Method for preparing fluorine removal agent and treating fluorine-containing waste liquid

Abstract

The invention relates to a method for preparing a fluorine removal agent and treating fluorine-containing waste liquid. The method comprises steps: adopting MgCl2, MgSO4, FeCl3, Fe2 (SO4) 3 and cane sugar as raw materials and adding according to a proportion; dissolving with deionized water, stirring on a magnetic stirrer, drying, calcining, taking out, cooling to room temperature, and crushing to obtain the modified magnesium-iron fluorine removal agent. The method for treating fluorine-containing waste liquid comprises the following steps: adding the modified magnesium-iron fluorine removal agent and a magnesium fluoride seed crystal into the acidic fluorine-containing waste liquid, stirring and standing to realize effective separation of mud and water; the method is used for treating the acidic fluorine-containing waste liquid containing high-concentration sulfate radicals, and the defect that high-concentration sulfate radicals in waste liquid in a traditional calcium salt method consume a calcium source can be effectively overcome by treating the acidic fluorine-containing waste liquid through the modified magnesium-iron fluorine removal agent; meanwhile, due to the existence of ferric salt, the problem that in a traditional magnesium salt method, magnesium fluoride sludge is poor in settleability, and consequently the fluorine content of supernate is too high is solved, magnesium fluoride in the waste liquid is induced to be nucleated and grow through magnesium fluoride crystal seeds, the reaction rate is increased, the treatment process of the acidic fluorine-containing waste liquid is shortened, the treatment cost is reduced, and the method is an efficient and environment-friendly technological method.

Description

technical field [0001] The invention belongs to the technical field of sewage treatment, and relates to the preparation of a fluoride-removing agent and a treatment method for fluorine-containing waste liquid. Background technique [0002] Fluorine chemical industry provides material support and linkage effect for my country's national defense, information and life engineering and other high-speed developing industries, as well as traditional chemical industry, metallurgy, building materials, machinery and other industries. In a long period of time, the fluorine chemical industry will also be the "golden industry" in the chemical industry. However, the environmental pollution caused by the rapid development of the fluorine chemical industry has become a huge obstacle to the sustainable development of the industry. A large amount of fluorine-containing waste liquid is produced in the production process of fluorine chemical products. Improper treatment can easily pollute water...

AI Technical Summary

Problems solved by technology

[0005] In view of the current low fluoride removal efficiency of fluorine-containing waste liquid, high cost of fluoride removal, and difficulty in meeting wastewater standards, the present invention provides a preparation of a fluoride-removing agent and a treatment method for fluorine-containing waste liquid, which can effectively avoid the influence of sulfate on the fluoride removal effect At the same time, it has good fluorine fixation and flocculation effects. The way of magnesium fluoride to provide condensation nuclei promotes the nucleation and growth of magnesium fluoride particles. Adding coagulants and coagulants can increase the particle size of precipitated particles and accelerate flocs. The formation of mud and water is easy to separate

Images