Downstream process of the copper concentrate is a major factor...

Downstream process of the copper concentrate is a major factor impacting the economics of regional Mt Isa mines and concentrators if and when the Mt Isa smelter closes down. Having a world class smelter at your doorstep is a great advantage.

However, I would suspect the whole logistics system of importing concentrate into Mt Isa would set Townsville as its new export destination, ~900km away. Plenty of foreign lead-zinc-copper smelters are screaming for more feed material for their hungry smelters.

In comparison,

• At the CSA mine in Cobar, 40,000 tonnes of copper concentrate is railed 700 kms to the Port of Newcastle for export to smelters in Asia.
• At the Cadia Cu-Au mining operation they rail their copper-gold concentrate to Port Kemba, 400 kms away. The rail network can handle up to 115,000 tonnes per annum with a copper concentrate grade of 20.8% copper and 9% moisture content. Cadia copper-gold concentrate is loaded into containers using a mobile loader and forklift. The current rail contract with Qube allows for trains of 44 wagons (88 containers) based on about 5.5 rail services per week.
• Mt Keith Nickel Operation truck and rail nickel concentrate to Kalgoorlie smelter which is 450 km away. Previously, Mt Keith exported 200,000 tpa of nickel concentrate out of the Port of Esperance, approximately 840 kms away.

The high value copper-gold bearing concentrates will always find a way to market.

Reference:
https://www.newcrest.com/sites/default/files/2020-10/Technical%20Report%20on%20Cadia%20Operations%20as%20of%2030%20June%202020_0.pdf