Modern Mining July 2021

TYRES

Oxair Gas Systems supplies equipment to mining operations around the world. Chief engineer David Cheeseman explains to Modern Mining why the time is right for the African mining industry to take on board the latest on-site gas generating technology to ensure a constant flow of nitrogen to keep truck tyres rolling, improve safety and reduce carbon footprint. Nitrogen generators can keep mining trucks moving

A frica’s mining industry is becoming a lot more technology-focused with advancements in autonomous underground mining technology and automated surface vehicles accelerat‑ ing the pace of sustainable solutions for equipment safety and reducing carbon emissions. However, despite rapidly adopting the latest technologies to modernise operations, mining in Africa is traditionally very labour intensive so reducing human exposure to risks like lightning strikes, exploding tyres on trucks, rock falls, earth tremors and other potentially dan‑ gerous situations, such as extreme temperatures, is a focal point for the industry. Just recently a lightning strike during a thunder‑ storm caused a tyre to explode on a truck parked up in a coal mine in Queensland, Australia, result‑ ing in two workers receiving injuries and damage to a crib hut from flying tyre fragments from the blast. Thankfully no fire was reported which could have made the incident even more serious. The International Council on Mining & Metals’ (ICMM) innovation for the cleaner, safer vehicles (ICSV) initiative – a supply chain collaboration with original equipment manufacturers (OEM) – is to be

On-site generators provide mines in Africa with a turn-key solution for getting a constant, reliable source of high-quality nitrogen where it is needed. applauded. However, the African climate and rug‑ ged terrain will still take its toll on the tyres of mining trucks, which are the workhorses of the extraction process. Why nitrogen? Nitrogen-filled tyres protect mine workers by pre‑ venting fires when ruptured – an extra tier of safety on large off highway trucks where the huge wheels are right underneath the driver’s position. They run cooler in extreme temperatures, remain inflated for longer and, unlike compressed air, nitrogen is an inert gas that does not react with other materials, so is resistant to corrosion. Filling with nitrogen has a lot of advantages but it is imperative that there is a constant supply at mining sites so that truck tyres can be fully inflated to reduce the risk of critical air leaks and rapid deflation espe‑ cially when vehicles are heavily loaded. Being at the mercy of the supply chain for nitrogen canisters in extreme locations, where conditions are challenging, is risky and costly. Nitrogen can be difficult to trans‑ port, not to mention the additional carbon footprint of delivery miles and safety hazards for staff manu‑ ally moving cylinders from one place to another, with the new threat of cross contamination posed by the coronavirus pandemic. However, companies can avoid the hassle of hav‑ ing to outsource their gas by switching to an on-tap supply. A compact nitrogen membrane or Pressure Swing Adsorption (PSA) nitrogen generator on site is the ideal alternative to manhandling canisters for heavy-duty equipment where precise or constant pressure is vital. Some of the world’s leading gold mining companies are already seeing the benefits of another gas, oxygen, on tap at sites rather than relying on deliveries of traditional cylinders. Like oxygen tonnage plants, nitrogen membranes and PSA nitrogen generators are efficient. They offer

African mines should consider the latest on-site gas generating technology to ensure a constant flow of nitrogen to keep truck tyres rolling.

36  MODERN MINING  July 2021