Mobile & Mechanized bolting equipment in South African u/g coal mines.
Research output: Thesis › Master's Thesis (University Course)
This started in 2007 with the request from Khutala coal colliery in South Africa, the mine which is one of the largest u/g operations in South Africa, is producing some 12 Mt of coal annually from its 14 sections of u/g room and pillar mining. The mine was facing with issues of fall of ground, and high roof hang up in older areas in particular, some places reach up to 7 meters in height. These areas need to be secured by means of roof bolts and wire meshes. Due to these difficult conditions the standard roof bolters used in production section does not fit to such application, the roof bolting crew needed to prepare special platform and use precautious support material to secure such areas. These tasks are dangerous as one or more operators are required to assist the change out of drills rod, to insert the resin cartridges and to install the bolts, all of these task must be done up on height level platform and just underneath the unstable roof. The temporary roof support (timbers or hydraulic props) will secured the areas during the operation but all these tasks required long time preparation, sometimes the access roadways to production sections have to be diverted, thus impacting negatively the flow of logistic and therefore the overall coal production. The safety culture from the mining management was a major drive for the safety improvement; they then made requisition to order mechanized bolting equipment from Sandvik. In June 2009 the mine commissioned the first two mobile and mechanized bolting machines (DS310) from Sandvik, those units were originally designed for hard rock u/g mining application and some modifications works were done locally by Sandvik South Africa at Delmas to make these units to comply fully with the South African coal safety regulation. Today these units performed well, the machine has full autonomy; the unit is tramming, drilling and bolting with its on board diesel engine. The units carry water tank of 500 L capacity for holes flushing. The resin capsules, bolts and wires meshes are all installed mechanically, without man assistance. The operator control the whole drilling & bolting sequence remotely from the safety canopy. Then other coal mines starting to investigate in similar mechanized bolting unit, the main issue for Sandvik is that such mechanized units are well proven in hard rock mines but these are not in standard offering for coal industry and therefore the equipments built in OEM do not fulfill entirely to the coal mines regulation. The units have to be modified by local Sandvik service organization to comply with the coal mines specifications, but such practices does not suit to long term strategy of Sandvik. The request for safer bolting unit was increasing in coal industry, however the supply side seems not be reacting actively, in as much as none supplier except Sandvik prone to take this challenge. Therefore I decided to bring this strong request and make this into my SIMS project as I feel there will be great potential for safety and productivity development or both Sandvik and the coal mine industry. At first understanding, the mines safety regulation and longer distance tramming in old mines section are driving the needs for safer & mobile drilling and bolting machine. Are these the only purchasing criteria from the customers? What would be market potential for such machines? Is this a sporadic request from a few mines asking for customized bolting machines for their specific application? Or is this the start for the new trends in coal mining industry?
|Translated title of the contribution||Mobile & Mechanized bolting equipment in South African u/g coal mines|
|Award date||28 Oct 2009|
|Publication status||Published - 2009|