Under the deal with Inco/Vale, they were actually financing more...

Under the deal with Inco/Vale, they were actually financing more like 98% of the capex. The deal was whatever the debt/equity ratio, Inco was to fund 100% of the debt component. The equity component was then based on the buy in (which was Inco 60% HRR 40%). So for HRR's 40%, Inco guaranteed HRR component (by way of loan - 80% of which was to be paid back out of future profits), but HRR had to initially fund 4.5% of the equity component up front as their share.

IB's example at the time went like this:
Agreed buy in percentage was Inco 60% / HRR 40%

IF: CAPEX: $1.4B and debt/equity funding was agreed at 70/30:
THEN:

• Inco would fund 100% of debt component - $980M (70% of $1.4B)
• Equity split is 60/40: Inco to fund $252M and HRR $168M

Of the HRR equity ($168M) required:

• HRR required to fund 4.5% of the equity component upfront, so $19m (4.5% x $420m)
• Inco would then lend the remainder of HRR's equity share, $149m (to be repaid from share of profits).

So HRR, in reality, would have only raised $19m to retain 40% of the project, and would have incurred none of the project costs.

Of course you would need to account for the fact that HRR had to repay the $149m loan to Inco 9over the life of the project), so in reality HRR's share of the $1.4B capex, was $168M (being 12% overall of the capex).
@Jogoo