JAP summed it up neatly.
But FWIW - the mineral sands go to Port Adelaide after processing at Broken Hill - if people think they should be doing it differently the private sector companies that mine the sands, process the sands and the private sector rail operators that run the trains are only a phone call away for the armchair socialists on here to tell them how they should be running their business.
The proposal to extend the Mildura line to Broken Hill mainly came from hick town pollies and the local member for the Portland area who wanted the mineral sands traffic to go through Portland. We all know how pro-rail the Port of Portland are, and the additional mineral sands traffic has not eventuated.
Once upgraded the southern leg of the Inland Rail route between Melbourne and Parkes will provide and alternative route for intermodal traffic.