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CN-122012938-A - Method for recovering gold from waste circuit board

CN122012938ACN 122012938 ACN122012938 ACN 122012938ACN-122012938-A

Abstract

The invention provides a method for recovering gold from a waste circuit board, and relates to the technical field of resource recovery. The method comprises the steps of stripping electronic elements on a waste circuit board, crushing, sorting and pouring to obtain a metal plate, carrying out electrolytic copper separation on the metal plate, separating to obtain copper-removed pug, mixing the copper-removed pug in gold separation solution, separating gold-containing solution, mixing the gold-containing solution with composite reduction solution, and carrying out reduction reaction to obtain pure gold particles, wherein 1-3 mol/L NaCl, 2-3 mol/L H 2 SO 4 , 0.1-0.2 mol/L NaClO 3 , 0.05-0.1 mol/L H 2 O 2 and 10-20 g/L silane active agent are dissolved in the gold separation solution. The invention can improve the yield of gold from the waste circuit board, and no toxic and harmful waste liquid and gas are generated in the recovery process.

Inventors

  • CHEN WENYUAN
  • HE ZHUAN
  • XU TE
  • ZHANG PENG

Assignees

  • 梧州市盛发环保科技有限公司

Dates

Publication Date
20260512
Application Date
20260121

Claims (8)

  1. 1. A method for recovering gold from waste circuit boards is characterized by comprising the steps of stripping electronic elements on the waste circuit boards, crushing, sorting and pouring to obtain metal boards, separating copper-removed pugs after electrolytic copper separation of the metal boards, mixing the copper-removed pugs in a gold separating solution for reaction, separating gold-containing solution, mixing the gold-containing solution with a composite reducing solution for reduction reaction to generate pure gold particles, wherein 1-3 mol/L NaCl, 2-3 mol/L H 2 SO 4 , 0.1-0.2 mol/L NaClO 3 and 0.05-0.1 mol/L H 2 O 2 and 10-20 g/L silane active agent are dissolved in the gold separating solution.
  2. 2. The method of claim 1, wherein the electronic components are peeled off after preheating the waste circuit board at 200-250 ℃, and/or the electronic components are peeled off and recovered, and/or the electronic components on the waste circuit board are peeled off, sheared and crushed at a low temperature, and/or crushed and pass through a 1mm-3mm screen, and/or the sorting comprises at least one of gravity sorting, electrostatic sorting and air flow sorting.
  3. 3. The method according to claim 1, wherein the metal particles and the nonmetal particles are obtained after sorting, the metal particles are subjected to molten casting to obtain a metal plate, and/or the metal plate is molten and cast at 1200-1500 ℃ after sorting, and/or the metal particles are subjected to molten casting after pre-calcining at 400-600 ℃ after sorting, and/or the metal particles and the fluxing agent are mixed in a mass ratio of 10:1 after sorting, and preferably the fluxing agent comprises borax.
  4. 4. The method according to claim 1, wherein the metal plate is immersed in an electrolyte, and electrolytic copper separation is performed by using the metal plate as an anode and stainless steel as a cathode, wherein soluble substances in the electrolyte comprise 1-3 mol/L CuSO 4 , 0.5-2 mol/L H 2 SO 4 , 0.2-0.5 mol/L HCl, 0.01-0.05 mol/L thiourea, 100-200 mg/L gelatin and 50-100 mg/L bone glue.
  5. 5. The method according to claim 1 or 4, wherein the electrolytic copper separation is carried out at a current density of 200A/m 2 -300A/m 2 , and/or the electrolytic copper separation is carried out at a temperature of 50-60 ℃, and/or anode slime is collected after the electrolytic copper separation, and solid-liquid separation is carried out after the anode slime is reacted with manganese dioxide in dilute sulfuric acid, wherein 0.2-0.5 mol/L sulfuric acid and 0.1-0.3 mol/L sodium chloride are dissolved in the dilute sulfuric acid, and the mass ratio of the anode slime to the manganese dioxide is 1 (0.1-0.2).
  6. 6. The method according to claim 1, wherein the decoppered pugs are mixed and reacted in a gold separating solution at 50-80 ℃ for 3-5 h, and/or the ultrasonic mixing and reacting in the gold separating solution, and/or the decoppered pugs are washed and dried by absolute ethyl alcohol in advance and then are mixed and reacted with the gold separating solution, and/or the solid-liquid mass ratio of the decoppered pugs to the gold separating solution is 1 (10-30), and/or the silane active agent comprises Tegopren-5885.
  7. 7. The method according to claim 1, wherein 1mol/L-2mol/L Na 2 SO 3 , 0.5mol/L-1mol/L ascorbic acid, 0.1mol/L-0.3mol/L EDTA, 3g/L-8g/L polyvinylpyrrolidone and/or the pH of the composite reduction solution is 1-3 and/or the gold-containing solution is desolventized to obtain a gold-containing pug, and the gold-containing pug is mixed and dispersed in the composite reduction solution, wherein the solid-liquid mass ratio of the gold-containing pug to the composite reduction solution is 1 (10-30).
  8. 8. The method according to claim 1, wherein the gold-containing solution is mixed with the composite reducing solution and then subjected to a reduction reaction at 30-50 ℃, and/or the gold-containing solution is mixed with the composite reducing solution and then subjected to a reduction reaction for 2-5 hours, and/or the gold-containing solution is ultrasonically mixed with the composite reducing solution, and/or the gold-containing solution is subjected to a reduction reaction and then subjected to suction filtration and separation, and is circularly washed with absolute ethyl alcohol and deionized water to obtain pure gold particles.

