Modern Mining October 2019

Weba assists Mexican mining operation

As part of a significant investment to improve its processing facilities and enable the recov- ery of 40 % of the gold that currently sits in its tailings as waste, a mining operation in Mexico called in a leading transfer point and chute systems OEM to conduct a thorough assess- ment of the functionality of existing chutes in the plant. Leveraging its in-depth knowledge of mate- rial behaviour in chute systems, Weba Chute Systems & Solutions was tasked with establish- ing the feasibility of introducing filtered tailings at a rate of 1 200 t/h onto the existing transfer system currently handling waste with a nominal size of 400 mm at a rate of 5 000 t/h. Alwin Nienaber, Technical Director at the company, explains that while the intention is for the filtered tailings to be conveyed when the waste rock is available, it would still mean that the same chutes would need to function transferring completely different material. “Optimally, one should be able to assess a working transfer chute handling the actual material; however, in the case of a feasibility assessment this is not possible, and we there- fore started with a review of the test work and studies prepared by independent qualified pro- fessional materials handling experts.” This was done by Weba Chute Systems & Solutions by calibrating the material conditions and behaviour using Discrete Element Method (DEM) software. “Use of DEM allowed our technical team to model the interaction between indi- vidual particles and boundaries and, in so doing, to accurately predict the bulk solids Becker Mining South Africa’s energy division has been awarded a contract to upgrade the Programmable Logic Controller (PLC) infrastruc- ture at a leading coal producer’s underground operations. “This project comprises the design, manu- facture and installation of 15 different PLCs, where each controller will monitor separate divisions underground. This new system will control the run and stop commands of conveyor belts and also manage safety signals,” explains Nico de Lange, Vice President: Operations & Systems, Becker Mining South Africa. “All PLCs will be linked to the mine’s SCADA system, with accessibility to control functions remotely from the control room. “This advanced system, which has been cus-

A simulation showing material flow from the front.

tom-designed by Becker Mining, is expected to enhance productivity, reduce energy consump- tion and improve safety on the mine. “The controllers are currently in production at Becker Mining’s manufacturing facility in Alrode to meet the mine’s exact specifications. Our project team will be responsible for removing the existing system and replacing it with the new controllers, without any loss of production time to the mine. The Becker Mining team will also carry out the commissioning of the new system.” The new enclosures have front and rear access, with a glass window on the front outer door for clear visibility of a 17-inch display fitted on the inner door. The units have an IP65 rating to guard against the ingress of dust and water. Becker Mining South Africa, website: www.za-becker-mining.com The feasibility assessment included the transfer of sedimentary dry tailings, sedimen- tary filter cake, Breccia dry tailings and Breccia filter cake. DEM modelling was done consider- ing material on its own and conditions where blended material would be conveyed. In total, there were four conveyor transfer points that had to be assessed. These included an in- line transfer point, a 90 deg transfer point, a transfer from conveyor to radial spreader inter- mediate conveyor and then onto the spreader boom conveyor. Weba Chute Systems & Solutions, website: www.webachutes.com behaviour,” Nienaber explains. Access to DEM software allows engineers to predict bulk material flow patterns and flow rates, as well as velocity patterns and dead zones within the transfer system. It also provides accurate information on particle dis- tribution in segregation and blending and the impact forces on particles and boundary sur- faces, showing wear patterns.

Becker to upgrade PLC infrastructure

October 2019  MODERN MINING  47