Tube Milling; A Treatise on the Practical Application of the Tube Mill to Metallurgical Problems (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1917 edition. Excerpt: ...have been worn Fig. 36.--Cast-iron screen for discharge end of tube mill. to 1 in. in diameter, more or less, they suddenly disappear, being ground so as to be undistinguishable from the ore. When a tube mill is emptied of its contents, one seldom sees small pebbles. Fig. 37.--Marcy mill periphery discharge. Fig. 36 illustrates the grating used at the discharge ends of the tube mills at the Goldfield Consolidated mill made of cast iron, but preferably made of manganese steel. The peripheral discharge is incorporated in the Marcy mill, Fig. 37, which shows the passage of the pulp through the mill and the level at which the pulp remains by reason of the radial ribs or lifters which removes the pulp as soon as it enters the chamber at the end of the mill. Chalmers and Williams have added to their tube mills an adjustable quick discharge device, Fig. 38, which consists of a perforated plate, interposed between the end of the tube mill and the body of the mill. Between the perforated plate and the end of the mill are radial blades which are used practically as elevators. The blades are arranged on hinges, so that by changing their inclination with respect to the tube mill end, the space between the perforated plate and the mill end may be more or less closed and the amount of pulp elevated greater or less. The following tests at the Gold Hunter mill, Idaho, show the value of the adjustable quick discharge fitted to a 5 by 14-ft. tube mill; test No. 1 being for the mill without the discharge in use and test No. 2 being for the mill using the adjustable quick discharge. The addition of the adjustable quick discharge lowered the cost of tube mill regrinding in the above instance by approximately 1% cts. per ton. In the Allis-Chalmers adjustable...