Volatilisation of Gold
The boiling point of pure gold has not been determined; calculated according to Wiebe’s formula it would be about 2,240°, or nearly 500° above the melting point of platinum. However, contrary to the belief of the older experimenters, it is sensibly volatile in air at far lower temperatures. Robert Boyle was unaware of this fact, […]
Gold and Copper Alloys
Gold and Copper Alloys dissolve in one another in all proportions, forming a complete series of homogeneous alloys, which are less malleable, harder, more elastic, and more fusible than gold, and possess a reddish tint. Those with less than 12 per cent, of copper are fairly malleable; when more than this is present they are […]
Gold and Silver Alloys
Gold and silver unite in all proportions, yielding alloys which are harder, more fusible, and more elastic than either metal. The hardest is that containing two parts of gold to one of silver. The colour of gold is sensibly lowered by the addition of very small quantities of silver, and on increasing the proportion of […]
Gold Alloys
Gold can alloy with almost all other metals, but most of the bodies thus formed are of little or no practical importance. Tin, zinc, arsenic and antimony unite with gold with contraction, and form pale yellow or grey coloured, hard, brittle and easily fusible alloys, of which all, except those containing zinc, are soluble with […]
Carbon Regeneration
In normal process streams activated carbon is exposed to a variety of chemicals. Organic compounds tend to adsorb readily on the hydrophobic activated carbon, which reduces site availability for gold cyanide. Other compounds such as calcium and magnesium carbonate commonly precipitate on the carbon surface and restrict gold adsorption access. Consequently, the performance of the […]
Procedure & Method for Activated Carbon Testing Program
OBJECTIVE: Evaluation of Westates Metasorb 321G (6×12) virgin activated carbon as compared to medium activity carbon from alternate vendors. PROJECT SCOPE: The following variables will be evaluated: Apparent density. Initial moisture content. Fine carbon losses following pre-soak. Particle size distribution of pre/post attrited carbon. Attritioning rates and losses with/without silica media. 24 hour adsorption rate and […]
Silver Gold Recovery Flotation Process
The ores from which silver and gold are recoverable by flotation divide themselves naturally into two general processing classes: ores in which the valuable minerals are those of the base metals, the precious metals being incidental constituents, and ores in which the gold and silver are of primary importance, the base-metal minerals, if present, being […]
Mechanical Roasting in Silver-Lead Smelting
What Colonel Dwight says regarding the treatment of oxidized ores holds true also of the silver-lead smelting operations in Utah. The ore sought for was such as would, with appropriate fluxes, yield slag, and “lead bullion,” as the lead reduced from the ore and carrying its gold and silver, was called. No matte, and probably […]
Gold Assaying Methods
To determine the amount of gold metal in ore, there are two kinds of gold assay adopted: The dry assaying method (i.e. by fusing the powdered ore with or without fluxes). The wet assaying method (i.e. by the agency of liquids). In the principal wet assay, the ore is thoroughly dissolved in acids, and, by […]
Agitated Cyanide Gold Leaching Test
In the old days laboratory tests were usually made by mechanically shaking up in a bottle for a given time a charge of ore and cyanide solution. The most generally convenient device for this purpose is a wheel, to which are attached boxes, each capable of containing a standard acid bottle, and with means for […]