Neometals Ltd (ASX:NMT) has converted lithium leach residue into a valuable advanced engineered material called zeolite which provides the opportunity to add revenue to its integrated lithium strategy.
The result comes from laboratory test‐work by CSIRO Mineral Resources, using a Neometals‐designed process aimed at developing a saleable product.
As well as adding co‐product revenue, this process also minimises waste generation and disposal costs.
Neometals managing director Chris Reed said, “We have been working on the zeolite synthesis project for some time and Neometals is delighted with the lab-scale outcomes from its unique process flowsheet.”
Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents, molecular sieves and catalysts.
They can be used to remove carbon dioxide in air purification, moisture and hydrogen sulphide from natural gas and in catalyst protection, amongst other things.
Images showing the crystal structure of synthetic industrial zeolite.
Having investigated the novelty of the process, Neometals has filed an application for International Patent Protection, that follows an existing Australian Provisional Patent application from 2017.
Strong market fundamentals
Reed said, “Synthesis of commercial grade zeolite is really exciting, but equally important are the market fundamentals that support our next steps.
“External market studies show a large addressable market where we have what appears to be a clear competitive advantage associated with zero cost feed material.
“Conversion of spodumene leach residues into a saleable zeolite co‐product also creates an opportunity to significantly reduce lithium production costs.”
Synthetic zeolites, like that produced by Neometals, are engineered materials manufactured to tight product specifications while others are naturally‐occurring, relatively low-value materials.
Existing synthetic zeolite production is based on combining various aluminium and silica-bearing minerals that are procured at market prices.
In 2017 the global market for synthetic zeolites was valued at US$13.7 billion.
Integrated lithium production strategy
Neometals has been developing processing technologies to potentially deliver favourable cost and environmental benefits in support of its integrated lithium production strategy.
The zeolite project has been designed to support exploitation of a significant annual quantity of material that would otherwise incur handling and disposal costs.
An engineering cost study for a manufacturing facility adjacent to a lithium hydroxide plant has been awarded to M+W Group, which is completing a FEED study for the Kalgoorlie Lithium Refinery Project.
Pilot-scale program will be considered
Neometals will use this study to assess the economic viability of a zeolite manufacturing process and will consider a pilot-scale test program using leach residues remaining from FEED study test work in 2017/18.
The process of converting spodumene concentrates to lithium hydroxide requires about 7 tonnes of concentrate feed to produce 1 tonne of lithium hydroxide.
In a nominal operation annually producing around 10,000 tonnes of lithium hydroxide, about 62,000 tonnes of 70,000 tonnes of starting feed material reports to waste.
Waste from the process is called leach residue.
Neometals has been motivated to reduce future waste from tailings, find a high-value application for its use and improve its competitive position on the lithium hydroxide cost curve.
The proposed Neometals lithium hydroxide refinery is expected to annually produce about 62,000 tonnes of residue at full capacity.
Neometals estimates that conversion of the residue at the refinery could produce in excess of 100,000 tonnes of zeolite product.
This has the potential to significantly improve the competitive position of lithium hydroxide production from spodumene.
Neometals owns a 13.8% stake in the Mt Marion lithium mine near Kalgoorlie, which operates one of the world’s biggest lithium concentrators.
It holds an offtake option, which forms the backbone to its fully‐integrated lithium business aspirations, which include a lithium hydroxide refinery and lithium‐ion battery recycling process.