Experimental study of calcium carbonate solution saturation in the separation process of palm kernel-shell mixtures using water clay bath systems

Continual use of CaCO 3 in the separation of the palm kernel-shell mixture causes CaCO 3 solution saturation. In this study, we aimed to evaluate the causes of CaCO 3 solution saturation during the separation process of palm kernel-shell mixtures. The process was carried out in the laboratory clay bath system using several factors in the separation process, including calcium carbonate to water ratios (1:2 and 1:3), palm kernel-shell mixture feed rates (2.5, 3.0, and 3.5 kg/batch), and times (1, 2, 3, 4, and 5 h) with density, pH, and oil content as the quantitative control. The results show that the density and pH of the separating solution dropped per unit length of processing, with the lowest values being around 1.0916 g/ml and 6.65 (CaCO 3 to H 2 O ratios of 1:3; feed rates 3.0 kg/batch; and times 5 h), respectively. In addition, the oil content of the separating solution was raised from 0.145 mg/L to 571.87 mg/L. Owing to the results, the dissolved oil in the solution was discovered as the cause of the saturation of the separating solution (decanting agent) during the process, corresponding to the inefficient separation of palm kernels and shells.