Method for stabilized solidification of mercury-containing waste salt slag by using petrochemical waste alkali slag

Abstract

The invention relates to the technical field of hazardous waste disposal, and particularly relates to a method for stabilized solidification of mercury-containing waste salt slag by using petrochemical waste alkali slag. The method comprises the following steps that the mercury-containing waste salt slag and the petrochemical waste alkali slag are subjected to first-stage mixing and ball milling,and then an auxiliary stabilizer is added into a material obtained after first-stage mixing and ball milling, the mixture is subjected to second-stage mixing and ball milling; and 2) the material obtained in the step 1) is mixed with a solidifying material, and stirred to obtain a uniform bulk granular solidified material. By the adoption of the method, waste can be treated with waste, important economic, social and environmental benefits are achieved, and a novel method is provided for terminal harmless treatment of mercury-containing waste salt.

Description

technical field [0001] The invention relates to the technical field of hazardous waste disposal, in particular to a method for stabilizing and solidifying mercury-containing waste salt residue by using petrochemical waste alkali residue. Background technique [0002] According to the "National Hazardous Waste List" (2016 edition), HW29 mercury-containing wastes come from natural gas mining, common non-ferrous metal ore mining, precious metal ore mining and dressing, printing, basic chemical raw material manufacturing, synthetic material manufacturing, common non-ferrous metal smelting, batteries Manufacturing, lighting equipment manufacturing, general instrumentation manufacturing and other industries. Because mercury and its compounds are highly harmful, improper disposal of mercury-containing waste will pose specific threats to the ecological environment and human body. Mercury is not easily metabolized and excreted in the living body, and it has a bioaccumulation effect ...

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Problems solved by technology

[0007] Chinese patent (CN 105598145 A) discloses an in-situ remediation method for mercury-contaminated soil. The method uses biochar, calcium polysulfide and sodium selenite as passivators. It can effectively improve the soil microenvironment. In alkaline and highly reducing soil, the mobility of mercury is greatly reduced. Biochar with a strong specific surface, porous structure, and complex organic functional groups can absorb a large amount of mercury in the soil. Mercury; watering calcium polysulfide solution in the soil can further promote the mineralization of mercury. After planting crops, the microenvironmental bioactivity of the soil microenvironment in the roots is enhanced. Sodium selenite solution is applied to weaken its bioavailability by using the antagonistic effect of selenium and mercury

It has been proved by many times that the existing methods such as cement (lime) solidification, sodium sulfide + cinder + cement (lime) solidification and related patents are not suitable for the disposal of mercury-containing waste salt slag. Not only the stabilization effect is poor, it is difficult to Meet the requirements of safe landfill, and the capacity increase ratio is too large

The main reasons for the difficult treatment of mercury-containing waste salt slag are: (1) the salt content (sodium chloride) in the mercury-containing waste salt slag is greater than 60%, which is difficult to solidify and form with cement, so it is not suitable for cement solidification; The chloride ions in mercury waste salt slag are too high, which directly affects the adsorption effect of adsorption materials such as zeolite, activated carbon, fly ash, etc., so it is not suitable to use adsorbents for disposal. (3) Since salt is easily soluble in water, too much water Or the medicament solution will inevitably cause a large amount of salt to dissolve. Although the stabilization is relatively fast, it brings difficulties to the subsequent curing operation, which inevitably leads to a relatively large increase in volume.

However, if the solid-solid mixed disposal method is directly used, it is difficult to achieve a sufficient reaction, and it is very easy to cause fluctuations in the stabilization effect.

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