Could you introduce METS Engineering?

I founded METS Engineering in 1988 in Perth, following a career in a number of roles, starting with my first job at Broken Hill for Rio Tinto, and progressing to Technical Services Metallurgist at KCGM, Plant Superintendent at Harbour Lights Mining, and Chief Metallurgist at Aztec Mining. The company had modest means, focusing on Australia, but we quickly expanded to the Americas, Southeast Asia, Africa, and Europe, becoming truly a global player. Most recently, we’ve been quite active in Chile, the U.S., Canada, but also Indonesia, the Philippines, and of course many places in Africa, especially Namibia, South Africa, Zambia, and Mauritania.

Our expertise spans mineral processing (crushing, grinding, flotation, thickening, leaching), hydrometallurgy, and pyrometallurgy. I am the author of about 230 technical papers. METS is not a generalist engineer, but a specialist company with a vast knowledge base across all commodities. Though we focus more on consulting, we have also delivered scoping, pre-feasibility, and definitive feasibility studies, as well as detailed engineering design.

What role does METS Engineering play in the due diligence?

A lot of the time, we are approached by banks and financiers who want access to our server of past projects before pouring millions into project capital; financial institutions and mining companies rely on our expertise to understand the strengths and weaknesses of a particular project before launching into a transaction, whether this is debt or equity financing, or a takeover. In a high-risk, high-capital sector like mining, getting that perspective from an experienced partner with decades of hands-on experience can be game-changing.

METS also offers training courses in Africa. Could you tell us more about it?

METS offers over 85 training courses in topics like advanced flotation and mineral processing, assaying, solid-liquid separation, materials handling, bacterial leaching, cost estimation, and beneficiation of low-grade iron ores, ranging from introductory to highly specialist. These are courses taken by metallurgists and mining professionals at high-profile companies in Africa. Mineral processing is a lifelong learning field, with a continuous, experience-driven learning curve. 

What’s your view on the future of hydrometallurgy vs. pyrometallurgy, and how is this influenced by carbon-reduction considerations?

The traditional pyrometallurgic basic oxygen steelmaking process, in use for over 200 years and heavily backed by investment in China, Japan, and Korea, is being disrupted by the demand for green steel, but pyrometallurgy is making a comeback through green iron. Energy costs, emissions reduction, and technological innovation determine the choice between hydro- and pyrometallurgical methods. 

That said, smelting remains the most cost-effective option for processing copper concentrates, whereas hydro has both higher CapEx and higher OpEx. However, carbon emissions remain a major challenge as regulations become increasingly stringent. In one Canadian project, for example, the discharged water quality was better than that of the receiving river, yet when regulators halved the permissible limit for one element, the project suddenly found itself at the compliance threshold, forcing additional work to meet the new standard. For smelting operations in particular, gas-cleaning technologies like baghouses, filters, scrubbers, and electrostatic precipitators are extremely costly, making emissions control a significant hurdle for the industry.

Meanwhile, direct lithium extraction, a hydrometallurgical process, also shows promise, but the market is very depressed right now and banks do not want to test new, unproven technologies on new projects.

Could you elaborate on how financing dynamics influence the adoption of new processing technologies?

Once a plant is operational, retrofitting is possible, but investors prefer to minimize risk early on. Some technologies, like HPGR, were once considered risky but are now industry standard. Recently, we faced pushback when we included ore sorters in a flow sheet. The bank dismissed it as “new tech,” but we pointed out that ore sorting is now widely used in lithium, nickel, manganese, gold, and copper operations, and in many cases, projects wouldn’t be viable without it. After this discussion, they agreed to reconsider it as an established technology.

What advice would you offer junior explorers or developers?

Early testwork is key. We’ve seen many cases of enormous amounts of assaying and drilling, only for the metallurgical tests to show the ore was too complex to treat, rendering the project unfeasible. 

Do you have a final message?

At METS, we need to make honest calls. Once I had to tell a bank that a project they had already approved with another engineering company had a fatal flaw. They were in disbelief, but we then spoke to the respective engineers and modified the flowsheet. They asked us how we knew, and we told them we’ve been doing it for many years and know what works and what doesn’t. There are people in this industry who hold a lifetime of knowledge and experience, but unfortunately, that knowledge is often not properly passed down when they retire. At METS, it’s more than just about money; we get a lot of personal satisfaction from doing a good job and helping clients make a project out of something.