PRE-CONCENTRATION AND FLOTATION OF ALUNITIC KAOLIN AND ITS POSSIBLE USE IN CERAMIC TILE INDUSTRY

Abstract

The aim of this research was to remove sulphur and alunitic parts by the flotation method from alunitic kaolin obtained from the Balikesir-Sindirgi region of Turkey, which is not currently used by the ceramic industry because of its high sulphur content. In the process, mineral alunite was floated while kaolinite was depressed. The effect of pre-concentration on the flotation process was also investigated. Pre-concentration included several processes such as wetting, mechanical scrubbing, and screening for removal of fine alunite particles and colouring oxides from kaolin as well as screening after consecutive milling for the separation of hard minerals such as quartz from kaolin. After the pre-concentration and flotation processes, kaolin concentrate having a SO3 content of 0.48% was obtained with a sulphur removal efficiency of 88.55%, and this kaolin was coded as F4. Afterwards, the use of F4 kaolin in the ceramic industry was investigated. For this purpose, the F4 kaolin was used in angobe preparation, and the angobes prepared were used for the production of floor and wall tiles. The properties of the angobes were also compared to those of commercial floor and wall tile angobes from a ceramic factory. These tests indicated that the floor and wall tile angobes prepared by using F4 kaolin could be used as an alternative for the angobes currently used by the factory.