Notably, the industry leading results replicated and improved upon Black Rock’s 90-tonne pilot plant test works performed in Canada.
Black Rock CEO John de Vries said: “We are very excited to have replicated and enhanced our industry leading processing performance from our second substantial pilot plant run.
“The 18 tonne pilot plant in China built on the earlier 90 tonne pilot plant run in Canada.
“Importantly we were able to deliver a higher specification material of +98% TGC while maintaining our target of +60% greater than #100 mesh.”
He added: “We also increased our recovery rate to 95.5%. All of this was delivered in front of our customers, partners and potential investors.
“A key objective of the plant operation was to enable representatives from China, Korea and Japan the opportunity to validate the remarkable metallurgy that characterises our Mahenge graphite.
“We are pleased to say feedback was very positive and we look forward to progressing discussions resulting from the review.”
Pilot plant operations
Over the course of the pilot plant operations a number of processing scenarios were tested. Scenarios were directed at determining the trade-off between size and final concentrate.
The trade-off analysis was directed at determining the maximum concentrate price achievable as a function of diminishing basket size relative to increasing concentrate grade.
Final steady state operations were based on explicit customer feedback to target >98% TGC.
Final pilot plant operations were targeted to produce Mahenge Premium branded concentrate and to determine the capacity to sustain >98% TGC on a steady state basis.
Particle size distribution at steady state is set out in the following table:
Summary of 18 tonne pilot plant test works at steady state operation – April 2019
The second objective was to enable the company’s Chinese EPC partners, Yantai, an ability to value engineer the Definitive Feasibility Study (DFS) process route with the objective of reducing capex and increasing operational efficiencies to enhance the current Mahenge DFS financial metrics.
Yantai has advised it is pleased with the results and is confident of reducing capex and increasing operational efficiency.
The pilot plant results will be included in the FEED (Front End Engineering Design) process currently underway and due for delivery in the coming months.