Why don't you consider a direct leach? Curtin University has developed a process to leach copper in alkaline medium with glycine as lixiviant. Glycine is a cheap, non-toxic, edible, non-volatile, non-flammable reagent that is highly soluble in water. It dissolves copper from oxides, carbonates, oxysulfates, chlorides, native copper and sulfides. It also dissolves gold and silver at the same pH but requires elevated temperature (60-70 deg C). Extraction with conventional SX-EW is easy. As it runs alkaline it does not react with acid-consuming gangue. Pyrite remains mostly unreacted and very little iron dissolve. Curtin University (Australia) has pending patents on the technology and the technology is being commercialized by Mining & Process Solutions Pry Ltd. Contact me for more information.

If you also want to test other processes, for example CESL Copper Process (autoclave leach-SX-EW, E-mail: info@cesl.com) and Outotec Hydrocopper Process (E-mail: info@outotec.com) are also available.

JohnnyD's leaching process is good. I think that will be an efficient and cheap process.

Hallochem Group also are cooperating with Johnny and his research team.

We can provide Mextral series copper solvent extraction reagents and technology support for the whole L-SX-EW process.

Hallochem is the largest manufacturer of extractants in China. 

Yes we used a number of SX reagents and the Mextral products from Halochem performed very well. Bob has been really helpful to provide the reagents in a short time. We'll publish more detailed results in forthcoming papers