Coarse tungsten trioxide has an apparent density of 1.2~1.6g/cm3. Coarse WO3 has greater apparent density as its particle size is larger than fine tungsten trioxide of 0.5~0.7g/cm3. Producing Method The production of coarse WO3 is treating “ammonium paratungstate – sodium paratungstate complex salt” with saturated ammonium chloride solution, the specific steps are shown as follows: Add complex salt and saturated ammonium chloride solution with a solid-to-liquid ratio of 1: 5.5 in a reaction vessel equipped with a high speed stirrer.…

Fine tungsten trioxide can be prepared by double salt method with apparent density of 0.5~0.7g/cm3. Smaller the particle size, smaller the apparent density. Its specific production process is show as bellow: Mix double salt and water. And pour 30% to 31% concentration of cold hydrochloric acid slowly into the slurry. At the beginning, colloidal tungstic acid with white amorphous appearance is formed. The white tungstic acid turns into yellow tungstic acid precipitate with the continuous increase of the hydrochloric acid,…

Cobalt tungsten oxide, also called cobalt tungstate, is a kind of net gray powder with molecular formula of CoO4W. As a type of dingal material, it can be widely applied in catalyst, additive of pigment and microwave dielectric ceramic, etc. Preparation – Low Temperature Molten Salt Method The specific steps of low temperature molten salt method to produce nanometer cobalt tungstate is shown as bellow: 1. Mix LiNO3-Na2WO4 with molten salt, the mass ratio of 1.17: 1. 2. The mass…

Cadmium borotungstate is a kind of yellow triclinic crystal with toxicity, CAS No. of 1306-26-9, relative density of 3.28g/cm3, melting point of 75 °C, chemical formula of B2Cd5H36O98W24, molecular weight of 6600.06000, and the exact weight of 6610.14000. It is mainly used for the separation of ore. Characteristics 1. Its solution is yellow or light brown. 2. It is stable in the air. 3. It can be decomposed in sunlight. 4. It is easily soluble in water and more easily…

Strontium tungstate is a type of tungstate with tetragonal crystal system, CAS No. of 13451-05-3, relative density of 6.187g/mL (25/4°C), chemical formula of SrWO4, molecular weight of 335.45800 and exact weight of 335.83600. There are different purity including 99% (2N), 99.9% (3N), 99.99% (4N) and 99.999% (5N). SrWO4 is stable under room temperature and pressure. And it should avoid getting contact with oxidants and halogen. Solubility in water under 15°C is 0.14g/100mL H2O. It decomposes in acid. And it is…

Lead tungstate is a white to pale yellow powdery solid with the chemical formula of PbWO4, molecular weight of 455.03800 and CAS No. of 7759-01-5. It belongs monoclinic system. It is insoluble in water. And it is soluble in alkaline, sodium hydroxide solutions. It is available in 99.9% purity grade. Producing Methods 1. By heating tungsten powder and PbO2. 2. The reaction between tungsten powder and lead oxide (Ⅱ) under high temperature. 3. By mixing solutions of lead nitrate and…

Nickel tungstate is also called nickel tungsten oxide with CAS No. of 14177-51- 6, molecular formula of NiWO4, molecular weight of 306.53100 and exact mass of 305.86600. It is stable under normal temperature and pressure. However, it still needs to avoid contact with acid and other materials. Preparation Under 800 degree celsius and in vacuum atmosphere, nickel powder would react with tungsten trioxide to obtain volatile W3O8, NiWO4 and NiW5O16. Ecology Data It is usually not harmful to water. However,…