How Arsenic, Antimony Silver Compounds Affects Leaching

Collecting Desulphurizing

Ores containing silver in Arsenic and Antimony combinations offer considerable difficulties in cyanidation and it has usually been considered that the removal of these compounds by concentration was the only way to deal with them. G. H. Clevenger, however, when working on the ores of the Nipissing Mining Company of Ontario, Canada, found that by […]

Sulphide concentrate leaching

Weights

The question as to whether concentration shall be included in the treatment of a given ore will often depend on the possibility or otherwise of recovering the precious metals from the concentrate at the mine. It may be suggested that if the concentrate can be cyanided after being separated from the gangue, why can it not […]

Effect of Manganese on Silver Leaching

manganese

In Mexico and elsewhere there are large bodies of valuable silver ore containing manganese which present great, and hitherto insuperable, obstacles to a satisfactory extraction by cyanide. The proportion of the silver that is soluble in cyanide varies greatly and may be as low as 5% only. The mere presence of manganese in the ore […]

How Arsenic Affects Cyanidation Leaching of Gold

The Influence of Arsenic in the Cyanidation of Gold Ores is explained by W. B. Blyth has he is of the opinion that the presence of arsenic in an ore does not necessarily cause that ore to be refractory to cyanide treatment. He thinks the idea arose from the fact that arsenic is so often accompanied by […]

Metallurgy for Recovering Gold from Telluride Ore

Weights

Gold ore associated with Telluride is hardly soluble in ordinary cyanide solutions and special treatment is necessary for its extraction. There are two methods in use in such cases. Roasting The ore is ground dry to about 30 mesh and roasted; it is then ground to a slime in water or cyanide solution, usually in grinding […]

Discrepancy Between Actual and Expected Recovery: Gold Metallurgy Accounting

Weights and Volumes

Everyone connected with cyanide plants has at some time or another been confronted with a real or apparent shortage of bullion in the clean-up, that is, the bullion recovered has been less than the amount expected when calculated from the assays of head and tail and the tonnage treated. Such a shortage will often occur […]

Continuous Gold Leaching and Tanks Short-Circuiting

The Dorr Thickener

The system of continuous treatment consists in allowing the stream of pulp to flow continuously through a connecting series of agitator tanks, as distinguished from the intermittent system where a charge is placed in a tank and agitated therein until the dissolution of the precious metals is complete. It may be applied to almost any […]

Calculating Gold Losses in Continuous Countercurrent Decantation

Flow Sheet Type B

This is an interesting development of the old decantation process, and while it contains the same principle, of displacement by successive dilutions, the action is much more rapid, the same result is attained by the use of considerably less barren solution and it is continuous in action needing little power and practically no attention. For […]

Pulp and Slurry Thickening Test and Calculations

The Dorr Thickener

The slime pulp or slurry on leaving the sand classifier with its proper admixture of lime is first led to some form of thickening device if, as is usually the case, the ratio of liquid to solid is too large for economic handling in the cyanide treatment. The form of thickener almost universally used in […]

Leaching Fine Gold

Many definitions of the word “slime” have been attempted to Leaching Fine Gold but the one that best expresses its meaning from a practical point of view is that given by Park that it is that part of the pulverized ore that is not percolable on a commercial scale without the use of pressure. The […]