Evaluation of soil-water ratio effectiveness in soil-bath wet separation process for kernel recovery

Abstract

An appraisal of the soil-water bath (wet separation) method showed that the method is based on the difference in density/specific gravity of the palm kernels and the shells. In this study, the separation of palm kernel-shell mixture using separating agent other than clay soil (kaolin) in wet separation have been considered. Measured masses of soil were added incrementally into 40 L of water and its density calculated and recorded. The separation efficiency of an alternative medium (laterite) was compared with that of clay soil (kaolin). Different mass quantities of kernel/shell mixture were poured into the red mud soil (laterite) slurry, and stirred. The part of Kernel/shell mixture that floated were scooped off and the Kernel selected and weighed. From observations made, the density/specific gravity increases with increase in mass of separating agent in water. The separating efficiency increased with increased soil input, till the 18kg mark of soil input for both separating agents, when the floated kernel weight begins to be constant and highest. The optimal separation efficiency was found at medium/ water ratio of 0.45:1. The effectiveness of the red mud (laterite) sample was found to be comparable to clay (kaolin) at a medium-to-water ratio of 0.45:1 giving 98.93% efficiency. Thus, it is recommended to be used as an alternative to clay for wet separation.

Keywords: Oil Palm Kernel, Kernel Shell, Wet Separation, Clay Soil, Red mud