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CN-121976046-A - Recovery method of gold, silver, copper, zinc, lead and iron in roasting cyanide tailings

CN121976046ACN 121976046 ACN121976046 ACN 121976046ACN-121976046-A

Abstract

The invention particularly relates to a recovery method of gold, silver, copper, zinc, lead and iron in roasting cyanide tailings. The method realizes the cooperative recovery of gold, silver, copper, zinc, lead and iron multiple valuable metals in the roasting and cyaniding tailings, effectively improves the comprehensive utilization efficiency of resources of the tailings, realizes the precise separation and enrichment of each metal through the step-by-step directional treatment, has good grade of the obtained concentrate product and higher economic value, has compact process step connection, is easy and controllable to operate, is suitable for conventional metallurgical production equipment, is easy to realize industrial application, and simultaneously effectively reduces the emission risk of pollutants such as lead, cyanide and the like through the targeted process design, and further saves resources through the design of cyclic utilization of residual liquid, and takes into account the environmental protection and economy of production.

Inventors

  • SUN RENFENG
  • GUO JIANDONG
  • LI SHAOMEI
  • Zhao Benming
  • XU LIJIE
  • ZHANG ZHAO
  • ZHANG YUCHAO
  • LIANG ZHIWEI
  • LI XIYU

Assignees

  • 山东国大黄金股份有限公司

Dates

Publication Date
20260505
Application Date
20260213

Claims (10)

  1. 1. The recovery method of the gold, silver, copper, zinc, lead and iron in the roasting cyanide tailings is characterized by comprising the following steps: (1) Acid leaching treatment is carried out on the roasting cyanide tailings, and acid leaching liquid and acid leaching slag are obtained after solid-liquid separation; (2) Adding a vulcanizing reagent into the pickle liquor obtained in the step (1) in two stages, controlling the pH value of the first stage to be 2-3, precipitating copper, controlling the pH value of the second stage to be 4-5, and precipitating zinc to obtain copper concentrate and zinc concentrate respectively; (3) Carrying out chlorination leaching treatment on the acid leaching slag in the step (1), and carrying out solid-liquid separation to obtain a chlorination leaching liquid and lead-removed slag; (4) Adding sulfuric acid into the chloridized leaching solution in the step (3) to carry out precipitation reaction to obtain lead sulfate; (5) Performing cyanide leaching treatment on the lead-removed slag in the step (3), and extracting gold and silver to obtain cyanide tailings; (6) And (3) mixing the cyanide tailings in the step (5) with a reducing agent, performing reduction roasting, and grinding and magnetic separation on roasting products to obtain iron concentrate.
  2. 2. The recovery method according to claim 1, wherein the acid leaching treatment in the step (1) is carried out under the process conditions that sulfuric acid solution is adopted as a leaching agent, the liquid-solid ratio is 1-3.5:1, the mass percentage concentration of sulfuric acid is 12% -18%, and the leaching is carried out under agitation at 60-80 ℃ for 1.5-3 hours.
  3. 3. The method according to claim 1, wherein in the step (2), the sulfidizing agent is Na 2 S and/or H 2 S gas, and the adding amount of the sulfidizing agent is 1.05-1.15 times of the theoretical required amount of the precipitated copper when the precipitated copper is sulfidized for the first stage.
  4. 4. The recycling method according to claim 1, wherein the process conditions of the chloridizing leaching treatment in the step (3) are that the leaching agent is a mixed solution of NaCl and CaCl 2 , wherein the concentration of NaCl is 20-30% by mass, the concentration of CaCl 2 is 3-8% by mass, the leaching temperature is 85-95 ℃ and the leaching time is 2.5-4h.
  5. 5. The recovery method according to claim 1, wherein the step (4) comprises the steps of cooling the chloridized leaching solution to 45-55 ℃, slowly adding concentrated sulfuric acid with the mass percent concentration of 90-98% to adjust the pH value to 1.2-1.8, and crystallizing and separating out lead sulfate.
  6. 6. The recovery method according to claim 1, wherein the process conditions of the cyanide leaching treatment in the step (5) are that the lead-free slag is slurried to 25-35% by mass, naCN is added, the NaCN mass percentage concentration is kept at 0.2-0.4%, the pH value is adjusted to 10-11, and leaching is carried out for 36-60 hours.
  7. 7. The recovery method according to claim 1, wherein the technological conditions of the reduction roasting in the step (6) are that the reducing agent is at least one of coke powder, coal powder or natural gas, the addition amount of the reducing agent is 6% -10% of the mass of cyanidation tailings, the roasting temperature is 1150-1250 ℃, and the roasting time is 1.5-3 hours.
  8. 8. The recycling method according to claim 1, wherein in the step (6), the magnetic separation is performed by using a permanent magnet drum type magnetic separator, and the magnetic field strength is 180mT or more.
  9. 9. The recovery method according to claim 1, wherein the roasting and cyanidation tailings in step (1) are crushed to-200 mesh of 85% or more before pickling; grinding the roasting product in the step (6) to-350 meshes to-300 meshes before magnetic separation.
  10. 10. The recovery method according to claim 1, further comprising recycling the residual liquid after the lead precipitation in step (4), and returning the residual liquid to step (3) for use as a chlorinated leaching agent.

