This patent relates to the byproduct recovery of mineral raw materials in the chemical industry, namely, processing aqueous solutions of hexafluorosilicic acid (HSA) formed specifically during the process of producing phosphoric acid with hydrogen fluoride (HF). This method consists of neutralizing an aqueous solution of HSA with an alkaline agent to produce ammonium fluoride and subsequently combusting it in a fire of an oxygen-containing oxidant and a hydrogen-containing fuel. It is characterized by the alkaline neutralization, which occurs in two stages. In the first stage, the aqueous hexafluorosilicic acid solution is neutralized with an alkaline agent to obtain a suspension of the correspondent hexafluorosilicate in water, after which the water is removed from the suspension. In the second stage, solid hexafluorosilicate is treated with an ammonia-containing agent to produce an aqueous solution of ammonium fluoride. Its solid products are filtered, then the aqueous ammonium fluoride solution is burned in an oxygen-containing oxidant. Hydrogen fluoride and water are condensed from the combustion products, and then the hydrogen fluoride is extracted. The technical result achieved by applying the proposed patent consists in the reduction of energy costs due to the removal of water, which is introduced into the process cycle with the hexafluorosilicic acid, by way of synthesizing a intermediate hexafluorosilicate poorly soluble in water, then crystallizing and separating it from water through filtration, centrifugation or any other method that leads to a significant reduction in energy consumption at the stage of separating water from ammonium bifluoride in the evaporator. 1 independent claim, 2 dependent claims, 1 FIGURE.

A gas nozzle (100), a gas reaction device (10) and a gas hydrolysis reaction method. A plurality of fuel gas channels (116) are provided on a side wall of a nozzle cavity (110) of the gas nozzle (100); the plurality of fuel gas channels (116) are arranged around the side wall of the nozzle cavity (110); a mixed gas introduced from a nozzle inlet (112) is surrounded by a fuel gas (21) introduced from the plurality of fuel gas channels (116); and the fuel gas channels (116) are inclined towards a nozzle outlet (114), and the fuel gas channels (116) are further inclined in the same clockwise direction. In this way, the fuel gas (21) introduced from the plurality of fuel gas channels (116) forms a downwardly conical spiral flame, and a flame formed by the mixed gas introduced from the nozzle inlet (112) is wrapped therein and sprayed out from the nozzle outlet (114).

A technique for obtaining anhydrous hydrogen fluoride (AHF) from an aqueous solution of hexafluorosilicic acid (HSA). A method for obtaining hydrogen fluoride from an aqueous solution of hexafluorosilicic acid can include mixing a solution of hexafluorosilicic acid with a sulfuric acid solution, desorbing the hydrogen fluoride from the resultant solution of sulfuric acid, treating it with sulfuric acid and condensing the anhydrous hydrogen fluoride from unabsorbed gasses. The generated gaseous products are then burned in a fire of hydrogen-containing fuel and an oxygen-containing oxidant, yielding a solid silicon dioxide. The remaining products are cooled and yield condensed anhydrous hydrogen fluoride.

This patent relates to the mineral waste treatment of the phosphate chemical industry, namely, treatments of hexafluorosilicic acid solutions formed specifically during the process of producing phosphoric acid with hydrogen fluoride. The method for obtaining hydrogen fluoride from hexafluorosilicic acid includes neutralizing the HSA solution with an alkaline agent, yielding a solid salt from the suspension, processing the salt in a fire of a hydrogen-containing fuel and an oxygen-containing oxidant, cooling the combustion products, eliminating the silicon dioxide from these products, condensing the hydrogen fluoride and water, and subsequently extracting the hydrogen fluoride.

A gas nozzle (100), a gas reaction device (10) and a gas hydrolysis reaction method. A plurality of fuel gas channels (116) are provided on a side wall of a nozzle cavity (110) of the gas nozzle (100); the plurality of fuel gas channels (116) are arranged around the side wall of the nozzle cavity (110); a mixed gas introduced from a nozzle inlet (112) is surrounded by a fuel gas (21) introduced from the plurality of fuel gas channels (116); and the fuel gas channels (116) are inclined towards a nozzle outlet (114), and the fuel gas channels (116) are further inclined in the same clockwise direction. In this way, the fuel gas (21) introduced from the plurality of fuel gas channels (116) forms a downwardly conical spiral flame, and a flame formed by the mixed gas introduced from the nozzle inlet (112) is wrapped therein and sprayed out from the nozzle outlet (114).