Repost of Kentors Update on Heap leaching MurchisonThe link below will provide a clear copy of that NR.
Heap leaching is very cheap when you have to mine low grade ore to access the higher grade ore for the Mill.
This will be the case at Murchison
Note the low heap leach cost of $500 to $550 AUD per ounce. Mixing in the already mined high grade tailings at Tumblegum is an iodeal auxillary feed source for both the mill commissioing and heap leaching. Note the short leaching period
https://www.asx.com.au/asxpdf/20120703/pdf/4276ckq7kj5lmk.pdf