Mid-Stream Project
and Testwork Update

Testwork, technical inputs and engineering supporting the mid-stream project scoping study complete

Pilbara Minerals Mid-Stream Project and Testwork Update


  • Scoping Study for the Mid-Stream Product Demonstration Plant nearing completion, with technical and engineering work now complete.
  • Work to-date supports the Mid-Stream Project objectives for exporting a value-added lithium product from the Pilgangoora Project:
    • calcination test work at Calix’s pilot scale BATMn reactor confirms high conversion rates (>95% for Alpha to Beta phase transition), for fine flotation spodumene concentrate* produced from Pilgangoora;
    • targeting a materially lower carbon emission footprint through extensive electrification of the calcination process powered by renewable sources, as well as reduced freight quantities; and
    • potential to re-shape the existing spodumene supply chain and present global markets with a cleaner and more efficient supply chain solution.
  • Next steps:
    • Economic and commercial evaluations contributing to a completed Scoping Study early in the New Year.
    • Subject to successful completion of the Scoping Study, progress negotiations for the formation of a joint venture.
    • Agree a work program to develop a Demonstration Plant and ultimately commercialise the Mid-Stream Product’s process technology.

*Conversion rates vary as a function of concentrate properties (including particle size) and further testwork is underway.



Following execution of a Memorandum of Understanding (MOU) in May 2021 between Pilbara Minerals and Calix, a Scoping Study for a Mid-Stream Product Demonstration Plant (”Scoping Study”) commenced, which is nearing completion. The Scoping Study aims to support the development of a Demonstration Plant at the Pilgangoora Project (“Pilgangoora”) to produce lithium salts from fines-flotation spodumene concentrate, supporting a pathway towards potential future commercial production of value-added lithium products at Pilgangoora.

The Scoping Study (undertaken by Lycopodium Minerals in conjunction with the Pilbara Minerals and Calix teams) is assessing the potential development of a new refining process to produce high purity lithium phosphate precipitate from Calix-calcined fines spodumene concentrate supplied from the Pilgangoora Project. This concentrated lithium salt from the Pilgangoora Project (“Mid-Stream Product”), could support downstream lithium raw material and cathodes demand.

Technical work contributing to the Scoping Study (including testwork, process design and engineering) is now complete. Completion of the commercial and economic evaluation contributing to the Scoping Study is expected early in the New Year, following which a final review of the results will be undertaken by the boards of Pilbara Minerals and Calix with results released shortly thereafter.

Subject to the results being commercially and technically satisfactory to both Pilbara Minerals and Calix, in accordance with the MOU the parties will then progress negotiations for the formation of a joint venture and agree a work program to develop a Demonstration Plant at the Pilgangoora Project and ultimately seek to commercialise the Mid-Stream Product’s process technology in respect of lithium phosphate applications on a worldwide basis.


The lithium-ion supply chain is rapidly evolving with large scale development occurring through all segments of the supply chain.  Several prominent forces are shaping the industry including product cost (per lithia unit), product quality (purity), carbon energy reduction and waste management (particularly for the European market).

Pilbara Minerals Mid-Stream Project objective is to deliver a superior value-added lithia product that exceeds across these metrics of product cost, quality, carbon energy reduction and waste reduction/handling.

The project work to date has comprised exploring alternate solutions to achieve these aims, including reviewing and testing alternate process paths, equipment selection and end-product types.

The project has now been narrowed down to a preferred process route and end-product.  The process route under investigation is unique in the use of both the calcination processing technology and chemical concentration process.

Although the project is in its early development phase, the test work and engineering to date which has contributed to the initial Scoping Study provides strong indications that the new mid-stream product (and process path) can be expected to deliver on the desired metrics of an improved value-added lithia product.  In particular through a reduction in carbon energy intensity, reduction in shipped volumes (through higher concentration product) and providing a more easily handled product.  The metrics of product production cost and quality will however need to be further assessed as the project moves through the subsequent phases of study and further development.

Australian spodumene is a raw material feed to a high-value chemical industry that is largely conducted outside of Australia. Producing a high lithium-content intermediate salt product on site at Pilgangoora, will result in a portion of the value traditionally retained by downstream spodumene converters outside of Australia being retained in-country.

The value-added Mid-Stream product is also expected to be able to access diverse markets worldwide.


