GOLD EXTRACTION.

Westport Times, Volume III, Issue 542, 14 August 1869, Page 3

GOLD EXTRACTION.

Mr Tt. D'Heureuse, in a communication to the San Francisco Mining and Scientific Press, remarks that only one-half or thereabout of the gold is extracted by quicksilver from the ore ; the rest is either carried away as float gold hy the water required for the batteries, or remains in the tailings. This fact, known to every intelligent operator, should alone be sufficient to point out the imperative necessity of devising other extracting agents for that great majority of ore containing more than 20 dols. to 25 dols. per ton, but not rich enough to leave a profit by direct chlorination. The case, therefor, stands thus—"What is required is an extracting agent that does the work complete, cheaper than chloride, and requiring no water to reduce the ore, except such as is needed for the engine. Ziuc, of all substances in existence, has the greatest affinity for gold. Its action, in a melted state, on gold is to instantaneously dissolve the same in any proportion. Its snecific gravity, about 70 is sufficiently high to float all debris, not excepting sulphurate of iron, the constant companion of gold. It meets at a conparatively low temperature, and requires but little heat to retain its melted state. It is sufficiently volatile to permit of retorting, as in the use of quicksilver, but by a covering surface, fßd a teinprature below a dark red £eat, the loss by volatilisation and ouramg is hardly appreciable, while the metal is obtained at a low price, and in ?ny quantity required. Thus we have ? lfl zi . nc a material manageable, and railing the conditions required of a gold extracting agent in a high deFhTSr tban any other know n. MID. Heureuse's mode of applying » consists simply i n gradually nitro-

during the gold bearing pulverised substance below the surface into a bath of melted zinc, which immediately attack and dissolve nearly every partical of gold, while the debris rises to the surface to be taken oif. The mechanism is very simple and durable. Should sulphurets, in which particles of gold are so firmly embedded as not to offer any contact even on the smallest point, prevent the extraction to such a degree that it will pay to work it over by concentration, roasting, and chlorination, it may be done. But all the gold, in another manner lost as float gold, and much more, is certainly saved by the zinc. Dry crushers should be used in preference.