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CN-122012954-A - Method for extracting gallium by using fly ash

CN122012954ACN 122012954 ACN122012954 ACN 122012954ACN-122012954-A

Abstract

The invention provides a method for extracting gallium by using fly ash, which comprises the steps of (1) adsorbing coarse refined liquid of the fly ash by macroporous strong base anion exchange resin, eluting by hydrochloric acid solution to obtain a first eluent, (2) adding sodium hydroxide solution into the first eluent to regulate pH, filtering and precipitating to obtain filter residues, (3) adding sodium hydroxide solution into the filter residues, stirring and leaching, filtering and removing solids to obtain gallium-extracting stock solution, (4) adsorbing the gallium-extracting stock solution by gallium-extracting resin, eluting by sulfuric acid solution to obtain a second eluent, (5) adding sodium hydroxide solution into the second eluent to regulate pH value, filtering, adding sodium hydroxide solution into gallium precipitate until the gallium precipitate is completely dissolved, and then removing impurity vanadium in the gallium solution to obtain the electrolyte stock solution, (6) carrying out electrolytic deposition on the electrolyte stock solution.

Inventors

  • GAO JIE
  • ZHANG ZHENMING
  • ZHANG WEIQI
  • GAO GUIMEI
  • CAO KUN
  • XU LIJUN
  • LIU RUIPING
  • ZHAO JIANQIANG
  • WANG LIPING
  • LI SHICHUN

Assignees

  • 中国神华能源股份有限公司哈尔乌素露天煤矿
  • 神华准能资源综合开发有限公司

Dates

Publication Date
20260512
Application Date
20260107

Claims (10)

  1. 1. A method for extracting gallium by using fly ash, which is characterized by comprising the following steps: (1) Adsorbing the coarse and fine coal ash liquid by using macroporous strong base anion exchange resin, and eluting the macroporous strong base anion exchange resin by using hydrochloric acid solution to obtain a first eluent; (2) Adding sodium hydroxide solution into the first eluent to adjust the pH, and then filtering and precipitating to obtain filter residues; (3) Adding sodium hydroxide solution into the filter residue, stirring and leaching, and filtering to remove solids to obtain gallium-extracted stock solution; (4) Adsorbing the gallium-extracted raw liquid through gallium-extracted resin, and eluting the gallium-extracted resin by sulfuric acid solution to obtain a second eluent; (5) Adding sodium hydroxide solution into the second eluent to adjust the pH value of the solution, obtaining gallium precipitate, filtering, adding sodium hydroxide solution into the gallium precipitate until the gallium precipitate is completely dissolved, obtaining gallium solution, and removing impurity vanadium in the gallium solution to obtain an electrolyte stock solution; (6) And carrying out electrolytic deposition on the electrolytic stock solution to obtain gallium metal.
  2. 2. The method according to claim 1, wherein in the step (1), the concentration of the hydrochloric acid solution is 0.5-1wt%; and/or the temperature of the elution of the hydrochloric acid solution is room temperature, and the flow rate of the elution of the hydrochloric acid solution is 2-3 BV/h; And/or the flow rate of the fly ash coarse refined solution flowing through the macroporous strong base anion exchange resin is 1-3 BV/h, and the adsorption temperature is 40-50 ℃.
  3. 3. The method according to claim 1, wherein in step (2), sodium hydroxide solution is added to the first eluent to a pH of 6 to 8.
  4. 4. The method according to claim 1, wherein in the step (3), the concentration of the sodium hydroxide solution is 50-60 g/L, and the mass ratio of the sodium hydroxide solution to the filter residue is (4.5-5.5) mL/1 g.
  5. 5. The method according to claim 1, wherein in the step (3), the temperature of the agitation leaching is 100-130 ℃, and the time of the agitation leaching is 160-210 min; and/or the stirring speed in the stirring leaching process is 100-200 r/min.
  6. 6. The method according to any one of claims 1 to 5, wherein in step (4), the flow rate of the gallium-extracting stock solution flowing through the gallium-extracting resin is 3-4 BV/h, the adsorption temperature is 25-45 ℃, and preferably the gallium-extracting resin is a dedicated chelating ion exchange resin for adsorbing gallium; And/or the concentration of the sulfuric acid solution is 1-2wt%; And/or the temperature of elution by adopting the sulfuric acid solution is 20-30 ℃, and the flow rate is 1.5-2 BV/h.
  7. 7. The method according to any one of claims 1 to 5, wherein in step (5), the concentration of the sodium hydroxide solution added to the second eluent is 2 to 3mol/L; And/or adding the sodium hydroxide solution to adjust the pH value of the solution to 4-6.5; and/or the temperature of the system in the gallium precipitate forming process is 25-30 ℃, the precipitate forming time of the gallium precipitate is 15-30 min, stirring is preferably carried out in the gallium precipitate forming process, and more preferably the stirring rotating speed is 140-160 r/min.
  8. 8. The method according to any one of claims 1 to 5, wherein in step (5), the concentration of the sodium hydroxide solution added to the gallium precipitate is 4 to 6 mol/L; and/or the dissolution temperature of the gallium precipitate is 45-60 ℃, and the dissolution time is 275-325 min; and/or stirring in the gallium precipitation dissolution process, wherein the stirring speed is preferably 400-500 r/min.
  9. 9. The method according to any one of claims 1 to 5, wherein in the step (5), the impurity vanadium in the gallium solution is removed, and the method comprises the steps of adding 30wt% of H 2 O 2 accounting for 8 to 12% of the volume of the gallium solution into the gallium solution, and adding calcium hydroxide for reaction; preferably, the reaction temperature is 60-70 ℃ and the reaction time is 8-10 hours; preferably, the volume ratio of the mass of the calcium hydroxide to the gallium solution is (30-35) g/1L.
  10. 10. The method according to any one of claims 1 to 5, wherein in the step (6), the temperature of the electrolytic deposition is 25 to 40 ℃ and the current density is 250 to 400A/m 2 , and preferably the anode used for the electrolytic deposition is a platinum sheet and the cathode is a 304 stainless steel electrode.

