pH Models for Monitoring the Conversion of ‘Kankara’ Clay to Alum

All industrial chemical processes are designed to transform cheap raw materials to high value products (usually via chemical reactions). This work which excluded the beneficiation process involved the transformation of Kankara clay which was reacted with sulphuric acid into alum with the sole aim of using pH measurement for process control and to developing a specific quality monitoring parameter for the conversion of kaolinitic clay to alum. The alum was produced by reacting Kankara clay with sulphuric acid under controlled conditions. 10g of Kankara sample clay was dissolved in an equivalent amount of water required stoichiometrically to prepare 40wt% of H2SO4 and the pH of the stirred mixture was measured at different concentrations by using buffer and pH measurement techniques. Furthermore, 10g of the sample clay was digested with a stoichiometric amount of H2SO4 acid and reacted at different temperatures for which the pH was monitored. pH models for monitoring the conversion of ‘Kankara’ kaolinitic clay were generated; validated using regression methods. The system model data compared with the experimental model data showed a linear correlation of determination, R2 = 0.999 at 5% level of significance. These models can be used as an effective tool for material balance, reactor design, process development and scale – up parameters for pilot plant design.