Description

Recovery method of gold, silver, copper, zinc, lead and iron in roasting cyanide tailings Technical Field The invention relates to a recovery method of gold, silver, copper, zinc, lead and iron in roasting cyanide tailings, and belongs to the technical field of solid waste recycling recovery. Background The roasting cyanidation method is one of the most commonly used gold extraction processes in the gold smelting industry, but the tailings generated by the process still contain a large amount of valuable metals including gold, silver, copper, lead, zinc, iron and the like. Millions of tons of tailings are produced annually at present, wherein the gold content can reach 0.5-3g/t, the silver content is 10-50g/t, and the copper, lead and zinc contents are respectively 0.5% -3%. With the increasing exhaustion of mineral resources and the increasing environmental protection requirements, how to efficiently recycle the valuable metals becomes an important research direction in industry. In recent years, hydrometallurgical technology and pyrometallurgical technology are applied in the field, but the problems of low recovery rate, long process flow, secondary pollution and the like are commonly existed. The current mainstream treatment scheme comprises a direct cyaniding method for recovering gold and silver through multiple cyaniding leaching, but other metals cannot be recovered and cyanide consumption is high, a pyrometallurgy method for producing noble lead through mixing and smelting tailings and flux, but high energy consumption and serious lead pollution, an acid leaching-extraction method for separating metals through solvent extraction after sulfuric acid leaching, but poor copper-zinc separation effect and high equipment investment, and a bioleaching method for decomposing sulfide to release metals through microorganisms, wherein the period is up to several months and the strain adaptability is poor. The methods have the defects of single metal recovery type, comprehensive recovery rate lower than 60 percent, high waste water and waste gas treatment difficulty and the like. The method mainly has the following defects that 1, the multi-metal cooperative recovery capability is poor, 2-3 main valuable metals can be recovered generally, 2, the process flow is long and needs a plurality of independent working procedures to be completed in series, 3, the comprehensive utilization rate of resources is low, iron and other bulk metals in tailings are not basically recovered, 4, the environmental pollution risk is high, and especially toxic substances such as lead and cyanide are easy to cause secondary pollution, 5, the economical efficiency is poor, and the treatment cost is close to or higher than the metal product value. Therefore, developing an economic and environment-friendly method for recycling solid waste with high efficiency is a problem to be solved. Disclosure of Invention The invention provides a method for recovering gold, silver, copper, zinc, lead and iron in roasting cyanide tailings aiming at the technical problems. The technical scheme for solving the technical problems is as follows: The invention provides a recovery method of gold, silver, copper, zinc, lead and iron in roasting cyanide tailings, which comprises the following steps: (1) Acid leaching treatment is carried out on the roasting cyanide tailings, and acid leaching liquid and acid leaching slag are obtained after solid-liquid separation; (2) Adding a vulcanizing reagent into the pickle liquor obtained in the step (1) in two stages, wherein the pH value of the first stage is controlled to be 2-3 to precipitate copper, and the pH value of the second stage is controlled to be 4-5 to precipitate zinc, so that copper concentrate and zinc concentrate are respectively obtained; (3) Carrying out chlorination leaching treatment on the acid leaching slag in the step (1), and carrying out solid-liquid separation to obtain a chlorination leaching liquid and lead-removed slag; (4) Adding sulfuric acid into the chloridized leaching solution in the step (3) to carry out precipitation reaction to obtain lead sulfate; (5) Performing cyanide leaching treatment on the lead-removed slag in the step (3), and extracting gold and silver to obtain cyanide tailings; (6) And (3) mixing the cyanide tailings in the step (5) with a reducing agent, performing reduction roasting, and grinding and magnetic separation on roasting products to obtain iron concentrate. The method realizes the efficient collaborative recovery of various valuable metals by treating the roasting cyanide tailings step by step, and solves the problems of single metal recovery type, long process, environmental pollution and the like in the prior art. Specifically, acid leaching treatment is carried out on roasting cyanidation tailings, and acid leaching liquid and acid leaching slag are obtained through solid-liquid separation, so that acid-soluble metal components are primarily separated,