The treatment methods applicable to comparatively higher grade ore averaging better than 0.2 ounce gold per ton and having a cutoff grade of about 0.07 ounce gold per ton, include gravity concentration, amalgamation, flotation, cyanidation or direct smelting. Such processes involve high capital investments as well as high operating costs. A conventional cyanidation plant used … Read more
The plant has a capacity of 1200 tons (imperial) per day. The mode of the occurrence of the precious metals is complex, and the physical nature of the ore highly variable. The incidence of primary fines, at times up to 40%, is a major problem. Immediately after grinding in circuit (cyanide) solution, a telluride concentrate is … Read more
A laboratory method for the simulation of in-situ leaching of uranium was developed under contract to the Interior Department’s Bureau of Mines. Simulation tests using sulfuric acid, ammonium bicarbonate and sodium carbonate as reagents, and hydrogen peroxide as oxidant were carried out with representative ores from Texas and Wyoming. The tests not only yielded recovery … Read more
Terms such as in situ mining, in situ leaching, solution mining, borehole mining, and slurry mining have been used in different ways to describe a wide range of mining operations where a commodity is usually extracted remotely by activities that are conducted from the surface. As used in this publication, in situ mining is a … Read more
Dump leaching and in-situ solution mining have received considerable attention during the past few years due to their apparent economic viability and minimal environmental impact. Solution mining actually dates back to the 17th century when leaching of copper ore was first reported. However, modern day leaching didn’t begin on a wide scale until the mid-1900’s. … Read more
Union Carbide began looking seriously at heap leaching in 1971- At that time some 1.6 million tons of mineral averaging 0.040% U3O8 were stockpiled at various sites around the Gas Hills, Wyoming, uranium facility. Several alternatives for economically exploiting these reserves were considered and heap leaching seemed the most attractive. At the time, Western Nuclear … Read more
There are no major innovations in any of these plants. In fact, Australia is really only beginning to get started in CIP research and in process and design development. The plants described here have borrowed from technology, primarily in the United States and South Africa, and although the plants were carefully designed and based on … Read more
Pinson Mining Company was formed to develop a gold orebody located in northern Nevada near Winnemucca. A feasibility study was undertaken in 1979 by a consortium of three Toronto-based mining companies arid a Reno-based exploration company. The Pinson plant has been described in some detail by Mcquiston and Shoemaker in the AIME’s Gold and Silver … Read more
In situ leaching has been an attractive means of recovering uranium from small or low grade ore deposits. The process involves injecting a lixiviant, typically ammonium carbonate-bicarbonate and an oxidant into the uranium containing ore body. As the solution passes through the ore body, the uranium is oxidized from the insoluble plus four to the … Read more
The Anaconda Minerals Company operates a molybdenite and copper producing mine and mill facility near Tonopah, Nevada. Included with the milling facility is a ferric chloride leach plant for removal of copper mineralization from the molybdenite concentrates. Discussed are the engineering and construction schedules associated with the leach plant. The chemistry associated with the process … Read more