Fluorine-containing waste recycling environment-friendly treatment system

Abstract

The invention relates to a fluorine-containing waste recycling environment-friendly treatment system, and belongs to the fields of environmental protection and inorganic chemical engineering. The system mainly comprises an absorption system, a cryolite preparation system and a water glass preparation system, wherein the cryolite preparation system comprises a reaction section and a drying section; and the water glass preparation subsystem is divided into a pretreatment section and a sealed reaction section. The structural design is reasonable; through the ingenious combination of the absorption system, the cryolite preparation system and the water glass preparation system, waste resources can be sufficiently used; and the complete absorption and preparation system realizes zero discharge of waste water and small-amount discharge of waste slag, and has the advantages of no pollution and high recovery rate. Thus, energy is effectively saved, and the purpose of green environment-friendly waste recycling is achieved.

Description

technical field [0001] The invention belongs to the field of environmental protection and inorganic chemical industry, and in particular relates to an environmental protection treatment system for resource utilization of fluorine-containing waste. Background technique [0002] At present, the vast majority of domestic phosphate fertilizer manufacturers further process fluosilicic acid into sodium fluosilicate products, which is a low-value product with a small market capacity, and the amount of secondary pollution control in the processing process is very large. In today's increasingly fierce market competition, saving energy and reducing consumption, forming an energy-saving production process with low investment, low consumption, low emission and high efficiency, and realizing the three principles of circular economy "reduction, reuse, and recycling" have become The main theme of the world's industrial production is also responding to the call for environmental protection,...

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Problems solved by technology

[0003] Therefore, a large amount of HF and SiF are produced in the phosphate fertilizer industry 4 The exhaust gas is poisonous and harmful gas, which must be treated before being discharged, otherwise it will cause serious air pollution. In industry, hydrofluoric acid and fluorosilicic acid are mostly absorbed by water, so that although fluorine-containing gas is avoided pollution, but at the same time produce waste residue or waste liquid pollution

[0004] Because fluorine-containing waste gas contains components for making cryolite, with the application of economical and environmentally friendly production processes, the requirements for cryolite products are getting higher and higher. The industrial production methods of cryolite mainly include soda ash hydrochloric acid method, clay brine method, fluosilicic acid production of cryolite and co-production of white carbon black, etc. These methods all need to occupy a certain amount of fluorine resources, the production cost is relatively high, and the current processes have different degrees of environmental pollution

Another domestic method is to add aluminum hydroxide to part of it after absorbing it with water, and add sodium carbonate to the other part to prepare cryolite. This method has simple process and low production cost, but because silica gel and aluminum fluoride are both precipitate , the separation of the two is difficult, and there is no good way, which leads to the stagnation of this process and the low utilization rate

In some fluorine-containing waste gases, aluminum hydroxide and hydrogen fluoride react in a fluidized bed, and the water vapor silicon tetrafluoride gas produced has not been effectively utilized or insufficiently utilized, which is a problem for today's society. waste of economy and resources

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