90 



DRESSING OF ORES 



Table of Crushing Mills fdr Hard Material 



Gear's Disintegrator. This machine, the invention of Mr. Thomas Carr, has proved 

 to be well adapted for the reduction of semi-elastic vein-stone, ores, and material 

 requiring to bo shattered rather than crushed or ground. The illustration, fig. 668, 

 shows an improved 6 feet 3 inches machine, with two solid shafts, blocks, and bed- 



668 



plate, the disintegrating wheels being without the necessary hood or cover. The 

 inventor in his description states : The machine consists of a series of four strong 

 cylindrical iron cages, of various sizes, formed of bars with open spaces of from three 

 to four inches between them, arranged concentrically one within another, around, and 

 parallel with the shafts or axles and rotated therewith with extreme rapidity in 

 contrary directions to ono another by means of an open and a crossed strap, tlio first 

 and third cages rotating to the right, and the second and fourth to the left, so that 

 while there are only two motions in reality, yet from the way in which the cages 

 intersect one another there are relatively four. 



' The material is thrown in at the central orifice, either by shovels or elevators, and 

 after the lumps, if very largo, are broken by a stationary knifo (fixed so that its blade 

 may extend into the interior of the innermost cage, but never used with very hard 

 materials), they are thrown out by centrifugal force from the first cage at a tangent 

 to its circle, precisely as stones are hurled from a sling, and at a spcr<l equivalent to 

 that at which the beaters of the said oaL-v ;irc rot-it ing (which is usually 50 feet per 

 second) when meeting the boaters of the next cage, moving in an opposite direct ion, 

 usually at 60 feet per second, a collision ensues similar to that which takes place 



