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CN-121992189-A - Smelting process for roasting gold concentrate by two-stage fluidized bed furnace

CN121992189ACN 121992189 ACN121992189 ACN 121992189ACN-121992189-A

Abstract

The invention discloses a smelting process for roasting gold concentrate by a two-stage fluidized bed furnace, which comprises the steps of sequentially carrying out primary dearsenification roasting and secondary desulfurization roasting on gold concentrate to obtain calcine, then carrying out cyanidation leaching on the calcine to obtain gold-containing leaching solution, adsorbing the gold-containing leaching solution by using activated carbon to obtain gold-carrying carbon, desorbing the gold-carrying carbon to obtain gold-containing noble liquid, electrolyzing the noble liquid to obtain gold mud, and carrying out fusion casting on the gold mud to obtain gold ingots.

Inventors

  • LIU FENG
  • WANG ZHONGFENG
  • XIA XIANGMIN
  • LIU LUQIANG
  • LIN YANG
  • LIU LIQIU
  • CHEN JINGXIU

Assignees

  • 矩阵资源(浙江)有限公司

Dates

Publication Date
20260508
Application Date
20260202

Claims (10)

  1. 1. A smelting process for roasting gold concentrate by a two-stage fluidized bed furnace is characterized in that gold concentrate is subjected to primary dearsenification roasting and secondary desulfurization roasting in sequence to obtain calcine, then the calcine is subjected to cyanidation leaching to obtain gold-containing leaching liquid, activated carbon is adopted to adsorb the gold-containing leaching liquid to obtain gold-carrying carbon, the gold-carrying carbon is subjected to desorption to obtain gold-containing noble liquid, the gold-containing noble liquid is subjected to electrolysis to obtain gold mud, and the gold mud is subjected to fusion casting to obtain gold ingots; when the first-stage dearsenifying roasting is performed, the concentration of O 2 is controlled to be less than or equal to 10wt%, and the temperature is 450-550 ℃; and during the two-stage desulfurization roasting, the concentration of O 2 is controlled to be more than or equal to 15 wt%, and the temperature is 650-750 ℃.
  2. 2. The smelting process for roasting gold concentrate by a two-stage fluidized bed furnace according to claim 1, wherein the gold grade in the gold concentrate is less than or equal to 20g/t, the arsenic content is more than or equal to 2wt.% and the sulfur content is 18-22wt.%.
  3. 3. The smelting process for roasting gold concentrate in a two-stage fluidized bed furnace according to claim 1, wherein the gold concentrate is slurried to form pulp, and the pulp is conveyed to the fluidized bed furnace in a slurry feeding mode for two-stage roasting, and the concentration of the pulp is 30-50wt%.
  4. 4. The smelting process for roasting gold concentrate by using a two-stage fluidized bed furnace according to claim 1, wherein the oxygen concentration is controlled to be 5-10%, the temperature is 500-550 ℃ and the roasting time is 0.5-2h, When the two-stage dearsenifying roasting is performed, the oxygen concentration is controlled to be 15-25%, the temperature is 650-700 ℃, and the roasting time is 0.2-4h.
  5. 5. The smelting process for roasting gold concentrate by using a fluidized bed furnace according to claim 1, wherein: Quenching the As 2 O 3 flue gas generated by the first-stage dearsenification roasting, and recycling the flue gas by a cloth bag dust collection system; SO 2 generated by the two-stage desulfurization roasting is directly connected into a sulfur acid making system; waste heat generated in the primary dearsenifying roasting and secondary desulfurizing roasting processes is recovered through a waste heat boiler and is used for power generation or heat supply.
  6. 6. The smelting process for roasting gold concentrate by using a two-stage fluidized bed furnace according to claim 1, wherein the calcine is placed in a solution containing sodium cyanide to obtain slurry for cyanide leaching, the pH of the cyanide leaching is 10-12, the mass fraction of sodium cyanide in the solution containing sodium cyanide is 0.05-0.2%, the liquid-solid mass ratio of the solution containing sodium cyanide to the calcine is 2.5-3.5:1, and the cyanide leaching time is 24-36h.
  7. 7. A process for preparing gold concentrate by two-stage fluidized bed furnace according to claim 5, wherein lime is used to adjust pH of the slurry and mechanical stirring or aeration stirring is used to intensify cyanide leaching.
  8. 8. The smelting process for roasting gold concentrate by using a two-stage fluidized bed furnace according to claim 1, wherein the countercurrent adsorption process is adopted when the active carbon is adopted to adsorb the gold-containing leaching solution, the flow rate in the adsorption tower is 5-10m < 3 >/h.m2, and the particle size of the active carbon is 1-3mm.
  9. 9. The smelting process for roasting gold concentrate by using the two-stage fluidized bed furnace according to claim 1, wherein the process of desorbing the gold-bearing carbon is characterized in that the gold-bearing carbon is loaded into a desorption column, preheated desorption liquid is pumped from the bottom of the column, gold-bearing noble liquid is obtained from the top of the column, the desorption liquid is a mixed solution composed of sodium cyanide and sodium hydroxide, wherein the mass fraction of the sodium cyanide in the mixed solution is 0.1-1%, and the mass fraction of the sodium hydroxide is 1-2%; During electrolysis, the noble liquid containing gold is used as electrolyte, the stainless steel plate is used as a cathode, the current density is controlled to be 10-30A/m 2 , and in the electrolyte, au is more than or equal to 50g/L, so that gold mud is obtained.
  10. 10. A process for smelting gold concentrate by roasting in a two-stage fluidized bed furnace according to claim 1, wherein the gold slurry is subjected to hydrochloric acid washing, drying and casting.

