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Title: Analysis of the applicability and probable cost effectiveness of advancing longwall-mining systems in the United States. Final technical report. [Advance vs retreat]

Technical Report ·
OSTI ID:5902386

In the first phase of this study it was concluded that there are a number of advancing longwall systems that might well be applicable in the United States and, furthermore, meet the health and safety requirements of MSHA, state inspectors, operating management, and unions. Comparative analyses showed that only two of the advancing-type systems evaluated in the Phase I report failed to approach or better, economically, the typical retreating method in at least some conditions; the others appeared to warrant further attention. And if the mining plan could be worked out to allow for a switch from advancing to retreating after the early years of mining, then almost any combination of advancing and retreating would provide a better return on investment, or in our terms, have a higher net present value than would a typical retreating system. The reason for this lies in the higher initial production rates of the advancing systems and in the lower operating cost and higher ultimate productivity of a retreating system once it is established. After analyzing the advantages and disadvantages of the various advancing longwall systems for a trial program it became apparent that the modified Z System offered the best combination of economic potential and lack of conflict with US mining laws. The major attraction of the modified Z system is that it provides separate roadways to the face for intake air, exhaust air and a beltway. Thus regulatory approval of the ventilation system should not be a major obstacle. The Kaiser Steel Corporation agreed to cooperate with the development of a specification for a trial of the system at its Sunnyside Mine in Utah. The specification was developed for one longwall face to mine a series of panels at Sunnyside.

Research Organization:
Ayers (Emory) Associates, Inc., New York (USA)
DOE Contract Number:
AC01-77ET12478
OSTI ID:
5902386
Report Number(s):
DOE/ET/12478-T1; FE-9061-1; ON: DE82002424
Resource Relation:
Other Information: Portions are illegible in microfiche products. Original copy available until stock is exhausted
Country of Publication:
United States
Language:
English