Abstract: A method of comminuting a mineral involves introducing into a grinding chamber which has an internal, rotatable impeller driven by an electric motor, water, a dispersing agent and pieces of said mineral not larger than 20 mm to form a slurry. The slurry is agitated in the grinding chamber and a slurry of comminuted minerals is continuously withdrawn from the grinding chamber. The rates of introducing the water, the dispersing agent and the pieces of mineral into the grinding chamber and the rate of withdrawing the slurry of comminuted mineral from the grinding chamber are such that the slurry of comminuted mineral withdrawn from the grinding chamber contains at least 50% by weight of solids. The volume of material in the grinding chamber is maintained substantially constant, and the power consumed by the electric motor driving the impeller is maintained between upper and lower limits.