• GLOBAL NEWS
Global news as an overhead beam type , are best suited for the operational conditions . The design of such machines enables them to process large volumes of material , yet remain robust and maintenancefriendly , since they provide easy access to the filter plates and filter cloths .
“ Sustainable water management , together with safety , are increasingly important topics for mining operations and all stakeholders around the world ; especially in areas where water conservation is critical and / or tailings failure risks are significant as has unfortunately been the case in Brazil . The Mineração Usiminas project is testimony that implementing a full DST solution , in line with the overall mine development plan , is an environmentally friendly and beneficial approach for stakeholders ,” noted Thiago Machado , Head of DELKOR products at TAKRAF Brazil . solutions that best suit a client ’ s specific requirements , as well as providing the client with a single point of responsibility during implementation . This approach has resulted in clients not only procuring equipment for tailings treatment , but also in contracting TAKRAF to carry out conceptual studies and economic trade-offs for DST systems .
DST system designed for Brazilian Mining Company The result has been a DST system designed early this year for Mineração Usiminas , one of the Usiminas companies , and one of the largest steel producers in the Americas . The order comprised basic and detailed engineering , manufacturing , supply , transportation , and site assembly supervision of equipment to process iron ore tailings .
The system is designed as a fully integrated dewatering process via thickening and filtration and includes the following main equipment :
• 1 x flocculant plant
• 1 x coagulant plant
• 1 x DELKOR high-rate thickener : 35 m-diameter , 680 t / h ( nominal ); 748 t / h ( design )
• 1 x 300 m2 slurry tank with agitator
• 4 x double stage centrifugal slurry pumps
• 4 x DELKOR filter press overhead beam ( FP OH ): 2 m x 2 m plates , each 170 t / h ( nominal ) and 187 t / h ( design ), capacity for 215 chambers
• 4 x compressors with tanks ( process and instrument air )
• 4 x TAKRAF belt feeders : 2.0 m width , 31 m length with transfer chutes
Mineração Usiminas implemented the DST system to enable the filtering and stacking of tailings as the deposit area of the existing tailings dam reached full capacity . The process dewaters the tailings slurry in a single stream – a two-stage process using a DELKOR high-rate thickener followed by the filtration of thickener underflow using DELKOR overhead filter presses . The next process step allows further water recovery through the filter press , designed to achieve a moisture content level of about 14 % ( dry basis ). Particular attention was given to the redressing of the slurry using reagents to improve maximum recovery . The result is a dry filter cake that can be effectively handled and deposited .
In order to supply site-specific solutions , the tailings material was extensively tested prior to the selection of the equipment . For example , the filter presses , designed with a collaboration partner
10 • African Mining • July 2022
GAF AG
For further information , visit : www . takraf . com
AMAZONIA :
SATELLITE DATA HELPS TO DETECT ARTISANAL MINING – GAF DEVELOPS ASM ALERT
Detailed example of ASM alerts for Quarter IV in 2021 – lilac dots on the BING map background indicate new activity along river courses . The closer the dots are to the river , the higher the probability is that the forest disturbance relates to ASM .
GAF has developed and implemented an easy-to-use web-based system to recognise indications of unlicenced artisanal and smallscale mining ( ASM ) in tropical forests - the “ ASM Alert ” platform .
The platform combines free and publicly available satellite data – in particular European Copernicus Sentinel imagery - with a number of other geodata layers and machine-learning for the analysis . The platform then enables the ordering of commercial , very-highresolution ( VHR ) satellite imagery for the identified target areas . The implementation project is being conducted by GAF , Germany , together with the partner IES , Netherlands , and is funded by the European Space Agency ( ESA ).
The ASM Alert platform is funded by ESA and has been implemented in a project being carried out by GAF ( lead partner ) and Institute for Environmental Security ( IES ), Netherlands . It provides analysis of high-end data from VHR satellite imagery , in particular from the European Copernicus Programme . The project aims to identify unlicenced ASM in tropical forests , which can have considerable negative effects .
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