A kind of harmless treatment method of cyanide tailings

Abstract

A method for harmless treatment of cyanide tailings, which is carried out according to the following steps: (1) prepare cyanide tailings as raw materials, or add additive CaO to cyanide tailings as mixed raw materials; (2) prepare raw materials or The mixed raw materials are heated to 250-450°C for pyrolysis, and the holding time is less than or equal to 90 minutes to obtain calcined sand; (3) The calcined sand is directly used for backfilling treatment, or pyrite is extracted by flotation. The method of the invention has good cyanide removal effect, and the cyanide tailings after low-temperature pyrolysis meet the requirements of common solid wastes.

Description

technical field [0001] The invention belongs to the treatment method of pollutants in the fields of nonferrous metal metallurgy and environmental protection, and in particular relates to a harmless treatment method of cyanidation tailings. Background technique [0002] Because gold mines use cyanide gold extraction technology in the production process, a large amount of cyanide tailings will be produced, and these cyanide tailings contain a large amount of pollutants, such as sulfur, copper, arsenic, mercury and highly toxic cyanide ; Except that a small amount of cyanide tailings can be used, a considerable amount of cyanide tailings is only stored or directly landfilled, which not only occupies a large amount of land resources, but also has the hidden danger of polluting surface water, groundwater and soil. It has great safety hazards and environmental protection hazards to the surrounding environment; at present, cyanide tailings have been listed by the country as HW33 ha...

AI Technical Summary

Problems solved by technology

[0002] Because gold mines use cyanide gold extraction technology in the production process, a large amount of cyanide tailings will be produced, and these cyanide tailings contain a large amount of pollutants, such as sulfur, copper, arsenic, mercury and highly toxic cyanide ; Except that a small amount of cyanide tailings can be used, a considerable amount of cyanide tailings is only stored or directly landfilled, which not only occupies a large amount of land resources, but also has the hidden danger of polluting surface water, groundwater and soil. It has great safety hazards and environmental protection hazards to the surrounding environment; at present, cyanide tailings have been listed by the country as HW33 hazardous waste in the "National Hazardous Waste List", with obvious pollution characteristics and serious pollution. The environmental protection pressure of the state and enterprises There is an urgent need to adopt practical control technology to eliminate the harm of this kind of hazardous waste to the environment

[0003] At present, the technology for treating cyanide tailings is mainly flotation method, supplemented by autoclave method, chlorination roasting method, molten salt roasting method, reduction roasting method, oxidation method, solidification method, preparation of Portland cement, etc. ; The flotation method (CN201410228170.5, CN201410099597.X, CN201510055236.X) is mostly carried out under weak acid conditions. - Unstable, resulting in bad working environment, and need to undergo multiple flotation treatments; autoclave method (CN201510023812.2) is mainly carried out in autoclave or autoclave, which requires long-term high temperature and pressure maintenance, and needs to deal with the pressure brought by autoclave. secondary pollution; the chlorination roasting method (CN201410317041.3, CN201410757942.4) is mainly a method of mixing chlorination agents and cyanidation tailings with high-temperature roasting, which requires high anti-corrosion capabilities of equipment and high energy consumption; The salt roasting method (CN201410317042.8, CN201611121854.0) uses molten salt or molten pool to roast cyanide slag, the roasting temperature is higher, and the time is longer; the reduction roasting method (CN201610825331.8, CN201610846576.9) uses a reducing agent in Reduction at high temperature takes a long time; the oxidation method (CN201711048319.1) uses ozone, hydrogen peroxide, sodium hypochlorite and other oxidants to oxidize the cyanide tailings, and the operating cost is high; the curing method (CN201710628397.2) uses a curing agent to solidify the cyanide residue , but cannot fundamentally solve the possible environmental pollution caused by cyanide tailings; preparation of Portland cement (CN201210002870.3, Kong Yapeng. Research on the comprehensive utilization of valuable elements in cyanide tailings [D]. Northeastern University), Ordinary Portland cement is prepared by using cyanidation tailings with high aluminum-silicon content; these existing methods either have high energy consumption or are accompanied by secondary pollution or incomplete cyanide breaking or complex technological processes and high operating costs; therefore, for As far as cyanide tailings are concerned, there is still a lack of economical and effective treatment methods for this type of hazardous waste

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