liquid inlet valves. After the reactor stabilizes for 45 minutes, start the feed and discharge pumps for continuous flow reaction. After the reaction is completed, collect the treated liquid and measure the TOC of the treated liquid, which is 54.53mg / L.

[0220] The results of Example 2 show that the method of the present invention has a good TOC removal effect, the TOC content in the product liquid is low, and the adsorption capacity of the activated carbon is high.

[0221] Comparative Example 1

[0222] The feed liquid to be treated is the same as that in Example 1. Granular activated carbon with a particle size of 40 to 80 mesh (180 to 380 microns) is used to treat the feed liquid to be treated. The activated carbon is filled in an adsorption column with an inner diameter of 2 cm for dynamic adsorption. The filling amount is 40 g and the filling volume is about 50 mL. The empty bed residence time (EBCT) is 15 min. The feed liquid TOC is 80.4 mg / L at the end of the treatment, and the treatment volume is 4.4 L. The activated carbon adsorption capacity is calculated to be 14.9 mg / g.

[0223] Compared with Example 1, which has the same feed liquid to be treated and substantially the same TOC content of the feed liquid at the end point of the treatment, Comparative Example 1 uses larger particles of activated carbon for dynamic adsorption, has a large amount of activated carbon, and has a low adsorption capacity of the activated carbon. This shows that the use of small particle adsorbents combined with the dynamic crystal filtration process in the present invention can effectively increase the adsorbent capacity and improve the TOC removal effect.

[0224] Comparative Example 2

[0225] The feed liquid to be treated is the same as that in Example 1, and a static mixed adsorption test is performed using powdered activated carbon of 200-325 mesh. In 1L of feed liquid, 1.5g of powdered activated carbon is added to reach an activated carbon equivalent of 1.5g / L. The feed liquid to be treated and the activated carbon mixed liquid are stirred at 200rpm for 30min. After stirring, a 0.45 micron PVDF filter membrane is used for vacuum filtration to separate the activated carbon from the feed liquid. After separation, the TOC of the test result is 115.3mg / L. The activated carbon adsorption capacity is calculated to be 66.7mg / g.

[0226] The results of comparative example 2 show that the TOC removal effect is poor when using small particle activated carbon for static adsorption. This shows that the use of small particle adsorbent combined with dynamic crystal filtration process in the present invention can effectively increase the adsorbent capacity and improve the TOC removal effect.

[0227] Industrial Applicability

[0228] The method of the invention can be widely used for removing organic impurities in hydrometallurgical liquid.

Claims

1. A method for removing organic impurities from hydrometallurgical liquid, characterized in that: Including the following processes: (1) Dynamic crystal filtration process The dynamic crystal filtration process is carried out in a dynamic crystal filtration device, which includes one or more dynamic crystal filtration elements, and the dynamic crystal filtration element includes a tubular filter housing and one or more filter tubes located inside the filter housing, and the tube wall of the filter tube is made of porous material; there is a gap between the inner wall of the filter housing and the outer wall of the filter tube for material flow; The dynamic crystal filtration process includes an adsorbent coating section, a filtration adsorption section, and a backwashing section; In the adsorbent coating section, the adsorbent is coated on the inner side of the tube wall of the filter tube; In the filtration and adsorption section, the hydrometallurgical liquid to be treated enters the interior of the filter tube, contacts the adsorbent coated on the inner side of the tube wall of the filter tube, and flows through the filter tube in a dead-end filtration or cross-flow filtration manner to obtain a liquid treated by dynamic crystallization filtration; In the backwashing section, the adsorbent coated on the inner tube wall of the filter tube is washed with the backwash material, so that the adsorbent is separated from the tube wall of the filter tube and discharged out of the dynamic crystal filtration device together with the backwash material; and (2) Advanced Oxidation Process In the advanced oxidation process, ozone-containing gas and hydrogen peroxide are mixed with the feed liquid treated by dynamic crystallization filtration and reacted to obtain a treated feed liquid.

2. The method according to claim 1, characterized in that The hydrometallurgical liquid contains nickel sulfate or cobalt sulfate, and is preferably a liquid containing nickel sulfate or cobalt sulfate produced in a process of producing nickel sulfate or cobalt sulfate by hydrometallurgy.

3. The method according to claim 1, characterized in that The adsorbent is one or more selected from carbon-based adsorption materials, resin adsorption materials or plant-based shell materials; Preferably, the adsorbent is activated carbon; Preferably, the tube wall of the filter tube is made of a flexible porous material; Preferably, in the dynamic crystal filtration process, the adsorbent coating section, the filtration adsorption section and the backwashing section are cyclically repeated in sequence.

4. The method according to any one of claims 1 to 3, characterized in that The advanced oxidation process is carried out in a continuous flow reaction tower, wherein the feed liquid treated by dynamic crystal filtration continuously flows into the reaction tower from the upper part of the reaction tower; the gas containing ozone is continuously transported to the reaction tower through the aeration device from the lower part of the reaction tower, and continuously leaves from the top of the reaction tower after the reaction; hydrogen peroxide continuously flows into the reaction tower from the top of the reaction tower; the ozone-containing gas and hydrogen peroxide are mixed and reacted with the feed liquid treated by dynamic crystal filtration in the reaction tower, and finally the treated feed liquid is obtained, which continuously flows out from the bottom of the reaction tower; Preferably, the surface load of the feed liquid of the reaction tower is 4 to 24 m 3 / m 2 -h, the reaction tower height is 2 to 4 meters; Preferably, based on the liquid treated by dynamic crystallization, the ozone dosage is 100-1000 mg / L; the hydrogen peroxide dosage is 20-240 mg / L.