Process Design

Pilbara Minerals together with Lycopodium Minerals embarked on a testwork programme to develop a flowsheet to produce a lithium phosphate salt. The testwork programme was initiated by using a produced synthetic lithium sulphate leach solution to produce small quantities of lithium phosphate precipitate. Subsequent testwork phases further developed the flowsheet to produce high purity lithium phosphate precipitates from Calix-calcined Pilgangoora spodumene concentrate.

Following laboratory scale testwork, lithium phosphate has been selected as the preferred product, having demonstrated superior performance to other alternatives evaluated to date. Other forms of lithium salts will continue to be considered for potential process optimisation in future study works.

Flowsheet test work to-date has demonstrated >90% overall lithium recovery to final high purity lithium phosphate product.

⇑ Midstream Demonstration Plant Design Model

Pilbara Minerals’ mid-stream project development is expected to be progressed utilising unallocated spodumene concentrate production capacity available from the Pilgangoora Project over time, without disrupting existing customer offtake arrangements, including the POSCO and Pilbara Minerals downstream joint venture.

Calcination Testwork

A series of spodumene flotation concentrate samples from Pilbara Minerals’ Pilgangoora Project were sent to Calix’s test facility in Bacchus Marsh, Victoria, for processing through their BATMn reactor. These samples were processed under a range of operating conditions to determine whether successful calcination of Pilgangoora spodumene flotation concentrate could be achieved using the Calix Flash Calciner (“CFC”); and if so, what the optimal conditions for this calcination would be.

Testing undertaken at the BatMn reactor was considered as a pilot scale initiative, given the scale of the facilities in use.

Calcination test work during the Scoping Study has demonstrated a >95% conversion (Alpha to Beta phase transition) of spodumene concentrate to facilitate subsequent lithium extraction, which is a very competitive result compared to industry norms utilising conventional technology.

Further, the Calix flash calcination technique is particularly well-suited to the finer fraction of the fines flotation concentrate at Pilgangoora (less than 75µm). This is very encouraging as it has the potential to solve for an existing challenge for the industry when dealing with flotation products through conventional calcining technology.

⇑ The Calix Flash Calciner and Electric Pilot Scale Plant (BATMn Reactor)
Decarbonising the Hard Rock Lithium Raw Materials Supply Chain

Conventional hard-rock spodumene processing is relatively carbon-intensive. The conventional processing route involves the export and shipping of low-lithium-content raw material (SC6 spodumene concentrate is only 2.8% lithium metal by mass). In addition, this raw material requires the disposal of the waste material at the customer’s site (the 97.2% proportion of the spodumene concentrate that is not lithium). Finally, conventional calcination of the spodumene concentrate is currently done exclusively using fossil fuels.

Producing a more lithium-dense intermediate product on site at Pilgangoora will facilitate a significant reduction in shipped product mass (an 8 to 10-fold shipping mass reduction can be anticipated from the production of a high-purity lithium salt on site), eliminating major waste disposal requirements at a customer’s site.

Additionally, an opportunity exists, through the partnership between Calix and Pilbara Minerals, to fundamentally change the method used to calcine fine spodumene concentrates – eliminating the requirement for fossil-fuelled calcining and enabling a fully renewables-powered operation.

The flowsheet proposed within the Mid-Stream Project adopts complete electrification of all unit processes (including calcination utilising Calix’s unique technology solution), which are expected to materially rationalise the carbon footprint across the supply chain through the application of renewable energy in the process, as well as the reduction in freight quantities.

“Collaboration, Calciners and Clean Energy” feat. James O’Loghlin, Andrew Okely & Corey Blackman

Welcome to the fifth Episode of INNOVATING FOR THE EARTH

with innovation expert and radio and TV presenter James O’Loghlin

In the fifth episode , James O’Loghlin welcomes Andrew Okely, Calix’s General Manager of Sustainable Processing, and Corey Blackman, Head of Technology at Swedish based SaltX Technology, to discuss the collaboration between Calix and SaltX.

SaltX Technology is a Swedish renewable tech company that has set out to solve the problems of renewable energy supply, demand and timing. SaltX’s grid-scale energy storage solution uses abundant, recyclable and energy dense nanocoated limestone-based materials. The thermochemical storage is charged with renewable energy and can be dispatched when needed, as steam or electricity.

Many industries are trying to decarbonise traditional heating processes. Efficient, low-cost energy storage systems are needed to accelerate the decarbonisation of electricity network and are a fast-growing, multi-billion market.

In 2021, Calix and SaltX combined their technology to develop a potential chemical energy storage solution. They built an electric powered direct separation reactor in Sweden to be used as part of a process for storing and dispatching renewable energy. The reactor will use excess renewable energy during the day to power the reactor to heat, charge and dehydrate salt. Then, when energy is needed, the salt will be recombined with water to produce heat and power.

