Small-scale miners seeking to move away from mercury use have been urged to first invest in laboratory test work to determine the nature of their gold ore and avoid investing in the wrong technology.
Speaking at the ongoing planetGOLD Zimbabwe Annual Conference, Nyasha Tauro from Perfomance Laboratory said miners need to understand what is contained in their gold deposit before choosing a processing method.
Tauro said different gold deposits occur differently, with some gold occurring as free gold while some is locked in sulphides and some associated with copper.
“So we have to do an elemental test to figure out what is in this gold deposit. This will then help the miner to know what kind of technologies they have to invest in for them to have a maximum recovery of their gold,” Tauro said.
She said this information is also critical when miners apply for loans and financing.
Besides assaying to determine the amount of gold in a deposit, Tauro said metallurgical test work is also done, citing work done with Applimex Gold in their Stage 1 project where pilot machinery such as gravity tables and leaching tanks were used.
“We then determine what amount of gold can be recovered using the gravity concentration methods, and we can also go further to determine how we can treat the tails that are coming out of the gravity concentration methods,” she said.
Tauro said this is where cyanide leaching and other acid leaching methods come in, adding that such information can only be obtained from the laboratory.
“This is information that you would only get from the lab, which is why we recommend that as a small scale miner who is trying to do away with mercury and move to a more efficient method, you should first of all invest in a laboratory test work to avoid losses by investing in the wrong technology,” Tauro said.
Laboratory tests also help miners to determine operating costs, including reagent consumption, size of equipment to invest in, as well as power and water requirements for planning and budgeting purposes.
“In closing, I would really recommend that the small scale miners go through the lab, do the assaying to know the total gold that is in their gold deposits, and then further do laboratory test works to determine what kind of technology that best suits their gold ore,” she said.
