Main factors affecting the selection of centrifugal concentrators

The factors affecting the selection of centrifugal concentrator are the structural parameters and process parameters of the equipment.
(1) Equipment structural parameters (1) Drum slope It directly affects the flow rate of the slurry in the centrifugal concentrator, thus affecting the concentrate yield. The slope is large, the concentrate yield is small, the concentrate grade is high, and the concentrate recovery rate is low. If the slope is too large, the slurry flow rate is too fast, and the concentrate is difficult to deposit on the drum wall, and the sorting effect is not obtained. On the other hand, if the slope is too small, although the concentrate yield is large and the recovery rate is relatively low, the concentrate grade is low, and the flow rate is reduced due to the small flow rate. Therefore, the slope should be appropriate.
(2) Drum diameter and length The diameter of the drum mainly affects the throughput. Large diameter, large selection area, high processing capacity. When processing a tin sludge, 800mm diameter centrifugal concentrator, the processing capacity can be up to 30 tons / day or so-station.
The length of the drum mainly affects the recovery rate. The drum is long, the sedimentation time of the ore is longer, and the recovery rate is higher, and vice versa.
(2) The process parameters include the ore size, the ore volume, the ore concentration, the ore feeding time and the drum rotation speed.
(1) Grain size of the ore The production practice proves that when the upper limit of the ore size of the centrifugal concentrator is greater than 74 microns, the rinsing of the concentrate is difficult, which affects the selection index. The most effective particle size recovery range for a typical centrifugal concentrator is 37 to 19 microns. Of course, according to the nature of the ore and the requirements of the mineral processing products, the optimum feeding size should be determined after the test.
(2) Feeding volume The size of the ore supply of the centrifugal concentrator affects the condition of the upper film of the drum wall. If the ore volume is too large, the flow rate is fast, the sorting effect is low, and even the sorting effect is not obtained. The figure below shows the test results of a sand-tin mine, showing the relationship between the ore volume and the selection index.

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It can be seen from the above figure that the ore supply volume of the centrifugal concentrator increases, the concentrate yield and recovery rate decrease, and the concentrate grade and tailings grade increase. When the concentration of the ore is 15~20%, the suitable ore volume is: rough selection of 90~100 liters/min. Taiwan; selected 70~80 liters/min.
(3) Concentration of the ore concentration The concentration of the ore concentration has a great influence on the production capacity of the centrifugal concentrator, and also affects the selection index. The figure below shows the relationship between the concentration of the ore and the selection index.

It can be seen from the above figure that under other conditions, within a certain range, the concentration increases, the concentrate yield and recovery rate increase, but the concentrate product decreases. The appropriate ore concentration should be determined according to the nature of the ore and the quality of the product. When processing tin mud, the appropriate grain size: 20~25% for rough selection and 15~20% for selection.
(4) Centrifugal concentrator for feeding time In the continuous feeding process, the grade of tailings increases with the increase of the feeding time, until the instantaneous tailings grade rises close to the ore grade, then the sorting is not possible. Function, but only for transportation. Therefore, the timing of the mine should be appropriate. The feeding time is too long and the recovery rate is low. If it is too short, the concentrate grade is low, the equipment is effectively used for less time, and the processing capacity is low. Generally, when processing tin mud, the feeding time is preferably 3 minutes. The figure below shows the relationship between the feeding time and the selection index. [next]