Method for curing heavy metals in copper tailings by using industrial waste carbide slag and kaolin

Abstract

The invention discloses a method for curing heavy metals in copper tailings by using industrial waste carbide slag and kaolin, which comprises the following steps: S1, drying, crushing and sieving theindustrial waste carbide slag to obtain calcium carbide powder, and drying, crushing and sieving the copper tailings to obtain copper tailing powder; S2, uniformly mixing calcium carbide powder and copper tailing powder according to a mass ratio of 0.15-0.25: 1 to obtain a mixture A; S3, adding NaOH into the water glass, uniformly stirring, regulating the modulus of the water glass to 1.2-1.8, and performing standing at normal temperature for 20-24 hours to obtain an alkali activator; S4, uniformly mixing the mixture A, an alkali activator and water according to a water-cement ratio of 0.2-0.4: 1 and a mass ratio of the mixture to the alkali activator of 100: 5-8 to obtain a mixture B; and S5, putting the mixture B into a mold, maintaining at 30-40 DEG C for 28 days, demolding, and performing standing at normal temperature for 24-28 hours to obtain the geopolymer. The method is simple to operate, the raw materials are cheap and easy to obtain, the curing cost of the copper tailings can be reduced, and the environmental pressure on the surrounding ecological environment caused by long-term stockpiling of the carbide slag and the copper tailings is relieved.

Description

Technical field [0001] The present invention belongs to the technical field of solid waste recycling, particularly to a method of curing of Cu tailings with industrial waste carbide slag and kaolin. Background technique [0002] With the continued socio-economic growth, the demand for copper ore have increased every year our country have a large number of copper mining and smelting was, which led to a large amount of copper tailings are discharged. According to "2019 China solid waste treatment industry analysis report" data show that emissions from copper tailings my country has reached 224 million tons / year. Our copper tailings discharged into the tailings are generally stored, along with copper tailings emissions continue to increase, there are at least ten thousand tailings on my country, the survey pointed out that our country is occupied by direct damage and tailings land up to 2 × 104km 2 , And the annual 200 ~ 300 km 2 The speed increase. Tailings large accumulation wil...

AI Technical Summary

Problems solved by technology

[0005] 1. Some solidified materials not only consume a lot of energy in the production process, but also produce air pollutants, which have adverse effects on the surrounding environment, such as cement;

[0006] 2. After some traditional solidification technologies solidify the heavy metals in copper tailings, the hardness of the geopolymers produced is not enough, which cannot meet the disposal requirements of landfills and mine backfills;

[0007] 3. After some traditional curing technologies solidify the heavy metals in copper tailings, the gel produced by the hydration reaction has a poor physical encapsulation effect on the harmful substance particles in copper tailings, and cannot effectively cure heavy metals in copper tailings. When it is used for backfilling in landfills and mining areas, the solidified heavy metals will be leached out by groundwater, rainwater, etc., causing secondary pollution.

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