Ann: Opportunity for significant near-term production increase, page-78

"once the stuff is on the ship you have almost no way of ensuring any payment at all from these smelters, you have zero trust and zero recourse in any dispute"

That's what escrow services are for. CAI sell the concentrate at an agreed price after the buyer has done their due diligence as to the composition and grade. The payment is transacted via an escrow agent, and loading doesn't even begin until the agent has the funds.