Case

Polyethylene piping systems in the mining sector

This case study provides a brief introduction to the use of polyethylene piping systems in mines across the world. It uses Australia, and the role of Fusion Plast in the distribution of spigot and electrofusion fittings, as a high-level case study and compares it to mining in South Africa.

The birth of polyethylene

Discovered in the 1930’s, a stable and consistent polyethylene manufacturing process was in place by the late 1950’s. Polyethylene’s (PE) popularity was further enhanced by the development of highdensity polyethylene (HDPE) in 1953. The adoption of PE pressure piping in water, gas and industrial applications gathered pace in the late 1960’s and 1970’s. Fusion Group, founded in 1971, was one of the early pioneers in PE pipe jointing and fittings.

Polyethylene in mines

Today, PE is recognised as the predominant pipe material for many mining processes. Such processes include the transportation of water, process water, slurry and tailings; mine dewatering and aquifer depressurisation; and, direct applications such as solution mining and heap leaching.

Polyethylene has many properties which make it attractive to mining engineers. Unlike steel pipes, the primary alternative material, PE doesn’t corrode. A PE system is fully jointed and delivers an ‘allowable water leakage’ of zero! Pipe sizes up to 180mm can be coiled allowing for long continuous runs and, depending on site access and transport infrastructure, sticks of 13.5m or longer can be used. There are many specialist PE installation techniques – horizontal directional drilling, sliplining, pipe bursting – that can be used on the rare occasions when standard pipe jointing is not feasible.

Polyethylene is resistant to the vast majority of chemicals used in mining processes, and its abrasion resistance accommodates tailings and other materials entrained in pumped fluids. Mines are busy sites and employ large plant and machinery. PE is able to withstand high external loads and live with the everyday knocks and scrapes of mining operations. A long service life, typically between 50 and 100 years depending on application, contributes to PE’s low lifetime maintenance costs.

Australia and South Africa

Depending on the method of measurement – mineral reserves, annual extraction, exports – Australia and South Africa both appear in the top 5 mining countries in the world.

Australia has over 400 operational mines which employ around 130,000 people. In South Africa, where the mines tend to be deeper, the industry directly employs about 450,000 operatives. Mponeg gold mine in Johannesburg is reputed to be the deepest mine in the world stretching 4km below the surface.

Australia and South Africa are internationally strong in gold, iron ore and coal as well as rarer metals and minerals, and both countries generate significant export earnings from their mining activities. For example, Australia is the world’s largest exporter of coal, iron ore and lead. South Africa accounts for 75% of the world’s diamonds and 90% of the world’s gold. Unsurprisingly, many of the world’s largest mining corporations such as BHP Billiton are active in both markets.

Australia was one of Fusion Group’s first export markets and it has had a permanent distribution presence in the country since 2005. Fusion Group has manufacturing facilities in China and a distribution facility in Indonesia, two further countries with strong mining sectors.

Fusion Group and mining

Fusion Plast, Fusion Group’s wholly-owned sales and operations company, is based in Banyo, Brisbane, Australia. A second depot opened in Western Australia in August 2019. Fusion Plast is led by Shaun Robb who has been with Fusion since 2000.

‘The Fusion Plast approach is to establish a strong national network of local distributors. Several of our distributors generate a significant proportion of their revenue from the mining and quarrying sectors. This is particularly true in Western Australia.

Although we are once removed from the end mining customer, we offer and are often asked to provide technical advice and guidance on polyethylene pipe systems used in mines. With exceptions for pipework in, for example, the plant room, mining companies favour the use of butt fusion over electrofusion. Whilst both systems deliver strong joints, butt fusion is typically quicker and allows long lengths of welded pipe to be towed with minimal risk of snagging.

Fusion Plast stocks the full Fusion Global PE Product offer. However, mining requirements are dominated by a demand for Fusion’s spigot fittings, stub flanges and backing rings. Many of our spigot fittings go into fabrications destined for use in mining applications.’

Whilst the drive for efficiency and automation is ever-present, Shaun Robb has noticed an ever-stronger focus on health and safety in mining during his time in Australia:

‘In January 2019, in the heartland of Brazilian mining, a tailing dam collapsed at an iron ore mine at Brunadinho in Brazil, releasing 11.7 million cubic metres of toxic mud, with catastrophic consequences. This was a worldwide wake-up call for all of us involved in mining. I believe it will lead to an increased focus on process safety, dewatering and depressurisation in both Australia and South Africa. PE has a huge part to play in ensuring mines operate both efficiently and safely.’