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What is high-grade gold and silver ore?
I'm looking for oz/ton, or g/ton in terms of concentration. I'd like a Geologist, Analyst, or Investment Banker to answer this. Please, no high-school answers.
3 Answers
- Tashkent TLv 69 years agoFavorite Answer
Large scale open pit mines have economies of scale that small underground mines don't have so it's very difficult to generalise.
However for a large open pit mine that is only producing gold, 0.05 - 0.06 oz/ton would be high grade. Because silver recovery, using the Merrill-Crowe process, is less efficient than recovering gold, a silver mine that is only producing silver would consider 3.0 oz/ton - 4.5 oz/ton as high grade. In practice, most mines in which silver is being recovered, also recover gold so that a high grade ore might carry 0.025 oz/ton Au AND 1.5 oz/ton Ag.
A smaller tonnage underground mine would have greater running costs per ton of ore mined. Here, high grade gold ore would carry perhaps 0.18 oz/ton of gold. High grade silver ore would carry around 13 or 14 oz/ton of silver. Once again combined silver & gold within the ore reduced the amount of specific silver or specific gold that high grade ore would need to contain.
Source(s): Professional gold exploration geologist who has sometimes worked at producing gold & silver mines - 5 years ago
whenever I ask a question, even if it is the simplest one, they cant offer me a proper informed answer on this site. What happened to people who actually make the effort to write an answer..
