Institute of Coal, Federal Research Center of Coal and Coal Chemistry, Siberian Branch, Russian Academy of Sciences, Kemerovo:

V. I. Klishin, Director, Corresponding Members of the Russian Academy of Sciences
B. A. Anferov, Leading Researcher, Candidate of Engineering Sciences
L. V. Kuznetsova, Leading Researcher, Candidate of Engineering Sciences, lvk@icc.kemsc.ru

Coals and their conversion and utilization products can be an unconventional mineral source of valuable chemical elements. The authors of the article propose a process flow chart for by-product extraction from top coal bed and/or roof rocks. The technology involves additional exploration of coal reserves and useful associates during first mining in an extraction panel for the reasoned decision-making on selective coal extraction. A face area is equipped with a set of stand-and-shield powered support units. The goaf-side shield of the support has a discharge window and a chute with a feeder, which allows the support to be operated without top coal discharge when the window is shut and with the top coal discharge to a face conveyor when the window is open. In the internal space of the safety screen, a shearer is located to exert the dynamic impact on top coal or roof rocks and to break them into transportable fragments. Using the different operating modes of the support enables reaching high selectivity of mining in coal beds of variable thickness. Moreover, no maintenance staff is required to be present in the working zone, which allows robotization of the technology. Making the process pauses in the operation of the face conveyor and loading of different kinds of rocks and coal on different types of transporters enable separating flows of coal and other mineral raw materials at the sustained natural quality (dilution of coal and dirt is eliminated). Transition to this technology, although at lowered face capacity in terms of coal, offers higher output of rock mass containing chemical elements of high value.
The studies have been partly supported under the Integrated Program of the Siberian Branch of the Russian Academy of Sciences, No. II.2P: Intergation and Development; Project No. II.2P/IX.132-8: Aerogasynamics and Technology Cointrol in Coal Mining toward High Safety with the By-Production of Methane and Chemical Elements of High Value.

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