Excelsior Mining Corp (EXMGF)

[rubberworm]

Leaching

Leaching offers an alternative to copper mining. First, the ore is treated with dilute sulphuric acid. This trickles slowly down through the ore, over a period of months, dissolving copper to form a weak solution of copper sulphate. The copper is then recovered by electrolysis. This process is known as SX-EW (solvent extraction/electrowinning).

Advantages of these processes are:

Much less energy is used than in traditional mining
No waste gases are given off
Low capital investment
Ability to be operated economically on a small scale.
It can be used on ore with as little as 0.1% copper – for this reason leaching extraction is growing in importance. It is estimated that in 2011 SX-EW represented 17% of total copper refined production.

https://copperalliance.org.uk/about-copper/extraction/

Florence Copper (Taseko)
? Test facility operations
? April 12, 2019: first copper produced
after a three-month leaching period

https://www.excelsiormining.com/images/pdf/Presentation/2021/February_25_2021_PPT.pdf