Statistical Optimization of Dry Deshaling for Indian Coals Using Response Surface Methodology

ABSTRACT

Dry deshaling is receiving renewed attention in the coal-mining industry. In this methodology, high-density rock is removed from run-of-mine (ROM) coal at the mine extraction point and prior to shipping. One of the popular technologies used globally, the density-based vibrating air-table, was tested on a pilot-scale at three different coal-processing facilities in India. In this article, statistical analysis of the resulting test data was conducted using response surface methodology (RSM). The study identified that out of the four major operating parameters (i.e., tilt, slope, fan speed, and table vibrations), vibration frequency and its combined effect with slope impact the deshaling performance the most. In addition, empirical equations formulated using regression analyses were used for simultaneous optimization of the significant parameters in order to achieve the highest performance for the separation of Indian coals. The optimal operating conditions were determined using a desirability function for the three coal types using the pilot-scale unit. The numerical solutions indicate that a high-deshaling performance for Indian coals can be achieved at operating conditions that include lower table vibration, higher slope, and lower fan speed.

KEYWORDS:

• Coal deshaling
• dry separation
• vibrating table
• inclined deck
• statistical optimization

Acknowledgement

The authors are immensely thankful to Dr. Rick Honaker, Professor and Chair of Mining Engineering — University of Kentucky and Dr. Tathagata Ghosh, Assistant Professor in Mining and Geological Engineering — University of Alaska Fairbanks for their assistance throughout the project. Special gratitude is also expressed to Eriez Manufacturing and Eriez, India, for the test equipment, field resources, and manpower that made much of this work possible. The authors would also like to acknowledge the tremendous support, field assistance, and cooperation extended by the management and staff at Aryan Energy, Bhushan Steel & Power, and Central Coal Ltd., Kargali Washery.

Funding

The authors would like to acknowledge the financial support for the pilot-scale test program in India provided by the United States Department of State under project S-L-MAQM-07-GR-341.

Additional information

Funding

The authors would like to acknowledge the financial support for the pilot-scale test program in India provided by the United States Department of State under project S-L-MAQM-07-GR-341.