IM 2020 March 20 | Page 28

WATER MANAGEMENT & TREATMENT Watering down Paul Moore reviews some water management developments in mining from desalination investment to dewatering pump news and water monitoring tools hile remains the centre of desalination activity in mining. Cochilco analyst Camila Montes recently presented their projections of water consumption in copper mining in the country in 2030. Seawater consumption will increase by 156% towards that year compared to 2019, reaching 11 m 3 / sec, while the use of continental water will decrease by 6%. By region, in the case of Antofagasta, seawater will represent 65% of the water used for copper mining by 2030, Tarapacá 60%, the Atacama 42% and in Coquimbo 25%. BHP recently announced that the Escondida Water Supply Expansion project was completed in December 2019, on schedule and budget, further increasing total desalinated water capacity to 3,800 litres per second. But this is not the only project in the region – plans are underway at BHP Cerro Colorado with a tender out for a project what will supply 562 l/sec, with 162 l/s in a first phase; while at Spence a desal plant is underway from JV SPV Caitan comprising Spanish developer Cobra Group (50%) through its affiliate Tedagua, and Japanese trading house Mitsui & Co (50%). Last November, Codelco cancelled a $1 billion contract that had been awarded to a consortium led by Japan’s Marubeni to construct and operate a desalination plant that would have supplied water to the miner’s Chuquicamata, Radomiro Tomic and Ministro Hales divisions. However, this is not the end of the story, a new tender process is starting for the plant but one that will supply the whole Codelco copper mining network in the Calama region. At Teck’s Quebrada Blanca 2, IDE Technologies was last year chosen to design and supply the desalination plant. QB2 is an extension of Teck’s existing Quebrada Blanca C 26 International Mining | MARCH 2020 operation in Chile. The desalination plant will be located at the port site for the QB2 copper mine in the Tarapacá region. Other plants are in the making at Collahuasi and Los Pelambres. Moving to another arid world region, as reported in The Jordan Times, the UK’s Solar Water PLC was recently selected by the Jordan Phosphate Mines Company (JPMC) to produce low cost, environmentally friendly water and supply freshwater to its phosphate plant on the Gulf of Aqaba. For the next 25 years, freshwater will be supplied by a Solar Water™ desalinator dome, positioned adjacent to the JPMC plant. Work will start this spring, and participants expect the desalinator to begin supplying freshwater by mid-2021, according to the statement. The technology involves a dome – a hydrological sphere – constructed from glass and steel into which sea water flows. The energy generated to super heat the continuous inflow of water and to create a constant water cycle within the dome – the equivalent of up to 20,000 suns – produced by focusing concentrating solar radiation, from a large number of parabolic mirrors (heliostats) surrounding the domes, onto the glass and super conductive steel frame structure. Through this process, the sea water evaporates, condenses and is precipitated as fresh water. The brine gathers at the bottom of the dome’s basin, is extracted and sold commercially. Water monitoring tools Outotec has launched a new real-time water monitoring tool to enable miners to simulate and evaluate proposed water-treatment investments and process changes, and keep tabs on water use across their operations. The unique desalination technology from Solar Water PLC involves a dome – a hydrological sphere – constructed from glass and steel into which sea water flows. The company is supplying this system to Jordan Phosphate Mines Company As the company says, water is a scarce and valuable resource, and mining operations are under increasing pressure to optimise their water usage in order to improve environmental and economic performance. Outotec Pretium Water Advisor enables real- time monitoring of the water balance across an entire site, allowing operators to create short- term forecasts for water volume and quality, it said. The platform predicts changes in water balance and quality based on changing production and environmental conditions. This enables simulation and evaluation of proposed water-treatment investments and process changes. “The solution combines intelligent water measurement stations and instrumentation with Outotec’s predictive water balance computing to eliminate the need to rely on time-consuming manual water-balance and key performance indicator (KPI) calculations,” Outotec said. Plant managers and engineers can view water KPIs as both graphical views and historical trends via a web-based interface and also access scenario management tools for performing simulations and evaluating the impacts of new water treatment investments, process changes, or the impact of expansion plans on the site’s water resources, the company said. “Water Advisor monitoring stations provide accurate and reliable real-time data on both