Arizona weekly citizen., 1895-11-23
IMPROVED GOLD MINING.

owing interesting article:
 Recent reports of increasing produc- tion of gold in this country and else where have attracted attention to new methods of mining and treating the ore. which have greatly red uced the cost of obtaining the metal, and made possible the working of mines containing very small percentage of gold. In the Colo this direction have not yet been reached. It is predicted that when the time comes for the enormous deposits of low grade ore proved to exist at Cripple Creek to
 be treated anywhere near as oheaply as
 the cost of Johannesburg. Cripple Creek will produce more gold than Johannes
 burg, where ores are treated by stamp
 mills, the "taiIings" being passed through cyanide mills. Ten years have
 been speut in reaching the high state Of efficiency and economy there.
 Rossiter Raymond, mining engineer
 who has had experience in the Colorado mines, says:
 "The reduced cost of obtaining gold from ores or rock containing it is due:
 "First, to the numerous new deposits of gold opened within the last few years. Such deposits are, of course, more cheaply mined while operations are conducted near the surface. In this country the increased activity in gold mining is doubtles due lar gely to the Encouragement of silver mining by the fall in the price of silver. A large army of prospectors formerly seeking for silver mlnes ID preference to gold, are now looking for gold. But the most import ant new developments ID gold are those ID South Africa, where the deposits (though they have been overestimated in the speoulations of the London stock ma. keD are unquestionably of immense value and productive capacity.
 "Second. to the increased efficiency of mining methods and machinery (high explosives, power drills, improved hoists and pumps, cable tramways. etc.) which permits large quantities of low-Rrade material to be handled at profit.
 "Third. to the cheapening of labor and supplies by the extension of rall- roads, the increase of population, etc.
 Fourth, to the multiplication (espe- cially in this country) of smelling and other reduction works which can utilize other ingredients 10 gold-bearing rock Qead or copper directly, and iron or sili- ca, as fuxes), so as to be able to pay to the miner, in some cases, the full value of the gold.
 Fifth, the only innovation in metal lurgical methods for the extraction of gold, apart from variations Tn smeltlng processes. is the so- called 'cysnide' pro- csss, which promises to treat cheaply certain classes of ores and 'tailings.' Its principal competitor is the chlorination process, which Is very old, but has been much improved and is now the most per. feet of all methods for gold extraction from material suitable to it. This pro- cess usually requires preliminary and it is claimed that the 'cy- snide' process car be successfully operat- ed without that preliminary. Probably the ultimate verdict of practice will be that each process has its special field and that the choice between them will depend uton careful consideration of all the elements of the special csse-ns- ture of materials, cost of chemicals and skilled labor, expenses of plant, etc. At the most successful of the southern gold mines, the Halle mine in South Carroll ns, profit IS secured from material coz tsining as mined about S4 per ton. This is first crushed and amalgamated in a stamp mill. and then the sulphide ores, unaffected by the amalgsmation, are saved by mechanical concentration, to be roasted, chlorinated and leached.
 Rock yielding free gold to the extent | of B per ton can be mined and amalga- mated with profit under favorable con- iitions ss to size and accessibility of de- posit, cost of power, wages. etc., provid- sd the operation is on large scale."