Can Hydrocyclone be an Alternative in solid-liquid Separation Process?

In mineral processing industry, most of the separation processes involve substantial quantities of water. The final concentrate generated has to be with low moisture content and recovery of water from the tailing stream has to be recycled. So dewatering i.e., separation of liquid from solid is an important step in mineral processing. As dewatering processes are expensive and inefficient in general, these need focused attention. In case of fine and ultra-fine particles, (fine <100µm, ultra-fine < 5 µm) screening, even if in wet condition, is not effective. As there are many limitations associated with thickeners and filtration units, hydrocyclone can be thought of as an alternative in the solid-liquid separation process. Because of the design and operational simplicity, high capacity, low maintenance and operating cost, hydrocyclone is found to be very attractive for dewatering purpose. So, if hydrocyclones can be used efficiently at this stage, then the load on filtration units or thickeners can be reduced. This paper is aimed at understanding the most important factors that are affecting the separation of solid and liquid in a hydrocyclone for dewatering application i.e., recovering maximum solid and minimum water in the underflow which means maximum water recovery in the overflow. In this study the effect of three parameters on dewatering efficiency was studied in a 2″ hydrocyclone keeping at maximum pressure to achieve the objective. From the experimental results on silica sand, it was found that maximum 98.6 % solid can be recovered with 42.6 % water in the underflow