Name | Sodium tungstate |
Synonyms | Sodium tungstate TUNGSTEN(13472-45-2) Sodium tungsten oxide Tungstate, disodium, T-4)- disodium tetraoxowolframate(2-) disodium dioxido(dioxo)tungsten Sodium tungsten oxide, Folin Reagent Grade |
CAS | 13472-45-2 |
EINECS | 680-637-4 |
InChI | InChI=1/2Na.4O.W/q2*+1;;;;;-2/r2Na.O4W/c;;1-5(2,3)4/q2*+1;-2 |
Molecular Formula | Na2WO4 |
Molar Mass | 293.82 |
Density | 4.18[at 20℃] |
Melting Point | 698℃ |
Boling Point | 5660℃ |
Water Solubility | 73.2g/L at 21℃ |
Vapor Presure | 0Pa at 25℃ |
Appearance | White lens |
pKa | 3.5[at 20 ℃] |
Storage Condition | Room Temprature |
MDL | MFCD00003505 |
Physical and Chemical Properties | Colorless crystals or white orthorhombic crystals. |
Use | Used in the manufacture of metal tungsten, tungstic acid, tungstate, dyes, inks, catalysts, etc |
Raw Materials | Sodium hydroxide Hydrochloric acid |
Downstream Products | Light Fast Violet Lake |
Reference Show more | 1. Xian Jing Ping Wang Yong Ma Huiling. Nitric oxide signaling pathway participates in the study of cadmium tolerance mechanism of Poa pratensis [J]. Journal of Grassland 2019 v.27(06):122-131. 2. Zeng Jing, Zhou Xuan, Rong Xiangmin, Zhang Zhenhua. Response of Rice Varieties with Different Cadmium Accumulation to NO Removal [J]. Journal of plant nutrition and fertilizer, 2021,27(02):322-331. 3. [IF = 2.914] Ejeromedoghene Onome et al."Photochromic property of ternary transition metal oxide nanocomposite prepared with co-solvated deep eutectic mixtures." Res Chem Intermediat. 2021 Sep;47(9):3807-3823 |
colorless or white crystals. Relative density 3. 25. Melting point 665 ℃. Insoluble in ethanol, slightly soluble in ammonia. Apoplexy in dry air. Soluble in 1.1 Water, slightly alkaline, pH8 ~ 9. In the case of strong acid decomposition into water-insoluble tungstic acid. Loss of crystalline water by heating to 100 °c
Anhydrous.
The alkaline hydrolysis of tungsten ore as raw material. Crushed to 320 mesh, and added with 30% sodium hydroxide into the reactor for alkaline hydrolysis. After alkaline hydrolysis, calcium tungstate is synthesized by reacting with calcium chloride, and calcium tungstate reacts with hydrochloric acid to produce tungstic acid, then react with sodium hydroxide to generate sodium tungstate, which is evaporated and crystallized, centrifuged and dried to obtain the sodium tungstate product.
sodium tungstate is a kind of anodic passivation film corrosion inhibitor, and its corrosion inhibition performance is better than that of molybdenum system and phosphorus system. It has good corrosion inhibition effect on halogen steel, copper, copper alloy, aluminum and zinc. When sodium tungstate is a single corrosion inhibitor, the dosage is large, about WO ~- 200mg/L or more, and the cost is high.
tungsten compounds are toxic, especially sodium tungstate. Rabbit intramuscular injection (mg tungstate/kg) LDso:105; Rat subcutaneous injection (mg tungstate/kg) LDso:240. After exposure to tungsten compounds, the human upper and deep respiratory tract are stimulated, suffering from bronchial asthma by dust action, gastrointestinal disorders. After contact with the skin, scales appear on the skin. The United States stipulates that the maximum allowable concentration of tungsten and its soluble compounds in air (in terms of tungsten) is 1 mg/m3, and the insoluble compounds (in terms of tungsten) is 5mg/ma. Staff should be protected. This product should be stored in a cool, dry warehouse, and pay attention to moisture. Keep the package intact during storage and transportation. It is not allowed to be stored and mixed with acid articles. Transport should be protected from sun and rain.
LogP | 0 |