A method of suspending, magnetizing and roasting high ferricyanide tailings to break cyanide and extract iron by magnetic separation

Abstract

A method for suspending, magnetizing and roasting ferricyanide tailings to break cyanide-magnetic separation and extract iron, which is carried out in the following steps: (1) breaking and grinding the ferricyanide tailings; (2) passing it into a pre-oxidation suspension roaster , the high-temperature flue gas enters the pre-oxidation suspension roaster, and the tailings powder is heated to 650-750°C in a suspension state to break the cyanide and roast, and the remaining solid material is the oxide slag powder; (3) The oxide slag powder is passed into the reduction roaster, and the reduction roasting The bottom of the furnace is fed with coal gas and nitrogen, and the oxidized slag powder is in a suspended state and reduced and roasted at 500-600°C, leaving the remaining reduced slag powder; (4) After the reduced slag powder is cooled, a stage of grinding and a stage of weak magnetic separation are carried out; (5) a stage of refining The ore undergoes secondary grinding and secondary weak magnetic separation, and the concentrate of the second stage is iron concentrate. The invention adopts the iron-extracting and cyanide-breaking process by suspending magnetization roasting, which can eliminate the threat of toxic waste water produced by wet cyanide breaking to environmental safety.

Description

technical field [0001] The invention belongs to the technical field of mineral processing, and in particular relates to a method for suspending, magnetizing and roasting ferricyanide tailings to break cyanide and extract iron by magnetic separation. Background technique [0002] Gold smelting enterprises discharge a large amount of cyanide tailings every year, and their long-term stockpiling not only occupies land, but also pollutes the environment. Cyanide tailings contain valuable metals such as gold, silver, copper, iron, zinc, etc. Among them, the high-ferricyanide tailings TFe grade reaches 30-40%, which is a valuable secondary iron resource. If it cannot be obtained effectively Utilization will cause a waste of resources; but due to the highly toxic cyanide remaining in the cyanide tailings, it is easy to produce cyanide-containing wastewater or waste residues when extracting valuable metals, making it difficult to obtain large-scale utilization; therefore , to develo...

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Problems solved by technology

[0002] Gold smelting enterprises discharge a large amount of cyanide tailings every year, and their long-term storage not only occupies land, but also pollutes the environment

Cyanide tailings contain valuable metals such as gold, silver, copper, iron, zinc, etc. Among them, the high-ferricyanide tailings TFe grade reaches 30-40%, which is a valuable secondary iron resource. If it cannot be obtained effectively Utilization will cause a waste of resources; but due to the highly toxic cyanide remaining in the cyanide tailings, it is easy to produce cyanide-containing wastewater or waste residues when extracting valuable metals, making it difficult to obtain large-scale utilization; therefore , to develop a new technology for the harmless and efficient utilization of ferricyanide tailings, which can not only solve the serious environmental pollution caused by its large amount of stockpiling, but also obtain iron ore resources

[0003] Patent CN201610618637.6 discloses a method for cleaning and converting roasted cyanidation tailings, and proposes to obtain TFe through the method of "first-stage acidification cyanide removal-first-stage dehydration-secondary acidification cyanide removal-secondary dehydration-magnetic separation-wastewater treatment" The iron concentrate with a grade of 55% has realized the clean conversion of roasting cyanidation tailings; but this method consumes a large amount of additives such as sulfuric acid, sodium sulfite, hydrogen peroxide and copper sulfate, as well as a large amount of clean water, and the acidification and oxidation time is as long as 11 More than one hour, there are problems such as high cost, low efficiency, low grade of iron concentrate, and large amount of waste water.

[0004] Patent CN201610129549.X discloses a method for recovering gold, iron, and lead in cyanide tailings, and proposes to use hydrochloric acid to leach iron, lead, and gold in cyanide tailings, and adopts a step-by-step separation method to gradually recover gold, iron, and lead , to realize the recovery of valuable metals; but this method does not point out how to remove the cyanide in the cyanide tailings, and needs to use a large amount of concentrated hydrochloric acid, which takes 1 to 2 hours in the leaching process, and the removal of cyanide is not complete. Concentrated hydrochloric acid is volatile and causes air pollution, and the separation process of gold, iron and lead in the leaching solution is complicated, etc.

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