00393nam a22001457a 4500008004100000040005500041080001300096100001900109245003100128260002900159300000900188490002600197650001200223653001200235230616b        |||||||| |||| 00| 0 eng d  aNational Science LibrarycNational Science Library  a622 bJ0  aWelwood, R J R  aMining technology in 1974   aCanada: bCANMET, c1976  a36p.  aCANMET report v76-29  aScience  aMining