Overcoming Five Deep Mining Challenges Using Bespoke Hydraulic Cylinders

Mining is a sector that presents particular challenges for people and equipment that work within the industry. It can be a very difficult environment for machinery, with failures and breakdowns being commonplace. Many mines see huge issues with corrosion from the atmosphere, including high acid levels, moisture, and corrosive gases. In addition to all of these challenges, normal hydraulic fluid cannot be used due to the risk of fire and explosion – so instead soluble oils are used, which are non-flammable, but far inferior to oil for protecting parts. All tools built to work within this environment have to be of extremely high standards.

With mine shafts often being many hundreds of metres below the earth’s surface, safety is the primary priority at all times. Keeping equipment in safe working order is vital, although it can pose a challenge due to the dirty, difficult environment and the distance from any maintenance providers.

Many tools within the mining industry require hydraulic cylinders to provide a lift, pull or push motion, and Apex Hydraulics have been providing hydraulic cylinders for machinery within mines worldwide over the past 30 years. They have developed hydraulic cylinders for innovative tools for mining safety, or adapted cylinders for current tools to optimise fabrications, making them safer and more durable.

It is not uncommon for cylinders weighing half a tonne to be carried to a coal face which could be two miles underground and then another five miles to the face. It could take days to get there; so any machinery that then doesn’t work upon arrival would create massive cost implications. Therefore, being thoroughly tested and highly reliable is vital for all new equipment.

Due to the huge depths of mine shafts and the weight of equipment, accessing hydraulic cylinders for maintenance and servicing is often simply not an option. Cylinders must be durable, with robust seals, valves and improved rod coatings to reduce the incidents of breakdown.

Contamination is a major issue for cylinders within all mines, with dirt and debris impossible to avoid. Regular impact on piston rods can cause cracks and chipping, leading to contaminants entering the system. With contamination being such a big cause of machinery breakdown, it is important to avoid it wherever possible. Specialist seals can be used to reduce the amount of impurities that can make their way into the hydraulic fluid. This can include a series of seals, each designed to work in a different way, ensuring that no contaminants can enter the hydraulic fluid.

While many mines use shafts, operated by lifts as an access, a number of mines utilise long sloping tunnels to access minerals. These are known as drift mines. Getting machinery into and out of the tunnels pose a particular problem. Apex hydraulics, in conjunction with a UK mining company, have developed a tool that can brake test vehicles before they make the journey out of the mine, to ensure that they are not at risk of brake failure which could result in accidents.

The tool has a specially created power pack, which reads and stores data on the braking strength of each vehicle, for the purposes of evidencing requirements.

Even in the largest of mines, restricted height is a problem. Machinery needs to be compact. Therefore, mining applications often utilise telescopic cylinders, used to allow a long push or pull length, without requiring excessively large cylinders. Dual acting telescopic cylinders are available, where both the push and pull motion are operated hydraulically. It is also possible to have these working at a constant speed – important for safety of nearby personnel, where it is best that the speed of heavy machinery does not see a sudden increase.

Most mines have an environment that is corrosive, due to warm and humid atmospheres, salts, gases and acidic water. Certain mined substances, such as pot ash (a type of salt), are particularly corrosive. Bespoke cylinder rod coatings have been developed as an alternative to standard Hard Chrome Plating. One such coating, COREX, has been specially developed by Apex in conjunction with industry specialists. It is able to protect from corrosion, as it is between one fifth and one tenth as porous as HCP. This gives steels coated in COREX a massive resistance to corrosion.

While mining will never be an easy industry, bespoke hydraulic cylinders go a long way towards allowing tools to cope with the difficult environment; making mining safer and more efficient.