Fines Recovery and Water Treatment Cost Reductions through Waste Fines Recovery and Water Treatment
As a result of their operating needs, the Australian building and construction materials supplier Boral invested in a fines recovery sand plant complete with an radial stockpile conveyor and flocculant make up and dosing system. Before the introduction of the new fines recovery plant, the operation was losing a significant proportion of quality fines to the waste ponds.
With the recent growth in the contracting sector, water and materials recycling has become an increasingly important consideration for the Australian building and construction materials supplier Boral Limited, in order to allow them to efficiently meet demand for quality aggregates whilst continuing to improve environmental management for the protection of areas in which they operate.
Situated in Moora, north of Perth, Boral Ltd are currently on contract with a quarry operation owned by Simcoa Operations, a company committed to producing the world's highest quality silicon from a site that has been in operation for over 20 years.
At the outset, Boral’s ultimate aim was to produce a high quality quartzite ore for use by Simcoa in their silicon production process. This ore is typically 75 to 25 mm in size, with all 0 to 7 mm previously being sent to the waste lagoons. Boral essentially wanted to implement a process whereby water could be recycled and recovered from within an extremely dry climate where water supply is limited. Paul O’ Brien, Boral’s Fixed Plant Engineering Manager began a consultation process with CDE Global. After this initial consultation, CDE offered a design and proposal that demonstrated efficiencies in operations and huge savings in material recovery. CDE ultimately designed, manufactured and installed a system that eliminated the loss of quality fines (0 to 5 mm) to nearby settling ponds whilst controlling water levels for reprocessing.
As a result of their operating needs, Boral invested in a CDE EvoWash 101 Fines Recovery Sand plant complete with an M1508 Radial Stockpile conveyor and a LQPP 25 flocculant make up and dosing system.
With the chosen equipment, the end result is a high quality, fine sand recovery with an efficient cut at 63 µm. Before the introduction of the new CDE fines recovery plant, the operation was losing a significant proportion of quality fines to the waste ponds.
The main ore product is 75 to 25 mm and is smelted by Simoca Operations for a variety of purposes including silicon chips, improving the strength of aluminium, optical glass, and use in solar energy, namely for the production of solar panels.
Boral’s quarry manager at Moora, Jeff Post, highlights, “The washing equipment from CDE Global has allowed operations to accurately separate at 63 µm which has in turn, produced a high quality sand product with low moisture levels, whilst rapidly re-circulating water following treatment processing. We are now recovering and producing 25 to 30 t/h of quality sand with the total feed rate to the plant being 225 t/h. This technology has allowed us to increase efficiency by reducing the costs incurred through pond dredging to recover sand we had lost using the previous system”.
The improved opportunities for the recycling of process water and reduction of fines to settling ponds have facilitated a move to production throughout the year, where previously the site was operating only over an 8 month period. The by-products of the production process are currently sold off to third parties in the region for various uses including further processing and general aggregate use, thus ensuring that there is zero waste from the process.