Capital Equipment News January 2018

WASHING

“We also offer screens with as many 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 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 im- portant process in aggregates production, water and energy management are equally significant priorities. Water restrictions, es- pecially on the back of recent drought condi- tions 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 environmental impact of quarrying and that includes reducing both water and energy consumption. For example, Haver & Boeck- er’s Hydro-Clean system recirculates 90% of the water it uses during processing, so min- imal fresh water is required. This can save operations substantial money over purchas- ing wash water recycling 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 sys- tem to operate with minimal energy con- sumption. 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 en- ergy,” explains Zlatev. Singleton says when it comes to water management, it again comes back to the effi- ciency of the cyclone. “If you have a cyclone operating at the optimum, you will immedi- ately 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-prod- uct from the ultra-fines or slimes, which can be sold into alternative markets as a by-prod- uct. This will result in zero discharge from your sand wash plant, if designed and oper- ated correctly,” he says. In terms of energy management, the cy- clone feed pump consumes the most energy,

Haver & Boecker’s Hydro-Clean Washing System with 2 000-psi high-pressure water jets effectively removes dirt and clay from aggregates and run-of-mine material, while minimising water and energy consumption.

according to Singleton. “With our new gen- eration Warman slurry pumps, the outstand- ing 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 ca- pacity, which reduces the total dynamic head of your pump, and customers will realise the double benefit of partnering Warman pumps with Cavex hydrocyclones,” 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 of- ten feed material properties change, such as grain size distribution, amount of fine materi- als and types of impurities. “They also must take into account what the end product will be and if they will need to move equipment or keep it onsite indefinitely. All of these con- siderations play a big role in choosing wash- ing equipment that will enhance efficiency 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 construction is also increasing.

Cavex hydrocyclone and Warman WBH pump increase uptime and production by 35% for sand and aggregate plants.

Haver & Boecker’s Hydro-Clean system recirculates 90% of the water it uses during processing, so minimal fresh water is required.

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 contin- ue to increase as the need for high quality building sand increases in the ever growing African population,” concludes Singleton. b

CAPITAL EQUIPMENT NEWS JANUARY 2018 24