Comprehensive utilizing method for fluorine-containing silicon dioxide

Abstract

The invention discloses a comprehensive utilizing method for fluorine-containing silicon dioxide. The comprehensive utilizing method comprises the steps that the industrial byproduct fluorine-containing silicon dioxide and industrial-grade calcium hydroxide serve as raw materials, the two raw materials at a certain calcium to silicon mole ratio are mixed with water, and the formed mixture is put into a reaction kettle for a hydrothermal reaction; the conditions of the hydrothermal reaction are controlled within the range that the calcium to silicon mole ratio is 0.4-0.9, and the temperature is 120-160 DEG C, the static constant-temperature hydrothermal reaction is carried out for 8-12 h, fluorine-containing hazardous materials are immobilized in the hydrothermal reaction process, a phosphate adsorbing agent with the specific area ranging from 120 m<2> / g to 500 m<2> / g is obtained at the same time, and thus waste is turned into wealth; the phosphate adsorbing agent obtained through the hydrothermal reaction has good phosphate adsorbing capability on wastewater including phosphate radicals, and a mixture obtained after phosphate adsorbing saturation can be further used for adsorbing heavy metal ions. According to the comprehensive utilizing method, waste is controlled by waste through waste conversion, and thus the purpose of high added-value utilization of by products is achieved while the phosphate adsorbing agent obtained through the hydrothermal reaction is used for eliminating environment pollution.

Description

technical field [0001] The invention belongs to the field of harmless treatment and comprehensive utilization of hazardous waste, and in particular relates to a comprehensive utilization method of fluorine-containing silicon dioxide. Background technique [0002] With the continuous acceleration of urbanization and industrialization in our country, people's continuous pursuit of materials and dependence on the environment have become seriously unbalanced, especially urban domestic garbage and industrial waste have increased significantly, and the relationship between human production and consumption and material cycles have become serious. Destruction, leading to serious environmental pollution in our country. [0003] In the field of fluorine chemical industry, H 2 SiF 6 or Na 2 SiF 6 or (NH 4 ) 2 SiF 6 The fluorine-containing silicon dioxide by-produced in the preparation of fluorine salts as raw materials is a hazardous solid waste, which belongs to the HW32 inorga...

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Problems solved by technology

The chemical precipitation method has excellent phosphorus removal performance and will not re-release phosphorus to cause secondary pollution. This technology is currently one of the commonly used methods for sewage phosphorus removal, but this technology also has the disadvantages of large dosage of chemicals, high treatment costs, Sludge pollution is difficult to be effectively treated and other deficiencies; biological phosphorus removal is a relatively economical method of phosphorus removal, which can complete the removal of organic matter at the same time as phosphorus removal, and can remove up to 90% of the phosphorus in sewage under suitable operating conditions. Phosphorus, but this technology also has a series of problems, such as poor stability of process operation, long and complicated process, high management technology requirements, strict operation control, and is greatly affected by conditions such as temperature and pH in the water body. The concentration of organic matter (BOD) in sewage is highly dependent; the adsorption phosphorus removal method is considered to be an efficient and universally applicable water body phosphorus removal method due to its simple equipment, wide range of raw material sources, low operating costs and high removal efficiency. It is an effective and economically beneficial method that can achieve the goal of phosphorus adsorption and recovery. It can be used as a necessary supplement to biological phosphorus removal, or as a separate means of phosphorus removal.

[0006] At present, many industrial production processes will inevitably produce a large amount of industrial wastewater containing toxic heavy metals, such as large-scale chemical enterprises, heavy industry enterprises, textiles, printing and dyeing, papermaking, etc. After these heavy metal ion-containing sewage is discharged into the water body, it will undergo migration and enrichment. Huge damage to the environment, agriculture and human health

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