Mindoro Resources’ joint venture partner TVI Pacific and its Philippine operating affiliate, TVI Resource Development (Phils) (TVIRD), have announced first nickel production from the pilot plant at Intertek Minerals Philippines in Manila, for the Agata North project, Agusan del Norte Province, northern Mindanao.
TVI Pacific’s chairman, president and CEO Cliff M James says this is another significant milestone that has allowed TVI to successfully validate both production and cost efficiencies of its process, adding that the technical program is on track to provide metallurgical data required to design the proposed full-scale pilot plant.
- A Nickel Hydroxide Product (NHP) filter cake was produced from TVIRD’s pilot plant on February 7, 2014 with a 52% to 54% nickel grade.
- NHP impurities such as iron, calcium and magnesium are low, thereby resulting in a versatile refined intermediate nickel product that may be directly processed to nickel oxide or nickel metal with no further refining required.
- Prior to NHP production, 8000L of iron and nickel rich Pregnant Leach Solution (PLS) was purified via TVIRD’s continuous counter-current ion exchange (IX) pilot plant, successfully validating the viability of this IX purification process as well as establishing all design parameters for full-scale plant design.
- IX nickel recovery from PLS to eluate was 99.3%.
As reported in October 2013, positive results were received from the pilot plant at the Beijing General Research Institute of Mining & Metallurgy (BGRIMM), marking at that time another key step forward for the Agata North project, located in the mining district of Agusan. These tests were designed to confirm and optimize the crushing, scrubbing, screening, milling, leaching and solution recovery circuit configuration. In particular, the test work focused on validating the leaching process developed by TVIRD.
TVI announced also at that time that it had installed and commissioned a continuously operating pilot plant at its metallurgical laboratory in the Philippines, comprising nickel solution purification, nickel precipitation to produce NHP containing slurry and NHP washing and filtration to produce final NHP filter cake product (50-53% nickel).
8000L of PLS was received at the TVIRD pilot plant from the BGRIMM pilot plant comprising crushing, scrubbing, screening, milling, leaching and solution recovery unit operations.
In addition to the TVIRD pilot plant unit operations, BGRIMM also produced a Mixed Hydroxide Product (MHP) containing an average of 36% nickel and testing has shown it is possible to produce an MHP containing >40% nickel if a 2-stage precipitation circuit is used.
The successful testing now at the TVIRD pilot plant and the production of NHP will allow a comparison of processes and products to enable the selection of a final process route as part of the Bankable Feasibility Study that is currently under way.
“The pilot tests confirm the viability of a two-stage atmospheric leach process in producing NHP containing about 50% nickel or a MHP containing some iron,” says TVIRD vice-president of operations Jake Foronda. The executive also explained that TVIRD chose the hybrid atmospheric/low pressure autoclave leaching process because it is more suitable to saprolites typical of the Agata laterites and significantly lower in required capital investment as compared to High Pressure Leaching (HPAL), which is more suitable for ore with high iron content.