Application of softrock mining equipment for hard rock mining in a Bord and Pillar operation at KGHM

Alois Leitner

Research output: ThesisMaster's Thesis (University Course)

Abstract

This report deals with a new opportunity for Sandvik Zeltweg located in Austria to use a soft rock mining machine within a hard rock mine, in this special case a copper mine, for advancing roads in a room and pillar mining system where the strength of the rock strength is limited to 140 MPa. This will open a new market area for Sandvik Zeltweg in terms of entering the hard rock sector with a mechanical excavator which will bring advantages in terms of equipment choice offered to customers. A trial with a bolter miner will be carried out at KGHM Rudna Mine located in Poland currently operating with a drill and blast method. Representatives of KGHM visited coal mines in South Africa in order to get an understanding of the room and pillar mining method used and how that mining method would be adapted to mine copper. The machine that would be used to mine copper at KGHM Rudna mine is called the bolter miner MB610 type. This bolter miner machine is able to cut the ore, load it onto a truck or shuttle car and support the roof simultaneously. It has the advantage of replacing a drill rig for drilling blast holes, a bolter for supporting the roof, and all equipment’s associated with the use of explosives in a typical drill and blast section. Because copper is harder than coal it is envisaged that a new generation of cutting tools will be used. The report will cover the technical aspect of using the bolter miner and the mining method changes envisaged, however, it will not cover the economic aspects of these changes. The mining layout or roadway shape at KGHM Rudna mine are in the shape of a trapeze because of safety reasons. The mine does not intend to change the shape of these roadways as this will pose difficulties when advancing these roadways with a cutter drum which is only able to cut rectangular shaped roadways. Although Sandvik would be able to provide an option of retracting the drum during shearing down, this will limit the machine in terms of performance and maneuverability. Sandvik believes that because drilling and blasting causes damage to the pillar more than mechanical cutting, it is best to have rectangular roadways. The report will cover in detail how the bolter miner will increase the productivity of the mine and therefore make this trial feasible. The mine has a production target of 20 m³/h of copper. Sandvik will demonstrate how this production target will be met using all the mining, geological and machine parameters. These parameters will take into account the cutting rate which depends on the roadway height as well as on the uniaxial compressive strength of the rock, detailed rock parameters, cutting width, cutting height, working shift cycles and expected cutting time on the face. Calculations will be shown that takes into account the best case scenario and worst case scenario. From the calculations it will be shown that the production targets would not be met in the worst case scenario because the uniaxial compressive strength of the rock reaches a maximum value of 140 MPa. However, in all the cases including the best scenario all the mine production targets are met and exceeded. Finally, the report will discuss the mining layouts and sequence of mining that would need to be adopted by Rudna mine in order to increase productivity.
Translated title of the contributionApplication of softrock mining equipment for hard rock mining in a Bord and Pillar operation at KGHM
Original languageEnglish
Supervisors/Advisors
  • Moser, Peter, Supervisor (internal)
Award date25 Oct 2012
Publication statusPublished - 2012

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