12182-82-0 - Names and Identifiers
12182-82-0 - Physico-chemical Properties
Molecular Formula | Cr2O3.H2O
|
Molar Mass | 170.004 |
Appearance | Powder |
Color | green |
12182-82-0 - Reference Information
Open Data Unverified Data
Introduction | chromium oxide is a light green to dark green fine hexagonal crystal. It turns brown when hot and green after cold. Crystal extremely hard, extremely stable, even in the red heat into the hydrogen also did not change. Soluble in heated potassium bromate solution, slightly soluble in acids and alkalis, almost insoluble in water, ethanol and acetone. And irritation. |
Application | chromium oxide has good spraying process performance, it is less sensitive to the overheating caused by spraying, and the coating is not easy to crack when the local overheating occurs. The spraying layer is very dense, the bonding strength with the substrate is high, and it is easy to carry out grinding, polishing and other machining (thermal spraying and remanufacturing). |
Last Update:2024-04-26 10:30:11
12182-82-0 - Nature
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hexagonal or amorphous dark green powder. Metallic luster. The relative density was 5. 21. Melting point 2266 °c. Boiling point 4000 °c. Insoluble in water, insoluble in acid, soluble in hot alkali metal bromate solution. The light, atmosphere, high temperature and sulfur dioxide and hydrogen sulfide and other corrosive gases are extremely stable. It has high hiding power and magnetic properties. Toxic!
Last Update:2024-01-02 23:10:35
12182-82-0 - Preparation Method
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- reduction method: 99.5% potassium dichromate and 98% sulfur were mixed in a mass ratio of 7:1 and then calcined to produce chromium oxide and potassium sulfate. After the reaction, the charge is wet-milled, then put into a washing tank with a stirrer and washed with hot water, and the chromium oxide is filtered out with a filter press to obtain a paste cake with a water content of 30% to 35%, the filter cake was dried at 300 ° C., cooled and pulverized to obtain a finished chromium oxide green product. The washing solution contains a large amount of soluble salts such as potassium sulfate, chromium sulfate and hexavalent chromium. Hydrogen sulfide can be introduced to reduce hexavalent chromium to form chromium hydroxide precipitate, which is separated by filtration. Hydrochloric acid was added to the filtrate, the solution was concentrated and crystallized, and potassium chloride was produced. The sulfur dioxide and sulfur trioxide gas released during roasting is absorbed by dilute ammonia water, and ammonium sulfate can be produced by-product.
- Thermal decomposition method: 99. 5% of chromic anhydride was calcined at a temperature of about 1400 ° C. For 1 to 1.5h to produce chromium oxide. After cooling, it was ground with a high-speed pulverizer to obtain a finished chromium oxide green product.
- Thermal decomposition chromium hydroxide method: sodium sulfide solution is added to the sodium chromate hot solution to react to generate chromium hydroxide. After filtration, the obtained chromium hydroxide filter cake is washed and centrifuged for dehydration, the chromium oxide is produced by roasting at a temperature of about 1400 ° C., and the charge is washed, dried and pulverized to obtain a finished chromium oxide. Sodium bicarbonate and sodium thiosulfate can be recovered from the alkali solution obtained by separating chromium hydroxide and carbonizing with carbon dioxide. The chromium oxide obtained by this method is dark in color and is not suitable for pigment. It is mainly used for smelting metal chromium and making polishing paste.
Last Update:2022-01-01 11:00:34
12182-82-0 - Use
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It is mainly used for smelting metal chromium and chromium carbide. Used as a glaze for enamel and ceramics. Colorants for artificial leather, building materials, etc. It is used in the manufacture of sun-resistant coatings, abrasive materials, green polishing paste and special inks for printing bank notes. Used as a catalyst for organic synthesis. Is advanced green
Pigments.
Last Update:2022-01-01 11:00:33
12182-82-0 - Safety
Open Data Verified Data
packed in woven bags or iron barrels lined with polyethylene plastic bags, 50kg net weight per bag or barrel. Should be stored in a ventilated, dry warehouse. Packaging must be sealed to prevent moisture. It is not allowed to be stored and mixed with food and flammable materials. During storage and transportation, it is necessary to prevent acid fog, rain and hot sun exposure. Handling should be careful to prevent packaging rupture. In case of fire, it can be suppressed by water, sand and all kinds of fire extinguishing. Toxicity and protection: the maximum allowable concentration is 1mg/m3. See other chromic anhydride.
Last Update:2022-01-01 11:00:35