Veitscher Magnesitwerke-actien-gesellschaft

Veitscheer Magnesitwerke-actien-gesellschaft

Helmut Grohmann

Michael Grill

Peter Stadler

In a process of preparing sinter magnesia from magnesium oxide in a sintering kiln evolving flue gases during sintering, the flue gases are washed before their removal from the kiln to the atmosphere with a portion of the magnesium chloride slurry formed during the preparation of the magnesium oxide and the magnesium chloride slurry used for washing the flue gases is recycled to the slurry wherefrom the magnesium sol for making the magnesium oxide is derived.

Process of preparing sinter magnesia

The present invention relates to a process for the recovery of magnesium oxide of high purity in which the magnesium oxide is obtained by thermal decomposition of a magnesium chloride brine previously purified. The magnesium chloride brine itself is obtained by decomposition of impure starting material with hydrochloric acid and purified before the thermal decomposition. In doing so the brine obtained by the decomposition is first concentrated and the separation of the impurities is effected only then. Calcium is separated in form of calcium sulfate. Optionally calcium sulfate and other impurities may be separated together.

Process for the recovery of magnesium oxide of high purity

In an industrial process of preparing high-purity magnesia from an impure magnesium-containing starting material, wherein the starting material is dissolved in HCl and the resultant acidic solution is subjected to a multistep treatment for precipitating the impurities out of the solution, the precipitate is separated from the residual purified magnesium chloride solution, and the magnesium chloride is thermally decomposed to obtain magnesia, the purified magnesium chloride solution is first concentrated and sulfate ions are then added thereto to precipitate calcium ions from the concentrated solution as calcium sulfate.

Growing community of inventors

Leoben, Austria

Helmut Grohmann