Jun 23, 2013· Simplified copper smelter contractPaymentsCopper Deduct from the agreed copper assay 1 unit, and payfor the remainder at the LME price for If over 30 gpt pay for the agreed silver content at90% of the LME silver If over 1 gpt pay for the agreed gold content at 95%of the LME gold charge £ 30 per dry tonne of .