Through on-site generation, mines, which typically operate in far-flung areas can fully benefit from using nitrogen for their tyre inflation requirements, African Mining Brief gathers from the Sales Director of South Africa based- NitraLife, Tom Sowry. Though originally targeted at the commercial transport sector, NitraLife’s on-site generation systems have a growing niche uptake in the African mining sector. Mining houses are appreciating the advantages of on-site nitrogen to their operations.
In an environment of fluctuating commodity prices, mining companies are seeking innovations that can help them to contain costs and enhance efficiency from pit to port. One area that they should seriously consider in this pursuit is tyre management, specifically adopting sound tyre inflation practices.
The inherent flaw of using tyre inflation methods of conventional compressed air, partly comprising of oxygen and water vapour, which has been substantially documented over the years, should be sufficient to elicit an attitude change in the mining industry. To date, amongst comparable alternatives that mines can consider, concrete evidence indicates that nitrogen tyre inflation is most viable from both safety and cost saving perspectives.
Through an interview with African Mining Brief, a specialist in nitrogen tyre inflation technology, the Sales Director of NitraLife, Tom Sowry, informs mining companies about the advantages of switching from conventional inflation using air to nitrogen for their tyre inflation requirements.
Over the years, Sowry reveals, NitraLife has been observing the scale of the impact of poor tyre inflation on mining operations, which is either overlooked or goes unnoticed. Established in 1996, NitraLife has been at the forefront of nitrogen tyre inflation technology, as the first internationally to use a membrane separation process to generate high-purity nitrogen for commercial tyre inflation and subsequently also in large off-the-road (OTR) mine vehicle tyres..
The downside of oxygen and water vapour
Firstly, addressing mine operators, Sowry draws attention to the expenses which mines incur by persisting on using conventional air tyre inflation and the potential safety risks that they face.
- Costly degradation and corrosion
What organisations are not aware of is the speed with which oxygen and water vapour escapes through a tyre, indicates Sowry. “Once air is pumped into a tyre, the water vapour and oxygen that permeates through the rubber casing, degrades the rubber compound and makes it more porous. -. This reduces the tyre’s ability to hold pressure and also leads to early casing failures.”
- High risk of combustion
What’s more, Sowry points out that, as oxygen is flammable, its use in tyre inflation can cause potential combustion or even an explosion. “All tyres flex during normal operation and this leads to the build-up of rubber particles inside the tyre. Rubber is composed primarily of carbon and therefore, when these very small particles are exposed to high heat levels caused by binding brakes or a wheel bearing failure, they can – when mixed with air – combust or even explode with potentially calamitous consequences,” he says.
Sowry continues: “On the other hand, with high-purity nitrogen filling a tyre, this cannot happen and the safety of driver, vehicle and valuable cargo is ensured.”
The benefits of nitrogen
Sowry outlines a number of factors which render nitrogen as the most feasible gas for inflating tyres in mining and other sectors, according to the data that NitraLife has gathered over the past two decades. This observation is substantiated by findings in similar scenarios globally.
- Tyres maintain pressure better
Firstly, as the slowest migrating gas, nitrogen escapes through tyre walls approximately four times slower than oxygen, and 117 times slower than water vapour. Nitrogen tyre inflation ensures that tyres run at the correct pressure, which reduces flexing, are therefore cooler and last longer. Tyres at the correct pressure flex less and are less likely to overheat. Heat build-up, which results in under-inflated tyres flexing beyond their specified limits, is a major cause of premature tyre failures. With nitrogen, tyres can achieve 99.5% inflation.
- Less tyre failure and improved re-treadability
Nitrogen preserves tyre rubber more effectively. Pertaining to re-treading of tyres, the casing is able to be re-treaded several times more than its air-filled counterpart. With nitrogen, unoxidised rubber casings remain flexible and are less susceptible to impact fractures and tyre failures..
- No oxidation of the inner liner
As oxidation inside the tyre cannot occur, nitrogen tyres will hold pressure better throughout the life of the tyre. Consequently, nitrogen tyre casings remain stronger and more flexible.
- Extension of tyre life through correct temperature
Tyres running at the right temperature and correct pressure will not only be safer but also last longer. A conservative estimate puts extension of tyre life at about 10% depending on the application.
- Fuel savings
Fuel consumes 30% of operating costs in a mining business, and correct tyre inflation results in related energy savings.
“From anecdotal evidence we have gathered not a single mine using our nitrogen generators has experienced a tyre explosion,” confirms Sowry.
Clearly, mines should consider using nitrogen for tyre inflation for a host of operational benefits. “The benefits of inflating fleet tyres with nitrogen are really significant for a mining company with dozens of vehicles that need to work with minimal downtime,” says Sowry.
NitraLife Nitrogen Systems: Tyre inflation as and when needed
Sowry is raising awareness about NitraLife nitrogen systems for off-the-road (OTR) tyre inflation, which are very convenient for mines. The on-site nitrogen gas generators are built to customer specifications, providing fast, reliable inflation of single or multiple tyres for any size trucking fleet.
On what sets the nitrogen apart from ‘conventional’ means, Sowry explains: “NitraLife nitrogren gas generators make nitrogen available – on-site and on- demand – continuously, through an air compressor. Moreover, as the generators are 100% pneumatic, they do not need electricity, and, due to their portability, the generators can be mounted onto a trailer or service vehicle, which is convenient for mines located in remote sites.”
For mines in the current environment, there are numerous benefits to be had by changing from cumbersome ‘conventional air’ tyre inflation to NitraLife nitrogen generators. In the main, Sowry cites the following:
- There is -reduced downtime for vehicles due to deflated (or under-inflated) tyres, as gas can be manufactured as and when needed;
- Owning a nitrogen gas generator considerably reduces costs in terms of eliminating delivery charges, refilling cylinders or replacing tanks, with no need for piping and manifold rental;
- Due to their modular design they allow for any volume of nitrogen gas to be produced; and
- Installation of the generator takes a few hours and thereafter requires very low maintenance.
Bearing in mind that clients have different requirements, NitraLife customises its membrane generators to suit their specific needs. NitraLife can supply its generators to both large and small mining companies, through either a rental or purchase option. Moreover, the portable nitrogen trailer, another innovation that NitraLife has introduced, is a perfect fit for business operations in remote sites requiring a mobile nitrogen solution.
Industry track record
To illustrate the reliability of on-site nitrogen gas generation, over 1000 companies are using nitrogen in tyre inflation in the USA. Nitralife’s on-site nitrogen generators for tyre inflation are being used in mines in northern Zambia, Southern DRC and Mozambique.
According to Sowry, end-users have been impressed with the difference the products have brought about. As a case in point, Sowry mentions a mine in Kimberley, in the Northern Cape, which has achieved a 17% improvement in correct tyre pressures in their first year, translating into substantial tyre cost savings. In the coming years, with mines streamlining their operations to cope with changing circumstances, NitraLife foresees mines on-site gas generation systems gaining increased traction in mines.
On recent developments which are set to change tyre inflation management, Sowry predicts digital automatic tyre inflation elevating safety levels in mines. “Digital automatic tyre inflation minimises the involvement of an operator and ensures consistency and accuracy. There is virtually no human contact with tyre during inflation, minimising injury risks.”