The coal industry prefers Osborn’s hardworking, long wearing machines

The coal industry prefers Osborn’s hardworking, long wearing machines
The coal industry prefers Osborn’s hardworking, long wearing machines

Despite tough times in the coal sector, Johannesburg-based equipment manufacturer Osborn reports continued demand for its robust coal handling equipment - from the local industry and as far afield as Turkey and China. The company has also launched a new service offering to ensure that coal industry customers can be assured of getting the ideal rotary breaker to meet their requirements.

Since January this year, Osborn has supplied a range of machines to coal producers in South Africa’s Waterberg area, Mpumalanga and KwaZulu-Natal, as well as in China and Turkey. The equipment supplied includes two 3054 Osborn double roll crushers, two vibrating grizzly feeders, a 6’ x 16’ triple deck modular screen, a 3600mm x 6700mm Osborn rotary breaker and two 3036 Osborn double roll crushers, reveals product specialist Etienne Swanepoel.

 “Osborn has been supplying the coal industry with tough, high quality equipment for more than five decades. The current economic climate may be challenging, but our customers clearly recognise the value of hardworking, long wearing machines that have proved themselves in the market and have the backing of a well-established, reputable manufacturer,” he adds.

Osborn supplies coal handling equipment ranging from the largest jaw crusher and rotary breaker to mineral sizers, double roll crushers, rolling ring crushers, modular plants and vibrating equipment, right down to the smallest components, laboratory crushers and conveyor idlers.

Rotary breaker resurgence

Swanepoel says that the company’s recent sales enquiries and its order for a rotary breaker for an Mpumalanga coal mine reflect the resurgence of this machine in the coal industry.  “The rotary breaker has come back into favour in the coal industry. Its simplicity and the fact that it offers reduced operating costs and minimal downtime is making it sought after - particularly in these difficult economic times.” He notes that the rotary breaker has proved to be the most efficient machine for use in “dirty” coal mining environments.

Explaining the rotary breaker’s operation, Swanepoel says that it works on a gravity method to break coal in a very efficient manner through impact crushing. “Material is continuously introduced at the feed end, repeatedly raised by the lifters and dropped until it is broken to size and falls through the perforations in the screen plates to a collection hopper below. Any hard rock present in the feed material assists with breaking the coal during the raising and dropping action. The Osborn rotary breaker is designed to crush coal, while the rock, refuse and other uncrushable debris is automatically carried to the end of the drum and is discharged through a chute. The Osborn rotary breaker design incorporates a chain and sprocket drive arrangement which drives a heavy duty reinforced drum. Renewable screen plates are fitted around the interior of the drum. Interchangeable lifters and ploughs are bolted on the inside of the drum.”

Osborn rotary breakers are capable of processing up to 2 000 tph with a maximum feed size of 600mm, depending on the type of coal being processed. Swanepoel says that the machine is generally fitted with screen plates to continuously produce one product size. “Should the product size need to be changed, new sized screen plates would have to be fitted. Due to variations in the types of coal being processed, capacities and power requirements will also vary from mine to mine,” he stresses.

Outstanding features

The outstanding features of the Osborn rotary breaker include heavy duty screen plates that ensure high cylinder strength and long life; large feed and discharge openings that allow for the passage of large run of mine (ROM) lumps of coal and tramp material, without the risk of blockage; and internal lifters and ploughs which can be arranged to alter the performance of the machine by retaining the material longer or pushing it through the drum faster. The machine also has drives at one end only and features a simple drive assembly comprising squirrel cage motor, fluid coupling, gearbox and final chant drive, Swanepoel explains.

He says that the Osborn rotary breaker’s benefits include its ability to simultaneously size and clean raw coal. “By removing the uncrushable material, it decreases the wear rates on equipment downstream. Fines generation is also minimised since the coal fractures along the natural cleavage lines.” Further benefits, Swanepoel adds, are the fact that the Osborn rotary breaker can be operated with minimal downtime and its operating costs are relatively low because power consumption is low compared to other machines performing a similar crushing duty.

New “drop test” benefits rotary breaker customers

A new service offering called a “Drop Test” has recently been launched by Osborn to ensure that rotary breaker customers get the ideal machine for their requirements. Swanepoel explains that this test is used to accurately size the rotary breaker needed for customers’ specific applications, based on coal hardness. He outlines what the test entails: “Sample lumps of coal and stone approximately 300mm in size are elevated and dropped from a predetermined height onto a rotary breaker screen plate. Broken material is then screened and each fraction is weighed.  Material bigger than the product size is dropped again, and the screened undersize is discarded. This process is repeated until all material is smaller than product size. Finally, a calculation is done to determine the required length of the rotary breaker drum.”

Other Osborn machines that he says are continuing to hold their own in the coal industry include the manufacturer’s largest jaw crusher. “Osborn’s immense Hadfields 80 x 60 single toggle jaw crusher is firmly positioned as the primary crusher of choice in the African coal industry. It handles up to 2m x 1.5m feed size with throughput in excess of 1 600 tph. This impressive machine, which weighs 140 000 kg and stands as tall as a double-decker bus, is one of the largest manufactured in the world.”

The Hadfields range of double roll crushers is designed and manufactured by Osborn primarily for use in the coal industry and similar related soft rock applications. Osborn’s rolling ring pulveriser crushers are also increasingly sought by the coal industry as this type of machine is being used by 90% of all thermal coal applications as a final product crusher, states Swanepoel.

Backing up Osborn’s range of machines for the coal industry is a 24/7 service department and spare parts division.

“Times may be tough, but our sales enquiries and recent orders for Osborn’s unrivalled range of coal industry equipment prove that there will always be a demand for tough, reliable machines that can minimise downtime and reduce operating costs,” Swanepoel concludes.