What is Metallurgy and Processing and What Does It Mean to a Gold Project?
Metallurgy is the discipline that works on how to extract gold from the rock it is found in. Some may imagine that gold is dug up in nuggets that are melted down into gold bars. This is far from the reality. In most modern gold operations the gold is so fine that it is not even visible even with a magnifier lens. This means a lot of technology needs to be applied to seperate the gold from the rock that is occurs in. The part of a gold mine where this happens is the processing plant.
The type of processing plant a gold mine has will be determined through testwork in the pre-feasibility and feasibility stages of a mine's development. The aim of the testwork is to identify the process that can extract the most gold from the ore at the least cost. As each deposit contains ore with unique properties, this can be a complicated task.
Metallurgy of a deposit is crucial to the economics of a potential gold mine. There a many deposits with a gold grade that is comparable to profitable mines, however, poor metallurgical properties render the deposit uneconomic and no mine can be developed because of this.
It is important then that in any consideration of a gold company that gold grade and tonnages not be viewed in isolation. This is true for the range of factors that ultimately allow for a mine to be economic, however metallurgy is after gold grade and tonnage, the most significant of these factors. For example, two companies may each have identical resource figures of 2 MOz Au for 65 Mt at 0.96 g/t Au. One of these deposits may have ore that can be processed through an in-expensive heap leach process, while the other may ore that must be put through a more expensive CIL/CIP plant. The cost difference for a deposit of this size and grade means that where heap leaching works, the mine is viable, but where only CIL/CIP works, the mine is not economic and so will not be developed.
Image credit Processing and Metallurgy
www.scross.com.au