Chemistry

Explain Occurrence and Principles of Extraction of Gold

Occurrence

Gold is mainly found in the native state either mixed with quartz in ancient rocks (vein gold) or scattered in sand and gravel (placer gold) or in the alluvial sand (alluvial gold).

Ores

The important ore of gold is – Alluvial sand or gravel

Nearly half of the total world production of gold comes from the mines in South Africa. India occupies 8th position among the gold producing countries of the world and account for about 2% of the total world production. The Kolar mines in Karnataka produce about 99.97% of our gold output.

Gold in periodic Table:

Atomic mass: 196.97;             Valency: 1 and 3

Atomic number: 79;                Symbol: Au

Position in the periodic table: Period Number -6, Group Number -11.