WATER MANAGEMENT
FLSmidth thickeners at Escondida copper mine , Chile
factor .” He added that Agnico Eagle and First Majestic Silver are good examples of companies that are implementing filtered tailings project using Metso Outotec equipment but the company is also supporting a number of feasibility cases evaluating filtered tailings .
Wisdom cited a recent order for FLSmidth to deliver an integrated dry stack tailings solution and a paste fill plant to a Hindustan Zinc Ltd ( HZL ) lead-zinc mine in Rajpura Dariba , Rajasthan . The solution will ensure environmental sustainability and significant process water recovery , as well as reduce the footprint of the tailings storage facility . It include supply of two Automatic Filter Presses ( AFP- IV™ ), two E-Disc filters and one 26 m diameter High-Density Thickener as the main pieces of equipment . The project is expected to be completed by February 2022 . This new order follows a previous tailings-related order for Hindustan Zinc at their Zawar mine site in 2018 .
Does all this mean thickeners will play a reduced role in these types of dry stack operations ? No , in fact they are still at the heart of the solution . Wisdom told IM : “ Thickeners will always play an important role in any filtered tailings project . Thickeners use gravity for dewatering which is free and always dependable making them cheap and reliable to operate . Maximising dewatering in a thickener significantly reduces total filtered tailings capital and operating costs on any project .”
Metso Outotec ’ s Palmer comments : “ Thickeners will continue to play an important role , in practice even more so as almost every case will require thickening . Thickening is still the most cost effective method of water recovery . Filtration plants also work best when the feed is thickened before filtration . What has changed is the degree of separation , paste type thickeners that push for highest possible separation are declining in popularity and high rate and high compression thickeners that have good water recovery with lower costs are favoured .”
Daniel Gutierrez , Metso Outotec Director of Process Optimisation , Consumables adds : “ Both
filtration and thickening are bonded process areas that are often overlooked , however , their dewatering responsibilities are extremely important as energy costs in mining sites . If the thickening process has efficient performance , filtration will succeed in holistic terms as one feeds the other . In addition , the benefits of dry tailings disposal are becoming increasingly appreciated from both environmental and social responsibility perspectives , and supporting filtration process with productive thickening performance will help customers reach their production / sustainability goals more easily .”
Later this spring , Metso Outotec will be introducing its complete filter portfolio , leveraging the strengths of the new company . Miika Keurulainen , Solution Sales Manager , Consumables added that a Life Cycle Services offering is currently being designed to make life easier and deliver true value for its mining customers . “ Based on Metso Outotec combined capacities , we are in a unique position to address the Overall Equipment Efficiency ( OEE ) of the equipment and operation . Integrating our knowhow on repairs , maintenance , metallurgical processes , digital tools , spare parts , modernisations development and delivery capability into LCS programs will allow us to better support our customers and differentiate us from the competition .”
IM
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MARCH 2021 | International Mining 47