Experimental study on performance of a continuous centrifugal concentrator in reconcentrating fine hematite

A pilot continuous centrifugal concentrator was used to reconcentrate fine hematite from a high gradient magnetic separation concentrate to study the effect of feed volume flow rate, feed % solids, drum rotation speed, drum inclination and reciprocating velocity of high pressure water sprays on concentrate upgrade ratio, iron recovery and separation efficiency. The results of this investigation indicate that the changes in reciprocating velocity of high pressure water sprays and drum rotation speed have the most significant influence on the performance of the concentrator; a too low or too high feed volume flow rate deteriorates the separation performance; the increase in feed % solids deteriorates upgrade ratio but increases recovery; the optimum values of feed volume flow rate, feed % solids, drum rotation speed and reciprocating velocity of high pressure water sprays are all related to the drum inclination and the change in the inclination of drum from 3° to 5° causes a rise in upgrade ratio and a drop in recovery. When all the variables were kept optimum, a concentrate assaying 62.32% Fe with 65.02% recovery can be achieved at a drum inclination of 5°. It was concluded that this kind of concentrator is efficient in reconcentrating fine hematite from a high gradient magnetic separation concentrate.