A NEW PROCESS FOR EXTRACTING GOLD.

Lyttelton Times, Volume XXIV, Issue 1574, 29 December 1865, Page 2

A NEW PROCESS FOR EXTRACTING GOLD.

TO TUB EDITOR Of THE LTTTKLTON TIMES.

Sib,—ln an article by Hunt on British Gold, in the October issue of the Quarterly Journal of Science, is mentioned a discovery in the amalgamating process. It was made by Mr. W. Crookes, F.H.S., and may probably be of utility in separating the fine gold from the sand on the West Coast beach washings, which have lately attracted so much attention. As the readiest means of making it known to our Canterbury miners who may not see the journal I refer to, I have extracted the gist, and send it to you:—

" Mr. Crookea's process possesses the following important advantages :—By the judicious admixture of a certain proportion of sodium with the mercury, its amalgamating powers are,under all circumstances, preserved and intensified. It will extract gold from sulphides, and from such other minerals as have hitherto resisted the ordinary process. It will seize upon gold tarnished by any of the metals named above,* and which would pass untouched through common mercury and be lost. It will absolutely prevent 1 sickening' and' flouring;' consequently the yield of gold is augmented, and a large saving in mercury ia the result. " A series of experiments were made to determine the action of the sodium under such circumstances as presented unusual difficulties, and the results of these trials were as follow :— (It should be stated that the mercury contained one per cent, of sodium. " 1. When a little of the sodium amalgam was added to ordinary mercury, the affinity of the latter for gold was greatly increased, so that when pieces of gold were dipped into it they were instantly covered with mercury, although, when dipped into mercury to which no Bodium had been added, amalgamation was very slow, and difficult to obtain. "2. 'Floured' mercury immediately ran together into a single globule on the addition of a little sodium amalgam, "3. When iron pyrites (bi-sulphate of iron), magnetic iron pyrites (sulphuret of iron), or copper pyrites) sulphuret of copper and iron), were triturated with sodium amalgam, the pyrites were decomposed, and on the addition of water, a black precipitate of sulphuret of iron was obtained. " 4. Triturated with sodium amalgam—o, arsenical pyrites was decomposed and arsenic amalgam formed; b, galena (sulphuret of lead) was decomposed, and lead amalgam formed; c, blende (sulphuret of zinc) was decomposed, and zinc amalgam formed; d, litharge (oxide of lead) and white lead (carbonate of lead) were decomposed, and lead amalgam formed. An extensive series of experiments has been made at the mines near Dolgelly, and in every case a considerable increase in the quantity of gold has been effected by the use of the sodium amalgam. The only thing which appears to be necessary to insure the usefulness of the sodium amalgam in all cases, is & preliminary experiment to determine the quantity of sodium which should be used with the mercury. When too much sodium is employed, it attracts the other metals present—in some cases to the rejection of the gold ; but when judiciously applied, it works with wonderful facility." Yours, &c., JOHN ROCHFORT. Lincoln Road, Dec. 27, 1865.