UBC Theses and Dissertations
A technical and economic evaluation of run-of-mine coal transport by open channel flow Lytle, Murray Bryson
The recent economic recession in the free market economics of Western and Third World countries has had a negative impact on coal sales by western Canadian coal producers. Slower worldwide economic activity has reduced the demand for metallurgical and thermal coal and competition in world coal markets has increased. In response to this changing economic climate, Canadian coal producers must make their mining operations more efficient in order to retain their share of the world coal market. The Coal Mountain Mine of Byron Creek Collieries (1983) Ltd. is an open pit mine in the mountainous region of southeastern British Columbia. The mine currently transports the run-of-mine coal from the operating pits to the preparation plant in large, rear dump trucks. The current study was undertaken to investigate the economic feasibility of transporting the run-of-mine coal through near vertical, steel lined raises to an underground flume, where it would be conveyed to the preparation plant by open channel flow. An experimental program to measure the transport of run-of-mine coal through a 15.2 centimeter diameter, high density polyethylene flume was carried out. The recirculating fluid test apparatus provided data which was used to develop an equation to predict the rate of transport of coarse coal through the flume. The experimental program also measured the degradation of coal particles resulting from plug flow conveyance through a vertical, steel lined raise. The plug flow movement of coal through a 300 meter long by 1 meter diameter steel lined raise was simulated by passing 1.5 tonnes of coal through a 3 meter long by 75 centimeter diameter steel tube 100 times. The increase in coal fines resulting from this test was 3 percent by weight and the particle size degradation was restricted to the outer 2 centimeters of the coal column circumference. A computer program to model the project economics for an open pit coal mine using either a flume transport system or a truck transport system was written. The program was used to model the project financial risk by: i) generating net present value and internal rate of return frequency distributions, and ii) testing the sensitivity of the project economics to changes in selected input variables. Mine project economics were developed for the following five production and mine development cases: i) gradual development of an expanding mine ii) rapid development of an expanding mine iii) gradual development of a new mine iv) rapid development of a new mine v) replacement of coal trucks for an operating mine. In all the cases, the flume system was economically superior and was subject to less financial risk than the truck haulage system.
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