Manufacturing process:
Magnesium oxide is produced by the calcination of magnesium carbonate or magnesium hydroxide. The latter is obtained by the treatment of magnesium chloride solutions, typically seawater, with lime.
Mg2+ + Ca(OH)2 → Mg(OH)2 + Ca2+
Calcining at different temperatures produces magnesium oxide of different reactivity. Calcining temperatures 1000 – 1500 °C produce hard-burned magnesia, which has limited reactivity and calcining at lower temperature, (700–1000 °C) produces light-burned magnesia, a reactive form, also known as caustic calcined magnesia.
MgO is hygroscopic in nature and care must be taken to protect it from moisture. Magnesium hydroxide (Mg(OH)2) which forms in the presence of water can be reversed by heating to separate moisture. In medicine, magnesium oxide is used as a magnesium supplement, to improve symptoms of indigestion, or as a short-term laxative (to evacuate bowels prior to some surgeries). Side effects may include nausea and cramping.
Applications of Magnesium Oxide:
- It is used by many libraries for preserving books, and as an insulator in industrial cables.
- It is also used as a medication to relieve heartburn, sore stomach, or acid indigestion. Medical uses of magnesium oxide also include using it as a short-term laxative, or used to supplement a diet with magnesium.
- Magnesium oxide is used as a basic refractory material for lining crucibles. Magnesium oxide is a principal ingredient in construction materials used for fireproofing.
- It is used as a reference white colour in colorimetry. The emissivity value is about 0.9 Pressed MgO is used as an optical material. It is transparent from 300 nm to 7 µm. The refractive index is 1.72 at 1 µm.
- Crystalline pure MgO is available commercially and has small use in infra-red optics. Magnesium oxide is also used in animal feeding industry and there are special grades available.
| PRODUCT IDENTIFICATION | |
| CAS NO. | 1309-48-4 |
| EINECS NO. | 215-171-9 |
| FORMULA | MgO |
| MOL WT. | 40.31 |
| H.S. CODE | 2519.90 |
| SYNONYMS |
Calcinated magnesia; Magnesia; Calcined Magnesite; Magnesium Monooxide; Akro-mag; Animag; Calcined brucite; Calcined magnesite; Granmag; Magcal; Maglite; Magnesia usta; Magnezu tlenek; Oxymag; Seawater magnesia
|
| DERIVATION | magnesite |
| PHYSICAL AND CHEMICAL PROPERTIES | |
| PHYSICAL STATE | white powder |
| MELTING POINT | 2800 C |
| BOIING POINT | 3582 C |
| SPECIFIC GRAVITY | 3.58 |
| SOLUBILITY IN WATER | Insoluble |
| pH | 10.3 |
| VAPOR DENSITY | 1.39 |
| NFPA RATING | Health: 1; Flammability: 0; Reactivity: 0 |
| STABILITY | Stable under ordinary conditions |
| SALES SPECIFICATION | |
| APPEARANCE | white solid |
| MgO | 93.0% min |
| CO2 | 1.5% max |
| INSOLUBLES IN HCl | 0.2% max |
| SiO2 | 1.0% max |
| SULPHATE | 0.2% max |
| CHLORIDE | 0.1% max |
| LOSS ON IGNITION | 7.0% max |
| PARTICLE SIZE | < 75 µm |
| TDS |  |
| MSDS | |