why is underground mining of coal so dangerous why is zinc added to gold cyanide,Mining and mineral processing - Everything Maths and ScienceMining is largely divided into surface and underground mining. . mining as tunnels can collapse and dangerous gases build up underground. . Coal miners used to take a canary with them down the mines. .. In the process of gold cyanidation, the ore is crushed and then cyanide ( CN − ) solution is added so that the gold.why is underground mining of coal so dangerous why is zinc added to gold cyanide,Gold mining - WikipediaGold mining is the resource extraction of gold by mining. As of 2014, the world's largest gold .. Other gold mines use underground mining, where the ore is extracted . Cyanide extraction of gold may be used in areas where fine gold-bearing rocks . Zinc is added to precipitate out residual zinc as well as the silver and gold.
why is underground mining of coal so dangerous why is zinc added to gold cyanide