" Australian Bauxite, in its September quarter report filed at the ASX on Wednesday, said that average prices for Indonesian bauxite rose by 20% in August to US$48.68 a tonne. This is the highest average monthly price since 2008 when Indonesian bauxite prices peaked at US$68.50 a tonne and the Australian bauxite price peaked at almost US$75 a tonne ”
" General manager, Bob Adam, estimates that Koumbia ore will be produced at a cash cost of about US$11 a tonne, and sell for between US$35/t and US$40/t – which could turn out to be conservative estimates "
Now consider the LOW production price for the Grande-Vallée clay, you just have to shovel it and maybe a little preparation, before going into the SGA plant beside the extraction site ! Figure in some storage in winter period, and also the major fact that clay only has about half the alumina content of good bauxite, and this is still incredibly cheap.