Method for producing calcium nitrate by carbide slag

Abstract

The invention provides a method for producing calcium nitrate by carbide slag, which comprises the steps of: grinding the carbide slag into coarse powders with 80-100 meshes, putting the coarse powders into a reactor to be abundantly mixed with the water, putting the excessive hydrochloric acid into a reactor, converting oxide in the carbide slag into soluble chloride, and filtering a reaction product to obtain filter liquor which takes calcium chloride as a main part; reacting the filter liquor which takes the calcium chloride as the main part with excessive carbonic acid solution, combining calcium ions with carbonate ions into calcium carbonate to be precipitated, and filtering to obtain a calcium carbonate filter cake, and reacting the calcium carbonate filter cake with hydrogen nitrate solution to obtain calcium nitrate precipitate and carbon acid solution mixture; and separating the calcium nitrate precipitate from the carbon acid solution mixture in a filtering way to obtain the carbonic acid filter liquor and the calcium carbonate filter cake, and drying and smashing the calcium carbonate filter cake to obtain a calcium carbonate product. The method is simple in operation and small in equipment investment, and the obtained calcium nitrate product is high in purity and economic value.

Description

technical field

[0001] The invention relates to the technical field of comprehensive utilization of carbide slag, in particular to a method for producing calcium nitrate by using carbide slag. Background technique

[0002] Carbide slag mainly comes from the production of calcium carbide polyvinyl chloride and vinyl acetate. The production of 1 ton of polyvinyl chloride consumes about 1.45 tons of calcium carbide, and each ton of calcium carbide produces 1 ton of calcium carbide slag after hydrolysis, so 2 tons of calcium carbide slag need to be discharged for every 1 ton of polyvinyl chloride produced. Calcium carbide slag is large in quantity, high in alkali content, and contains harmful substances such as sulfur and arsenic. If discharged without treatment, it will block sewers, accumulate river beds, and endanger fishery production. Stacking on land takes up land and pollutes the environment.

[0003] The main composition of calcium carbide slag is calcium oxide, which ...