More pressure than fibreglass pipe

Dewatering using layflat hose at a large iron ore mine.

Crusader Hose has successfully developed ultra-high pressure hose for the purpose of mine dewatering that is capable of going into deeper depths. Introducing the Flexibore 300 series hose.

Crusader Hose is an innovative Australian manufacturer of layflat hose, flexible rising main and mine dewatering hose.

The Melbourne-based company has continued to develop advanced solutions for ground water pumping over its 35-year history.

A recent breakthrough by the research and development team has been the development of ultra-high-pressure hose for the extraction of bore water. The six-inch Flexibore 300 series hose is the highest pressure layflat hose in the world for mine dewatering, which boasts a burst pressure of 90 bar or 900 metres.

The iron ore mines in the Pilbara region of Western Australia are a leading powerhouse for the Australian economy. These mines are at the cutting edge of best practice in efficiency and safety. Australian mining engineering is highly rated across the world due to its skilled processing and ore extraction techniques.

“In some of the larger open cut iron ore mines, they have been working for over 30 years, non-stop, removing ore out of the pit. Some of the larger mines are longer than 25 kilometres, so you can imagine the experience gained plus size of hole in the ground,” Crusader Hose managing director Francois Steverlynck says

In order to extract the ore in a dry state, the open cut mine needs to keep the water table lowered. This is typically achieved by pumping groundwater out from in-pit bores.

These are the bores that are inside the open cut mine, as opposed to around the perimeter. Due to the constantly changing topography inside the pit, as the mine extends and deepens, these in-pit bores need to be moved and relocated.

Flexible rising mains have been the system of choice for in-pit bores due to the simplicity with which the submersible pumps can be retrieved and installed.

The typical installation method uses a roller, crane or mechanised spool, as the riser pipe is one continuous length.

Flexibore 300 series hose REACHES a burst pressure of 90 bar.

As the need to extract the ore from deeper depths inside the pit has evolved, so has the importance of lowering the water table below the pit base. As the water table goes deeper down, the end result is a need for higher pressure pumps and higher-pressure riser pipes. 

Until recently, only fibreglass riser pipe had the pressure rating for this application, as Australian-made Flexibore and Well hose, an imported hose from the United Kingdom, both reached their safe operational pressure limits.

Fibreglass, however, is not the ideal solution as it is bulky, expensive and cumbersome to install. Therefore, discussions were initiated with dewatering supervisors of the large Western Australian mines for the need of a higher pressure Flexibore hose.

The engineers at Crusader Hose rose to the challenge of developing a world-first product, and in June this year successfully trialled a six-inch Flexibore, which bursts at 90 bar.

Groundwater can now be safely pumped from 360 metres below, or at higher pressures.

The tensile load reached was 25 tons (22.6 tonnes), which represents the pump plus water weight that can be safely suspended from the Flexibore hose.

“This is a pioneering achievement in the history of our company,” Steverlynck continues. 

“This Australian development will hopefully be keenly adopted by mining companies and enable them to keep at the forefront of productivity and continuous improvement.”

This article also appears in the August edition of Australian Mining.

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