Glencore had supplied Iralco with about five tons of alumina for every ton of aluminum that Glencore received in return, according to the intelligence report.
It described how Baar, Switzerland-based Glencore provided Iralco with thousands of tons of alumina last year in exchange for a lesser amount of aluminum metal.
And of course Iralco now has some alumina which it has bought, using its energy and the use of its plant to pay for it, which it can then process into aluminium for domestic use.
Given that on average it takes only about two tons of alumina to produce one ton of aluminum, the barter deal may have left Iralco with more aluminum after processing the alumina than it supplied to Glencore.