JOHANNESBURG (miningweekly.com) – Following a pilot test, which formed part of a definitive feasibility study (DFS), Canadian potash producer South Boulder Mines found that its Colluli project achieved ultrahigh potassium sulphate purity grades of 98%, with typical industry product being only 94%.
The company added that the tests, which were conducted in March, showed that the project had “exceptionally low” chlorine levels at less than 0.1%.
The pilot test process consistently delivered potassium oxide results greater than 52% and gave an overall average of 52.9%, putting the Colluli potassium at the top of the quality spectrum, the company stated.
The pilot tests provided potassium sulphate samples that could be introduced to potential commercial partners. Samples were still being generated, with the pilot plant trials moving from 20-hour trial runs to 40-hour trial runs.
Two more repeatability tests were planned to round off the DFS metallurgical programme. “However, given the results to date, it is unlikely that there will be any material differences in the results,” the company noted.
A prefeasibility study, completed in February, indicated that the Colluli sulphate of potash (SOP) project would be in the bottom quartile of production costs. According to South Boulder, Colluli also had the lowest capital intensity of all advanced SOP projects globally.
“The Colluli project simply gets better and better. We have a process and a unique resource that combines to produce a premium fertiliser with a premium grade. The repeatability of the results with a diverse range of feed material demonstrates the robustness of the process," South Boulder MD Paul Donaldson said.