NST’s $5B Deal: Most Expensive Undeveloped Gold Mine Ever

The POX autoclave oxidizes the sulphide ore which means the Au is let loose for CN to be able to leach it in the downstream CIL process. At the same time the discharge out of the autoclave will come out at extremely low pH as the sulphide in the concentrate converts to sulphuric acid (100's of g/L) which can't have NaCN added to it directly to leach the Au. The flotation tail from the flotation concentrator has carbonate minerals in it that can neutralise the sulphuric acid and bring the pH up to suitable ph 10.5 and above from pH 1-2 to allow for CIL processing. It also allows the gold that didn't float into the concentrate to be recovered when recombined with the treated concentrate in the CIL circuit. The use of flotation tails reduces the amount of lime and limestone that need to be trucked into site which make up a significant portion of the plant operating costs and hence why they tend to be used as a technology of last resort. The need to keep S consistent in the feed is so you can keep your neutralization requirements consistent and also is limited by the size oxygen plant that gets installed. If you feed too high a S concentrate grade into the Autoclave and the oxygen plant is undersized you can either reduce throughput to ensure all the S ore is oxidized to maintain high recoveries or you simply end up partially oxidize the s concentrate and lose recovery in the down stream leach as you haven't sledge hammered it enough.

Saltbush lol😂 merkanooka maybe but not old salt bush dad and dave show

Great episode. Very informative lads 👌

Overs?