EXTRACTION OF FINE GOLD FROM TAILINGS.

Westport Times, Volume III, Issue 560, 28 September 1869, Page 3

EXTRACTION OF FINE GOLD FROM TAILINGS.

An invention which promises to cause a revolution in the work of washing tailings i 8 thus described by the Pleasant Creek News :—The discoverer, Mr Robert Tweedie, of Pleasant Creek, has his rough machine at work, by which he is at present busily employed in treating mullock; that is to say, stuff which by the common test of the tin dish will not reveal the color. The whole of the machinery requisite is a large iron basin, the plates composing which resemble the segments of an orange ; they are fastened with the one overlapping the other so that we presume the junction of the plates form ripples, which doubtless assist in the amalgamation. This bason is fixed for revolving at an angle of about twenty-five degrees, and here b'es one of the principles which the process embodies. When we say that the rate of the revolution is also slow, and that the tailings are treated with quicksilver, and barely sufficient water to form a pulp, we relate the whole of the process by which an average of five pennyweights to the ton is extracted from the Pleasant Creek quartz tailings—by which mullock or refuse which has been treated by Europeans and Chinese is again taxed by Tweedie, and yields him a return of three to four pennyweights to the ton. The plan will be" readily conceived when we explain that the slow rotatory motion of' the pan disturbs the tailings pulp just sufficiently to carry it to almost the top of the pan in its revolutions, from whence it falls to the bottor, rolling and rolling over by the slow and continuous motion, so that every particle of the tailings is exposed, and turned, and moved and exposed again as regularly and constantly that it becomes simply a matter of impossibility that any particle of the pulp can escape permeation by the quicksilver, or that any particle of' gold, no matter how fine, can escape being gripped with it. The proof of the efficacy of the process of this nature is simply to be found in the result. The basin now Jused by Tweedie is small as compared with those he Las ordered at Ballarat, but he is able to treat now almost two tons in the twenty-four hours; with a large basin he will be able to treat four tons per basin. Tweedie assists the amalgamating process much by the use of alum and carbonate of soda. This has the effect of causing the flowing globules of mercury to unite, or those particles which in amalgamating parlance are called " sick." It will scarcely be credited how fine is the yield which is thus saved. The operator will take a shovelful of the pulp, and after washing it off in the usual manner, the enquirer is able by very close scrutiny to discern a yellow tinge upon the edge of washed sand. This is the quality of the gold saved from the tailings by the process we have described. In the new basin there will be three taps, one below the other; the first to let off the refuse ,the second pyrites, and the last for the sediment in which the amalgam is contained. Tweedie states that one man can with ease attend to twenty basins, and he reckons at a moderate calculation from one bason four tons per twenty-four hours. Tweedie has taken out a patent for his process. The cost of a basin with requisite gearing for horse power is £25, the royalty on each of which is £l4, and £2 per month. The results obtained by Tweedie are little short of startling to those who know the vast accumulation of tailings in the colony.