Highly Selective Lignite Mining and Supply

Abstract

Lignite is still the most important source of energy in Germany. In 2012, a total of 185.4 million tons of lignite was mined here. In addition to electricity generation and district heating, processed products such as briquettes, dust and coke are also produced. Besides this, a very small amount of lignite (~1% of the lignite mined worldwide) is used for non-energetic utilisation. In central Germany, the ibi alliance was formed to further promote this particular sector. The aim is to use lignite as a source of hydrocarbons by further developing technology, plants and processes. An alternative method of producing basic chemical products would reduce Germany’s dependence on oil and natural gas imports. The successful implementation of this goal requires not only the development of chemical processes but also a secure supply of lignite.Since deposit conditions in Germany will become more and more challenging (in deposit depth, seam splitting and - dips), more well developed extraction and conveyance techniques as well as mining technology will become preconditions if deposits are to be mined sustainably and economically.It is this issue that the companies MIBRAG, FAM, TAKRAF, ABB and Freiberg University of Mining and Technology are addressing in one of a total of five joint research projects within the ibi alliance.MIBRAG’s involvement includes the conception of mining technology where the selective extraction of different coal qualities plays a key role. Typical deposit data were defined and then used to formulate the specific technical requirements in terms of mechanical engineering.In most cases, the use of large machinery is favoured when planning mining operations. The research focuses on compact bucket wheel excavators that allow improved handling of biaxial inclination (up to 10%) as well as greater mobility.On the stopes and at the border slope system, continuous conveyor systems are considered for the transportation of overburden and coal. Due to the depth of the deposit, more challenging requirements have to be set for the conveyer system along the border slope system. Moveable transfer systems are to replace the conventional central, stationary mass distributors. Since the intention is to use the conveyer system in the border slope system to transport several qualities of coal before then transferring them to 2 main conveyer belts leading towards the coal pile, another crucial focus of the joint research project is on material tracking, controlling the conveyer routes (including for overburden) and stockpiling.Further research activities are focusing on the identification of mayor geological layers which shall be done during the mining process on the excavator. The main focus here is on contactless systems. Online raw material analysis can be used to write the data back directly into the deposit model.These innovations in the fields of engineering and sensor technology allow modified mining technologies. Furthermore it opens up the potential for significant improvements by mining geologically challenging deposits. In the ibi process, research is currently focused on lignite products only. Additional focus on “overburden products” in the future will make it possible to carry out accepted, resource-efficient and sustainable surface mining operations.KeywordsCoal SeamBiaxial InclinationJoint Research ProjectCoal QualityMining MachineThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.