Mark Doyle discusses how leveraging OEMs’ knowledge can help improve materials handling safety.
Responsible mining companies have an unwavering commitment to the health and safety of workers and their families, local communities and the wider society. Original equipment manufacturers (OEMs) also have a vital role to play in developing solutions that reduce risk on-site and championing a zero-harm culture.
In recent years, the industry has come to think about and understand harm reduction in broader terms, including things such as environmental safeguarding. Crucially, product and process optimisation – aimed, for instance, at reducing water and energy consumption – serves an important function in reducing an operation’s carbon footprint, which has obvious health benefits for the communities surrounding the mine. Similarly, increasing wear life reduces consumables, while also reducing maintenance requirements and limiting the amount of time operators spend in the line of fire.
Weir Minerals’ Linatex rubber has been protecting capital equipment from abrasion and corrosion while also keeping operators safe for a century. Linatex’s inventor, Bernard Wilkinson Sr, observed that conventional rubber processing – with its high shear mastication and high-temperature curing – destroyed the molecular structure, diminishing the original mechanical strength of natural rubber. He developed a ‘liquid phase low temperature vulcanisation’ process that retained natural rubber’s desirable properties – its toughness, resilience and abrasion resistance. The formula and process have remained unchanged for 100 years, and, today, it’s used at all stages of the mining process.
Partnering with miners to increase wear life
OEMs are well-placed to provide operators with equipment insights that may ordinarily be missed; in addition to designing and developing the machinery, they’ve seen it tested and operated in a multitude of applications and environments. Miners are increasingly leveraging this knowledge to optimise their processes, maximise equipment performance and keep their people safe.
Oyu Tolgoi, a gold-copper mine in Mongolia, has been working with Weir Minerals for several years in various capacities, including using its Linatex rubber to protect its Cavex hydrocyclone cluster underflow launder.
In this application, oversized particles can range from 3mm up to 50mm in diameter and can include scat and other foreign materials. This material is forced into the underflow launder, which is a common high-wear zone in most concentrator plants.
Determining the problem
The Weir Minerals team noticed repeat orders for rubber lining patch repair, the normal method for repairing high-wear parts of the plant. The installed rubber was the right choice of material, but it was wearing out quickly in certain areas. The launders were slowly degrading because of the patchwork style maintenance that had been undertaken in the past.
With an increase in tonnage through the plant, Oyu Tolgoi needed to overcome the declining condition of the clusters to reduce its maintenance costs. Furthermore, health and safety guidelines meant the need to reduce the at-risk work by the rubber liners at every shutdown patching the worn areas using solvent-based adhesives.
Developing the ideal solution for launder wear
A six-month preliminary trial using bolt-in, steel-backed, moulded Linatex panels proved successful in preventing the worst of the wear on the launders – it lasted beyond the initial trial by over 12 months.
The OEM and miner determined that the bolt-in panels offered a considerable improvement over standard rubber lining in this application. The panels can be installed during routine maintenance in a single 12-hour shift, reducing the time necessary for the maintenance team to spend in a confined space, which is a hazardous and potentially dangerous work environment.
A satisfied customer
“It improved safety significantly. We basically had to go into the underflow tank every five weeks. Now we don’t even go for another 32 weeks. It reduces material costs associated with changing out too frequently. On the cost side, most importantly, it enabled us to produce more copper,” details Ankhbayar Enkhsaikhan, Oyu Tolgoi’s maintenance manager. “These are the sorts of solutions we are looking for to enable us to operate safer and obtain the desired throughputs on the mine,” he adds.
The bolt-in panels were replaced without the use of chemicals and adhesives, which was another important factor in reducing the risk to workers. Moreover, the panels are made from 25mm Linatex rubber sheets with a 6mm steel backing, which is twice as thick as standard rubber lining but still below the stipulated weight limit.
All of the panels in the hydrocyclone clusters were installed a day earlier than expected. The clusters were put back online within minutes, and no problems occurred once the panels were in place. The panels decreased maintenance downtime and eliminated the need for small patch repairs.
Ultimately, miners are starting to recognise that decisions that may have been previously made solely for commercial reasons actually have ramifications in terms of health and safety. It is just one of the ways a safety-first attitude is changing the mining industry.
Mark Doyle is with Weir Minerals
