A system for the regeneratlon of caustic soda solutlons used In etching aluminum Invokes the hydrolysis of sodium aluminate to llberate free sodium hydroxide and produce a dry, crystalllne hydrated alumlna byproduct. The system has been used extenslvely In Japan, and, by adjusting process parameters, can be adapted to North American practice. By otlllting the system in a typical plant, soild ai...

The desilication of sodium aluminate solutions prior to precipitation aluminum tri-hydroxides is an essential step in the production high purity alumina for production. This study evaluates derived from leaching calcium-aluminate slags with carbonate, using CaO, Ca(OH)2, and MgO fine particles. influence amount CaO used, temperature, comparisons Ca(OH)2 were explored. Laboratory scale test work...

Experimental work has been performed to investigate the precipitation mechanism of aluminum hydroxide phases from sodium aluminate/sodium carbonate pregnant solutions by carbon dioxide gas purging. Such result leaching calcium aluminate slags with solutions, in accordance Pedersen process, which is an alternative process for alumina production. The concentration ions solution revealed as a key ...

Mineral wools are the most common insulation materials in buildings worldwide. However, mineral wool waste is often considered unrecyclable because of its fibrous nature and low density. In this paper, rock wool (RW) and glass wool (GW) were studied as alkali-activated material precursors without any additional co-binders. Both mineral wools were pulverized by a vibratory disc mill in order to ...