Modification and innocuous treatment method of phosphogypsum

Abstract

The invention discloses a modification and innocuous treatment method of phosphogypsum, comprising the following steps: (1) cleaning, (2) neutralizing, (3) dehydrating, (4) calcining, and (5) packaging. The modified phosphogypsum prepared by the invention is a raw material for building material, can be used for preparing a phosphogypsum high strength cement fiberboard. The modified phosphogypsum sandwich panels prepared by the phosphogypsum high strength cement fiberboard can be applied in wall material, floor and roof panel, and has the advantages of good antifreezing performance, thermal insulation performance, heat shielding performance, corrosion resisting performance, fireproof performance, high intensity, light specific gravity, easiness in installation and the like. According to the invention, the waste residue phosphogypsum of phosphorus chemical enterprises are recycled through modification treatment and can be used for producing building materials after recycling, so that the national energy saving policy and the development direction of circular economy are satisfied; even temporarily unable use occurs because of investment or other reasons, the modified phosphogypsum can be stored in long term without environmental hazard, so that the harmlessness is realized.

Description

technical field [0001] The invention relates to the treatment of chemical waste, in particular to the modification and harmless treatment of phosphogypsum. Background technique [0002] As we all know, the production of compound phosphate fertilizer and phosphate requires phosphoric acid, and the production of wet-process phosphoric acid will inevitably produce a large amount of waste residue - phosphogypsum. Phosphogypsum is an acidic waste that contains a large amount of sulfate radicals, compounds of arsenic and fluorine, and various heavy metals. So far, except for a small amount of phosphogypsum used in phosphorus chemical enterprises, most of them are still piled up in the yard. Stacking like this, once it rains, the harmful substances therein will overflow with the rainwater, which will cause serious pollution to the surrounding land and water bodies and endanger the environment. A certain enterprise once collapsed because of the dam piled with phosphogypsum, and th...

AI Technical Summary

Problems solved by technology

[0003] At present, the number of patent applications related to the utilization of phosphogypsum is gradually increasing, such as No. 200410021766.4 "Method for producing building decoration materials and wall materials with phosphogypsum", No. 200410081601.6 "Profiles produced with phosphogypsum and their preparation methods", No. 200510021180.2 " A Method for Comprehensive Utilization of Phosphogypsum", No. 200610048734.2 "A Method for Comprehensive Utilization of Coal Gangue and Phosphogypsum", No. 200710112768.8 "Method for Recycling and Utilizing Leach Water from Wet-process Phosphogypsum Storage Yard" and No. 200820081540.7 "A Kind of Phosphogypsum Gypsum Decomposition Circulating Fluidized Bed Waste Heat Utilization Integrated Device", etc. These technical solutions using phosphogypsum require high investment and are difficult to implement, so the amount of phosphogypsum that can be processed is limited

At present, there are still a large amount of phosphogypsum piled up like a mountain, and its safety hazards still exist