Contract crushing is gaining popularity as quarry operators try to match production to market need
Demand for aggregates in Spain has been steadily rising over the last decade and the growth looks set to continue. But regional variations mean that keeping production in line with demand is a challenge.
Hanson Hispania is the biggest aggregates producer in the Murcia region and acquired the Cabezo Gordo quarry in 2001 to increase its presence and reserves in the area. The quarry has a fixed crushing plant, built in 1975 by Spanish provider Granier, with a capacity of 370tonnes per hour. During 2006, the quarry had an annual production of 1.5 million tonnes which is mainly supplied to the concrete and civil works markets.
Hanson is investing in new plant in its European quarries but the lead times involved and investment needed means that demand may run ahead of production capacity. Contract crushing is providing the company with an effective way of bridging the gap and maintaining its market position. According to Hanson, around 60% of the quarry's aggregates are produced by the fixed plant, while the remainder is processed by the mobile equipment.
Mar Manor is using a Lokotrack LT1213S impact crusher fitted with detachable screen and return conveyor and two Lokotrack ST352 screens to meet the extra demand at El Cabezo. The crusher is loaded with 0 to 400mm rock by a 29tonne
The basic range of products produced by Mar Manor at El Cabezo include 0 to 2mm, 0 to 4mm, 4 to 8mm, 8 to 12mm and 12 to 20mm, which are mainly used for cement production and construction applications. According to Metso, Mar Manor can process up to 220tonnes per hour using the crusher and screens, depending on the size of the material being produced. Mar Manor usually operates the plant for up to 11 hours each day.
According to Mar Manor, the mobile process is very efficient. The crusher and screens only need three people to operate it per shift: an excavator driver to feed the crusher, a wheeled loader operator to stockpile the end products, and a back up driver to cover breaks and monitor equipment to ensure continuous operation.
The LT1213S is fitted with Metso's IC500 intelligent control system and the screens have SmartScreen technology, which makes management of the crushing process easier. The crusher and screens are linked by cable and the control system constantly measures the load on the ST532 screens and automatically adjusts the feed from the crusher to maintain steady but high capacity production levels.
Mar Manor had previously used other crusher brands for contract work and is pleased with the results that the Metso system has delivered at El Cabezo. Managing director Daniel Egea said: "The availability of the mobile equipment has been excellent and it is also easy to operate." The company is expecting the trend for contract crushing to continue growing in Spain and has just bought another mobile Lokotrack crushing system.
