Intensive Cyanidation
The upgrading of gravity concentrate for smelting purposes by use of intensive cyanidation is still in the experimental stage. It involves the leaching out of the gold into solution, using a strong cyanide mix, and then the electrowinning of that solution so as to recover the gold on the steel wool cathodes. This system is […]
Gold Cyanidation Circuits
The principle of dissolving gold and silver values in solutions of potassium or sodium cyanide is old and has been thoroughly carried out in practice for many years. There have been only a few changes in the chemical procedure and also few changes in the type of equipment used. The gold and silver are dissolved […]
Designs for Small Portable and Mobile Gold Leaching Plant
Agitation capacity based on 36 to 48 hours of agitation time. Thickener area based on 6 to 7 square feet per ton of dry solids per 24 hours. Pregnant cyanide solution (Primary Thickener Overflow) is treated in a Precipitation System which includes: Clarifier, Vacuum Tank, Vacuum Pump, Clarifier Pump, Zinc Dust Feeder, Zinc […]
Agitated Leaching Circuit Operation
Ground slurry from the trash screen enters this EXAMPLE Agitated Leach circuit at a rate of 35.5 cubic meters per hour, and 45% solids. The slurry passes through each of the four tanks, and should remain in each tank for a period of approximately 12 hours. Each tank is 8 meters in diameter by 8.5 […]
Eliminating Copper from Gold Ore
When reviewing Methods of Eliminating Copper from Gold Ores we see that several methods have been suggested to eliminate copper from ores prior to cyanidation. Preliminary extraction of the copper with sulphuric or sulphurous acids may be applicable to ores containing oxidized copper minerals such as malachite, azurite and chrysocolla but these acids have but little […]
Iron in Cyanidation -Ferrocyanide Compounds
Practically all ores treated by the cyanidation process contain iron minerals. In addition, the equipment in cyanidation plants with which cyanide solutions come in contact is made largely of iron and steel. Fortunately, cyanide solutions have very little action on metallic iron and most iron minerals, otherwise the cyanidation process would be impractical for die […]
Effect of Temperature on Gold Cyanidation
When heat is applied to a cyanide solution containing metallic gold, two opposing factors affect the rate of dissolution. The increase in temperature would be expected to increase the activity of the solution and thus increase the rate of dissolution of gold. At the same time the amount of oxygen in the solution would decrease […]
Effect of pH Alkalinity on Gold Leaching
The role pH has in affecting gold leaching rates by cyanide and the functions of calcium hydroxide in cyanidation are as follow: 1. For safety and to prevent loss of cyanide by hydrolysis. 2. To prevent loss of cyanide by the action of carbon dioxide in the air. 3. To decompose bicarbonates in mill water […]
Process of Cyanide Gold Extraction
Here I present an Process EXAMPLE of Gold Extraction Cyanide in which the cyanidation feed consists of a pyrite concentrate floated after the selective flotation of a copper-gold concentrate. The pyrite concentrate is reground to 90% minus 325 mesh and aerated in a high-lime solution prior to cyanidation. It contains 99% sulphides of which 10 to […]