113 results about "Sodium hexafluoroaluminate" patented technology

The invention discloses high-performance wet green sand for a steel casting and a preparing method of the high-performance wet green sand. High-performance wet green sand is composed, by weight, of 40-60 parts of zircon sand, 15-20 parts of sea mud, 10-15 parts of ardealite, 25-35 parts of diopside, 20-30 parts of polyphenyl granule, 5-10 parts of sodium fluoroaluminate, 15-20 parts of coconut shell powder, 10-15 parts of crushed brick powder, 4-8 parts of hydroxypropl xanthan gum, 3-6 parts of sulfonated asphalt powder, 5-10 parts of bitter ling soil, 2-4 parts of calcium sulfite, 3-5 parts of poly aluminum chloride, 4-6 parts of polyoxyethylene, 2.5-4.5 parts of sodium hexametaphosphate, 5-10 parts of modified kaolin and a proper amount of water. The wet green sand is good in comprehensive performance, has the high green compression strength, the high compaction rate and the low thermal expansivity, also has the good high-temperature resistance, ventilating performance and fluidity and can effectively overcome the defects that air holes, scabbing, sand clamping, sand holes and the like can happen on the steel casting, the surface quality of the steel casting is improved, the finished product rate of the steel casting is increased, and the high-performance wet green sand has important economic benefits.

The invention discloses a covering agent for smelting copper alloy, which is prepared by adopting the mixture of calcium chloride, potassium chloride, sodium chloride, sodium fluoaluminate and calcium fluoride; one layer of favourable protective layer with the thickness of 5-80 mm is formed on the surface of smelting furnace solution so as to effectively prevent oxygen in air outside a molten pool from entering and avoid oxidation burning loss of alloy elements in the smelting process, and the covering agent has the action of thermal insulation. The covering agent of the invention can ensure that copper alloy requiring vacuum smelting can be smelted under the atmospheric environment. The covering agent of the invention is suitable for smelting copper alloy, such as copper zirconium, copper chromium, copper magnesium, copper chromium zirconium and the like which contain oxidizable elements, and is suitable for ingot blank casting, vertical continuous casting, horizontal continuous casting, up-drawing continuous casting and the like.

The invention provides a preparation method of sodium hexafluoroaluminate, and belongs to the technical field of preparation of sodium hexafluoroaluminate. The preparation method provided by the invention comprises the following steps: mixing denitrified aluminum ash with sodium hydroxide, carrying out alkaline leaching reaction, and separating to obtain a supernatant solution; and crystallizing the supernatant solution to obtain the sodium hexafluoroaluminate. According to the method, the denitrified aluminum ash is used as a raw material, and the F element in the aluminum ash is fixed whilethe Al element in the aluminum ash is finely taken through alkaline leaching reaction, so that aluminum and aluminum oxide in the aluminum ash can be utilized at the same time, and the aluminum ash can be harmlessly treated; and the sodium hexafluoroaluminate is prepared through crystallization, and the purity of the sodium hexafluoroaluminate is high.

The invention discloses a crystallization system and a crystallization method for generating sodium fluoroaluminate (Na3AlF6) crystals by utilizing a hydrofluoric acid waste liquid. The crystallization system is characterized in that a given-flow-rate and uniformly-dispersed medication section is arranged in a notch of a reaction trough, so that chemicals can be quantitatively controlled in different batches and uniformly dispersed into the hydrofluoric acid waste liquid to be reacted, and the crystallization method which is matched with the crystallization system comprises the steps: feeding the hydrofluoric acid waste liquid, charging sodium aluminate, crystallizing, precipitating the sodium fluoroaluminate crystals, filtering and discharging the water, the hydrofluoric acid waste liquid is purified by adopting a crystallization operation mode to substitute the well-known chemical coagulation operation mode, the reaction efficiency of the hydrofluoric acid waste liquid and the chemicals and the crystallization purity can be improved, and the purposes for effectively recycling the fluoride, reducing the size of chemical sludge and generating the high-economic-benefit sodium fluoroaluminate crystals can be realized.

The invention discloses a method for co-producing sodium hexafluoroaluminate and biurea. The method comprises the following steps: (1) adding ammonium hexafluoaluminate into a sodium carbonate-removed refined hydrazine hydrate solution wherein sodium chloride in the refined hydrazine hydrate solution performs double decomposition reaction with the ammonium hexafluoaluminate, thus generating the sodium hexafluoroaluminate and ammonium chloride, and separating the sodium fluoroaluminate, thus obtaining a mother solution 1; (2) adding urea and hydrochloric acid into the mother solution 1 where hydrazine hydrate and urea in the mother solution 1 performs condensation reaction with the hydrochloric acid, thus generating the biurea and ammonium chloride, and separating the biurea, thus obtaining a mother liquid 2. According to the method, the sodium hexafluoroaluminate, the biurea and the ammonium chloride which are high in yield and high in purity can be respectively produced; the yield of the sodium hexafluoroaluminate is up to 99.3 percent or above, and the contents of fluorine and aluminum in the sodium hexafluoroaluminate can meet the requirement of the national standard; the yield of the biurea is up to 97 percent or above, and the purity is 98 percent or above; the yield of the ammonium chloride is 98 percent or above, and the purity can meet the industrial standard.

The invention discloses a lead residue reducing agent and a preparation method thereof and belongs to the technical field of chemical industry. The lead residue reducing agent comprises the following components in percentage by weight: 30 to 70 percent of active carbon, 5 to 20 percent of sodium sulfate, 5 to 15 percent of sodium hypophosphite, 1 to 15 percent of sodium hexafluoroaluminate, 3 to 18 percent of calcium oxide, 7 to 20 percent of precipitated silica, 1 to 5 percent of aluminium oxide, 1 to 5 percent of magnesium chloride, 0.1 to 2 percent of titanium trichloride and 0.5 to 5 percent of triethyl aluminum. The lead residue reducing agent can directly reduce oxide-state scum produced during alloy preparation of lead, calcium, tin and aluminum alloys and casting of grids of storage batteries into metal-state residue, so the residue amount of the lead, calcium, tin and aluminum alloys is reduced obviously. When the agent is used, the lead residue produced during the preparation of the lead, calcium, tin and aluminum alloys and the casting of grids can be directly reduced into molten metals of lead, calcium, tin and aluminum to flow back to an alloy pot, so the lead residue is reduced while the lead, calcium, tin and aluminum in the designated alloys are hardly lost; and thus, the effective ingredients of the grid alloys of the storage batteries are ensured.