Description

Method for recovering gold from waste circuit board Technical Field The invention relates to the technical field of resource recovery, in particular to a method for recovering gold from a waste circuit board. Background Along with the continuous development of global economy, the resource problem is more serious, and the current era of the rapid development of the positive electronic information industry is increasingly accelerated, so that a large amount of electronic wastes are generated, the metal content in the waste circuit board which mainly consists of the electronic wastes is higher, the potential of recycling is huge, and the important point of resource recovery is always the point of resource recovery. From the composition point of view, the waste circuit board is a composite of metal materials and non-metal materials, wherein the metal components mainly comprise base metals such as copper, lead, tin and the like and noble metals such as gold, silver and the like, and particularly the grade of gold is far superior to that of primary ore. The current recovery method of gold in the waste circuit board mainly comprises two methods of pyrometallurgy and hydrometallurgy, wherein the pyrometallurgy relies on the existing copper and lead smelting systems, the waste circuit board is used as ingredients to carry out cooperative treatment with primary ore, smelting is carried out at high temperature to promote base metals such as copper and the like to form molten phases, noble metals are enriched in metal melt, and finally different metals are obtained through separate purification. However, the energy consumption of pyrometallurgy is huge, and non-metal components in the circuit board easily generate highly toxic substances such as dioxin in the high temperature process, so that the environmental protection cost is greatly increased, while hydrometallurgy needs to use more toxic and harmful reagents, so that a great potential safety hazard exists, the post-treatment procedure of the waste liquid is complex, a great amount of cyanide-containing waste water or nitrogen oxide waste gas can be generated, and the environmental risk is increased, so that the scheme is needed to improve the problems. Disclosure of Invention The invention aims to provide a method for recovering gold from waste circuit boards, which can improve the yield of gold from waste circuit boards and can not generate toxic and harmful waste liquid and waste gas in the recovery process. The invention provides a method for recovering gold from a waste circuit board, which comprises the steps of stripping electronic elements on the waste circuit board, crushing, sorting and pouring to obtain a metal board, carrying out electrolytic copper separation on the metal board, separating to obtain a decoppered mud material, mixing the decoppered mud material in a gold separation solution for reaction, separating a gold-containing solution, mixing the gold-containing solution with a composite reduction solution, and carrying out reduction reaction to generate pure gold particles, wherein 1-3 mol/L NaCl, 2-3 mol/L H 2SO4, 0.1-0.2 mol/L NaClO 3 and 0.05-0.1 mol/L H 2O2 and 10-20 g/L silane active agent are dissolved in the gold separation solution. Optionally, the electronic component is peeled off after preheating the waste circuit board at 200-250 ℃. Optionally, the electronic component is peeled off and recovered. Optionally, the electronic components on the waste circuit board are peeled off, then sheared and crushed at a low temperature. Optionally, the crushed material is passed through a 1mm-3mm screen. Optionally, the sorting includes at least one of gravity sorting, electrostatic sorting, and air flow sorting. Optionally, after sorting, metal particles and nonmetal particles are obtained, and the metal particles are subjected to melting pouring to obtain the metal plate. Optionally, after sorting, the metal plates are melted and poured at 1200-1500 ℃. Optionally, after sorting, pre-calcining at 400-600 ℃ and then casting in a melting way. Optionally, after sorting, metal particles and fluxing agent are mixed in a mass ratio of 10:1 and then are poured in a melting way. Optionally, the fluxing agent comprises borax. Optionally, a metal plate is immersed in the electrolyte, and electrolytic copper separation is performed using the metal plate as an anode and stainless steel as a cathode. Optionally, the soluble substances in the electrolyte comprise 1-3 mol/L CuSO 4, 0.5-2 mol/L H 2SO4, 0.2-0.5 mol/L HCl, 0.01-0.05 mol/L thiourea, 100-200 mg/L gelatin and 50-100 mg/L bone glue. Optionally, electrolytic copper separation is performed at a current density of 200A/m 2-300A/m2. Optionally, electrolytic copper separation is performed at 50-60 ℃. Optionally, collecting anode slime after copper separation by electrolysis, stirring and reacting the anode slime with manganese dioxide in dilute sulfuric acid, and then carrying out solid-liquid separation t