WORLD PROSPECTS
allmineral to refine Spanish ore to world market standard
For the construction of its new processing plant in La Parrilla, W Resources is banking on the Duisburg technology leader allmineral three times over to achieve its ambitious extraction targets. The Duisburg-based systems specialist was once again contracted by the mine operators in January 2018 after it had successfully completed the execution planning and construction of the‘ pre-concentrator’ using two alljig ® jigs. A fully customised processing plant to be commissioned on site by allmineral is soon to go online as the last process stage in the tungsten ore enrichment.
The La Parrilla mine close to the Portuguese border is one of five sites on the Iberian peninsula mined for mineral raw materials by W Resources( WRES). In the years to come the two alljig ® fines jigs and the adjoining processing plant will help double annual output in the Extremadura region to 5,000 t / y, without compromising on the competitive product quality, which is world market standard.
Thanks to the innovative processing technology the mine operators are confident of achieving a metal recovery of at least 90 % from the dressed ore minerals. The emphasis is on scheelite, a tungsten mineral that can be enriched through gravimetric grading, then enriched into concentrates with a tungsten content in excess of 66 %. The La Parrilla mine also extracts cassiterite, the world’ s most important tin ore, with a theoretical tin content of 78.8 %.
With a throughput of 350 t / h the two alljig ® jigs will provide reliable and adaptable grading, enrichment and cleaning of the pre-ground ore. The air-pulsed, resource-friendly twin jigs remain physically stable during operation, a precondition for an optimum jigging stroke with minimised energy consumption. With the alljig ® process the feed material is initially fluidised with pulsed water, with the grains graded according to density. The jigs separate the specifically lighter scheelite-poor yield from the specifically heavier scheelite-rich ore from the stratified material bed. The jigging motion used to separate the grains does not cause any wear and tear and is induced by adding air so the stroke movement( frequency, amplitude and waveform) can be adjusted across a broad range of operating parameters.
The Concentration Project was only commissioned by W Resources as recently as January 2018. allmineral is to install it as the third core component of the plant infrastructure and then adapt and commission it on site along with all the auxiliary units. The processing plant with a capacity of 155 t / h connected to the pre-concentration stage
ABEL tackles salt tailings in Austria
through the alljig ® jigs will ensure that the tailings are separated from the valuable material, thereby achieving a 65 % WO 3 recovery. The fines produced in several processing stages are to be recovered in a separate circuit.
For Michael Masterman, Chairman of W Resources, commissioning allmineral with the Concentrator Project is both a milestone and a mainstay in La Parilla’ s development and financing programme. All the key plant components are now contractually bound and aligned with the $ 30 million credit financing. allmineral is responsible for planning, building and supplying the main machine units, facilitating and expediting the timely completion of the plant as a whole within the stipulated cost framework. www. allmineral. com
Salinen Austria AG is one of Europe‘ s leading salt suppliers. Its three sites( Bad Ischl, Hallstatt, Altaussee) produce more than 3 million m 3 of brine. Because of this, Austria is one of the most important salt producers in Europe. The Altaussee mine is currently the largest producing salt mine in Austria, and it is one of the most fully automated subsurface raw material producers in the world. Almost 50 % of Austria‘ s salt production originates in the salt deposit of Sandling. Using targeted leaching of the salt-rich“ Haselgebirge”, they extract concentrated brine, chiefly from borehole caverns.
Salinen Austria AG contracted with Altmayer Anlagentechnik Gmbh & Co KG to construct a system that would be used to transfer tailings from the brine purification process which are used to pack the salt cavities that have been created. The method is, on the one hand, highly ecologically conscious in the sense of closed loop waste management, and, on the other hand, packing excavated caverns increases the stability of the underground works. The packing material is delivered by truck from the Ebensee salt works at a dry weight of approximately 70 % and unloaded into two hoppers. Using walking floors and screw conveyors, which are found on the floor of both hoppers, the packing material is conveyed into a mixing container( capacity approximately 84 m 3). Then, using an agitator, it is mixed with the brine
removed from the mine to form a homogenous solution with about 30 % dry matter.
The ABEL pump pumps the packing material out of this hopper at an internal design pressure of 40 bar and a capacity of 6 to 45 m 3 / h into the mine via a pipeline that is about 2.5 km long. The mined caverns are then refilled with the packing material. Once the suspension has had time to settle in the caverns, the brine is pumped back up to the surface and is again used for mixing.
Salinen Austria AG had planned to use a hydraulically driven double piston pump, known as a‘ thick matter pump’ or‘ solids handling pump’, for transporting the packing material. Because ABEL has this type of pump as well as piston membrane pumps in its product line, it was possible to convince the customer that a piston membrane pump was technically the better solution for this application. In contrast to solids handling pumps, which are primarily used for highly viscous, almost compacted media, the HMQ, as a piston membrane pump, is ideally suited for abrasive, liquid media.“ For this reason, the HMQ was clearly the better choice for conveying the packing material in this application.”
Because of the type of medium used in this case, ABEL equipped the HMQ-E-100-0500-ED for Salinen Austria with some custom features. Due to the high salt content of the packing material,
the suction and pressure lines, as well as the cone valve housing and pump housing, are made of stainless steel, so that the pump parts that come into contact with the product do not corrode. The integrated reversing valves are suited for use with the pumped medium and the process pressure. The reversing valves are installed in such a way that the medium‘ s direction of flow through the pump is reversed. The normal direction of flow for piston membrane pumps is from bottom to top; in this case, the medium now flows from top to bottom. The advantage gained through reversing valves is that the medium is pumped in the same direction of flow in which sedimentation may take place. This means that larger particles cannot lodge in the product valves and the membrane housings, and possible damage to the membrane can be avoided. s
4 International Mining | FEBRUARY 2018