Hi,

Sepro Leach is a chemical additive used to increase the rate of gold leaching within cyanide systems. Sepro Leach is typically used for intensive cyanide leaching of gravity concentrates but can also be used to improve leach kinetics in conventional cyanide leaching systems. Additionally, laboratory testing can be used for rapid determination of cyanide extractable gold.

I attach a Gekkos paper. I invited Acadia to post here - we are waiting.

Wadzanayi,

                 Interesting topic, I currently have a similar issue with Au con @ 500 - 4000g/t , Ag 200 - 5500g/t, batches 4500kg -5000kg /day in Acacia Leach Reactor.  Intensive Cn leaching time avarage 12hrs. Both recovery and leach time can vastly be improved with leaching accelerent whilst reducing costs of reagents. 

                  Will be contributing to this feed as we collectively gather more information. 

You might wonder what a hick from SK knows about leaching. David knows far more about this topic than I do. But my 2 cents ... if you look at the 3 curves on David's graph, we achieve "aggressive" concentration between 80 and 90% in the 5 hour period with all of the curves. We then need 4 - 5 times longer to reach the maximum. At the 5 hour period, economics comes into play. Are you paying more for the accelerant past the 5 hour period than the increase in recovery returns to you? Has anyone plotted the Hydrogen Peroxide on the same parameters to compare? Keeping in mind that the Hyd. Per. is both an oxidizer and reducer, PH may have to be adjusted.

Hi Wadzanayi,

Ndiepe, the Gekko offering is exceptionally good for us. We have been using it to replace the peroxide addition, which has given us excellent results and cuts the costs hugely. 

Hi Bobin,

We are currently doing an evaluation of our current practice of using peroxide and are considering switching to SeproLeach as well.  We did four bottle rolls comparing oxygen, air, peroxide and SeproLeach on a sample of our gravity concentrate under typical intensive leach conditions. 

I have attached the results. Clearly oxygen sparging is the best option but we have found that SeproLeach is similar but outperforms peroxide addition.

We have also had some issues with peroxide in terms of safety, cyanide and caustic consumption as well as increased arsenic content in our bullion.  Our first bullion pour using SeproLeach instead of peroxide has lead to a signficant decrease in arsenic in the bullion.  Does anyone know why?