Recently, researchers at the St. Petersburg University of Mining and Technology developed a highly efficient technique for producing alumina by sintering limestone with kaolin and adding a carbon-containing activator.
The value of this technology is significant in countries and regions with insufficient reserves of high-quality bauxite.
As the world's demand for aluminum increases, the depletion of high-quality bauxite requires the search for alternative raw materials.
For example, this could be chardonite, low-quality bauxite, clay, and kaolin ores.
Researchers at the University of Mining and Technology believe that kaolin will be used more widely in the industrial production of alumina in the future.
The research team, led by engineering doctor Vyacheslavbrichkin, managed to find the optimal amount of the additive, which increased the extraction rate of alumina by more than 7 per cent.
Efficiency is highest when the proportion of carbon in the charge is between 1.5% and 3%, depending on the nature of the carbon-containing material.
The greatest achievement of this technology is that the grinding cost of limestone kaolin is reduced by the dissipation effect, and the extraction rate of alumina reaches 93.5%.
This index has no direct relation with the chemical composition of the original kaolin ore.
