A new generation of advanced minerals processing is quietly gaining traction in Western Australia, where a technology-focused operator is refining a modular flowsheet for producing ultra-high purity alumina — and it’s already hitting 5N grade in pilot tests.
At this month’s RIU Sydney Resources Round-up, Cadoux Limited (ASX: CCM) managing director Roland Hill laid out the company’s dual-stream development strategy: one arm focused on 4N and 5N alumina from kaolin feedstock, and another building a rare earths processing hub to take third-party mineral sands concentrates through to downstream-ready oxides. But the flagship, for now, is the HPA.
“We’re not a producer yet, but a technology developer,” Hill said, adding that the flowsheet is already well proven in testwork. “It’s not a gold or base metals project — it’s specialised, complex, and very high value.”
Roland Hill
Cracking 5n: from kaolin to microelectronics
The Cadoux HPA Project, located in WA’s Wheatbelt, has been engineered from the ground up to deliver high-spec alumina for sapphire glass, ceramics, lithium-ion battery separators, and — more recently — AI-era semiconductors. The company’s bench and pilot programs have confirmed the process can reliably hit 99.999 percent purity (5N), with engineering now in the front-end design phase.
The flowsheet takes a low-impurity kaolin ore and subjects it to:
Calcination, converting aluminosilicates into reactive alumina compounds
Acid leach and purification, stripping out silica and trace elements
Crystallisation and finishing, to produce fine, high-purity α-alumina powders
The proprietary process is scalable, modular, and designed for phased construction — a key factor in capital efficiency. The company plans to move from pilot scale to a Customer Service and Innovation Centre (CSI) to support offtake testing, then on to a commercial small-scale plant, before full-scale build-out. Final investment decision is targeted for late 2025.
Commercial traction, backed by economics
While upstream purity is key, downstream pull is what gives this project its tailwinds. According to Hill, market response has been strong, particularly from manufacturers working in LED wafers, ceramic substrates, and microelectronics.
“We’ve cracked the code — customers love the material,” he said. “And AI is emerging as a real driver for growth — it’s not even in most of the forecasts yet.”
Pricing for 4N material remains firm, while 4N5 and 5N grades are commanding rising premiums, especially in energy storage and chip-related applications. The company’s 2021 DFS pointed to a post-tax NPV of over US$1 billion, supported by stable opex, a secure domestic feedstock, and strong margin potential.
Smart plant design for a smarter market
From a plant perspective, the key differentiator here is flexibility. The processing facility is being designed for modular deployment, with simplified logistics for reagent handling, tailings control, and utilities. Critical components include:
Kiln units for calcination
Automated leach reactors
Multi-stage crystallisers
Packaging and bulk material handling systems
This approach is particularly relevant given market uncertainties. Rather than committing to a monolithic plant, Cadoux is planning to stage capacity growth in sync with product qualification and market pull.
Site and supply chain details
The kaolin feedstock is sourced from Cadoux, northeast of Perth, where Proved and Probable Reserves underpin a 25-year mine life. Cadoux’s metallurgy consultants include Independent Metallurgical Operations Pty Ltd and Orelogy for mine planning, with CSA Global involved in resource classification.
While the project’s location in the WA Wheatbelt introduces some logistics challenges, Hill emphasised the opportunity for local jobs, low sovereign risk, and alignment with Australia's critical minerals strategy.
ESG without the marketing spin
What stands out from this project is not just the product purity — but the fact the ESG approach is actually built into the flowsheet. Quarterly reporting aligns with TCFD and UN SDGs, and the company is pursuing lower-carbon pathways through energy-efficient processing and on-site renewable power integration.
“ESG isn’t just about ticking boxes — it’s about giving our customers confidence,” Hill said. “And it’s about building something that lasts.”
The wrap
For mining professionals watching the evolution of downstream strategy in Australia, Cadoux’s HPA project represents a practical, technically advanced, and commercially realistic approach. It blends process chemistry, modular plant design, and product-market alignment into a compelling critical minerals play — with real-world traction and off-take interest already forming.