Andrew and Corey discuss how the collaboration between Calix and SaltX came about, why the two companies decided to work together, how they developed the project, and it’s results.


Calix files a new patent for zero emissions iron and steel

Calix is pleased to announce the filing of a patent covering a new application of its core technology for the production of zero CO2 emissions iron and steel.

Iron and steel making sits just behind cement and lime as the second largest source of man-made industrial CO2 emissions, estimated at 7% of the global total, or around 2.6 billion tonnes per year.


80 to 85% of the industry’s CO2 footprint is associated with the production of iron, as 90% of all iron is produced by metallurgical coal- and coke-fuelled blast furnaces, producing approximately 1.8 tonnes of CO2 per tonne of iron produced.

Iron produced via direct reduction of iron ore using a “syngas” of hydrogen and carbon monoxide (made from natural gas) in a shaft furnace is a less CO2 intensive method, at around 0.6 tonnes of CO2 per tonne of iron, however this process route has traditionally been more expensive, and hence only 10% of the world’s iron is produced by this method. The method requires cheap natural gas, as well as pelletisation of iron ores to prevent fines loss.

Methods to lower the carbon footprint of iron production have started to consider using “green” hydrogen as the major reductant instead of natural gas and coal. The use of hydrogen in blast furnaces is being tested, but there will be limits on the amount of coal it could replace due to a reduction in the conversion rate of iron ore to iron. A “direct reduction process” with hydrogen is currently being assessed in the HYBRIT process in Sweden with SSAB, Vattenfall and LKAB. However as with a normal direct reduction process, the iron ore requires pelletisation, and ultimately consumes about 72 kg of hydrogen per tonne of steel (Source: McKinsey & Co -Decarbonisation Challenge for Steel, P9).


Following the production of iron, steel is then produced either by removal of impurities in a basic oxygen furnace (usually following a blast furnace) or electric arc furnace (usually following a direct reduction process). Both production routes allow for the recycling of scrap steel at this point. In both routes, impurities in the steel need to be removed, and this is partially achieved via the addition of lime both before and during the steelmaking process, typically between 25kg to 70kg of lime per tonne of steel, or about 46 million to 130 million tonnes of lime.

Diagram above is from the European Steel Association


Calix’s “ZESTY” (Zero Emissions Steel TechnologY) Iron process involves the use of Calix’s core “kiln” technology to reduce iron ore to iron in a hydrogen atmosphere at between 600oC to 800oC, about 1000oC lower than a conventional blast furnace, due to the ability of Calix’s technology to handle small particle sizes in a controlled atmosphere. Calix’s kiln can also be easily electrically heated and handle intermittent operation – and thus the process can be energised via renewable energy sources. Because expensive hydrogen is not consumed as a fuel, and only as a reductant, Calix’s process is targeting the theoretical minimum hydrogen use of 54 kg per tonne of iron.

In summary, Calix’s ZESTY iron technology allows for:



Calix’s “ZESTY” (Zero Emissions Steel TechnologY) Steel process involves the use of the ZESTY Iron process feeding a standard (continuous) electric arc furnace (C-EAF), with the addition of a LEILAC kiln to produce zero-emissions lime. The “hot, active” lime produced from the LEILAC technology can be directly fed to the ZESTY reactor, and in addition any extra CO2 required in the C-EAF for the final steel mix can be fed directly from the LEILAC reactor. Some extra lime from the LEILAC reactor can also be used to scrub any excess carbon dioxide, as well as other pollutants such as sulphur compounds, from the exhaust gas from the C-EAF in a carbonation step (“CL” in the diagram). In addition to the advantages of Calix’s ZESTY Iron process, Calix’s ZESTY Steel technology allows for:



Professor Paul Fennell – Professor of Clean Energy at Imperial College London said “The Fennell group at Imperial College is currently conducting its own independent investigation of the use of powder gas reactors, such as that embodied by ZESTY for iron and steel production and have found no substantial obstacles so far in our studies. We believe that tight control of particle size to prevent internal diffusion limitation will be necessary, and there will no doubt be other phenomena to be considered as the technology is scaled. However, the production of iron from iron ore is clearly the most obvious next generation use of the Calix technology, and one that I consider to have great potential”.


