Sodium Metaborate (Tetrahydrate)
Product Description
Sodium Metaborate Tetrahydrate - Technical Information
Molecular Formula: NaBO2.4H2O
Molecular Weight: 137.86
CAS No: 10555-76-7
| Product Properties | Standard Specifications |
| Contents, % | ≥98.0 |
| Bulk Density , g/L | 1650-1800 |
| pH | 9.5~10.5 |
| Ferric , % | ≤ 0.002 |
| Melting point | 57° |
| Appearance | White granular, free flowing |
| Packing | 25KG/700kg PP-PE Bag |
Production method
1. The carbon alkali method adds an appropriate amount of caustic soda or soda ash to the solution of boron magnesium ore processed by the carbon alkali method, evaporates, cools, crystallizes, centrifuges, and dries to obtain the finished product of sodium metaborate.
2. Pressurized alkaline hydrolysis (caustic soda method): The pre-treated boron magnesium ore powder and caustic soda solution are first mixed into a slurry in the batching tank, and then sent to the alkaline hydrolysis reactor. The alkaline hydrolysis is carried out at a pressure of 0.35-0.55MPa and a temperature of 150-165 ºC for 8-10 hours. The alkaline hydrolysis slurry is filtered to remove slag. The filtrate is evaporated, concentrated, cooled, crystallized, centrifuged, and dried to obtain a finished product of sodium metaborate.
If the tetrahydrate is placed in a vacuum dryer, a semi hydrate can be obtained. Further heating the semi hydrate in a vacuum dryer containing phosphorus pentoxide to 200 ºC yields anhydrous material. Slowly heat the equimolar mixture of sodium carbonate and boric acid in a platinum dish until it finally melts, and then cool the molten material to obtain crystalline block products.