Gold Metallurgy & Leaching in Cyanicides
Cyanidation as applied to ordinary gold and silver ores is a relatively simple process. When cyanicides {cyanide-consuming elements) are encountered in small amounts in the treatment of such ores, the various schemes already discussed, such as use of a lead salt or wasting barren solution, can usually be resorted to and successful operation maintained. When, […]
CCD Filtration System
Slime treatment, as commonly used by metallurgical engineers, includes thickening, agitation, and filtering and as applied, to cyanidation also includes washing by continuous countercurrent decantation (C.C.D.) and/or filters. “Slime” is the general term used to describe the finer portion of pulp in a combination sand and slime-treatment plant and is usually finer than 100 mesh. […]
Counter Current Decantation Design Formula
The principle of Counter Current Decantation is simply that, when water or solution is to act upon solids, both are made to pass, in contact, in opposite directions, so that at each end the strongest or most potent portion of either is acting upon the weakest or most exhausted portion of the other. The recovery […]
Gold Leaching Agitation Tanks
The mixing of solids suspended in a fluid medium is still largely an art. The development of fundamental laws governing the operation is complicated by the large number of variables involved, some of which can hardly be evaluated in mathematical terms. Practical studies of the circulation patterns of the more common types of agitators are […]
Leaching Agglomerated Slimes
More recent work along these lines is reported in T.P. 790, A.I.M.E.’ by 0. C. Shephard and C. F. Skinner presented at the New York meeting in 1937, under the title of “Stabilizing Agglomerated Slimes for Gold Cyanide Leaching.” The paper describes the development of a method of stabilizing agglomerated slimes by the formation of […]
Vat Leaching of Finely Crushed Gold Ore
Vat leaching is carried out in vats ranging in capacity from 30 to 1200 tons. Sand for leaching is separated from slime in cones, V boxes, classifiers, and in collecting vats filled by distributors—the overflow in each case being slime or finer portion of the ore. As a rule, leaching is a simple process, involving […]
Leaching of Clay Ore
To solve the problem of treating and leaching a clay ore in which the gold was finely disseminated, the author was able to suggest a unique method which he had seen described twenty-five years previously in a paper, “Occurrence and Treatment of Gold Ore at Bidi, Sarawak, Borneo,” by T. C. Scrutton, which appeared in […]
Heap Leach Amenability Test
In cases where fine grinding is not necessary to liberate the gold values, it is often possible to classify the coarsely ground ore into a sand and slime product (at, say, about 200 mesh) treat the former by so-called percolation leaching and the latter by the agitation method that has been described above. This is […]
Gold Leaching
The following gold leaching test procedure has been found satisfactory for carrying out cyanide leaching tests by agitation. Winchester bottles of about 2.5- to 4-liter capacity are used. It is convenient to number the bottles and determine their tares, etching the figures on the bottle by means of hydrofluoric acid and then marking over the etching […]
Analytical Methods for Total Cyanide Assay Determination
SCOPE AND APPLICATION The method is designed to determine the concentration of total cyanide in aqueous/water and soil/sediment samples taken from hazardous waste sites. SUMMARY OF METHOD Aqueous/Water and Soil/Sediment The cyanide as hydrocyanic acid (HCN) is released from cyanide complexes by means of a reflux-distillation, using either a midi- or micro-distillation process, and absorbed […]