A professional who tends ball mill that grinds ore and classifier that separates coarse from fine particles. Respnsibilities include:

• Turns pump valves and moves conveyor-control levers to feed soda ash, starch, lime, water, ore, and other materials into ball mill to make slurry.
• Adds chemical reagent to slurry that causes fine particles to float and enables classifier to separate fine from coarse particles and to return coarse ones to mill for regrinding.
• Obtains sample of slurry in bucket from mill and classifier.
• Weighs sample and calculates density of mixture or titrates sample to measure alkalinity.
• May examine ore tactually or observe its color to ascertain size of particles.
• May set automatic device to regulate amount of ore passing on conveyor belt to ball mill.