I submitted a resume, heard back from a Phoenix Tailings admin roughly two months later. The first round was with an HR person. He seemed disinterested but I didn't take it personally, my impression was that he's very overworked. They sent over a case study, but it didn't really look like a true case study. My impression was that it was for an acquisition they were currently mulling over. They wanted an in-depth analysis, Excel spreadsheets, and PowerPoint presentation slides. The following round was with a Corp Dev professional who was a nice guy. I walked through the analysis and then is when I became suspicious that this wasn't a business case at all, but rather a live deal. In other words they wanted me to give them insight and early financial due diligence as an unpaid consultant. The Corp Dev professional thanked me, told me he was impressed with the work, and predictably that was the end of the interview process.
After two weeks I looked them up on Glassdoor. And it doesn't surprise me that they've played similar games with other job applicants who also feel that they have been rendering free consulting services.
My recommendation is to read the other reviews and note the similarity. This doesn't look like coincidence, it looks like their modus operandi. The same jobs have been unfilled for well over a year, yet they still interview candidates.