41 results about "Cobalt Sulfate Heptahydrate" patented technology

The invention provides a method for efficiently removing nitrate radical impurities in a cobalt sulfate solution. The method comprises the steps of firstly, adjusting the pH value of a crude cobalt sulfate solution to be lower than or equal to 2.5 with dilute sulphuric acid; then adding a formaldehyde solution with the concentration being 40% and the mass of nitrate radicals being 0.4-0.5 time to the cobalt sulfate solution; conducting a reaction at the temperature of 75-85 DEG C; then removing formaldehyde left by the reaction with hydrogen peroxide with the concentration being 30% and the formaldehyde amount being 1.4-1.5 times; then conducting filtration, concentration, cooling and crystallization, so that high-purity cobalt sulfate heptahydrate is obtained. The impurity removal method is easy and convenient to operate, short in production procedure, mild in technological condition and easy to control; no other impurity is generated in the reaction process except a target product, gas and water; the nitrate radical impurities can be effectively removed; the content of the nitrate radical impurities in an obtained cobalt sulfate hexahydrate product can reach 0.02% or below; the method meets the using requirements of such industries as electronic information, batteries, catalysis and analytical tests.

The invention discloses a preparation method of a porous cobalt phosphide nanowire catalyst. The method comprises the following steps: using urea as a precipitating agent, cobalt sulfate heptahydrate as a cobalt source, and glycerol and deionized water as solvents to prepare a solution. The solution is added into a high-pressure reaction kettle for hydrothermal reaction, and after sufficient reaction, suction filtration, washing, and vacuum drying are performed to obtain linear basic cobalt carbonate. In a tube furnace, the linear basic cobalt carbonate is air-fired at a certain temperature to obtain tricobalt tetroxide. Using sodium hypophosphite as the phosphorus source, the precursor of tricobalt tetroxide and sodium hypophosphite are placed on both ends of the same porcelain boat in a certain proportion, the phosphorus source is placed in the upstream of the air flow, and placed in a tube furnace under an inert atmosphere for low-temperature calcination to achieve Preparation of Porous Cobalt Phosphide Nanowire Catalysts. The invention has the advantages of simple production process, low cost, can effectively improve the electrochemical activity and stability of the catalyst, and has wide application.

The invention provides a cobalt sulfate heptahydrate production method. The method includes steps: (1) precursor preparation, to be more specific, adding an alkaline precipitator into pure cobalt sulfate solution, filtering and washing precipitates to obtain cobalt carbonate or cobalt hydroxide precursor, and returning precipitation mother liquor to a vitriol precipitation procedure in cobalt hydrometallurgy; (2) precursor acid dissolution, to be more specific, stirring and pulpifying the precursor with pure water or mother liquor in a dissolving tank, and adding concentrated sulfuric acid for acid dissolution, so that acid solution slurry is heated by reaction heat and dilution heat; (3) acid solution cooling and crystallization, to be more specific, stopping addition of concentrated sulfuric acid after dissolution is completed, cooling and crystallizing in a crystallization tank, cooling to the room temperature, subjecting crystal slurry to solid-liquid separation to obtain a cobalt sulfate heptahydrate product and crystallization mother liquor, and returning the mother liquor to the precursor pulpifying procedure. Steam consumption in evaporation and concentration in an existing cobalt sulfate evaporative crystallization production process is avoided, so that cost is sharply reduced while formation of water insoluble matters in an evaporation process is avoided. In addition, cobalt liquid precipitation and precursor dissolution equipment is simple, and investment cost is low and operations are simple as compared with those of an evaporation procedure.

The invention provides a colorful trivalent chromium passivation liquid. A plurality of raw materials are dissolved in deionized water to form the passivation liquid. The passivation liquid comprises the following components by a ratio: 5-9 g / L chromium sulfate hexahydrate, 2-4 g / L cobalt sulfate heptahydrate, 4-8 g / L sodium chlorate, 2-3 g / L ammonium fluoride, 1-2 g / L of nitric acid, 2-3 g / L citric acid, and the balance of water. The resulting passive film has good corrosion resistance, the time can be up to 120 hours or more in a salt spray test, the surface has no any white rust or white spots, the porosity is low, and a blocking agent does not need to be used for treating.