Numerical modelling of out-of-seam dilution in longwall retreat mining

Date

2010-06-01

Author

SAEEDI, G.
SHAHRIAR, K.
REZAI, B.
Karpuz, Celal

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

236
views

0
downloads

Longwall mining is a common mining method in Iran that is often affected by out-of-seam dilution (OSD). The field investigations performed in Tabas coal mine show that OSD often occurs due to roof falls in front of the face area before support setting and also removing some floor material. The increase in unsupported roof span above the shearer may cause difficulty in controlling the roof and consequently increases dilution of the run of mine (ROM) coal. The paper presents the results of a study on some dominant factors causing OSD in prop-free front of the face in longwall retreat mining method. A series of two-dimensional numerical models are developed and analyzed to examine the effects of mining depth, in-situ stress, unsupported roof geometry above the shearer as well as roof and floor strata quality and dip of coal seam on OSD. Two criteria were established, one considers the roof falls, defined as low stress level or plasticity zones under yield tension which roof material unravels and other is about removing floor, defined as depth of support and shearer sinking into the floor. The equivalent linear relaxation depth (ELRD) and depth of removing floor (DRF) concepts were used to quantify OSD. The methodology presented in this study is useful since it can be applied to develop mine-specific design tools for the prediction of OSD.

Subject Keywords

Geotechnical Engineering and Engineering Geology

URI

https://hdl.handle.net/11511/36667

Journal

INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES

DOI

https://doi.org/10.1016/j.ijrmms.2009.11.005

Collections

Department of Mining Engineering, Article

Suggestions

OpenMETU
Core

Penetration rate prediction for diamond bit drilling by adaptive neuro-fuzzy inference system and multiple regressions BASARIR, HAKAN; Tutluoğlu, Levend; Karpuz, Celal (Elsevier BV, 2014-05-01) In many mining, civil, and petroleum engineering applications diamond bit drilling is widely used due to high penetration rate, core recovery and its ability to drill with less deviation. Recently, many research have been conducted to estimate the penetration rate of diamond drilling which can be considered as one of the most important parameters in project planning and cost estimation of the operation.
Seismic Risk Assessment of Masonry Buildings in Istanbul for Effective Risk Mitigation Erberik, Murat Altuğ (SAGE Publications, 2010-11-01) Unreinforced and non-engineered masonry buildings are highly vulnerable to seismic hazard and constitute a significant percentage of earthquake losses, including both casualties and economic losses. This study presents an engineering application on seismic safety assessment of unreinforced masonry (URM) buildings in Istanbul, Turkey, a metropolitan city under very high seismic risk. Nearly 20,000 masonry buildings were examined through a two-stage assessment procedure in order to identify the addresses of t...
Empirical attenuation equations for vertical ground motion in Turkey Kalkan, E; Gulkan, P (SAGE Publications, 2004-08-01) In the aftermath of two destructive urban earthquakes in 1999 in Turkey, empirical models of strong motion attenuation relationships that have been previously developed for North American and European earthquakes have been utilized in a number of national seismic hazard studies.. However, comparison of empirical evidence and estimates present significant differences. For that reason, a data set created from a suite of 100 vertical strong ground motion records from 47 national earthquakes that occurred betwe...
Performance assessment of cement grout borehole plugs in basalt Akgün, Haluk (Elsevier BV, 1994-01-01) Flow tests have been conducted on expansive cement grout plugs with diameters of 160 mm and 200 mm, and length-to-diameter ratios of one, in boreholes in basalt blocks and in steel pipes. Two types of flow tests have been performed: pseudo-constant head tests and transient pulse tests. Hydration temperatures of cement grout plugs have been monitored in steel pipes with inside diameters ranging from 110 mm to 200 mm. During flow tests, basalt blocks have fractured, presumably due to water injection pressure,...
Assessment of grinding additives for promoting chromite liberation Camalan, Mahmut; Hoşten, Çetin (Elsevier BV, 2019-06-01) Liberation of the valuable minerals of an ore from its gangue is a prerequisite for the economic recovery of the valuable minerals to concentrates. Mineral liberation is achieved by reducing the size of ore particles in various crushing and grinding devices. The fineness to which the ore must be ground, so as to yield sufficient degrees of liberation, increases if the valuable minerals with small grain sizes are disseminated throughout the gangue. Intensive fine grinding, however, increases energy costs and...

Citation Formats

G. SAEEDI, K. SHAHRIAR, B. REZAI, and C. Karpuz, “Numerical modelling of out-of-seam dilution in longwall retreat mining,” INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES, pp. 533–543, 2010, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/36667.