Manganese Silver Ore Treatment Method
The present is to discuss some of the current silver-treatment plants and also reviews briefly some of the older practices in important silver-mining areas since closed down. The greater part of the world’s production of silver is derived from the refining of the base metals, particularly lead ores, and complex ores of lead, copper, antimony, and […]
Handling Waste Cyanide Solution
Tailings pulp carrying traces of cyanide and the discard of barren solutions in some cases constitutes a hazard to both humans and animals, and methods have been devised for destroying the contained cyanide. A recent paper “The Treatment of Cyanide Wastes”by Chlorination by J. G. Dobson published in the Sewage Works J., November, 1947, discusses […]
Gold Chlorination Processes & Methods
In Liddell’s Handbook of Nonferrous Metallurgy, Vol. 2, 1945, there is to be found a very complete account of the uses of chlorine as applied to the recovery of gold and silver, in Chlorination Processes & Methods. Introducing the chapter entitled “Chlorine Metallurgical Processes” Liddell says: Chlorine as a metallurgical agent appears to have lost ground […]
Bromocyanide Process
Bromo salts are a mixture of 57 per cent sodium bromide, NaBr, and 43 per cent sodium bromate, NaBrO3, in the form of light-gray, light- yellow, or reddish-brown crystals or powder. The use of bromo salts for treating a telluride concentrate in the Wright- Hargreaves plant at Kirkland Lake is described by J. T. Willey […]
Cyanide Regeneration Processes and Methods
Cyanide regeneration offers a practical means of overcoming the otherwise heavy cyanide consumption frequently encountered in the treatment of gold and, especially, silver ores, where cyanicides (cyanide consuming minerals) are present. Miscellaneous processes used for the extraction of gold and silver values by hydrometallurgical means are also discussed in this chapter. These include the carbon-cyanidation, […]
Carbon Cyanidation
Countercurrent carbon cyanidation with simultaneous dissolution of gold by cyanide and its adsorption by carbon offers several advantages over other carbon cyanidation processes as: the rate of dissolving the gold is faster, higher grade gold-bearing carbon is obtained, less carbon per ton of ore treated is required, separate dissolving and absorbing units are not needed, adsorption […]
Aerating or Oxygenating Cyanide Solutions
A process for aerating or oxygenating cyanide solutions was announced by T. K. Prentice in the Jour. C.M. and M.S.S.A., February, 1934 (see Fig. 56). It immediately attracted attention, and the article was reprinted in part by United States and Australian technical journals. The process received practical plant trials at the Nourse mine on the […]
Effect of Impurities on Cyanide Leach Solution
That cyanide solutions in works practice do not remain pure in a chemical sense is to be expected, having in view their contact during treatment with the many contaminants found in gold or silver ore amenable to cyanidation. Impurities cause a chemical cyanide loss and at times detrimentally affect the extraction of the valuable metals […]
Effect of Altitude & Pressure on Gold Leaching Kinetics
Altitude-pressure and Standard Saturation Curves: Chart A (Fig. 55) is used to determine barometric pressure at various altitudes; Chart B is used to determine standard saturation values for various temperatures and pressures. In Chart A, altitudes, in feet, are plotted on the horizontal axis and pressures, in millimeters, on the vertical axis. To find the pressure […]
Cyanide Gold Dissolution
Manufacturing Cyanide Sodium cyanide is a white, deliquescent, crystalline material easily soluble in water. The basic sources are alkalis or alkaline earths, atmospheric nitrogen, and carbon. In the United States it is derived (1) from sodamide which is produced from sodium and ammonia. The sodamide is heated with charcoal, and the resultant soda cyanamid is […]