The batteries powering a decarbonised world will need millions of tonnes of minerals to make them, and yet many suitable resources are scarce. Manganese has emerged as a suitable and plentiful battery metal resource, but where are the best fit-for-purpose deposits? CSIRO researchers are working to discover the answers. JANE NICHOLLS writes
Across the history of resources exploration, manganese has "received very little attention in the research and development space", says Dr Sam Spinks, Senior Research Geoscientist and Team Leader, Minerals and Water at CSIRO Mineral Resources.
"Partly because it's been a relatively inexpensive commodity, it's not been seen as a high-value ore by explorers."
Now manganese is about to come into its own as a critically important mineral for battery production.
The northwest of Western Australia is already known to be particularly well-endowed with this hot commodity. Now sophisticated exploration and analysis efforts are underway to identify where manganese deposits of the right composition lie.
A key element for energy transition
Batteries are an essential part of global energy-transition efforts, and demand for battery minerals is growing exponentially.
"If we're going to have batteries in every truck, car, home, office, factory, street – everywhere," says Dr Spinks, "manufacturing them will require an enormous amount of metal, and I can’t envisage the existing 'popular' battery metals – nickel and cobalt – meeting that demand growth."
To date battery metals such as nickel, cobalt and lithium have been the primary focus for explorers and researchers.
"The cost of these minerals has been one of the barriers to battery uptake," explains Dr Spinks. “Numerous improvements in manufacturing technology have reduced the cost of lithium-ion [Li-ion] batteries, but the unchangeable part of the equation is that metals cost what they cost [on the commodities market] and nickel and cobalt cost tens of 1000s of dollars a tonne. We have even seen cobalt rise above $120,000 a tonne in the past few years! What drives these prices for cobalt is that it’s very rare, and also that it often occurs in association with harmful elements such as arsenic."
Could this signal the end of cobalt?
This geological scarcity of cobalt, coupled with the fact that much of the global reserves of the mineral lie in the Democratic Republic of Congo, where there are serious environmental and humanitarian concerns, is leading many companies to "design cobalt out of their batteries", says Dr Spinks.
At Tesla Battery Day in September 2020, chief executive Elon Musk revealed that the company is moving to high-purity-manganese as a primary raw material for its batteries, and that batteries made in its new manufacturing plants will contain one-third manganese, two-thirds nickel and zero cobalt.
A bulk-commodity mineral for future batteries
The West Australian government's Future Battery Industry Strategy aims to have the state positioned as a world-leading producer and exporter of future battery minerals, precursor chemicals and technologies by 2025.
"This is a gigantic challenge, also supported by the Future Battery Industries CRC, in which CSIRO is an associate participant," says Dr Spinks. "The ambition is to develop a massive new battery industry for Australia that captures the full value chain from mineral exploration, mining, to manufacture on a massive scale for the global market, and to do that we need to produce a bulk commodity. Manganese can fill this role."
The good news is that "Australia is uniquely placed to access those manganese resources cheaply and easily," says Dr Spinks.
The challenge is to identify manganese ore deposits of high quality and in the right mix. Unlike iron ore, explains Dr Spinks, there is a complex range of manganese minerals, and all need to be processed differently, particularly for battery manufacture.
Because of the historic low interest in manganese when its value was only $8-$10 a tonne, Dr Spinks says that while "We know we have gigantic manganese resources in Australia, we currently don't understand what that total resource in terms of overall tonnage is like across the continent, just that there is lots."
The growing value of the resource, especially high-purity manganese sulphate and manganese oxide – critical precursor components for Li-ion batteries – is an incentive to change that.
Collaborating to speed discovery and understanding
CSIRO Mineral Resources is partnering with miners who are eager to realise this business opportunity, as well as appreciating the mineral’s importance in the decarbonisation race.
"It will require minor manganese explorers to join forces with us as well as some of the larger players, too, to really understand what and where the manganese resources are in Australia."
CSIRO are planning a large collaborative project involving industry that will seek to understand the range and distribution of manganese ore minerals across WA, and gain a better understanding of the ore forming processes in order to target higher 'battery quality' manganese deposits.
Investigating the rich belt of manganese in WA
Dr Spinks and the CSIRO Mineral Resources (Discovery) team also worked on the Capricorn Distal Footprints Research Project, which successfully identified a 'WA Manganese Belt'. The next step is gaining a better understanding of the makeup of the deposits.
"CSIRO has also been working on how to process manganese ore into a battery metal precursor chemical, using the least number of steps, with the lowest CO2 footprint," says Dr Spinks.
"To do that, we need a fundamental understanding of what the different manganese minerals are and, in doing so, we learn about how these ore deposits are formed, the broader exploration implications and we ultimately model where we can predict high-quality manganese ore deposits. We need the best mix of minerals for processing techniques, with as few contaminants or deleterious trace elements as possible, and requiring the least energy to process into a battery precursor."
This push to assemble new information and interrogate old data sets is crucial research to uncover the all-important first step of the value chain for Australia’s domestic supply of future battery minerals, as well as export resources.
Critical scientific discoveries advance future exploration
A few years ago, Dr Spinks was a lead scientist in a CSIRO collaboration with Stanford University to study the formation of manganese deposits throughout geological history, and why there is so much manganese in the Capricorn Oregon zone of WA.
They proved their hypothesis that, contrary to prior beliefs that the earth was anoxic during the period, there was "strong enrichment of oxygen in the atmosphere and oceans" 1.1 billion years ago, allowing for manganese to be deposited.
The discoveries from that work are now helping them, he says, "unravel what has happened since then – such as how these deposits become enriched to the point that they're ore grade".
Understanding those processes is critical to understanding the makeup of manganese minerals in the ground.
"We've unravelled the first part of the puzzle, understanding the big change in oxygen. The next part is more complex: working out where, and what the manganese minerals are in the orebodies today."