INDIA 2016

Best of Germany 2014 - Mining Equipment and Mining Technology

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2016 • VDMA MINING SUPPLEMENT VDMA 35 Primary and Secondary Sizers With hundreds of complete systems, as well as individual machines, having been supplied to clients all over the world, Tenova TAKRAF is a key supplier of equipment and systems for open-pit mining and bulk handling. Recently, TAKRAF enhanced its product portfolio with the ad- dition of sizer equipment, which now enables the company to integrate its own crushing machines into complete mining solutions for its clients. TAKRAF offers standardized primary and secondary sizers for var- ious crushing applications. The primary sizer product range accepts feed sizes from 2.5 m to 4 m with a throughput of up to 10,000 metric tons per hour (mt/h); the secondary sizer range accepts feed sizes from 2 m to 4 m with a throughput of up to 3,500 mt/h. Both sizer product ranges are suitable for the comminution of all material types, from stan- dard to most challenging. During the sizer's initial development, TAKRAF paid close attention to attributes such as ease of maintenance, reduced downtime and long equipment service life. Some of the innovative solutions adopted in- clude the quick and easy changing of crushing segments, as well as the use of advanced wear-resistant materials such as hard-faced segments and tungsten picks. Other innovative solutions include an inching drive for roll maintenance, which increases safety significantly, a heavy-duty drivetrain system, as well as adopting an efficient oil lubrication system with a view to greater environmental sustainability. The TAKRAF sizer model type TCS 12.16 will be installed at the test facility in Germany. BWEs Engineered for Harder Formations The engineers at thyssenkrupp have announced two smaller BWEs (the Barracuda and Mine Shark) that can be used for harder formations (compressive strengths to 50 megaPascals). Traditionally, BWEs work well in soft formations with compressive strengths well below 20 MPa, mining mostly lignite, oil sands, phosphate, etc., that run 5 MPa to 10 MPa. To convert the BWEs to cutting from digging, improvements have been made to both the bucket and the teeth, as well as to the power train and the steel structure. Thyssenkrupp's R&D teams determined that a larger number of stronger teeth and buckets, combined with more cutting torque, would be key for the extraction process. Of course, com- bining the extraction and loading process into a single machine gives the BWE a great advantage and it eliminates the need for blasting. These new BWEs are expected to produce more than 3,000 mt/h. "These news BWEs could handle some of the hard coals found in Australia, Indonesia and India," said Thomas Jabs, executive vice president, thyssenkrupp. "We are trying to incorporate this BWE cutting technology into machines that are smaller, more flexible and easier to operate than the traditional BWE." Solids Handling Pumps Many gold operations process ore through autogenous grinding mills. Ground ore is classified by hydrocyclone separators and ball mills re- grind the coarse material. Sized materials are sent through a flotation process where the sulfide minerals are separated and concentrated (flotation concentrates) and sent to a thickener/filter press circuit prior to roasting. The thickener/filter press circuit reduces the amount of water in the flotation concentrate and is typically pumped using horizontal centrif- ugal pumps. The use of this type of pump can be counter-productive because water must be added on the thickener cone bottom to assist transport by the pump. Also, gland seal water must be added to the centrifugal pumps in the two pumping stages. In total, the volume of water introduced back into the thickened underflow fed to the filter press can be increased by as much as 25%. One plant replaced their centrifugal thickener underflow pumps with ABEL series EM 100 electromechanical diaphragm pumps. Cone water additions and gland seal water were no longer required thus helping the process substantially. Also the maintenance costs associated with the thickener underflow pumps was greatly reduced. This same plant's filter press feed pumps had also originally been centrifugal slurry pumps. Wear on the centrifugal pumps was consider- able with pump wet ends wearing out as often as every two weeks, and costing as much as $20,000 each time. Downtime and lost production mounted with each repeated occurrence. To mitigate the problem, the centrifugal filter press feed pumps were supplemented by ABEL series HMD-G-80-1000 piston-diaphragm pumps. The ABEL pumps employ a hydraulically balanced elastomer- ic diaphragm, ideal for moving abrasive slurry at higher pressures. By working in parallel, the centrifugal pump "fast-fills" the filter press at lower pressures, then hands over consolidation of the press cycle to the ABEL. The resulting pump maintenance costs and down-time were greatly reduced. Filter cake quality was improved due to the positive displacement action of the ABEL pump. In early 2011, the same plant added another process train of thickener and filter press to increase the Hydraulic Diaphragm Pump HMD-G-80-1000 gold production. ABEL EM 100 pumps were specified for thickener underflow and ABEL HMD-G-80-1000 pumps were speci- fied for filter press feed duty. The ABEL HM series pumps are hydraulically-driven, piston-diaphragm pumps. Reciprocating motion of the piston moves an elastomeric di- aphragm by means of a hydraulic end. Ball checks and seats on the product end are available in various materials. This characteristic de- sign allows the pump to transfer abrasive slurry or sludge at pressure up to 1,450 psi (10 MPa). The ABEL EM series pumps as used on the thickener underflow have a similar wet end construction as the HM . i nno V a T ions: a n a ssor TM en T o F e qui PM en T F or Mines and Mills

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