HART'S QUARTZ-CRUSHING AND AMALGAMATING MACHINE.

Colonist, Volume VIII, Issue 803, 7 July 1865, Page 3

HART'S QUARTZ-CRUSHING AND AMALGAMATING MACHINE.

(From the Melbourne Age)

Tftebe wa? an exhibition, on the premises of Messrs. W. Clarke and Son, in Elistabetlislreet, equally interesting as a proof of thoughtful mechanical ingenuity, and in its connection with the economic development of our mineral resources. It was a working model, or rather a working machine on .a reduced scale, of the quartst-crusher and amalgamator, the invention and patent of Mr. James Hart, the engineer, of Little Collins-street west; and, if we may take the expressions of interest and approral by the practical men present as conclusive, results may be looked for alike satisfactory to the mining interest and the inventor. The advantages urged by the inventor over the old Chilian mill are that it will enable millions of tons of quartz, cement, and other goldbearing materials to be worked with profit which are now perfectly worthies!; simplicity and freedom from stoppage by accident ; durability, the manufacturer being willing to keep the cylinders in repair at a cost not exceeding 10 per cent, per annum on the outlay for the machine; large saving of motive power ; consequent reduction in the cost of crushing, the whole cose ranging from 6d. to Is. fd. per ton; the machine being gelf-cleansing; it not being required to wash out tailings when taki»g out amalgam; the gold not being crushed after separation from matrix; the quicksilver being placed bo as to take «p gold immediately after separation and before the gold is coated with foul water or grease, whereby the floating gold is caved ; certainty and ease of operation ; and commercially, the undertaking to convey the machines to the place required at the price of ordinary loading

These are large promises, but they seemed to be performed, so far as could be judged from the experimental workings of yesterday. The distinguishing principle of the machine is Gravitation instead of friction. The crushing is accomplished by the revolution of a loose cylinder, with large perforations inside an outer cylinder, also revolving and driven by hands. The machine is fed with the quartz by an easy process which conveys it to the outside of l.lie loose cylinders, through the apertures of which the stone finds its way between the two cylinders, and is crushed at the bottom of the outer cylinder by the pressure of the loose one. Each cylinder will weigh from ten 10 forty tons, according to quantity of work required. The water required, according to Mr. Hart, will be about one-eighth of what is required for stampers. The amalgamation is effected by placing quicksilver at the bottom of the outer cvliuder, by which it is kept in constant motion, and all escape of fine gold is

prevented,

Any more detailed, explanation of the process will be best yiven by a statement of vrhai. was shown in I lie experiment, premising 1 hat ihe.model at work yesterday has been nt work privately for about three yeai's, and has actualh' crushed,- accord" in:* to the aceounr kept, about 2800 tons of stuff. The outer or enclosing cylinder is l-i inches lori£, liv i\ iliamc-'ter of* 1.2, or on a scale for ordinary working of onc-1 weH'iii. The first tiling that slrikcs observation is 1 he slight motive power !'ei|uired to work the machine. The cylinder, wiih its enclosures, weighing three cwt., was set in mouon by a mere touch of the wrist to the handle of the fly-wheel, and kept up with little more.exertion. In stamps, taking the figures given, by way of illustration,' to the working for every 3c\vt., 1001b. of steam power would be required for the lift, with an additional four per cent, allowance for friction to perform the same amount of work. It is estimated that a machine of twelve times the dimensions of the model will crush 3500 tons a week. The materials crushed in the course of the experiment were sandstone and the common blue basaltic rock of the district, each of which was reduced as completely as the other, and with equal celerity ; In fact, Mr. Hart lias based his invention on the desire to use all that is now considered debris in gold mining. All the stuff runs out, and there is no washing required as with the usual stamps. This was quite satisfactorily shown by the machine. It was likewise shown that, should a piece of iron go in, no damage is done, and the iron itself comes out uninjured. The same thing was asserted of it as to gold. A nugget would come out a nugget still, uncrushed. We need not dwell on the mechanical action of the quicksilver, further than that it seemed to be thoroughly diffused over all parts of the cylinder, presenting a large surface to the exercise of its affection for gold. The mercury is put in with the quartz. Mr. Hart, amongst other proofs given that he acted on the principle of gravitation, not friction, pointed to the rust on the cylinder, which had arisen in consequence of a short interval of disuse.

The machine, as it meets the eye, is an iron cylinder, supported on a simple wooden frame. Within the first is a second cylinder, pierced by four rows of holes, of three in each, and within this second cylinder is a loose roller. After the three years toil o!" this machine neither rollers nor cylinders exhibited any signs of wear ami tear, Some one present having remarked that a 100 tons machine would rather astonish Wood's Point if it could be got there. " Step this way, gentlemen," said Mr. Hart; "carriages are usually required to cany' machines to gold reefs—we make the machine carry the carriage;" and, if models apeak truly, the inventor spoke like a mathematician. In siiorr. locomotion is proposed garden roller fashion. The cylinder is made to do the duty of wheels, and, atticliel to a six-bullock team, yoked by iron cable and a simple carriage frame, may be moved, as was stated, ni the rate of eight miles a day, and surmount heights at an angle even of forty-five degrees, and descending safely by means of a system of breaks. Frail bridges and narrow creeks will be crossed by moveable wooden tramways of easy transport. Mr. I! art seems to have perfect confidence in li'.s power to transport, seeing that he undertakes to CDiivey a crushing machine any-

where, at the ordinary rate of carriage in the district.

As regards cost of machine, one of capacity to crush 300 tons per week, with a motive power of four horses, would cost £1000, eidusive of framework; one to crush 2000 tons, of 21-horse power, £4750; with a variety of prices within these limits.