MR ALVES' PATENT GOLD CON CENTRATOR AND A MALGAMATOR.

Inangahua Times, Volume IX, Issue 1345, 7 January 1884, Page 2

MR ALVES' PATENT GOLD CON CENTRATOR AND A MALGAMATOR.

* — Mr Alve.3, of Dunedin, has ju.t completed the coastruetioi of one of his patent gold concentrators and amalgamators for export to New South Wales, and it can now be seen r.y anyone interested in gold mining at the Otago Foundry. The i machine is specially constructed for sea or river beach workings, and for saving gold from quartz tailings, being substituted for the ordinary tables used in connec tion with quartz crushing i-atteries. It is not a pulveriser, but simply an extractor of the finest particles of gold, silver, &c, and at the. same time, it is ;so constructed as to save coarse grains. The price at which it can be supplied is so reasonable that it is quite within the reach of any miner carrying on operations on beach diggings. The machine is about 6ft long by 2ft 6in wide, aud stands about 3ft high to the top of the screen. The lower part consists of a trough containing water about lOin deep. ' Above this trough the concentrating belt or trav-elling-table is set on pivots to enable it to be set at the pitch required for working, according to the material to be used. About the concentrator is a screen, perforated at the upper end, but not perforated at its lower end. Between the screen and the travelling-table a shoot is placed to carry the sand to the lower end of the belt. The belt is provided with shaking rollers in the trough, which lifts it up and down in the water, washing out any deposit which may have adhered to it. Under the belt in the trough, and well uuder the water, is suspended a tray about sft long by 2ft wide. This tray is shaken backwards and forwards for the purpose of gathering together any pyrites or piracies of metal, and floating off the sand. The mode- of working is as follows : — A 2in pipe ot water, with about 18in fall, is tuni'-'d into the screen above and another 2in pipe is tamed on to the upper spreader U-rween the shoot and the belt : the trough is filled with water to the overflow ■ the material to be operated upon is then put into the screen at its upper end. The water takes the sand through the perforations, the stones, shells, and gravel running over the end of the screen clear of the machine. The sand and water, after going through the perforations in the --or- on, run down the shoot to tlie lower end A the belt, and pass throu.*h a sf •.:'.. so as to distribiu-' th- . -. • : across- the width of i-he U;,. As the belt travels uphill it takes the sand with it, but they water from the upper spreader washes the sand down to the end of the belt and through tlie amalgamator. The pyrites and tine gold sticking on tlie belt live carried into the trough, where they are washed out by the shaking-roil.rs, and fall into the shaking-tray which further separates the sand by being shaken under. The sand falls to the bottom, where a value is fixed on the side about -i-in above the bottom. This valve is suffi -ion tiy j^a.i io allow the water and sand to discharge, and also to keep the level '

in the trough. A door is fixed at .heend of the trough to enable the tray tobe taken out, and also to scrape out. any deposit hat may bo in the trough. The whole apparius is driven by a crank, and takes vory little power, ai* a boy can turn it The amalgamator is- on a new. principle. It consists of a float lined with copper sheet, with vertical strips of copper plate on its lower side. These coppers are silvered, and rest in a chamber of mercury. Tho float is connected by an iron rod to a lever weighted so as to- balauce,. so- that when the sand and water reaches it it is floated, causing the sand, &c. to pass etween two silvered surfaces, also between silvered vertical walls £in apart. It is also arranged so that the coppers occasionally dip down in tho mercury for the purpose of re-silvering the plates. Above the ineroiiry cham ber there is another chamber without silver, to take up auy particles of pyrites that may escape the belt ; and after the mercury-chamber a small' save-all is constructed, to- catch auy* particles.of silver that may escape..