Method for directly preparing mercury oxide from mercury-containing organic sludge

Abstract

The invention provides a method for directly preparing mercury oxide from mercury-containing organic sludge. The method comprises an organic matter removal process, an acid dissolution process and animpurity removal-mercury oxide preparation process. By utilizing the high difference of temperature gradient dissolution of anthraquinone byproduct organic matters and mercury compounds in water, warmwater is adopted for thermal extraction in organic matter removal, and the total removal rate is greater than 99%; and a HCl-NaClO3 mixed solution is adopted to dissolve valence mercury and oxidize elemental mercury so as to ensure that the mercury content of the residues is lower than 0.08%. Impurities in an acid solution containing HgCl2 are removed by adopting a Na2CO3-Na3PO4 combined technology; and the removal rates of calcium, magnesium and iron impurities are respectively greater than 95%, 93% and 96%. A full-wet mercury oxide preparation process is adopted, the prepared mercury oxideproduct is high in quality and can be directly returned to the production process, and the metal mercury purchase quantity of enterprises is reduced; and high-quality utilization of mercury-containingorganic sludge can be realized, and the secondary pollution problem of pyrogenic mercury extraction is thoroughly solved.

Description

technical field [0001] The invention relates to the field of hazardous waste treatment and disposal, in particular to the field of resource utilization of mercury-containing waste, and proposes a method for directly producing oxidized mercury from mercury-containing organic sludge. Background technique [0002] Mercury-containing waste is included in the National Hazardous Waste List HW29 category because of its toxicity. Mercury-containing wastes are generated from a wide range of sources, including processes and products that are discarded after use. The accumulation of mercury-containing wastes will be washed by rainwater and runoff, and mercury will be transferred to soil and water bodies, polluting the environment. Inorganic mercury such as metallic mercury and divalent ion mercury in the environment will be converted into methylmercury and dimethylmercury under the action of organisms, especially microorganisms. Methylmercury is the most toxic of mercury compounds. It...

AI Technical Summary

Problems solved by technology

The distillation method is an ancient traditional process with high maturity and can effectively recover metallic mercury in the sludge, but the process is cumbersome, the equipment is huge, the maintenance is inconvenient, the secondary pollution is serious, and the recovery rate is low; the chemical oxidation method has the advantages of simple operation process and low energy consumption. low, but can only realize the regeneration of waste mercuric chloride with better morphology and mechanical properties; the disadvantages of poor selectivity and difficult control of the amount of oxidant; low-temperature thermal analysis-solid-phase electric reduction combined method has good labor hygiene conditions and a high degree of automation , effectively avoiding the harm to the operators and the surrounding environment, etc., but the equipment cost is high, the investment is large, and the economy is average

[0009] Utility model patent 201721789816.2 discloses a device for removing heavy metals by electrolysis of cyclone slurry. This utility model has simple structure, low energy consumption, high separation efficiency of heavy metals, and good removal effect. This utility model is only suitable for The treatment of mercury waste residue or soil with high mercury content is not suitable for the treatment of mercury-containing organic sludge

The process of the above two patents is clean and does not generate mercury vapor; the treatment cost is low; the economic, environmental and social benefits are remarkable, but they are only suitable for the recovery of mercury soot or mercury salts with high mercury content, not for organic mercury-containing sludge. processing

[0011] The invention patent CN201410741444.0 discloses a kind of equipment and recovery method for environmentally friendly recovery of mercury and activated carbon from waste mercury catalyst multi-components, which solves the problems of environmental pollution and low recovery efficiency

However, it cannot meet the treatment requirements for treating organic mercury-containing sludge

[0012] Invention patent 201310156412.X; 103233126B and utility model 201821022679.4 and above have high microwave pyrolysis efficiency and good environmental protection, but are not suitable for the treatment and disposal of organic mercury-containing sludge with poor conductivity

The method of chlorination and roasting has heavy pollution, serious equipment corrosion and difficult operation.

[0018] Invention patent CN201710736348.0; 107649483B discloses a method for low-temperature thermal desorption combined with chemical stabilization to treat mercury-containing hazardous waste residues. This method can realize the removal of mercury in low-boiling point forms and the stabilization of high-boiling point forms of mercury in mercury-containing hazardous waste residues. Greatly reduce the mobility of mercury in hazardous mercury-containing waste residues; this method uses thermal desorption and stabilization technology. After thermal desorption, the residue contains high mercury, and there may be potential environmental safety hazards after the waste residue is stabilized.

[0019] The existing technologies and processes have their own advantages and disadvantages, and all of them have the problems of relatively high equipment investment, high maintenance costs, and secondary pollution. At the same time, most of them produce metallic mercury, which cannot meet the production and application requirements of enterprises.

There are few reports on the direct production of mercury oxide from organic mercury-containing sludge

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