Description

Smelting process for roasting gold concentrate by two-stage fluidized bed furnace Technical Field The invention belongs to the technical field of noble metal metallurgy, and particularly relates to a smelting process for roasting gold concentrate by a two-stage fluidized bed furnace. Background The traditional gold concentrate smelting process generally adopts pretreatment technologies such as single roasting, biological oxidation or high-pressure leaching and the like to decompose sulfide and release encapsulated gold, and further recovers noble metals through cyanide leaching. However, for complex gold concentrates of low grade (e.g. Au. Ltoreq.20 g/t), high arsenic (As. Gtoreq.2%) and medium and low sulfur (S. Ltoreq.20%) the prior art has significant limitations: 1. The co-removal of arsenic and sulfur is difficult, and the differential removal requirement of arsenic and sulfur is difficult to be considered in the primary roasting process. High-temperature roasting can be used for high-efficiency desulfurization, but arsenic is easy to volatilize too early to form virulent As 2O3 smoke dust, so that the smoke purification cost is increased, while low-temperature oxygen-control roasting can be used for preferentially removing arsenic, but low-sulfur mineral materials are difficult to maintain self-heating balance, and are required to be supplemented by exogenous fuel, so that the economy is poor. 2. Gold recovery is limited in that arsenic residues react with cyanide to form stable complexes (e.g., as (CN) 3), greatly increasing cyanide consumption and inhibiting gold dissolution, and underoxidized sulfides encapsulate gold particles, reducing leaching rate. The leaching rate of gold after conventional roasting is often lower than 80%, and the resource waste is serious. 3. The contradiction between environmental protection and reclamation, namely that the traditional process adopts lye absorption or direct discharge to treat SO 2, thereby not only wasting sulfur resources, but also facing severe environmental protection regulation. The technical threshold for preparing acid from low-concentration SO 2 flue gas is high, and the stable supply of gas with proper concentration is difficult in the existing single-stage roasting. 4. The low-grade ore has poor adaptability, namely unstable roasting process caused by insufficient heat value of low-gold and low-sulfur ore materials, high-grade ore or fuel is required to be mixed, and the source flexibility of raw materials is limited. The traditional gold concentrate smelting process has significant technical bottlenecks. For example, patent CN201010567569.8 discloses a secondary oxidation pretreatment process of refractory gold concentrate containing arsenic, sulfur and carbon, which can effectively improve gold recovery rate, has simple flow and basically has no environmental pollution. But the process is complex and requires biological oxidation and chlorinating agents, and the process sequentially comprises the steps of concentrate regrinding and removing drugs, biological oxidation, chloridizing oxidation and cyanide gold leaching. The process adopts a biological oxidation process to oxidize gold concentrate, and hypochlorite is used for treating oxidizing slag after biological oxidation, so that the harmful influence of carbonaceous matters on fluoridation to extract gold is greatly reduced through chloridization oxidation. Patent CN 202311284213.7A novel green and efficient smelting process of gold concentrate adopts a direct cyanidation method to extract gold after superfine grinding, and finally, cement auxiliary materials are produced after the tailings are finely ground. The process is high in recovery rate, green and environment-friendly, but does not carry out roasting, directly cyanide gold extraction, and cannot treat impurity arsenic and impurity sulfur in concentrate. Patent CN202410809848.2, "a process for recovering gold from arsenic-containing gold concentrate by two-stage roasting", adopts two-stage roasting pressurization pretreatment, and is matched with an activating agent to effectively remove harmful impurities of arsenic, carbon and sulfur, thereby creating favorable conditions for chemical leaching. The grade of gold in the gold concentrate treated in the process is 73g/t, the grade of impurity arsenic is only 0.6%, and copper in the calcine is recovered specially, so that the method is not suitable for gold concentrate with low grade gold and high impurity content. Patent CN100404708C "two-stage roasting method recovery Au Ag Cu As S production process from arsenic-containing carbon gold concentrate" adopts two-stage roasting method recovery Au, ag, cu, as, S production process technology from arsenic-containing carbon gold concentrate, after gold concentrate is treated by activating agent and two-stage roasting, arsenic, carbon, sulfur and the like enter flue gas in gaseous form, for copper As metal impurity entering calcine in CuSO