5. The method according to any one of claims 1 to 3, characterized in that: The advanced oxidation process is carried out in a sequencing batch mixing reactor, wherein the feed liquid treated by dynamic crystallization filtration is fed into the reactor from the upper feed port of the reactor, and then the ozone-containing gas and hydrogen peroxide are continuously fed into the reactor at the same time, so that the ozone-containing gas and hydrogen peroxide are mixed with the feed liquid treated by dynamic crystallization filtration and react; after the reaction is completed, the feeding of the ozone-containing gas and hydrogen peroxide is stopped, and the treated feed liquid in the reactor is discharged from the bottom of the reactor; The ozone-containing gas is fed into the reactor through an aeration device disposed at the bottom of the reactor, and hydrogen peroxide is fed into the reactor through a hydrogen peroxide feed port at the bottom of the reactor; Preferably, the reaction time is 30 to 60 minutes; Preferably, the hydrogen peroxide feed port is set at a position 1 to 5 cm away from the top of the ozone aeration device; Preferably, the reactor height is 2 to 4 meters; Preferably, based on the liquid treated by dynamic crystallization, the ozone dosage is 100-1000 mg / L; the hydrogen peroxide dosage is 20-240 mg / L; Preferably, the flow rate of the ozone-containing gas is designed to be 0.017 to 0.42 L / min based on the treatment of each liter of liquid subjected to the dynamic crystallization filtration.

6. The method according to any one of claims 1 to 3, characterized in that: In the adsorbent coating section, an adsorbent slurry is transported to the interior of the filter tube, and a cross-flow filtration operation is performed to allow the adsorbent to adhere to the inner side of the tube wall of the filter tube, wherein the adsorbent slurry contains the adsorbent and the treated feed liquid; Preferably, the adsorbent is in granular form with a particle size of 0.05 to 500 microns; preferably 12 to 200 microns; Preferably, the coating amount of the adsorbent is 20 to 1920 g / m 2 ; preferably 240~960g / m 2 ; Preferably, in the cross-flow filtration operation, the flux through the tube wall of the filter tube is 30 to 800 LMH; preferably 200 to 400 LMH; Preferably, the flow rate of the adsorbent slurry entering the filter tube is 0.5 to 5 cm / s; Preferably, the content of the adsorbent in the adsorbent slurry is 5 to 50 g / L; Preferably, the cross-flow filtration operation time is 1 to 60 minutes; preferably 3 to 30 minutes.

7. The method according to any one of claims 1 to 3, characterized in that: In the filtration and adsorption section, the flow rate per unit area of ​​the filter tube wall is 20 to 800 LMH, preferably 100 to 200 LMH; Preferably, in the case of cross-flow filtration, the ratio of the cross-flow flow rate to the effluent flow rate is 0.5:1 to 5:

1.

8. The method according to any one of claims 1 to 3, characterized in that: The backwashing process includes (a) upwashing, (b) backwashing and (c) downwashing operations, wherein: (a) Upwashing is to allow the backwash material to enter the interior of the filter tube from the lower end of the filter tube, cross-flow wash and flow out from the upper end of the filter tube; (b) backwashing is to allow the backwash material to enter the gap between the inner wall of the filter housing and the outer wall of the filter tube, and flow through the tube wall of the filter tube to the interior of the filter tube; (c) Downwashing is to allow the backwash material to enter the interior of the filter tube from the upper end of the filter tube, cross-flow wash and flow out from the lower end of the filter tube; Preferably, the backwash material is treated liquid; Preferably, during (a) the upwash operation, the flow rate of the backwash material entering the interior of the filter tube is 10 to 40 cm / s; preferably 15 to 30 cm / s; (a) the duration of the upwash operation is 5 to 30 s; preferably 5 to 10 s; Preferably, (b) during the backwashing operation, the flux of the backwash material passing through the wall of the filter tube to the interior of the filter tube is 2000-6000LMH; preferably 3000-4000LMH; (b) the duration of the backwashing operation is 5-30s; preferably 5-10s; Preferably, (c) during the downwash operation, the flow rate of the backwash material entering the interior of the filter tube is 10 to 40 cm / s; preferably 15 to 30 cm / s; (c) the duration of the downwash operation is 5 to 30 s; preferably 5 to 10 s; Preferably, the operations of (a) up-punching, (b) back-punching and (c) down-punching are performed once in sequence, or repeated 2 to 5 times in a cycle, preferably 2 to 3 times.

9. The method according to any one of claims 1 to 3, characterized in that: In the advanced oxidation process, the concentration of ozone in the ozone-containing gas is 50 to 250 g / m 3 ; The concentration of hydrogen peroxide in hydrogen peroxide is 0.1 to 33% by mass; The molar feed ratio of hydrogen peroxide to ozone (H2O2:O3) is 0.28:1 to 0.76:

1.

10. The method according to any one of claims 1 to 3, characterized in that: The backwashing section also includes a post-backwashing material processing operation, wherein the post-backwashing material is a mixture of the backwashing material and the adsorbent obtained by (a) upwashing, (b) backwashing and (c) downwashing operations, and the post-backwashing material processing operation includes solid-liquid separation of the post-backwashing material. Preferably, the solid-liquid separation is performed by plate and frame separation or centrifugal separation; Preferably, when the backwash material is a treated liquid, the liquid obtained by solid-liquid separation is used as the liquid to be treated in the filtration and adsorption section.

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