Stamp Mills for Quartz Crushing.

Cromwell Argus, Volume III, Issue 124, 26 March 1872, Page 7

Stamp Mills for Quartz Crushing.

i sl li: (Th a mes Guard lan.) A well-known American author states tha the expression “Stamp Mill,” in a limited sense, signifies simply the batteries ; but ii a broader sense, embraces not only the bat teries, but the prime movers and all the ma chinery applicable to the reduction and cun centration of ores, the amalgamation and th: further treatment of the precious metals. The works to which stamps are peculiarly well adapted, is the reduction of fragmentary ores coming from the “ Ore Crusher,” so a; to pass through No. 4 and No. 5 screens. Ii this capacity, stamps arranged in straigh batteries are unrivalled in efficiency, dura bility and simplicity. To accomplish tin the same kind of work, many different ma chines have been tried, failed, and cithe found their Way as old iron to the furnace or left where first reared as monuments of ; sad experience. A stamp weighing six hundred and fifty pounds, and making ninety ten-inch drops ; minute, will in twenty-four hours reduu about two and one-half tons of hard rock from and to the respective sizes named, am requires nearly one horse power for one to: of rock so reduced. The feeding of the rock into the batter should he uniform, the practical rule bein to feed so that iron to iron shall be heard ;; often as every tenth or fifteenth fall of th stamp. (This may do very well where pic points and gads never find their way to tli stamper box, but with them occasional!} such feeding would play sad havoc with shot and false bottoms, though made of cast stei or chilled iron.) Looking to the erection of a stamp-mil location is a subject of scarcely less impoi tancothan that of determining the pmspcclh value of the mineral deposit for which th machinery is intended. The site should b selected with a view chiefly to its elevatioi its accessibility to the mine and comma thoroughfare, and to facilities offered for fue timber, and water. The height of the elev: tion for immediate mill purposes should m be less than twenty foot ; besides, the fa below for carrying oif the tailings should 1 at least one-aud-a-half inches to the foot, m less there may be a surplus of water. The floors of the mill should be arrange i in steps, so that the material under trea ment shall pass from machine to machii through the series with the least haudl'm; The foundations of all the machinery mu be firm—those of the stamper boxes in pa ticnlar. The timber is placed as to its grai —either horizontal or vertical. The hoi zontal foundation is sometimes composed < a single timber, and sometimes of sever!; j In either case they are laid across mud sill or on brick or stone work. «A single timbe | termed a “stamper-bed,” being employes I the stamper-boxes arc secured in their place | either by large bolts or being let into it. several pieces arc used, they ave bolted t gethcr, one piece acting as a bed for the bo and other two as side clamps. The vertic foundation is constructed in distinct section each of which, designed for a single box, composed of several timbers framed and s curely bound together with bolts, pegs, ai hoops. In case of their being several sc tions, they are connected by clamps runnn lengthwise utf the batteries. The hed-roi i is usually sought for as the base of the vi • tical foundation, but when this lies too doe i resort is had to mud sills, brick, or sto: | work. The end of each frame of timb should be dressed level and smooth, so as ! make an accurate tit with the planed bottn iof the stamper box, which is to he bolted it. The vertical foundation is prefer,able 1 the horizontol : for, being separate from t | battery frame, the jar occasioned by the f; i of the stamps is not communicated to t | other machinery. It is also firmer, thus re i dering the blow of the stamp more etieclh Besides, in case of decay it can readily be i | paired without detriment to the frame of t battery. Tiie main driving shaft is, in some i ! stances, coupled with the cam-shaft, and j others is connected wit'.i it by means of I counter-shaft and gearing, or bolt and pi leys. When the coupling is used, the cai shaft is frequently employed as a drivin shaft for the machinery. In case of t countershaft being .adopted, it is usuT placed at the foot and in front of (fie hj; I teries, but sometimes is put from fifteen | twenty feet from them and ten or more f< i above the level of tin's position. The cc | nection between the intermediate and mob I shafts may be made by direct-coupling or j intervening machinery. Thcstanq is, griudo | and amalgamators, and commonly the i 1 parators, are driven by this shaft. | Another counter-shaft for the orc-cr.isln [and sub-counter shafts, deriving their n | tions from the main intermediate sfia | for driving respectively the amalgamate land the concentrators, ave generally inti | dneod. "When the elevated counter shaft ; | employed, (fie ore-crusher is driven by j sub-countov-shaft placed on the top of t . j battery frame. As a general proposition t application of intermediate shafts is prof I able to that of the direct couplings ; for . j the former case, the batteries, and the am i | gamating machinery maybe run'ov stop] Mat pleasure, the. one without interlering \v • j the other ; whereas in the latter case, i • I amalgamating machinery, receiving its moli through tin; cam-shaft, is subject to all i j delays. Besides, both the motive machim • and that driven from the cam-shaft are ■ ; posed to no little wear and tear, prodm i by the fall of the stamps, and the concuss [ of the cams and discs, although much of tl . is saved by the use of fly- wheel - : an the ca

shafts. But whether it is better to put the intermediate shaft near the foot of the bat* tt-ry or to elevate it as described, is not fully settled. If it is placed on the hover position, its journals and bearings are liable to be injured by crushed ore from the battery getting into the pillow-blocks. Another important objection is, that the cam-shaft belt is rendered too short to secure the best mechanical results ; otherwise, as the running machinery is entirely out of the way of the workmen, the plan seems almost faultless.