HYDRAULIC MACHINES.- The improved Ore Washer consists of a long. inclined box, in which revolve two parallel logs, studded spirally with broad, flat teeth. The logs are from 17 in. to 18 in. in diameter, hewn hexagonally, and 30 ft. long, covered with iron their entire length. The washer box is placed on an incline of from 2 to 3 ft. in its length, thus practically submerging the logs one-half their entire length, the back end of the washer box being 4 ft. high. The teeth with which the logs are studded are made with detached bases, the bases being secured to the logs, so that the chilled teeth may be re newed without disturbing the bases. The logs are provided with heavy flanged gudgeons, the back or lower gudgeon being protected with a chilled thimble, which runs in a chilled step or bearing.
The logs are both driven from the front or discharge end by spur and bevel gearing. Two or more washers may be set side by side. all driven by the same main line shaft, with counter shafts to each washer, this countershaft being fitted with a shifting clutch, so that any one machine may be readily stopped without interfering with the operation of the others. Some times it is desirable to drive from the back end, but in all cases both logs are driven from the same end. and logs are always submerged at back end. The ore to be washed is brought from the mines in tram-cars and discharged directly into the washer-box through a coarse grating, or " grizzly," which prevents very large lumps going into the washer. As the teeth agitate and feed the ore forward toward the discharge, it is met by a stream of water which carries the clay back to the mud discharge. The ore, after being thoroughly separated from the adhering clay and soil, passes into a revolving sand screen, where it receives a final rinsing, and passes clean and bright onto an inclined conveyor, which serves as a table from which any foreign material may be hand-picked as it is slowly carried forward into loading bins, or discharged direct into ears. No ore washer is complete without the revolving screen and conveyor. both of which are of simple construction, made of iron and steel, and especially designed for this work. The screen is driven by gearing from the discharge end. The back end, being carried on friction-roller wheels. admits of large opening to receive the ore from the washer, The conveyor is made of steel pans 24 in. wide, secured to double-link chain of x 1i-in. iron, and 11-in. steel pins, with wearing blocks in joints to protect the links.
The Thomas Weaker, which is very similar to the preceding, consists essentially of a rectangular box having cast-iron ends and heavy oak bottom and sides. The box is usually
about 23 It. bug, 5 It. wide, and ft. deep, haying two heavy pieces of timber (see Fig. 10), extending from end to tail, and fitted with gudgeons to revolve in suitable hearings in the cast-iron ends of the box, These shafts, or " logs," are provided with a series of blades, or shovels, of ca.4.iron, arranged helically, in such manner that the logs, which are turned in opposite directions, form two large screws. The main box is set at a small angle from the horizontal, mid receives the ore at its lowest cud, while a stream of water enters at the upper end. The logs revolve in the ore, and move it, gradually, to the upper end of the box. whence it is discharged, cleaned, through a proper opening, the currrnt of water haring washed off the light and worthless gangue. The water and tailings leave the box at the lower end. The angle at which the machine is inclined, and the quantity of water used. &Tends upon the character of the ore treated. The manufacturers of these machines give the following data : average amount of water required for a 25-ft. double-log washer, 35 to 50 gallons per minute ; capacity, 50 to 75 tons of ore per day ; power required, 12 to 15 horse-power.
The Crinkling Jiy consists of a circular sieve, suspended from one end of a lever in a wooden tub 4 ft. 11 in. square and 4 ft. 8 in. deep (inside measurement), being moved up and down by a cam striking the opposite end of the lever. The concentrates pass through the sieve to the bottom of the tub ; the tails pass out by means of an annular opening around the jig shaft. The general arrangement of this jig. as used at the works of the chateaugay Ore and Iron Co., at Lyon Mountain, N. V., is shown in Fig. 11. The spider is made in one piece of east-iron, with a taper bore to receive the jig shaft, which is keyed into it. It is also supported by the standards from the flange, which may be moved by the tipper and lower nuts. A sheet-iron hoop, 12 in. high, is bent around the spider, and fastened by the holding down bands, which are riveted to the rim, pass through the holes in the end of the arms, and are fastened below with nuts. The screen plates rest on the arms of the spider, and are held in place by U-bolts passing under the arms and through the holes in the screens. The screen plates are in. thick, made of cast-iron, in segments of of a circle ; the holes are in, in diameter on top, and in. below.