Development of an Automated ΔP Instrument and its Application to Mining, Handling and Preparation Problems

Abstract

The L\P instrument measures the rate of gas release frorn coal under standard conditions. The original development of the technique took place in the USSR and France for use as an indicator of a coal seam's susceptibility to gas outburst in underground operations. In Canada, the L\P technique was applied to coal degradation, oxidation and handling problems.This paper describes the development of a L\P instrument for industrial use. The original glass instrument was redesigned in order to automate control of the entire procedure and record experimental data by using a desk top computer. Principles of operation, instrument design and test procedure are detailed along with relevant data. Application of the L\Pdata for prediction of gas outburst propensity, handling, degradation and oxidation properties are discussed and compared with operating data and/or alternate predictive measurements. Emphasis is given to applications relevant to coal handling and preparation problems.

Application of a δP Technique to Monitor Oxidation of Nigerian Coals

“…The AP index correlates well with the quantity of fines produced (Mikhail and Mikula 1989) and with size degradation data obtained from conventional wet attrition tests (Belin and Chiche 1962). The AP index measurement is faster and requires a smaller quantity of sample than for the wet attrition test (Mikhail and Mikula 1989).…”

“…The AP technique has proven to be useful in predicting and/or monitoring coal oxidation, explosions as a result of gas (particularly methane) outbursts, and size degradation that may occur during coal mining, handling, transportation, and storage (Mikhail and Mikula 1989). Oxidation or weathering generally affect coal quality and preparation (Berkowitz 1989).…”

“…This technique was also used to monitor the degree of oxidation of western Canadian coals (Mikhail and Mikula 1989), and has many advantages over the conventional methods. It is relatively simple, cheap, adaptable for field use, less laborious, more-orless comparably accurate, and as an empirical method has applications for a wide range of rank and type of coals.…”

“…Sudden outbursts of gas such as methane result in safety problems during mining, handling, and storage of coal, while size degradation or fines production affects the performance, design, and cost (capital and operating) of coal preparation plants. The higher the quantity of fines produced, the higher the cleaning costs and the higher the cost of dewatering coal-water mixtures transported by pipelines (Mikhail and Mikula 1989). Measurement of each of these characteristics (oxidation.…”

“…The AP index measurement is faster and requires a smaller quantity of sample than for the wet attrition test (Mikhail and Mikula 1989).…”