Resource efficiency in mining and minerals processing
Rupal Mehta explores how mining and minerals processing companies can improve operational performance and ensure resource efficiency.
‘Companies in the mining sector cannot ignore the risks associated with climate change,’ says Skipp Williamson, Managing Director of Partners in Performance (PIP). The consultancy, based in Sydney, Australia, works with mining and minerals processing companies in North America, Europe, Africa and Australasia to help them become more resource efficient.
‘Countries like Australia are likely to face more intense and frequent fires, droughts, floods and storms. Increased droughts mean that mines [will] compete fiercely for scarce water,’ she adds.
Alongside burgeoning raw materials and energy costs, she explains that firms are also encountering a backlash from local communities who have greater influence over whether licences to operate are given based on environment impact. ‘Mining applications, particularly for coal mines, are being upset because of their [potential] greenhouse gas emissions,’ says Williamson. ‘Environmental groups are lodging objections with regional boards/governments.’
Although unable to reveal clients’ names, Williamson talks through some case studies and largely attributes operational changes to simple root cause analysis.
On the road
One client runs a fully integrated facility, from mining to production and distribution of the finished product. It consumed over 15 million litres of diesel per annum during distribution. Partners in Performance has reduced this by between six and nine per cent, depending on the equipment, resulting in lower carbon emissions and costs savings.
Road conditions on site were identified as impacting on the quantity of diesel used. Too many stoppages and steep gradients were increasing fuel consumption. Williamson explains, ‘Reducing dust is fairly standard – we increased the frequency of spraying water on the road. But reducing the friction between the tyres and the road is also important. We made sure the roads are smooth, especially on sharp corners’. Tracking tools, such as a fuel card usage policy, have also been introduced.
An indirect benefit has been reduced wear of tyres. This is particularly pertinent in light of the shortage of tyres in the sector.
Another client, involved in smelting coke, is locked into a four-year contract with its coke supplier. The team at PIP conducted a mass balance study down the supply chain to identify where and how resources were being consumed. It found that a ‘significant amount’ of excess water was being sprayed by the supplier to cool the material down. Moreover, the supplier was weighing delivery-haul ehicles shortly after water quenching. ‘Effectively, the client was paying for water at the same rate as coke,’ says Williamson. ‘The last thing you want is to put energy into burning water.’
To address this, existing moisture specification clauses in the contracts are now implemented more rigidly. The client initially oversaw this, until trust was restored, by moisture sampling every inbound truck to determine a dry weight for each coke load.
As well as tackling existing minerals operations, PIP argues that resource-efficient practices should be considered at the outset of mine design. Alongside road maintenance, continuous automated conveyors can be introduced on site. Furthermore, by collecting energy from railways and conveyors going downhill, energy can be reused to transport minerals uphill.
Training staff is also important. Williamson says, ‘The ore going into a blast furnace can be variable, so you have to adjust the amount of oxygen and check the temperature. Give the workers a decision matrix to monitor these levels carefully’. Avoiding unnecessary downtime is vital for saving energy.
Ultimately, Williamson acknowledges that mining companies must see a cost-benefit to implementing operational changes. However, she warns that the same outlook applies to employees. ‘You cannot expect behavioural change unless you align incentives and remuneration, and develop resource efficiency key performance indicators. It is essential to get your wiring right to support ongoing improvements.’