SCREENING TECHNOLOGY
Using the current footprint , a customer wanted to replace an existing screen in a SAG mill copper installation with a General Kinematics STM- SCREEN™ . The SAG discharge screen experienced surges of material ( 25 %-40% solids ) from the SAG mill , which overloaded their existing screen . During these frequent overload surges , the stroke / throw reduced significantly . This caused a substantial reduction in screen efficiency . “ The excessive fines & moisture carryover occurred in the screen oversize feed to the pebble crushing circuit . The existing SAG mill discharge screen had a single deck design of 3.6 m x 8.5 m and handled less than 1,900 t / h when screening at 13 mm . This quickly became the process limitation . In an attempt to assist the movement of material off the deck and reduce the frequency of overloads , the customer decided to incline the screen and upgrade the drive . Even with the modifications , the screen could not meet the desired capacities .” General Kinematics ’ STM-SCREEN™ retains material for approximately 26-33 seconds versus a typical brute force screen that retains material for approximately 6-8 seconds . The longer retention time allows for an optimised material separation as fines have more time to drop out . Equally as important is the ability of the STM-SCREEN™ to process at a higher bed depth , without sacrificing throughput . A higher bed depth at the screen feed end spreads out across the width , while the increased retention time processes the specified tonnage .
“ The Two-Mass design utilises the weight of opposing forces running 180 ° out-of-phase . During material surge conditions , common in mining operations , the added weight that hits an STM- SCREEN™ does not cause it to dampen out . An STMSCREEN™ picks up in stroke as material surges . This consistency of stroke ensures that there is no loss in screening efficiency . Material surges on competitive brute force screens dampen the stroke and diminish screen efficiency . The efficiency improvement , even at depressed copper prices , returned the full investment in the GK STM-SCREEN™ in only a few days .”
Binder + Co ’ s innovative BIVITEC e + range
The Austrian specialist for processing technology for raw materials and recyclables , Binder + Co has recently launched the latest innovation in its flip flow screen series with the BIVITEC e +. " Innovation at Binder + Co does not only mean the development of new machines , but also providing our customers with the possibility of achieving the greatest possible benefit from valuable raw and recyclable materials during processing ,” explains Jörg Rosegger , Binder + Co Management Board member . The aim of the product range extension is to offer customers an economic solution in terms of investment and operating costs . In order to achieve this , Binder + Co has combined two
AKW ' s AKA-SCREEN success
For more than 55 years AKW Equipment + Process Design has been successfully active in the field of wet mechanical processing . Known for capabilities in providing mining customers with high performance and state-of-the-art process solutions , it extended a few years ago its scope of supply by the addition of wet classification screens , type AKA-SCREEN – with it says significant success .
“ The AKA-SCREEN series is using two unbalanced motors with up to 2 g acceleration . This generates a composite-vibration of linear motion of the whole screen frames and additionally mesh vibration . The vibrating parameters can be controlled through frequency conversion . The AKA-SCREEN consists of up to five individual screen decks , available in standard or long version .” Screen mats are made of reinforced polyurethane . The screen frame is entirely coated with polyurethane , and integrates a spraying system as well as a repulper ( as option ) for optimum screening efficiency . AKW says the AKA-SCREEN brings to the customer unique advantages : n Efficiency : open screen area ranging from 30 % to 40 % n Product range : the screen mats are available with mesh size from 63 μm up to 2 mm n Quality : from the screen frame down to the screen mats , as well as in the performance accuracy granted n Flexibility : customised sizes are available upon request n Design : standard or long screen version , fast exchange of panels , optimised footprint
“ Besides theoretical knowledge and practical supports , AKW Equipment + Process Design has made a unique step through the installation at its German Technical Centre of a lab-scale AKA- SCREEN screening test device , able to carry out lab and pilot tests for , and with , its customers . Be it for ores and minerals , commodity or specialty sands , the AKA-SCREEN series breaks a monopoly and offers a fully automated and low energy system that is robust , performant and competitive ,” explained Thibaut Richard , General Manager at AKW Equipment + Process Design .
The mining applications of the BIVITEC e + range include metallic ores and industrial minerals like salt designs from its screening machine programme in one machine : the low dynamic loads resulting from mass balancing of the resonance screening machine and the BIVITEC flip flow system . The mining applications of the BIVITEC e + range includes metallic ores and industrial minerals like salt .
This machine fusion results in a lightweight construction and the associated lower drive power . This means that the BIVITEC e + can save up to 40 % in weight and up to 65 % in energy . The low dynamic loads of the latest Binder + Co flip flow screen permit a smaller dimensioning of the substructure , which can significantly reduce investment costs . This is also of interest for retrofitting or machine replacement in existing plants , as the existing infrastructure can be used without the need for expansion or reinforcement .
The BIVITEC e + can be designed as a single deck screening machine as well as a multi deck version and can be stacked as often as required . A further advantage of this flip flow type is the adjustability of the vibration characteristics . “ Each screen deck can be individually adjusted , which is particularly advantageous when both unproblematic and difficult-to-screen separation cuts are to be made on one machine .”
Derrick continues iron ore success in Brazil and Ukraine
Derrick Corporation has continued the introduction of its new SuperStack ® high frequency vibratory screening machine with more installations at Vale ’ s Carajás beneficiation plant in the Para state of Brazil . Vale is one of the largest global producers of iron ore . The 8-deck SuperStack offers a significantly higher production capacity in a smaller footprint than conventional screening equipment , while also offering increased quality of iron ore concentrate . The SuperStacks will be installed at the Gelado project , transforming tailings into concentrate product . By using SuperStack screens , this new
46 International Mining | OCTOBER 2020