4 results about "Sodium fluoride product" patented technology

The invention discloses a resource recycling method for electrolytic aluminum overhaul slag, and relates to the technical field of resource recycling. The recovery method comprises the following steps: crushing the overhaul slag, stirring with water, washing, and separating to obtain water washing liquid and washing slag; washing residues are leached by adopting an acid solution in a synergistic heating manner, cryolite and other substances in the washing residues are efficiently dissolved, and leached residues are mainly carbon materials. And hydrogen fluoride gas generated in the leaching process is introduced into alkaline water washing liquid, aluminum salt is added for impurity removal, and a sodium fluoride product is obtained through evaporative crystallization. And adding ammonia water into the leachate to adjust the pH value, cooling and crystallizing to obtain an aluminum ammonium sulfate product for recovering aluminum. And the separated mother liquor is subjected to impurity removal, alkalization, evaporation and concentration, ammonia gas is recovered, and a lithium-rich concentrated solution is obtained. Extracting lithium from the concentrated solution, and evaporating raffinate to obtain a sodium sulfate product; and the lithium-loaded organic phase is subjected to reverse extraction by phosphoric acid, and a lithium dihydrogen phosphate product is directly obtained after reverse extraction liquid is subjected to pH-controlled evaporation. According to the invention, collaborative recovery and high-value utilization of fluorine, aluminum, sodium and lithium resources are realized.

This invention relates to the field of chemical production technology, and particularly to a continuous recovery system for fluorinated silicon slag. The continuous reaction module, from front to back, includes a preliminary digestion device, a multi-stage reaction device, and a circulating sedimentation device. The preliminary digestion device is used to hydrothermally treat the fluorinated silicon slag with sodium carbonate to obtain a mixed solution. The multi-stage reaction device is located at the rear of the preliminary digestion device and has multiple overflow chambers, ultimately generating overflow liquid and sodium fluoride solid phase. The circulating sedimentation device is located at the rear of the multi-stage reaction device to receive the overflow liquid from the multi-stage reaction device. A filtration module is located at the slag outlets of both the multi-stage reaction device and the circulating sedimentation device to filter and separate the solid phases discharged from both devices. The continuous recovery system for fluorinated silicon slag provided by this invention converts fluorinated silicon slag into high-value-added silica and sodium fluoride products, achieving dual recovery of silicon and fluorine resources, and has significant industrial value.

The invention provides a method for preparing sodium fluoride from calcium fluoride sludge, and belongs to the technical field of recycling of fluorine resources in fluorine-containing solid waste. Comprising the following steps: S1, mixing pretreated calcium fluoride sludge with concentrated sulfuric acid in a corrosion-resistant reactor, and carrying out a thermochemical conversion reaction to generate hydrogen fluoride and carbon dioxide mixed gas and solid residues; s2, hydrogen fluoride gas generated in the reaction in the step S1 is captured and absorbed, a sodium fluoride product is obtained, and tail gas containing carbon dioxide is generated in the absorption process; s3, collecting and treating carbon dioxide-containing tail gas generated in the reaction process to obtain a sodium carbonate solution, and further separating out a sodium carbonate solid by cooling; and S4, carrying out post-treatment on solid residues after the reaction in the step S1 to obtain a solid by-product. According to the method, the fluorine element in the fluorine-containing sludge is efficiently recycled, meanwhile, residues are converted into building materials with utilization value, and harmlessness and recycling of the fluorine-containing sludge are achieved.

This invention relates to the field of fluorinated silica gel utilization, and in particular to a high-yield method for fluorine recovery from fluorinated silica gel, comprising the following steps: adding fluorinated silica gel byproducts to an alkaline solution in a specified proportion, heating and stirring to react; after the reaction is complete, cooling the solution to room temperature, adding sodium salt for salting out; filtering, the filtrate being a high-modulus water glass product; the filter cake, after washing and drying, being a high-purity sodium fluoride product. This invention uses a simple and feasible operation to effectively recover and harmlessly treat fluorine resources from fluorinated silica gel, recovering fluorine elements for use in the preparation of high-purity sodium fluoride, while simultaneously producing high-modulus water glass. This avoids the large-scale landfilling of fluorinated silica gel slag, reduces environmental pollution, and creates industrial value.