Page 30 - Hub Issue 54

Quarrying
Superior Industries develops new low-water sand washing solution
A new, field-proven low-water sand washing system from U.S.-based Superior Industries offers a cost-effective, eco-friendly solution to efficient crusher fines management and higher-quality manufactured sand products. As a single-source supplier of aggregate processing equipment, Superior Industries has developed the new Alliance Low Water Washer, which allows the washing and classifying of fines right within the crushing circuit – and provides a cost-efficient alternative to high-water-use washing with cyclones or sand screws.
Cost-effective sand washing
“Versus conventional sand washing methods, the Alliance Low Water Washer is a unique, first-of-its-kind solution that’s particularly advantageous to those who operate dry crushing facilities, or portable plants; or operations limited by a smaller footprint or available water resources,” says John Bennington, a well-recognized washing and classifying expert who serves as the director of wet processing technologies for Superior Industries.
The new system combines a specially- designed agitator and a dewatering screen within one machine. Allowing operation on a small footprint, crusher dust is processed within the crushing circuit, eliminating the cost of handling and hauling the fines to a separate washing site. Importantly, he says that the system accepts a dry feed directly from the crushing circuit and processes the material into a higher-value manufactured sand, while requiring significantly less water consumption.
With an increasing demand for manufactured sand throughout Europe, Bennington says that many operations have typically turned to cyclone dewatering plants. “Consider that the water requirement for a 200-MTPH- capacity cyclone dewatering plant will run between 450 to 600 m3/hr. The cost of using that much water, along with stringent environmental regulations,
makes the use of a cyclone plant or sand screw increasingly prohibitive,” he says.
agitator is equipped with a spray bar along about half the length of the agitator shaft for thorough cleaning. The slurry is fed to a robust dewatering screen that is outfitted with a series of spray bars that help to push the -75 micron material down through the screen. “Using a sand screw requires lifting the silt over the weirs of the screw with high water usage. Alternatively, when the Alliance Low Water Washer pushes the material down through the screen, much less water is needed,” he says.
Depleted natural sand reserves and environmental constraints are driving a fast-growing demand for high-quality manufactured sand and cost-efficient crusher fines management. “With the Alliance Low Water Washer, some operations have cut water usage by 80- percent, while eliminating additional material handling,” says Bennington.
Efficient fines management
Since washing crusher fines with a cyclone or sand screw typically requires the transfer of material from a crushing circuit to a separate washing circuit, some operations stockpile material to be washed. When necessary, material is hauled to the wash plant, with the multiple handling of material resulting in higher operating costs per tonne.
The Alliance Low Water Washer, says Bennington, provides efficient fines management. Its agitator section is positioned at the front end of the screen where water is added to the dry feed and mixed, producing a thick slurry. The
www.hub-4.com Jan 2019 - Issue 54
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