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Example 10a . Tri - State Field , Zinc and Lead Mining ( Concluded ) Table 38. Average Cost per Ton of Ore Mined and Milled 1921 1922 1923 1924 Labor ( all classes ) Salaries .. Explosives .. Supplies and repairs .
Example 18. Noranda Mines , Ltd , Hudson Bay Mining & Smelting Co Table 53. Operations for 1937 Ore mined , tons .. 3 667 920 Metals recovered , Ib : Copper . 138 160 353 Tellurium .. 12 850 Zinc .. 68 972 224 Cadmium .
Example 21. Iron Mining Costs Efforts made to obtain representative current costs of producing iron ore have been without success , for the reasons given in the Introduction to this Section . In the absence of recent costs , it has been ...
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LibraryThing ReviewUlasan Pengguna - wackyvorlon - LibraryThing
I only have the second volume of this work, and I love it! Found at a local Value Village, it is filled with fascinating information. Details of all aspects of mine engineering, including compressed air, ventilation, and supporting structures. Baca ulasan lengkap
Conditions Methods in General
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