Calix’s patent outlines the use of Calix’s core technology to produce zero emissions iron and steel. The technology will need to be scaled and tested, and the patent upheld, to achieve commercial success. Initial testing is taking place at Imperial College in London. If positive results are confirmed, Calix will then conduct scale-up testing at the Company’s Bacchus Marsh facility with ores from a potential customer, who Calix has already engaged in discussions.

CEO of Calix Phil Hodgson said: “These are early days for the Calix ZESTY technology, however, given the materiality of both the potential for our technology in iron and steel production and the size of the environmental challenge, being similar to the one our LEILAC business is addressing, we will be pursuing this opportunity as quickly as possible – the world cannot wait any longer.

Calix and Pilbara Minerals team up to explore a new and more sustainable lithium refining process

Pilbara Minerals has signed a memorandum of understanding with Calix to jointly undertake a scoping study to evaluate a new refining process for lithium.

Under a new memorandum of understanding, Calix and Pilbara Minerals will undertake a scoping study to assess a new refining process using Calix Technology, which will be used to create a concentrated lithium salt midstream product for lithium batteries.

Pilbara Minerals owns the Pilgangoora deposit, one of the world’s largest lithium resources. Currently, the ore is processed to produce a spodumene concentrate which is then shipped to customers overseas for use in lithium battery material production.

The scoping study will investigate taking fine, lower grade spodumene concentrate and further processing it on site using renewable energy to create a low carbon, concentrated lithium salt.

The Calix Technology solution involves heating fine spodumene concentrate in an externally heated kiln for a very short time. This facilitates the phase change in the spodumene mineral from Alpha to Beta without the associated melting observed in traditional rotary kilns when treating fine concentrates.

The study is expected to run until late 2021 and, if successful, Pilbara and Calix will form a joint venture to build a demonstration facility at the Pilgangoora spodumene mine in Western Australia, with the vision to produce a higher value lithium salt, while reducing carbon emissions.

Pilbara is expecting the facility to be capable of up to approximately 2400 tpa of lithium salt production capacity.

“Re-thinking calcination” feat. James O’Loghlin & Phil Hodgson

Welcome to the second Episode of INNOVATING FOR THE EARTH

with innovation expert and radio and TV presenter James O’Loghlin

In this podcast we’re exploring some new technology developed by Calix.

In ep 1, we heard Mark Sceats tell us about the history of Calix, and how a simple idea became a global company.

In this second episode, we take a closer look at the technology, to understand how the Calix calcination process can be used to develop environmentally friendly solutions to protect crops, treat wastewater, and reduce the amount of carbon produced in industrial processes.

Phil Hodgson is the Managing Director and CEO of Calix. He joined Calix as CEO in 2013, and became a Director in 2014. He previously worked with Shell, then ran his own consultancy in areas such as Biofuel, Clean Coal, Geothermal Energy, and Logistics.

“From an idea to a global company” feat. James O’Loghlin & Mark Sceats

Welcome to the first Episode of INNOVATING FOR THE EARTH

with innovation expert and radio and TV presenter James O’Loghlin

We live in a time of great change. Hardly anyone does things the same way as they did them 20 years ago, even 10 years ago, and the pace of change isn’t slowing down. Climate change will bring huge change to many industries, especially energy, and the drive to operate sustainability will intensify.

This podcast is going to examine what one company, Calix is doing to identify and meet some key challenges that have emerged in the last decades.

Calix uses patented technology they developed to provide industrial solutions that address global sustainability challenges. Their technology is being used to develop environmentally friendly solutions in areas that include crop protection, aquaculture, water and wastewater, advanced batteries and carbon reduction, and we are going to find out how their complex technology went from being just an idea to becoming a thriving international business, how the technology works and what it does.

Mark Sceats was there from the beginning. He’s a physical chemist with 40 years’ experience. In 2005 he founded Calix, and today is a Director. Prior to 2005 Mark had worked at the University of Chicago, the University of Rochester in New York, and then at the University of Sydney in the School of Chemistry. He’s published over 140 academic papers in physical chemistry, and – Get this – is an inventor of 36 patented inventions.

Project SOCRATCES Targeting low cost / low carbon energy supply

Innovating for the next generation of renewable electricity and heating technologies.

Calix is a member of the SOCRATCES Project, which is currently completing construction of an exciting new application of Calix’s technology at the University of Seville in Spain. Seville is one of the leading locations for concentrated solar power (CSP) research and operation globally.

The pilot plant comprises a solar field, a hybrid CSP-electric direct separation reactor (DSR) from Calix, a carbonator, and a power block. The facility is under construction and operations should begin in the next couple of months.