Production mode of conventional seawater brown fused alumina:
The method of using seawater and lime to produce magnesium hydride. Chesny in 1936, the industrial production of magnesium hydride production mode, has been done in the press, but completely and in the way the absorption has not been too large changes in the way. The way to obtain high quality magnesium hydride is: 1 out of the raw materials of the limestone impurities; 2. Removal of impurities and carbonic acid composition in seawater; 3 to improve the deposition and purification of the formation of magnesium hydride.
Lime kiln in Baja, bacon burnt in rotation slaker curing a lime milk. However, the quality of this kind of lime milk has a very great impact on the quality of the produced magnesium hydride. So there is no hot disintegration and the remnant of the calcium carbonate and coarse impurities with the centrifugal separator removed the refined lime milk.
The way to remove the CO2 component in the sea water, first of all, is the alkali method, that is to add the lime milk, as the calcium carbonate to remove. Second is the acid method, that is to add acid as the removal of carbonate. The ratio of acid to CO2 components was high (95%). The basic law has the advantage is: when the water through the calcium carbonate deposition trough, can be decreased by SiO2 and Al2O3 and other impurities, CO2 content can be decreased to kg-1.
Hydride generated by seawater and lime magnesium alloy is a paddle liquid, particle radius small, around 0.1 M, the existence of things is to thickener concentration, deposition, salt extraction and purification of. To this end, after the addition of magnesium hydride crystal cycle and the addition of condensation agent, so that the two particle radius of 2 to 3 m, things are resolved.
Sintering process of brown fused alumina. According to the quality of brown fused alumina can be divided into two stages of sintering and sintering. From the sea of corundum industrial development at the beginning of 1955, has been the hydrogenation of magnesium alloy block direct firing furnace sintering to carry out investment. Please combine investment magnesium block, in order to mobilize the sinterability, of adding mineralizer and firing are discussed. In 1955, the process of sintering after drying, pressing and forming of magnesium hydride was cited. Along with the combination of magnesium content to mobilize, since 1957 has hydrogenated magnesium alloy block light burned, magnesium combined income to carry out compression molding and sintering, in order to achieve the high density. Light burned Road 5 uses time-division Hearst multiple hearth furnace and rotary kiln; forming machine adopts is pressure ball machine, pressure molding machine; sintering furnace adopts the shaft kiln and rotary kiln. Compound magnesium content of 97% the following corundum in 1500 ~ 1800 DEG C to carry out sintering; more than 98% of the Gao Chunzong corundum in 1900 to 2100 DEG C to carry out sintering.
