Fast-changing mining conditions require customised chemical processing solutions, says Axis House MD, Justine Stubbs
While emerging technologies and other digital disruptors are both inevitable and welcome innovations to improving mining production, discounting the value of a physical inspection of operations would be a mistake, especially during the processing phase when chemicals are required to morph oxide or sulphide materials into useable end-product minerals.
Justine Stubbs, MD and one of the founders of Axis House – a South African organisation that has built a global reputation over 18 years for the supply of chemicals and reagents to the mining industry – notes that sensory observations, particularly those of mine managers and operators, are invaluable to the highly consultative and synergistic solutions that Axis House has built its reputation on.
‘These are super-talented individuals who have a fundamental understanding of their often complex operations. They instinctively know – when they “walk their plant” – what doesn’t look or feel right. Input from plant managers and operators, procurement and administrative teams is taken very seriously by the metallurgists and sales teams who undertake Axis House monthly on-site surveys,’ she says.
Such surveys are so comprehensive they almost belie the fact that Axis House is a supplier of chemical mining products. The company presents itself more as a solutions provider. ‘It’s important to give chemicals the best chance to perform, so it’s imperative to understand the circuit, for no two are alike. When things go wrong, the blame is often placed on the chemicals,’ says Stubbs. In many ways this is understandable because of the number of varied chemical processes used to separate metal from ore, and which in turn are dependent on whether the virgin material is oxidised surface material or the deeper, less-exposed sulphide mineral/ore body.
An example would be platinum, which – when associated with chromite – is initially similar to copper and cobalt. It is upgraded by physical separation or ore sorting before flotation, smelting and leaching. Solvent extraction and electro-winning follows, requiring large quantities of reagents. Gold processing is somewhat similar but requires different types of chemical reagents, often very hazardous.
‘The ore-to-metal process is complicated, requiring a large amount of chemicals, some of which are hazardous, and this is why we aim to be on site within 24 hours when problems are detected; to undertake a survey and provide a solution.’
This is where the combination of analysis and a visual inspection merge. Because mining conditions change frequently, Axis House needs to be informed of the whole scope of an operation. ‘It may be that the quality of the ore, water or even chemical has changed, or perhaps mechanical or operator issues have emerged.
‘Sometimes it’s as easy as looking at, for example, the colour or shape of the bubble in the frothing process, which can indicate a change in dosage is required.’ Sometimes, but not always… And that’s the beauty of an additional Axis House service – the pilot project, which ‘can be set up to run alongside existing operations so that we can compare feeds in a like-to-like scenario. Mining decision-makers and operators can see immediate results from optimising chemical formulas; changing dosages. It’s a platform for how a new reagent will perform’.
Solution-finding also means running and supporting plant trials and test work on site or at the Axis House Cape Town or Sydney laboratories, both of which also conduct batch control, with back-up quality control samples held for 12 months. These laboratories also guide research and product development – putting the organisation at the forefront of technical service offerings.
‘Oxide collectors, for example, have advanced rapidly over the past decade, providing more financially viable solutions,’ says Stubbs. ‘Our sulphide collectors are now able to replace xanthates, which improves selectivity and increases flotation kinetics and grades. The latest depressant range has improved pulp viscosity, allows for improved froth drainage, and is also effective in rejecting carbon. We are currently undertaking research, a large portion of which has been guided by solving client problems, to provide the industry with improved chemistry for better efficiencies. Ultimately, and in line with the rest of the world, we also want to help reduce the number of hazards that are aligned to chemicals, be that in reduced handling, spill avoidance and/or negative environmental impacts.’
Axis House research is also targeting phosphates, rare earth oxides, platinum group metals and gold – the latter three being relatively new introductions to the organisation. Not limited to flotation, which is a particular strength of the company, Axis House is now also presenting an improved and full range of reagents for leaching, inclusive of solvent extraction and electrowinning.
The flotation chemical (or reagent) segment is also by far the biggest contributor to global mining chemical revenue generation, at 45%. The 2018 Mining Chemicals Market Report estimates that by 2023, mining chemicals will reach a value of nearly US$4.098 billion, based largely on the growing demand for more pure forms of minerals and new mining projects on various continents, including Africa. Axis House is well positioned to tap into a share of this business boom. In addition to the oxide/sulphide collectors and depressants/dispersants it provides, frothers, flocculants, smoothing agents, acid mist suppressants and commodities are also marketed by the company, which holds in excess 20 000 tons of chemical stock at any given time.
It also boasts more than 20 000 tons of a range of 60 commodities, exported monthly into the DRC, which along with Zambia – given the region’s large copper and cobalt mining activities – has traditionally been the organisation’s strongest market. ‘We offer a complete supply chain solution for the region. We hold stock, control its quality and offer consign-ment stock services,’ says Stubbs. ‘In fact, we take full responsibility for the chemical supply chain from beginning to end.’
Axis House has established a presence in South Africa (Johannesburg and Cape Town), Zambia (Chingola), the DRC (Kolwezi and Lubumbashi), Australia (Sydney and Melbourne), Peru (Lima) and Russia (Moscow), yet new offices could be added at any time.
‘Once we have up to three or four clients in a region, we deem it time to open a new office, forming partnerships and employing local talent with the same drive as Axis House. This is not as easy as it sounds given our criteria, which is essentially about having the talent to make quick, sound decisions; a drive to problem-solve; and the desire to be a technical partner to the end-user.’
The organisation is also keen to investigate acquisitions and mergers, especially those with skills that are complementary, such as water treatment specialists, ‘which is a natural step in our growth strategy’, says Stubbs. ‘We are particularly interested in partnering with relative South African operations given that most of our business to date has been focused outside of its borders. ‘Overall, our medium- to long-term aim is to increase sales with our existing products in markets that we are already active in, broaden our reagent offering in those same territories and extend it into other markets, increase the product range, and explore new regions, such as the new Axis House branches that are forthcoming in the Middle East and North Africa.’
These plans will not change the bottom line business structure, which has always been to be a premier chemical supply chain and logistics provider, a technical chemical mining specialist, and optimiser of ore quality through its product range. ‘Our bottom line is not absolutely about how many sales we can make,’ according to Stubbs. ‘It’s about having a genuine concern for mining operations; the partnerships we have with operators based on communication and trust; and providing solutions to actual problems.’
By Kerry Dimmer
Image: Marc Shou