Description

Method for extracting gallium by using fly ash Technical Field The invention belongs to the technical field of gallium extraction, and particularly provides a method for extracting gallium by using fly ash. Background Gallium, because of its unique physical and chemical properties, has been known as a support for the modern electronics industry, and has found wide application in the fields of semiconductors, optical materials, solar cells, communications, medical diagnostics, and metallurgy, leading to technological advances in various leading-edge fields of the world. With the rapid development of new energy, artificial intelligence and other technologies, the application prospect of gallium is wider. The global gallium metal is rare, the exploration reserve is about 180 ten thousand tons, the quasi-golgi coal field contains about 85 ten thousand tons which is equivalent to 47 percent of the total global amount, and the coal is effectively enriched with metals such as gallium after being burnt. In the process for producing alumina by the fly ash hydrochloric acid method, elements such as Al, fe, ga, ca, mg in the fly ash are dissolved out by hydrochloric acid, and then the alumina product is obtained after the steps of filtering, impurity removal, crystallization, roasting and the like. The invention is based on the eluent obtained in the iron removal process for recovering and extracting gallium. At present, some existing methods for extracting gallium from fly ash generally have the problems of complicated working procedures, more materials adopted, high cost or low gallium recovery rate (the gallium recovery rate is basically lower than 70%). Based on the existing technology for extracting gallium from fly ash, the gallium recovery rate, production cost and the like of the process for extracting gallium from fly ash are still to be further optimized. Disclosure of Invention The present invention aims to solve at least to some extent one of the technical problems in the prior art. To this end, an object of the present invention is to propose a method for extracting gallium using fly ash. The invention provides a method for extracting gallium by using fly ash, which comprises the following steps: (1) Adsorbing the coarse and fine coal ash liquid by using macroporous strong base anion exchange resin, and eluting the macroporous strong base anion exchange resin by using hydrochloric acid solution to obtain a first eluent; (2) Adding sodium hydroxide solution into the first eluent to adjust the pH, and then filtering and precipitating to obtain filter residues; (3) Adding sodium hydroxide solution into the filter residue, stirring and leaching, and filtering to remove solids to obtain gallium-extracted stock solution; (4) Adsorbing the gallium-extracted raw liquid through gallium-extracted resin, and eluting the gallium-extracted resin by sulfuric acid solution to obtain a second eluent; (5) Adding sodium hydroxide solution into the second eluent to adjust the pH value of the solution, obtaining gallium precipitate, filtering, adding sodium hydroxide solution into the gallium precipitate until the gallium precipitate is completely dissolved, obtaining gallium solution, and removing impurity vanadium in the gallium solution to obtain an electrolyte stock solution; (6) And carrying out electrolytic deposition on the electrolytic stock solution to obtain gallium metal. According to the method for extracting gallium by using the fly ash, provided by the invention, the coarse and fine fly ash liquid is firstly adsorbed by macroporous strong base anion exchange resin, and then the macroporous strong base anion exchange resin is eluted by hydrochloric acid solution, and most impurities are removed in the process, so that a first eluent containing Fe, al, ga and other elements is obtained. And adding sodium hydroxide solution into the first eluent to adjust the pH, forming hydroxide of Fe, al, ga and other elements to precipitate in the eluent, and filtering the precipitate to obtain filter residues containing Fe, al, ga. Adding sodium hydroxide solution into the filter residues, stirring and leaching, selectively leaching the filter residues by using the sodium hydroxide solution, and efficiently separating Ga, fe, al, ca and other elements by regulating and controlling the leaching technological parameters, so as to reduce impurity elements entering a subsequent process, and further purify gallium element to obtain gallium extracting stock solution. And (3) adsorbing the gallium-extracted raw liquid through a gallium-extracted resin, eluting the gallium-extracted resin by using a sulfuric acid solution, and adsorbing gallium through the gallium-extracted resin, so that gallium can be further effectively enriched, and a second eluent enriched in gallium is obtained. And adding sodium hydroxide solution into the second eluent to adjust the pH value of the solution, filtering after gallium precipitation, adding sodiu