Method for treating mercury tailings adopting oxidation leaching

A technology for leaching and tailings, applied in the fields of metallurgy and environmental protection, can solve the problems of difficulty in large-scale application, high cost, and high processing cost, and achieve the effects of reducing disposal costs, fast leaching, and low operating costs.

Active Publication Date: 2019-01-11
NORTHEASTERN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] At present, mercury-containing solid waste is mostly treated by fire distillation, and mercury is cooled and recovered from the flue gas; however, fire distillation requires high temperature operation, and for safety and environmental protection considerations, the flue gas needs to be strictly purified and dust collected. The overall cost is high; for a large amount of mercury-containing tailings that have been stockpiled in the past, the treatment cost of fire distillation is high, and it is difficult to apply on a large scale

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Oxidant TCCA and pH adjuster hydrochloric acid are dissolved in water, make leaching solution, the concentration of TCCA in the leaching solution is 0.5g / L, and the concentration of HCl is 3g / L;

[0026] The mercury tailings used are the flotation tailings obtained by the flotation process of mercury mines. The mercury content is 118g / t, and 87.4% of the particles are smaller than 150μm. The main gangue components are quartz and dolomite. Mercury exists in the form of cinnabar. Grinding treatment is required;

[0027] Put the mercury tailings in the leaching solution, leaching under stirring conditions, the leaching time is 10min, and the leaching material is obtained after the leaching is completed; the amount of mercury tailings added in each liter of leaching solution is 0.4kg, that is, 1kg of mercury tailings is placed in In 2.5L leaching solution;

[0028] Filter the leached material to separate the leached residue and the leached liquid; the leached residue is a ...

Embodiment 2

[0032] Method is with embodiment 1, and difference is:

[0033] (1) The concentration of TCCA in the leaching solution is 1g / L, and the concentration of HCl is 3.5g / L; the mercury tailings used are the flotation tailings obtained by the mercury mine flotation process, and the mercury content is 187g / t, 83.5 % of the particles are less than 150μm, the main gangue components are quartz and dolomite, mercury exists in the form of cinnabar, and does not need to be ground;

[0034] (2) The leaching time is 15 minutes; the leaching residue contains 0.03mg / L of mercury, and the leaching solution contains 71.6mg / L of mercury as measured by the toxicity leaching test, and the leaching rate of mercury reaches 95.7%;

[0035] (3) Ferrous sulfide is 40% of the total mass of TCCA, and the precipitation reaction time is 35 minutes; the solid content in the precipitation contains 18.7% mercury by mass percentage, and the precipitation rate of mercury is greater than 99%.

Embodiment 3

[0037] Method is with embodiment 1, and difference is:

[0038] (1) The concentration of TCCA in the leaching solution is 1.5g / L, and the concentration of HCl is 4.5g / L; the mercury tailings used are the flotation tailings obtained by the mercury mine flotation process, and the mercury content is 306g / t. 71.0% of the particles are smaller than 150μm, the main gangue components are quartz and dolomite, mercury exists in the form of cinnabar, and does not need to be ground;

[0039] (2) The leaching time is 15 minutes; the addition amount of mercury tailings in each liter of leaching solution is 0.2kg, that is, 1kg of mercury tailings is placed in 5L of leaching solution; Mercury content is 57.2mg / L, and the mercury leaching rate reaches 93.4%;

[0040] (3) Ferrous sulfide is 25% of the total mass of TCCA, and the precipitation reaction time is 40 minutes; the solid content in the precipitation contains 17.1% mercury by mass percentage, and the precipitation rate of mercury is ...

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PUM

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Abstract

The invention provides a method for treating mercury tailings adopting oxidation leaching. The method is carried out as per following steps of (1), dissolving TCCA and hydrochloric acid into water toprepare a leaching solution; (2), putting the mercury tailings into the leaching solution, leaching under a stirring condition; and (3) filtering leached materials, separating out leached residues andleached solution; and adding a precipitator, namely ferrous sulfide, into the leached solution, then carrying out precipitation reaction under a stirring condition, and standing and filtering the materials after precipitation reaction so as to separate out precipitate and filtrate. According to the method, the materials do not need to be subjected to grinding and heating treatments, the treatingcost of hazardous waste, namely the mercury tailings, can be effectively reduced, and the potential damage to the environment can be reduced; meanwhile, the operation condition is mild, the leaching of mercury is fast in speed, high in efficiency; and the method has the advantages of being low in energy consumption, low in reagent consumption amount, and low in operation cost.

Description

technical field [0001] The invention belongs to the technical field of metallurgy and environmental protection, and in particular relates to a method for treating mercury tailings by oxidation leaching. Background technique [0002] Mercury is the only liquid metal at normal temperature, and it mainly exists in the form of metallic mercury, inorganic mercury and organic mercury compounds in nature; mercury is persistent, easy to migrate and highly bioaccumulative, and highly toxic; While mercury and mercury-containing resources are widely used, a large amount of mercury enters the environment with human activities, and the environmental pollution caused by mercury pollution has gradually attracted people's attention. [0003] Since August 2017, the Mercury Convention has officially entered into force in China. China has clearly banned the mining of new primary mercury mines, but the mercury tailings left over from historical mining still have potential environmental pollutio...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B43/00C22B3/10C22B3/44
CPCC22B3/10C22B3/44C22B43/00Y02P10/20
Inventor 孙诚畅永锋林琳汪云飞
Owner NORTHEASTERN UNIV
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