Construction of Quarry Site a Novel Grinding

Incombination, a horizontally rotatable rod mill provided with axialy arranged feed and discharge means, closure means for said feed and discharge means, said feed means including a verticaly disposed reversible screw conveyor arranged in a stationary cylindrical housing, a tank surrounding saidhousing and extending above the upper endthereof, a tubular conduit connecting said feed means withsaid tank,construction of quarry site said feed closure means being contained within said tubular conduit.SThis invention relates to the classification of minerals and the like, and contemplates improvements in apparatus for such classification. More particularly the invention is concerned with the classification of minerals in the presence of liquid such as water.

As a result of my investigations I have developed a system of classification whereby the density of a classified overflow, its volume, and the size of the particles in said overflow are controlled within very close limits.Briefly my invention comprises a classifier of improved and novel design, as well as a novel grinding circuit in which this classifier may be Is incorporated. My invention also contemplates a novel system of control mechanism whereby the character, density, volume, etc., of the classifier feed or the classified product may be controlled within close limits.

The classifier of my invention comprises a tapered or conical chamber having its apex at the bottom, an agitating mechanism disposed centrally within the chamber, means for withdrawing material from the bottom of the cham23 ber, a peripheral launder around the upper part of the chamber, and means for varying the rate of withdrawal of material from the bottom portion of the chamber in response to variations in the density of the material in this portion. The novel classifier circuit into which my improved classifier may be incorporated comprises a wet grinding means, means for feeding coarse material to the grinding means, a classifier, a...