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AXIS HOUSE – FROM LAB TO PLANT

World Mining Magazine

Since its establishment in 2001, Axis House has become a major supplier and distributor of chemicals to the mining industry. Managing director Trevor McLean-Anderson and senior technical advisor Paul Woods tell Martin Ashcroft how a customer-focused approach has helped the company thrive.

As a process for separating valuable minerals from unwanted material (known as gangue), froth flotation has been around for 100 years. The steady development of this technique has improved the recovery of copper and other minerals, effectively reducing the cost of production and allowing the recovery of minerals economically from lower grade ore than was previously possible.

Axis House has forged a reputation as a world-class supplier of novel flotation and hydrometallurgical reagents for mineral processing, with a comprehensive range of proprietary collectors, depressants and frothers designed to aid recovery of mineral particles. The range is constantly expanding through research and development, and is finding new applications in the flotation of platinum group metals (PGM), rare earth oxides, phosphates and lithium bearing ores.

“We do research and development in our laboratories and that R&D is focused on a couple of different angles,” says managing director Trevor McLean-Anderson. “The first one is product development, where we look at trying to innovate new chemistries for existing applications. We also try to invent new applications for existing processes. And we also look at chemistry on a molecular level to try and find cheaper alternatives where we haven’t found a novel chemistry. We try to find similar molecules that are maybe more readily available, closer to market, or more economical, so that we produce a cost per output benefit to the customer. That’s the first pillar of our R&D.”

The chemistry is important, of course, but it’s the focus on understanding the customer that elevates Axis House. No two ore bodies and no two flotation plants are the same. There are too many variables involved in a flotation process for a one-size-fits-all approach to be effective, so an Axis House solution is tailor made for the customer’s application.

“The next pillar is to scale down the production process at a specific customer’s site in our laboratory and work on the customer’s own ore,” says McLean-Anderson. If a cheaper reagent can be developed to lower the customer’s output cost, that’s a solution in itself, but “it’s more interesting to find ways of making mines more efficient, so they can improve their output with chemistry,” he adds.

“In an ideal world we would develop a reagent package, dosing combination and dosing procedure that is cheaper going in, and gets more mineral out at a higher grade,” he says, “and we often achieve that.” When the perfect solution is not possible, however, more often than not the cost of the chemicals goes up slightly but the amount of copper produced goes up by a higher factor, meaning that the customer’s cost of mineral production still goes down.

A tailored chemical recipe is produced by replicating the customer’s process and using the mine’s own ore, leading to the third pillar of the Axis House approach. “We now have a laboratory case study for the improvement of a mine’s efficiency and profitability,” says McLean-Anderson, “and that’s all well and good, but laboratory work is done in a very controlled environment. Plants are different from labs because there are a lot more variables. There’s soil dynamics, there’s water quality, there’s ambient temperature differences, operator knowledge and training. So we have a team of onsite engineers that will take the customer through the process of implementing the technology on their site, and we do that until such time as we have proved our technology on the mine site.”

The market, at the moment, is mainly the central African copper belt of Zambia and the DRC, but is expanding in terms of geography and mineral range. “The bulk of our operations is in Africa,” says McLean-Anderson, “but we also have laboratories in Australia. We have staff and offices in Peru and we serve Chile also from our Peru office. We also have offices and technical people in Mexico, and we’re doing some work in Kazakhstan and Russia.” While it’s normal practice for customers to send their ore to one of the Axis House laboratories, some countries are reluctant to allow ore to be sent out, so Axis House scientists will travel there to do the test work.

The company has also been busy expanding its range of chemicals. “A large portion of our business is in copper and base metals. In 2009 we bought a very novel patented copper oxide flotation technology from an Australian company called Ausmelt. That was when we first saw the cost to the customer going up by about 50 cents or a dollar per tonne of ore, but the customer getting far more at the end. For a hundred thousand dollars more per month on chemicals, the customer would be getting $7 million more out in extra copper. So that was a no-brainer.“

Owning a technology like that allowed Axis House to improve it, and to develop it for other applications. “We have applied our knowledge into various other streams,” says McLean-Anderson. “Similar chemistries are used in the flotation of industrial minerals, so we’re now quite strong in fluorspar and phosphate flotation. We also have flotation chemistries and technologies in platinum group metals and rare earth oxides.”

Mineral prices are notoriously volatile, and copper in particular has been up and down in recent years. How vulnerable is the company to this kind of fluctuation? “If you had asked me that question before 2009 when the bottom fell out of the copper market,” says McLean-Anderson, “I would have said our business was reliant on the copper price and that we were very vulnerable to it. But since then we have seen a lot more interest in the Axis House offering.

“Marginal mines are struggling,” he continues. “They need to be efficient. When the price is high, it’s all about volume and they care less what it costs to get the metal out. They just want tonnes. We thought it was going to be awful for us but it was exactly the opposite.“

Although the copper price has recovered a little, the market is still somewhat uncertain, so mines are still receptive to technology and novel ideas, he explains. “When copper is at $8000 a tonne they don’t want to lose any production, but when the mines are on care and maintenance or five day weeks, they have time on their hands to invest in improving efficiencies. Technology is more interesting to customers when they need to be efficient.”

Flotation works by exploiting the properties of the materials involved in relation to water. Hydrophobic materials are water-repellent, while hydrophilic materials are attracted to water. A flotation cell recovers mineral particles from a slurry when the particles attach themselves to air bubbles pumped through the mixture. The ore is initially crushed and ground to separate a proportion of the copper sulphide ore particles from the gangue. The ore is then wetted, suspended in a slurry, and mixed with reagents which accentuate the particles’ hydrophobic properties. As air is forced through the slurry, bubbles attach to the hydrophobic copper sulphide particles, which rise to the surface where they form a froth and are skimmed off. Frothing agents, known as frothers, may be introduced to promote the formation of a stable froth on top of the flotation cell. Axis House has a range of these called Hydrofroth™, too.

Paul Woods heads up the company’s Australian market developments, but is also MD of the frother business, Hydrofroth Pty Ltd, and technical advisor across the group. He endorses the customer-focused approach as fundamental to the way the company works. “Our focus is to understand the customer’s aims and objectives and then understand their process,” he says. “So our approach is a collaborative one. Our flotation technicians and engineers out in the field will go to the customer’s site to see how the operation is run, and work with the metallurgists and operators on site to determine the best way to increase the yield. Our focus is always on increasing the yield for the customer. We don’t go to a mine site simply looking to replace the reagents they use with our own. We’re not trying to tell them how to run their operation either, but with our experience with the chemicals, and the expertise of our technicians, we can suggest ways to increase the yield, either by using a different chemical or by changing the process slightly.”

The lab work is carried out in a very controlled environment but the real work happens in the field, says Woods. “We look at it very holistically to give our chemicals and processes the best chance of succeeding,” he says. “We employ local people who have been in the field a long time. They know a lot of these plants and they know the operators well. That’s our key difference in the market.”