In the TECH Project, all valuable metals will be leached into solution and then recovered and refined into saleable products. The remnant residue is only ~25% of the dry ore feed and it is typically comprised of silicates including quartzsand. The ability to utilise this residue as an engineered fill would mean that 100% of the ore processed by the TECH Project reports to a commercial application, effectively positioning the TECH Project as zero solids waste. Such a feat would be an industry first in the resources sector, particularly in nickel laterite processing which typically requires large tailings dams that leave significant environmental footprint. Such tailings dams usually have to hold more than 1.2 tonnes of tailings per tonne of feed ore.
Commercial Uses for TECH Project Residue Discovered through JCU Testwork
Testwork conducted by James Cook University (JCU) revealed that the residue from the TECH Project, when mixed with a simple binder, demonstrated the requisite structural properties for engineered fill. Additionally, chemical leaching tests, including the Toxicity Characteristic Leaching Procedure (TCLP), Inductively coupled plasma mass spectrometry (ICP-MS), and X-Ray powder diffraction, demonstrated that QPM comfortably met the threshold for all elements of potential concern under the Townsville City Council (TCC) guidelines, with the exception of nickel. QPM and JCU are confident that additional washing will bring nickel levels to below the threshold.
This is an exciting development for QPM as it opens up the possibility of finding alternative uses for the residue from the TECH Project. The company is committed to protecting the environment and adhering to regulatory guidelines, and this testwork is a step in that direction.
TECH Project Residue on Track for End of Waste Code Approval
QPM held a pre-lodgement meeting with the Queensland Department of Environment and Science to discuss the JCU test work, potential commercial applications, and the next steps required to finalise an End of Waste (EOW) Code. An EOW Code allows a previously characterized waste stream to be re-classified as a resource, in this case, engineered fill.
Typically, obtaining an EOW Code requires a large scale field trial, but due to the positive results from test work conducted by JCU, DES indicated that this may not be required. This would eliminate a hurdle and fast track QPM’s ability to obtain the EOW Code approval and immediately utilize the residue in commercial applications.
Initial Commercial Application of Residue
Encouraging discussions have occurred between QPM and the Office of Coordinator-General, one of the owners of the Townsville State Development Area (“TSDA”), for using this engineered fill at the TSDA. One of the major benefits of the TSDA is that the location is directly on the backloaded route from the TECH site to the Port of Townsville. QPM will continue to advance these discussions and is working closely with the Office of Coordinator-General as a Queensland Prescribed Project.