Process for deep impurity removal and resource recovery of gold smelting wastewater

Abstract

The invention discloses a process for deep impurity removal and resource recovery of gold smelting wastewater, the process comprises the following steps: firstly, removing zinc and copper in barren liquor wastewater by adopting a mineralization sulfuration agent under the conditions that the pH values are 5-6 and 2.5-3 in sequence, then carrying out acidification stripping and neutralization reaction under the conditions that the pH values are 1.5-2 and 8.5-9.5, and finally introducing sulfur dioxide gas for aeration treatment, completing deep impurity removal and resource recovery of barren liquor wastewater, wherein the mineralization and vulcanization agent is prepared by mixing ferrous sulfate, calcium sulfide and water. The process provided by the invention has the advantages of high safety coefficient, high treatment efficiency, good impurity removal effect, high resource recovery yield, environmental protection and the like, and can realize deep impurity removal treatment of barren liquor wastewater and effective recovery of valuable heavy metals; and ferrous ions, calcium ions and sulfate ions contained in the mineralizing and vulcanizing agent are basically not remained in the cyanogen-removed liquid, so that the use value is high, and the application prospect is good.

Description

Technical field [0001] The present invention is in the field of gold smelting waste water treatment, in particular to a deep gold smelting waste and resource recovery impurity process. Background technique [0002] Gold smelting production process cyanide gold extraction process for its recovery efficiency of many advantages, is the most important gold extraction method in which the gold smelting process cyanide gold extraction process Jingui liquid rich in zinc that is output by the replacement of the filtrate It is a lean liquid waste, the waste water lean liquid containing valuable metal impurity ions of zinc and copper, and the valuable recyclable recycling cyanide, comprising recovering a waste water reuse. [0003] Currently, conventional wastewater treatment methods as lean solution acidified stripping method, direct acidification process in which the lean liquid wastewater, zinc and copper ions complexed with the cyanide is converted to hydrogen cyanide, a cyanide combine...

AI Technical Summary

Problems solved by technology

The main disadvantages of this traditional treatment process are: the concentration of cyanide in the treated liquid is too high to meet the discharge requirements, and advanced treatment is required; the acidification process produces mixed metal slag, including cyanide ions converted by metal copper ions during the acidification process. Copper precipitation, which is a highly toxic substance, that is, the mixed metal slag produced during the acidification process is a hazardous waste that cannot be sold directly and the economic efficiency of the metal slag treatment process is low

However, the existing method of combining sulfuration and acidification still has the following defects: (a) not only includes sulfuration and acidification treatment steps, but also ultrafiltration / nanofiltration treatment steps, the treatment process is long, the treatment efficiency is low, and the treatment cost is high , low return on recycling

(b) The vulcanizing agent used is sodium sulfide or sodium hydrosulfide, which is easy to introduce a large amount of sodium ions, resulting in an increase in the salinity of the system, low resource utilization benefits, or even no profit. At the same time, due to the sodium sulfide or sodium hydrosulfide The activity is strong, and it will react rapidly during the acidification process and convert a large amount of hydrogen sulfide gas, which will increase the amount of acid used in the acidification process, and the existence of newly generated hydrogen sulfide gas requires more safety precautions for the processing equipment / processing system. High, there is also a certain security risk

(c) In the existing vulcanizing agent, in addition to introducing a large amount of sodium ions, other impurities may also be introduced. If the vulcanizing agent used contains Mn 2+ or Zn 2+ When used, these metal impurities will enter the decyanide solution, which will affect the recycling value of the decyanide solution, and even cannot be reused in the cyanide gold extraction process of gold smelting production.

(d) In the existing treatment process, it is difficult for the vulcanizing agent to remove zinc and copper in the wastewater quickly and efficiently. As a result, the concentration of zinc ions and copper ions in the liquid after vulcanization is still high, while the concentration of zinc sulfide slag and copper sulfide slag The purity of zinc and copper is relatively low. At the same time, there are still defects in the concentration of cyanide and heavy metals that exceed the standard after adding lime to adjust the pH value of the solution after sulfidation and copper removal. It cannot be directly discharged or directly returned to the production process, that is, the existing treatment The impurity removal effect of the process still needs to be improved, and it is difficult to obtain zinc sulfide slag and copper sulfide slag with high recovery value, and it is difficult to realize the resource utilization of the liquid after cyanide removal

(e) In the existing recycling process, the treatment method of tail gas is mainly to pass the tail gas directly into the lye, and convert it into a mixed salt solution of sulfide salt and cyanide salt by reacting with the lye, but the mixed salt solution cannot Directly returned to the production system for use; at the same time, in the existing treatment process, different types of gases in the tail gas are not treated separately, and different types of gases in the tail gas cannot be recovered separately, so it is difficult to realize the effective resource utilization of the tail gas

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