The sustainable use of natural resources is a key focus for Iluka’s operations, with efficient and innovative solutions to water usage constantly being developed. The use of hyper saline water, and recycled water where appropriate, represent some of the initiatives being utilised. Iluka has co-authored a publication on the process implications of ferrolysis in hyper-saline environments, available via the AUSIMM website here.
Water is a key resource in most of Iluka’s mining, processing and separation processes. In the mining process, water is used to slurry and transport ore by pipeline after oversize material has been removed. Where the ore contains fine materials (slimes or tailings), water is used for its removal using desliming cyclones, and concentrated by thickeners before being disposed into tailings facilities.
Iluka’s heavy mineral concentration plants use water in gravity and magnetic separation processes. Heavy mineral concentrate is pumped in a water medium to stockpiles, where excess water is removed and recycled. In mineral separation plants, the heavy mineral concentrate is separated into its various mineral components, using either water driven processes or dry processing. In synthetic rutile plants, water is used in leaching processes and environmental control.
Iluka has differing approaches to water supply and sourcing depending on the nature and location of its operations. At Iluka’s Woornack, Rownack and Pirro operation, dewatering is required due to the ore being located below groundwater level. Water at Woornack, Rownack and Pirro is recycled from dewatering to provide hyper saline water for process activities at the site. In contrast to this, the ore at Iluka’s Jacinth Ambrosia site is located above groundwater level, and given the operation’s remote location, the hyper saline water used for processing activities is sourced from a palaeochannel and bore field located 34 kilometres from the site.
Iluka recycles water where possible and fresh water discharges normally only occur when there are seasonal imbalances in water supply and demand. In such instances, the discharges are licensed and the strict conditions imposed by such licenses are followed. Groundwater resources are further protected by means of monitoring programs and regular interpretation of monitoring data is performed during aquifer reviews.
Water management data for 2014 can be found in the Sustainability section of the 2014 Annual Report.