A technical and economic evaluation of run-of-mine coal transport by open channel flow
Bibliographic record
Abstract
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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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".