Rotary coal breakers work on a gravity method to break coal in a very efficient manner through attrition. 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.
Considered an “old classic” by many in the mining industry, the continued demand for these machines is as a result of their robustness and reliability, says product sales specialist at Osborn Rotary Breakers, Etienne Swanepoel.
“For rock removal, rock and coal separation, the rotary breaker is the best machine for the job. This tough, hardworking unit has come back into favour in the coal mining industry in recent years, and it is once again making its mark as the most efficient machine for use in 'dirty' coal mining environments, where there is a lot of rock in the run-of-mine material.”
Swanepoel explains that the Osborn Rotary Breaker is designed to reduce soft to medium coal and is not entirely suitable for hard coal or coal with a high moisture content. Mine 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’s design incorporates a chain and sprocket drive arrangement which drives a heavy duty reinforced drum. Renewable perforated plates are fitted around the interior of the drum. Interchangeable lifters and ploughs are bolted on the inside of the drum. Due to variations in the types of coal being processed, capacities and power requirements will vary from mine to mine.
The company has recieved two recent orders of the machine – one from a new customer in the Kriel area, and one from a coal mine in Secunda. “At the Kriel coal mine, our customer has installed a 3 600mm x 6 700mm Osborn Rotary Breaker to optimise the performance of its plant, remove rock and contamination, and increase the operation’s yield. This machine has a design capacity of 1 350 tons per hour, but our customer is running it at 500 tons per hour,” Swanepoel says.
Osborn supplied, installed and commissioned the new machine, including the chute work and the support structure.
