grade is important but if the ore is metallurgically poor,...

grade is important but if the ore is metallurgically poor, forget about it. Windimurra ore is both low grade, heavily oxidised and difficult to get good yields to a clean concentrate.

reagents consumables and energy are  also important. Originally, windimurra used waste sodium oxalate from Local alumina industry as its source of solubilising agent for the roasting. Because of high silica in the kiln feed, the reagent conaumption is horrendous and so the use of conventional sodium carbonate is very costly. They also had a cheap supply of ammonium sulphate which was a waste product from the nickel laterites then operating in the eastern goldfields. The Amsul used in the hydro plant to make the ammonium metavanadate. All spare amsul is now diverted to fertilisers so they have to pay full price now.

the government also built its mates a gas pipeline sealed roads and powerhouse at the original windimurra operations which public funds continued to pay for long after its closure. Gas could be contracted for single digits per GJ back then.