Method for preparing light calcium carbonate from carbide slag as raw material

Abstract

The invention provides a method for preparing light calcium carbonate from carbide slag as a raw material. The method comprises following steps: (1), performing slurrying to remove toxins and foul smell; (2), performing filtration and dissolution separation; (3), performing spraying carbonization; (4), performing drying and powder grinding, or performing washing, drying and powder grinding or performing spray drying to obtain the product. The method is simple to operate, free of secondary pollution, easy to implement and low in energy consumption, main raw materials only comprise industrial residue carbide slag and CO2 captured in carbon capture and emission reduction projects, the cost is low, and the method has market competitiveness; a large quantity of limestone resources can be savedindirectly, and therefore, environmental protection and blue sky and green water social engineering construction are facilitated.

Description

technical field [0001] The invention relates to a method for preparing light calcium carbonate, in particular to a method for preparing light calcium carbonate by using carbide slag as a raw material. Background technique [0002] Carbide slag is an industrial waste produced after the hydrolysis of calcium carbide to produce acetylene gas. Its pH value is greater than 12, and it is strongly alkaline and adhesive. Because the main component of industrial calcium carbide is calcium carbide, the purity of calcium carbide is about 70%-86%, and the rest is free calcium oxide, carbon, silicon, magnesium, iron, aluminum compounds and a small amount of phosphide, sulfide and trace heavy metals Compound, its appearance is gray, brown, purple or black depending on the content of calcium carbide and different impurities. Therefore, calcium carbide slag is off-white to dark gray because it contains 1-3% carbon and a certain amount of sulfur, silicon, aluminum, iron, magnesium and other...

AI Technical Summary

Problems solved by technology

In addition to the large investment and doubtful economic efficiency of this type of method, although it can effectively remove some insoluble impurities in carbide slag, acid-soluble or complexable impurities and other metal ions will enter the calcium salt solution at the same time, and the problem of odor is difficult to guarantee. solution, and the biggest problem is that it is easy to produce secondary pollution of gas, water and slag which is more serious than calcium carbide slag pollution, and the filter residue or waste residue produced in the process of preparing light calcium carbonate contains a large amount of chloride salt or organic matter, which cannot be used for The production of cement or building material products can only be landfilled separately

[0008] Through the inventor's analysis and a large number of experimental studies, the existing various methods of making light calcium carbonate with calcium carbide slag, the main technical problems that cannot be effectively solved include: (1), the cleaning treatment problem of toxic and peculiar smell; (2) Removal of fine carbon particles, especially the effective removal of carbon particles with a particle size distribution of 0.048mm to 0.150mm; (3) Effective removal of other solid impurities without pollution, especially solid impurities with a particle size larger than 0.048mm

There are objectively unpredictable hidden dangers in deep sea or geological deep burial to store carbon dioxide, and the disposal cost is high