A process for preparing building gypsum powder from phosphogypsum

Abstract

The invention discloses a process for preparing building gypsum powder from phosphogypsum. The process comprises the technical links of: phosphogypsum drying, fine grinding and powder sorting; suspended dehydration; proper aging and the like. According to the process system disclosed by the invention, the phosphogypsum fine grinding, drying and dehydration process is divided into two relatively independent links, the negative-pressure operation is adopted, and a hot blast stove, a feeding device, a phosphogypsum fine grinding, drying and powder sorting device, a suspended dehydrator, an aging bunker, a dust collecting device, an induced draft fan and the like are provided in the process. The process is stable in production process, capable of saving energy and realizing large-scale production and high in product quality.

Description

technical field [0001] The invention relates to the technical field of waste residue treatment and utilization, in particular to a two-step process for drying and dehydrating phosphogypsum in a suspended state to prepare construction gypsum powder. Background technique [0002] Phosphogypsum is a solid waste discharged from the industrial production of wet-process phosphoric acid and phosphate fertilizer, and its main component is CaSO4.2H2O (with a content of more than 90%). The production of one ton of phosphoric acid will produce about five tons of phosphogypsum waste residue. The production of phosphate fertilizer in my country will discharge tens of millions of tons of phosphogypsum every year, requiring a large amount of land to be piled up and causing serious pollution to the environment. The environmental protection pressure caused by gypsum discharge has become one of the important restrictive factors for the development of the phosphate fertilizer industry. [000...

AI Technical Summary

Problems solved by technology

[0006] At present, my country's small and medium-sized enterprises mostly use internal or external firing rotary kilns, intermittent or continuous frying pans and fluidized fluidized furnaces for production. The scale is small, the supporting facilities are not perfect, the product quality is not stable enough, and the energy consumption is high.

In recent years, several fluidized fluidized furnaces and direct-heating rotary kilns developed by my country with an annual output of more than 100,000 tons have been put into production (the production process parameters still need to be optimized)

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