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008181121s1976    onc    #ot   f|0| 0 eng d
020 |z0660005786
040 |aCaOODSP|beng
041 |aeng|bfre
043 |an-cn---
0861 |aM38-13/76-29E-PDF|zM38-13/76-29
1001 |aWelwood, R. J. R.
24510|aMining technology in 1974 |h[electronic resource] / |cR. J. R. Welwood.
260 |a[Ottawa] : |bEnergy, Mines and Resources Canada, |c1976.
300 |aiii, 36 p. : |bfigures.
4901 |aCANMET report ; |v76-29E
500 |aCover title.
500 |a"September 1976."
504 |aIncludes bibliographic references.
520 |a"The tonnage of metallic ore mined underground in Canada decreased slightly to 64.4 million tons in 1974 from 65.5 million tons in 1973, a decrease of 1.7%. An increase of less than 1% in surface-mined ore brought the total from surface operations to 239.7 million tons, i.e. approximately 79% of the total metallic ore mined in Canada. In the non-metallic mines, there was a 10.6% increase from underground, largely owing to increased production of potash. A minor increase occurred in surface-mined non-metallic ores. During 1974, approximately 40% of the metallic underground ore was mined by cut and fill methods or variations, followed by open stoping with about 36%. The tons mined by other underground methods were slightly reduced. Sharp rises in underground mining costs are noted for 1974. This trend is expected to continue at a high rate in 1975. Surface mining costs in general showed only slight increases"--Summary, p. i.
546 |aIncludes summary in French.
69207|2gccst|aMining technology
7101 |aCanada. |bEnergy, Mines and Resources Canada.
830#0|aCANMET report ;|v76-29E.|w(CaOODSP)9.852792
85640|qPDF|s978 KB|uhttps://publications.gc.ca/collections/collection_2018/rncan-nrcan/m38-13/M38-13-76-29-eng.pdf