We know that the proper number of revolutions can be increased to improve ball mill productivity, but not for this reason one-sided pursuit of high rpm grinding . Because the number of revolutions to improve , there will be some problems.grinding mill For example, the ball is now at less than the theoretical critical design and manufacturing revolution , if a critical number of revolutions or supercritical revolution movement , one will be lost due to the centrifugal force leaving the mill grinding action ; second is due high speed mechanical vibration and sports wear parts intensified greatly reduced equipment life . Meanwhile ball mill grinding action inside was destroyed , Pai mine thicker, increasing the grading load, so that the products reach the qualifying size requirements . And grinding media and liner wear sharp rise .
Therefore , most of the plant used in the production of work rather than the critical speed rpm operation .
Mill work refers to the actual number of revolutions revolutions mill in good working condition .
The current production of the most suitable working number of revolutions :
n = (0.76-0.88) × critical number of revolutions n. Rev / min .
Proof of actual production , grinding media filling rate of 54% , the critical transfer rate as the number of revolutions of the grinding productivity is higher than the 76% of the time when 88 & ; For finely ground ore ( when the feed size less than 3 mm , grinding minerals in the 0.1 mm or less ) , if the transfer rate is set at 88% of the critical number of revolutions is clearly high, affecting the quality should be slightly lower.
When the production rate of the current transfer is less than 76% of the mill of the critical number of revolutions , called low speed grinding ; revolutions higher than the critical number of revolutions of 88% , referred to as high speed grinding ; revolutions is greater than 100% called supercritical rpm grinding .
Practice has proved that the use of...