In production, many concentrators more or less encountered spiral classifier classification efficiency significantly reduced problem, The root cause of this problem is that fine and heavy ore particles and coarse and light ore particles in the process of classification settlement disorder, resulting in the phenomenon of equal fall, so that a large number of grader settling fine and overflow run coarse. So, what measures should we take to improve the classification efficiency of spiral classifier?
Increase screw speed properly
The rotating speed of the screw should be sufficient to conveying the settling coarse particles. The faster the rotating speed of the screw shaft of classifier, the stronger the stirring effect of slurry, the more coarse grains entrained in overflow products. In order to obtain a larger overflow and processing density of large settlement faster material, can be appropriate to increase the rotation speed of the spiral, but not too large so as not to destroy the classification effect, generally more control in the range of 1.5-10r / min.
In the classifier used in the second-stage grinding or grinding cycle, screw speed should be slowed down as much as possible. In the spiral classifier generally use lower speed, especially for large spiral classifier. For example, to obtain a coarse overflow, the diameter of 2m spiral speed should not exceed 6r / minute, general diameter of 1m more than the helical speed should be controlled in 2-8r / minute.
Rational Control of Slurry Concentration
The viscosity of pulp decreases with the decrease of pulp concentration. As a result, the settling velocity of ore particles is also accelerated, and the overflow product size is fine, whereas overflow product is coarse.
But when the slurry pulp concentration decreases to a certain extent, if the concentration continues to reduce, it will make overflow product size coarser. This is because when the concentration decreases a lot, the pulp volume (or pulp volume) is also large, so that the classifier pulp flow rate (upward flow rate and horizontal flow rate) also increased. As a result, the coarser particles are also washed into the overflow product, so the pulp concentration must be controlled reasonably according to regulations.
When there is more mud or fine grain in the grading feed, water can be properly increased to reduce the pulp concentration and obtain the required overflow fineness. When the feed contains little mud, or has been deslimed treatment, it should be appropriate to increase the concentration of slurry, to reduce back sand entrainment of too much fine-grained materials.
For spiral classification beneficiation, on the one hand, it is recommended to find professional equipment manufacturers to purchase, in accordance with the technical parameters given by manufacturers to operate; On the other hand, it is suggested that the spiral classifier operators improve their own operating skills, pay attention to every detail in the selection process, and timely respond to various emergencies to ensure the smooth operation of classification.
Dasen mining provides free customized solution maintenance & installation guide after-sales service overseas. if you need a gold flotation reagents quotation, kindly send a WhatsApp message to me:+8613319277356 Email:[email protected]