Determination of usage areas of the products obtained from alunitic kaolins by means of different enrichment approaches

Since almost all kaolin deposits in Turkey have occurred as a result of hydrothermal alteration, they typically contain alunite. The largest kaolin beds with estimation of 70 million ton capacity are reported to be found in the district of Balikesir-Sındırgı, Turkey. Since a large part of kaolins located in this region contain high amounts of alunite, quartz, and iron oxide, they are not suitable for particularly the ceramic industry and for any other industries owing to the content of impurities.In the present study, we planned to investigate usage areas of the products derived from alunitic kaolins by means of various enrichment methods.In this study, alunitic kaolins, enriched by various methods, uses of the products obtained were investigated. We used three different methods to enrich alunitic kaolins. At the beginning, we used the enrichment method of mechanical dispersion-screening and grinding-screening to eliminate alunite, quartz, and iron oxide from the kaolins. With the use of this approach we managed to reduce SO3 grade in K2 coded alunitic kaolin from 4.05% to 3.44%, and Fe2O3 grade from 1.08% to 0.62%. Thus, this method can be used in the pre-enrichment. Secondly, we used the flotation method and primarily optimized optimum conditions for the flotation. Later, we tried ultrasonic flotation, stage flotation, and flotation of pre-enrichment products in optimum flotation conditions. Eventually by using flotation method, we were able to obtain kaolin concentration containing %0.48 SO3 from E3 sample generated at the end of the pre-enrichment method. And then, we determined that SO3 grade in kaolins were reduced with respect to the calcination temperature and SO3 grade in K2 kaolin, E1 kaolin and C1 kaolin samples at 900°C calcination was recorded to be 0.44%, 0.59%, and 0.31%, respectively.At the end of the enrichment stages, we showed that kaolin samples can be used in the ceramic industry for manufacturing engobe for wall and floor tiles and ceramic tile. In addition, after calcinating by products of pre-enrichment, they can be used as a pozzolan in the cement sector. Finally, the presence of alunite in kaolin is considered to be an advantage with a completely different approach; therefore, alunitic kaolins were shown to be used for producing the porous ceramic.