A method for rapid separation of calcium and sulfur from industrial by-product gypsum

Abstract

This patent discloses a method for rapid separation of calcium and sulfur from industrial by-product gypsum. The industrial by-product gypsum is quickly decomposed to obtain sulfur dioxide flue gas and solid products; the solid products are sorted to obtain atmosphere regulators, calcium oxide and calcium sulfide ; Calcium sulfide is hydrolyzed to obtain calcium hydroxide precipitate and calcium hydrogen sulfide solution; carbon dioxide gas is introduced into the calcium hydrogen sulfide solution to obtain calcium carbonate precipitate and hydrogen sulfide gas; hydrogen sulfide gas is absorbed and floated to obtain elemental sulfur. Compared with the existing technical solutions, the method has the characteristics of low production cost, high production efficiency and good product quality.

Description

technical field [0001] The invention relates to the field of resource utilization of industrial waste residues, in particular to the utilization of industrial by-product gypsum. Background technique [0002] Gypsum is a sulfate mineral with the chemical formula CaSO 4 ·xH 2 O. Gypsum is divided into natural gypsum and industrial by-product gypsum. At present, industrial by-product gypsum is mainly phosphogypsum, desulfurization gypsum and titanium gypsum. [0003] Phosphogypsum is a by-product of the wet-process phosphoric acid industry, and every ton of phosphate fertilizer produced (in P 2 o 5 Calculation) produces about 4.5-5.0 tons of phosphogypsum. According to statistics, my country's phosphogypsum discharge amounted to 80 million tons in 2014, and the accumulation of phosphogypsum over the years has exceeded 300 million tons. Nationally, the comprehensive utilization rate of phosphogypsum in my country was only 30% in 2015. The remaining gypsum is piled up nea...

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Problems solved by technology

The discharge of titanium gypsum not only occupies a large amount of land, but also pollutes the environment

Due to the washing of rainwater, the titanium gypsum on the stacking yard will be lost. At the same time, after the titanium gypsum is washed and soaked by rainwater, soluble harmful substances will dissolve in water, and the flow and circulation of water in the environment will seriously pollute surface water and Groundwater; on the other hand, after the accumulation of titanium gypsum is exposed to the sun and blown by the wind, a small part will be scattered in the atmosphere in powder form and settle on the surface of foreign objects that may come into contact, polluting the environment and threatening health [Li Guozhong, Zhao Shuai, Yu Yang. Application research of titanium gypsum in the field of building materials [J]. Brick and tile, 2008, (3): 58-60]

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