Top 5 Questions Asked About Attrition Mills
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Jay Hazen | Chief Executive Officer | Met Pro
Servicing the aggregate mining industry, Met Pro has many years of experience with attrition mills, and many units have been installed on a variety of applications. Attrition mills are designed to scrub, liberate, and break down materials with a particle-on-particle action.
As a leading provider of mining solutions used by hundreds of customers across the U.S and Canada, we’ve put together the following list of questions that are asked most about attrition mills.
What is the capacity of an attrition mill cell?
Each manufacturer’s machine has a given volumetric capacity. This should be determined not by the overall height of the cell but by the overflow or discharge of the cell. This capacity will then dictate how many tons-per-hour at the needed residence time the machine can process.
How important is horsepower to the effectiveness of an attrition mill, and how much is needed?
Efficient scrubbing takes horsepower to force particle-on-particle at high solids. It is attractive sometimes to install less horsepower, for cost savings, but having too little installed can lead to a failed installation. Proper scrubbing is energy intensive. Turning blades or paddles through a slurry of 72% to 75% solids by weight takes a lot of power. If too little horsepower is installed, the machine cannot power through the slurry, making it necessary to dilute, thereby decreasing efficiency.
What is the importance of a properly sized reducer/mixer drive, and what size reducer is recommended?
Best practice recommends a reducer with a service factor of at least 2 to 1. The reducer or mixer drive is one of the more expensive components. It can be tempting to cut corners to sell at a lower cost, but it is also the heart of the machine. When it fails, the machine is down, and with supply chain challenges today, drives are not always sitting on the shelf, so repairs could be delayed.
What style of mixer is best: propeller style or blade/paddle style?
Propeller-type mixers are the preferred style for Met Pro. While they are a more expensive option, two propellers are used, one up-thrust and one down-thrust, with solids in between being forced against each other. Propellers also give more surface area on the blades versus paddles, so they come in contact with more particles.
For more information about attrition mills and how Met Pro can support your aggregate mining needs, contact us at (863) 425-7155.