Gold is extremely ductile. A single ounce of gold (about 28 grams) can be stretched into a gold thread 5 miles (8 kilometers) long. Gold threads can even be used as embroidery thread. Malleability is a measure of how easily a material can be hammered into thin sheets. Gold is the most malleable element.
Cyanide. Several processes can then be used to separate the gold from the ore. The most common techniques in the United States use cyanide in various ways. In one, the ground ore is put into a tank containing a weak cyanide solution and zinc is added. The zinc causes a chemical reaction which separates the gold from the ore.
It is particularly appropriate for low grade gold and silver ore processing (e.g. less than 5 ppm gold) but its use is not restricted to such ores. There are many environmental hazards associated with this extraction method, largely due to the high acute toxicity of the cyanide compounds involved.
Gold The primary mineral of gold is the native metal and electrum (a goldsilver alloy). Some tellurides are also important ore minerals such as calaverite, sylvanite, and petzite. Some tellurides are also important ore minerals such as calaverite, sylvanite, and petzite.
Uses of Gold in Industry, Medicine, Computers, Electronics
Uses of Gold in Electronics. The most important industrial use of gold is in the manufacture of electronics. Solid state electronic devices use very low voltages and currents which are easily interrupted by corrosion or tarnish at the contact points. Gold is the highly efficient conductor that can carry these tiny currents and remain free of corrosion.
Small traces of gold have been found in the leaves of Eucalyptus trees. More gold is recoverable from a ton of personal computers than from 17 tons of gold ore. Olympic Gold Medals only contain 1.34% of gold. 3 Olympic swimming pools can hold all the gold ever mined in the world. Six tenbillionths of the Sun is gold.
A "refractory" gold ore is an ore that has ultra fine gold particles disseminated throughout its gold occluded minerals. These ores are naturally resistant to recovery by standard cyanidation and carbon adsorption processes. These refractory ores require pretreatment in order for cyanidation to be effective in recovery of the gold. A refractory ore generally contains sulfide minerals, organic carbon, or both.