Yes! We're ordering muffle furnace, and checking the price of AAS unit. We have muffle furnace and AAS unit in our another factory (Jewerly manufacturor) but not in this small lab.Deano said:The mining industry standard cyanide level is 0.1% sodium cyanide in solution, this is around 500ppm actual CN-.
You can play with lesser cyanide concentrations in order to minimise base metal dissolution and relatively enhance the gold dissolution.
High copper ores can be run with cyanide levels at 0.01% or even lower.
As the cyanide level is lowered the protective alkalinity will also lower so you will have to add lime or caustic for pH regulation.
Induction furnaces are not useful for carbon ashing, you need to have an air flow through the carbon with the temperature around 650C. Ashing needs to be complete. Get yourself an electric muffle furnace and some porcelain dishes for the ashing.
Usually you monitor the metals in solution values to see how the leach is going, get yourself a good second hand AAS unit to do this with.
Selling loaded carbon is usually an opportunity for dodgy assay methods to be used, much smarter to do your own stripping and then reuse the carbon, that way you maintain control over the gold.
Carbon in leach levels are usually around 5 grams per litre, much higher and attrition of the carbon becomes a major issue. Gentle agitation is needed.
Deano
Regarding the cyanide cocentration, I guess I had been doing too wrong. I will run some more experiments on the Cu-1% ore with much lower concentrations.
Here's a tricky question I wonder: Regardless of the matrix metals, does the increase of cyanide concentration induce the cyanidation speed? I know I may seem greedy and matrix metals can mostly like NOT TO BE IGNORED, but I just wonder.