Improved Machinery for TREATEMENT OF QUARTZ.

Te Aroha News, Volume V, Issue 241, 11 February 1888, Page 2

Improved Machinery for TREATEMENT OF QUARTZ.

DuitiifG tho present week, Mr John Chambers (who is no largely interested in the mines at Tui Creek, Te Aroha) in company with his son, Mr J. M. Chambers, spent several days at Te Aroha on business in connection with the Tui mines and their developement. They left Tb Aroha for Karanghake on Thursday morning, and after a good look round the mines they will proceed to Thames, where new machinery is now being erected by them. About two years since Mr J.M. Chambers went to f-iondon, in order to avail of tho best medical advice obtainable, with respect to an injury he had sustained to one of his feet; and during his stay in the Old Country, extending considerably over a year and a half, ho rtevotea a very large portion of his time in investigating the respective marits of all tho most modern and approved appliances to bo found in London, Glasgow, France, or Germany, for the treatment of gold and silver ores. To assist him in his investigations with respect to the various processes in use, Mr Chambers had the advantage of being able to have exhaustive practical test« made of New Zealand ores (from the Tui and elsewhere, tailings from Thames foreshore, etc.). sent home for that purpose. The result of these investigations led Mr Chambers to decide, that for the purpose he had in view, viz., the reduction of the I class of ores common to Coromandel, Thames, and portions of the Upper Thames; in fact for ores generally in which the gold and silver is found iti a metallic state, Molloys Hydrogen Amalgam process was by far superior to any of the others. This process was patented in October last, since when about a hundred complete plants have been erected by a very powerful English company which was formed, and is known as the "Hydrogen Amalgam Company, Limited, (Mclloys Patent)." The! machinery used in this process is made either for wet 01 dry crushing. Briefly tho process the ore passos through is somewhat as follows :—lt: — It is first reduced by being passed through a Blalces stone breaker, from whence it is conveyed direct by a shoot into what is known as

" Askams'|Patent Centrifugal Pulverizer," stationed at a bwer elevation, from which it escapes so thoroughly reduced us to' be an exceedingly fine powder. But the machinery can be altered to pulverise the ore to any required decree of fineness so as to pass through' gratings varying from th >se usually found in ordinary stamp b itterie*, up to tho.se containing 10,000 holes to the squire inch. The quartz is crushed bv four rolls of: chilled steel with centrifugal action. These rolls revolve at a speed of about 250 per minute within two rims of steel several inches in thickness and of extra hardness, and by means of this the toughest quartz is in a moment cracked up and reduced to dint. An iron gan, shaped something like the propeller of a fltenmsr, is fixed in the cylinder on the outer side of eawh roll, and, revolving at great speed, dashes the pulverised material against fixed seives, through which it is driven, and falling into a cavity beneath it is thence conveyed to tho separator by means of an elevator. From two to three tons of quartz an hour can thus bo reduced to an exceedingly fine powder. The separator does its work well and quickly, separating tho fine from any coarse particles which may have escaped tho rolls, and which are returned to i tho pulveriser to bo again crushed; the fine stuff passing through shoots into a sluice, from whence it is convoyod direct to the amalgamators. The latter consists of circular pans uf about 3ft 6 in diameter, and about tho same in height) the bed of tho pans being covered with mercury. Upon this bed of mercury a slate disc is made to slowly revolve, in the centre of the disc being a hopper, through which the ore (as received from the separator), passes underneath the disc and into direct contact with the mercury, with which the gold becomes incorporated, the ore, by action of the disc gradually working outwards to the edge of the pan, from whonct it overflows as it were, and escaping overhead of the disc, and over the side of the pan into a flume whioli runs round the whole circumference of the pan, ia conveyed to any required place. By means of a curront of hydrogen gas kept constantly passing through tho bed of mercury, it in thereby kept active, and "sickening" prevented ; the eras being generated by means of an electric current. The mercury thus being kept active, cleaning up can really be made a matter of convenience ; and when decided on, by means of a vent the mercury is allowed to run off, and can be squeezed and retorted in the ordinary way. A set of five of these pans are capable of putting through from 25 to 50 tons per day. It may here be notod one, (by no means t<a be despised) feature in these pans is, the absolute security provided to owners o f quartz against amalgam being meddled with ; it being absolutely impossible once tho ore pisses into ths amalgamator, for the g')ld extracted to be tampered with without first teninving the disc or opening the vents, which latter are kept sealed. Mr J. M. Chambers bus been appointed sole agent in New Zealand for tho sale of the Hydrogen Amalgam Cos. machinery, mid one of these complete plants is now being erected to tho order of a firm in the South Island ; whilst, (which more nearly concerns us) another is in course of erection at Thames in connection will) tho old Herald battery, and will be so arranged as to be capable of being altered and used for either dry or wet crusning. It is expected this plant will be ready to start work in about six weeks from now. P.ircek of ore will be sent down to Tlnmes for treatment by this now process from this district, when a start has been mad.'. With respect to the more lefractory ores, such as those known to exist in such vast quantities ;it T.i creek, and machinery foi their treatment, Mr Chambers informed us an expert is now on his way out from Home to make personal and thorough inspection sind investigation both as regards the ore, its characteristics, situation, cost of breaking it out, etc., with a view to the erection of a suitable plant, 'embracing the most modern improvements. Great credit, and the thanks of all interested in mining aro due to the Messrs Chambers for their efforts in the direction of developing the mineral resources of the Hauraki gold field, and we trust their new plant will, in practical work, fully come up to expectations, and wish tho proprietors much success.