A method of modifying fluorine gypsum by a composite modifier

Abstract

A method of modifying fluorine gypsum by a composite modifier is disclosed. The method includes: subjecting fluorine gypsum to thermal treatment at 180-220 DEG C for 1-2 h after the fluorine gypsum is ground and sieved; adding 0.5-1.2 parts by weight of Portland cement, 0.7-1.3 parts by weight of steel slag, 0.7-1.5 parts by weight of acetylene sludge, 0.8-1.2 parts by weight of phosphogypsum, 1.0-1.5 parts by weight of sodium tripolyphosphate, 1.0-1.5 parts by weight of glauberite, 0.2-0.5 part by weight of rice straw fiber, 0.2-0.5 part by weight of tartaric acid, 0.3-0.8 part by weight of sodium tripolyphosphate, 0.2-0.8 part by weight of polypropylene fiber, 0.3-0.5 part by weight of magnesium acrylate, 0.5-1.0 part by weight of modified cotton straw fiber, 1-2 parts by weight of a polycarboxylic acid modifier, 0.5-1.2 parts by weight of mycelium residue, 0.3-0.8 part by weight of wood shavings, and 0.5-1.2 parts by weight of aluminium oxide into 100 parts by weight of thermally treated fluorine gypsum; grinding; smashing; and maintaining the temperature at 50-80 DEG C for 5-10 h. The fluorine gypsum modified by the method is short in time of coagulation and excellent in mechanical performance, protects the environment and saves the cost.

Description

Technical field [0001] The invention relates to the technical field of gypsum, in particular to a method for modifying fluorogypsum with a composite modifier. Background technique [0002] Fluorogypsum is the main by-product in the production of hydrofluoric acid and sodium fluoroaluminate. It is mainly produced from inorganic fluoride and organic fluoride production plants and other hydrofluoric acid production plants. About 3.6 tons of anhydrous fluorogypsum are produced for every 1t of hydrofluoric acid produced. The main component of fluorogypsum is calcium sulfate, and contains some calcium fluoride and other fluorides, and sometimes H 2 SO 4 The high content makes the discharged fluorogypsum acidic, which is a highly corrosive, toxic and hazardous waste. Untreated fluorogypsum cannot be disposed of directly and is difficult to use. Because fluorogypsum has low solubility and slow dissolution rate, long setting time, and low strength of hydrated hardened body, these defects...

AI Technical Summary

Problems solved by technology

The main component of fluoride gypsum is calcium sulfate, and contains some calcium fluoride and other fluorides, and sometimes H 2 SO 4 The high content makes the discharged fluorine gypsum acidic, which is a highly corrosive toxic and hazardous waste. Untreated fluorine gypsum cannot be disposed of directly, and it is difficult to be used

And because the solubility of fluorine gypsum is low and the dissolution rate is slow, the setting time is very long, and the strength of the hydration hardening body is very small, these defects limit its application.

At present, except for some fluorogypsum being used, most of it is stored as general solid waste, which not only occupies land, but also pollutes water bodies and poses a threat to the natural environment.