Modern Quarrying Q4 2018

Warman slurry pumps, the out- standing pump efficiency results in minimal energy consumption from your cyclone feed pump. Couple that with the Cavex hydrocyclones that are designed to operate at low feed pressures due to their superior hydraulic capacity, which reduces the total dynamic head of your pump, and customers will realise the double benefit of partnering Warman pumps with Cavex hydrocy- clones,” says Singleton. Looking ahead As washing becomes a crucial operational process, what should be some of the considerations when it comes to decisions on what washing equipment a quarry needs? Singleton says the type of equipment one chooses should be the most efficient equipment on the market, supported by a local service centre network to partner with them through the life of the operation. “It is essential to buy products and a system from OEMs that understand the product range and the implication of each product in the sand washing system to achieve optimum results,” says Singleton. Zlatev says quarries must consider how often feed material properties change, such as grain size distribution, amount of fine materials and types of impurities. “They also must take into account what the end product will be and if they will need to move equip- ment or keep it onsite indefinitely. All of these considerations play a big role in choosing washing equipment that will enhance effi- ciency and profits,” says Zlatev. Looking ahead, OEMs are convinced that the outlook of the African washing market is looking up. Zlatev believes that Africa’s population is growing and as a result new infrastructure construc- tion is also increasing. Because of this, the demand for high-qual- ity aggregates and the washing equipment needed to produce it, will continue to rise. “The African washing market will continue to increase as the need for high quality building sand increases in the ever growing African popula- tion,” concludes Singleton. l

energy savings in mind, meaning that the growth in wet processing does not have to significantly impact on water and energy consumption. While wet processing is becoming an important process in aggregates production, water and energy management are equally significant priorities. Water restrictions, espe- cially on the back of recent drought conditions across regions such as southern Africa, compounded by increasing energy costs in a continent faced with acute energy shortages, translate into difficult operating conditions for producers. There is a big trend towards consideration of the environmen- tal impact of quarrying and that includes reducing both water and energy consumption. For example, Haver & Boecker’s Hydro-Clean sys- tem recirculates 90% of the water it uses during processing, so minimal fresh water is required. This can save operations substantial money over purchasing wash water recy- cling systems. Ideally, the customer can use simple settling ponds, or if this is not possible, the customer would need filtration equipment or centrifuges for water recycling. “We also designed the Hydro-Clean system to operate with minimal energy consumption. The machine’s jets are powered by the water’s high pressure so little electrical energy is required for rotating parts. We also use high-efficiency electric drives to save energy,” explains Zlatev. Singleton says when it comes to water management, it again comes back to the efficiency of the cyclone. “If you have a cyclone operating at the optimum, you will immediately make more saleable product and send less product to the thickener or slimes dam. We can provide full turnkey solutions with thickeners and filters to deliver a dry by-product from the ultra-fines or slimes, which can be sold into alternative markets as a by-product. This will result in zero discharge from your sand wash plant, if designed and operated correctly,” he says. In terms of energy management, the cyclone feed pump consumes the most energy, according to Singleton. “With our new generation

JD Singleton, Process Director – Weir Minerals.

Both the SLR and WBH pump ranges are designed to reduce wear, energy consumption and maintenance time with replaceable wear liners, and deliver increased hydraulic capacity. The Cavex hydrocyclone is fed through Linatex hoses that are proven to be durable and long lasting, and the underflow of the Cavex hydrocyclone discharges on high efficiency, high capacity, low-headroom Enduron dewatering screens that are designed to operate at reduced operating and maintenance costs. Hydro-Clean washes in Tomeet the growing need for innova- tive washing solutions globally, Haver & Boecker designed its Hydro-Clean Washing Systemwith 2 000-psi high-pressure water jets to effectively remove dirt and clay from aggregates and run-of-mine material while minimising water and energy consumption. “We also offer screens with asmany as five screen cuts in a single machine, minimising the number of necessary machines and associated costs,” says Zlatev. Because the Hydro-Clean uses water jets, the system experiences minimal wear and tear, saving operations time and money on parts replacements. The system takes up less space and weighs less than a washing drum or log washer, which not only makes it ideal for stationary plants, but also mobile and semi-mobile applications. Minimising water and energy impact The latest washing innovations have also been designed with water and

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QUARTER 4 - 2018 MODERN QUARRYING