Effective Crushing.

Thames Star, Volume XVII, Issue 5147, 16 July 1885, Page 2

Effective Crushing.

The London Times gives a favorable notice to the Sutherland Quartz Crusher, which, it is stated, will grind quartz, pyrites, coprolite, phosphate of lime, cement rock, flint and other hard substances, at the rate of from seven to fifteen cwt. per hour, up to a sieving fineness of 50 to 120 mesh per linear inch. Dealing with refractory ores is one of the specialities of the invention, and we have been assured by a competent authority that such a system would work well here. The Times states that —"Having had practical experience of the disadvantages attendant upon the use of the ordinary stamp batteries in pulverising quartz rock and other refractory substances met with in mining, Mr Sutherland has designed a new form of crushing machine, the working of which we recently witnessed. The apparatus embodies several novel features, and constitutes a departure from the ordinary practice in this class of machinery. It is, in fact, a mill, constructed upon the pestle and mortar principle. The mortar, which is stationary, consists of a large cast'iron basin, 2ft. 9ins. diameter, and 2ft. 4ios. deep. Within the upper part of the basin is fixed a corrugated steel ring, lft. 4ins. deep, the corrugations becoming gradually reduced in size towards the bottom edge of the ring. The pestle, which is made to revolve, is of smaller diameter than the mortar, the annular space being about 3ins. wide at the top, and being gradually reduced to nothing at the bottom, where it impinges upon the mortar. Tbe pestle is carried by a central vertical ihaft con> nected with the engine by gearing. There are arrangements for adjusting the pestle to suit the degree of fineness required. The material to be crushed having been roughly broken is fed in at the top of the machine, and is quickly reduced to fine powder and discharged at the bottom. A private demonstration of this machine was recently given at the Enterprise Work's, Bowling Green Lane, Farringdon street, London, and at which Mr F. Claudet, the assayer to the Bank of England, was presenti The materials tried were BuJl River phosphate of lime, and quartz rock ; broken flint glass was also afterwards put through the machine, and in all cases the results were satisfactory, the work being done at the rate of 9001b per hour. In the case of the Bull River phosphate, of a sample of 21b put through the mill it was found on sieving the resulting powder that 250 ounces passed through a sieve having 90 meshes per linear inch, and six and a quarter ounces through another sieve of 120 meshes per linear inch, the waste being only yoz. The mill is capable of dealing with coprolites, cementclinkers, and in fact all kinds of refractory substances."