Sandvik primary breaker solves face stability issue
RF Aggregates (South West) Ltd are using a Sandvik BR4511 as a safe, productive and environmentally sound alternative to blasting at a newly acquired quarry in Paignton, Devon. Mounted on a Komatsu PC450-8 hydraulic excavator, the breaker was supplied by Sandvik Mining and Construction via their local dealer, M&M Plant of Launceston.
RF Aggregates purchased the 5.0ha Yalberton Tor, and another quarry at Exeter, in 2008 when the incumbent owner went into liquidation. Previously used for the extraction of Devonian limestone, the site had also been used as an inert material landfill for several years.
One of the first challenges facing new owners was processing some of this inert material as part of an ongoing reinstatement programme. The company is now busily recycling the material that has been placed within part of the void space so it can achieve a future objective for the recycling operation and workings of the site, with specific emphasis on 6F5, 10, 20 and 40 mm fractions.
‘We have inherited a site that due to the previous owner’s circumstances had been poorly managed for some years, so our first job is a major programme of tidying and reinstatement,’ said RF Aggregates’ project manager Mark Cage. ‘All the material that we’re recycling is being thoroughly tested to ensure that it is not contaminated and we expect to be able to recycle more than 70% of all the remaining inert materials subject to permissions.’
Another key challenge facing RF Aggregates is that of mineral extraction, which had previously taken place using drill and blast techniques, despite the fact that the site is bordered by a commercial and residential area. According to Mr Cage, the previous owner’s mineral extraction operations had been something of a sore point with local residents, resulting in complaints about dust and noise pollution from the site’s crusher and, more importantly, the blasting operations. This, however, was only part of the blasting challenge.
Mr Cage explained: ‘According to our geotechnical survey, previous blasting has left several of the faces in an unstable and fractured state, rendering new blasting unsafe. It was decided even before an extraction license was granted that the limestone faces would need to be stabilized, and the loose material removed. As blasting was out of the question, a primary breaker was the most logical solution all round.’
The solution was a Sandvik BR4511 hydraulic breaker, a suitable match for the company’s existing 45-tonne Komatsu excavator. Working from a 5m high bench, the 3,800kg breaker uses its productive blow energy to further loosen the fractured rock which is then processed through the site’s crushing and screening plant.
‘The Sandvik BR4511 is absolutely perfect. It does everything we hoped it would do,’ Mr Cage commented. ‘We’ve been very impressed with the performance so far and the operator says it is an extremely powerful piece of equipment. We particularly like the build and the special features such as the Ramlube self-lubricating systems. It is a lot cheaper to service and we are at little risk of burn outs because of the build quality.’