There are some things not quite adding up as you say,like sales-...

There are some things not quite adding up as you say,like sales- EBITDA being less than cash costs. Maybe some difference between metal produced and pricing of such (as I recall there is a time lag in the pricing?). Despite this, the stated figures are attractive:
If they borrowed US$80M recently and had US$3M at 30/6/19 and repaid $15M, then they have $68M debt remaining with US$33M cash on hand and earned 0.6*US$50M = US$30M EBITDA in the last quarter, then I would expect them to enter a nett cash position by 31/12/19. The option to increase to 80% ownership for each line costs US$60M per line. They will earn close to US$40M each quarter assuming the same metrics as per the last quarter, meaning that by 30/9/20, we could own 80% of each line and be in a nett cash position based purely on cashflow. After that, assuming the same metrics, we could be generating ~US$40M (AU$57M) per quarter EBITDA. That's about 3.4 cents per share per quarter. Methinks I need to buy a few more, bearing in mind the NPI produced is not amenable to the battery market which is driving the Ni price upwards. However, stainless steel still needs Ni, and this delivers into that market.