PASTE & TAILINGS 2021 allows intuitive operation , crossing barriers of language or training . The control system provided has the resources for remote monitoring in the future , also enabling remote support for fast interaction between the on-site machine and the ANDRITZ specialists .
Stackable , safe , sustainable : the smart approach to tailings
ANDRITZ outlines how state-of-the-art filter presses equipped with a Metris addIQ control system enable the switch from wet to dry tailings , as seen at Brazilian iron ore miner Itaminas
Itaminas , founded in 1959 , is an iron ore extraction company located in Minas Gerais , Brazil . The material left over after the production of concentrated sinter feed , highsilica sinter feed , haematite and pellet feed is known as tailings – and safe disposal of these materials is one of the mining industry ’ s greatest environmental challenges .
As one of the first mining companies in Brazil to decommission dams associated with the production of iron ore concentrate , Itaminas has already achieved considerable environmental , economic and social success in recovering the areas impacted by dams that were operating and then decommissioned . Faced with an operational need related to the end of the useful life of the B4 dam , currently used by Itaminas , and looking for a new alternative to dispose of its tailings , the company turned its efforts towards the implementation of the filtering system and subsequent stacking of dry tailings .
Various technologies from ANDRITZ ‘ s comprehensive solid-liquid separation portfolio were studied , from vacuum belt , ceramic or vacuum disc filters to filter presses , the latter then being used in implementation of the project . The ANDRITZ team , together with
Itaminas , proved the feasibility of filtration by carrying out tests with different cake thicknesses , drying times and membrane packages on a pilot filter press on at the ANDRITZ laboratory in Pomerode , Santa Catarina .
Overhead filter presses with futureproof control & automation
In a highly competitive market , the ANDRITZ solution turned out to be the safest , smartest and most sustainable option . The differentials were consistently achieving the final residual moisture required of just 17 %, and long-standing expertise was applied to develop a future-proof solution together with the customer . Four ANDRITZ overhead filter presses , manufactured in Brazil , in the largest size of 2,500 x 2,500 mm were chosen as the ideal equipment for high throughputs . Tests showed that a membrane pressurisation system with water is the best way of achieving the geotechnical moisture content in the cake required for dry disposal . Easily upgradable in terms of volume and filtration area , the filter presses for this specific application were equipped with double-opening , double-washer , bilateral feeding and a package of mixed membrane / chamber plates that can be easily accessed from the side .
The real stand-out feature is the automation – the Metris addIQ Prime control system including the optional Metris addIQ Connect . With high-end trending and diagnostic functions , this full process line control system maximises the performance and operation of the individual machines . With a 12 in panel touchscreen as standard , its design
Consistent high performance
The result was stackable tailings with optimised operation , lower OPEX and less water consumption . Thanks to the full support of a multi-disciplinary team on site for supervision , and the supply in form of modular kits , the third unit was assembled within a record time of just 21 days . The filter presses are now consistently achieving a moisture content of around 17 %, the performance tests produced a cake density of 2.5 t / m 3 and delivered final performance that was 34 % higher than expected . With three of the four presses already in operation , performance has been very satisfactory , aided by the reliable Metris addIQ Prime control system .
Dry stacking of tailings through smart technology reduces the risks to everyone involved – the environment , the community , and the operator ’ s employees . In the past , the OPEX of filter presses was considered higher than that of maintaining tailings dams . But the value is incalculable and incomparable when it comes to an extreme case caused by the rupture of a dam . With regard to the controls and associated risks , the safe stacks of dry tailings are an advantage over the dams . Another advantage in dewatering the tailings is the reuse of water in the production process itself , reducing the need for fresh water from springs , lagoons and wells . The recovery of clean water from the filtration process is currently estimated at approximately 80 %, avoiding plant outages during the dry season . With the ANDRITZ solution , an average of 8,800 m 3 of water is recovered per day at the plant .
“ We are innovating our beneficiation processes for tailings treatment . ANDRITZ ’ s solution made it possible to eliminate the use of tailing dams , making our processes more secure and creating a new profile of sustainability and productivity ,” says Gedeon Junio , Itaminas - Production and Processing Director . “ The successful partnership between Itaminas and ANDRITZ demonstrates that the mineral industry is undergoing modernisation and building new paths for the future ,” added Jonathan Izidro , Itaminas - Filtration Process Supervisor .
William Leonardi , ANDRITZ - Project Manager concludes : “ Our technical delivery was excellent – great teamwork . We delivered more than just equipment or a good project margin : our solution saves lives , reduces the environmental impact and prevents tragedies . The community is thrilled to see a dam deactivated .”
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