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2 536 209 $ 3 078 586 $ 3 218 734 $ 2 890 011 Tons of ore produced ( Table 3 ) .. Operating cost per ton ore . Total expenditure per ton ore . Average grade of ore mined .. 194 480 $ 9.63 $ 13.04 $ 37.98 266 867 $ 9.
Table 3 shows that the NO2 red fumes , which in smallest amounts are dangerous to breathe are produced when dynamite is burned instead of detonated . Also , in blasting coal with black pow . der , the products differ from those in the ...
In Idaho mills , treating coarsely disseminated lead ores , shipping ore picked out ranges to 60 % of total concentrate produced . Labor for sorting is generally unfit for heavier work : boys , girls , women , or old or crippled men .
Apa yang dikatakan orang - Tulis resensi
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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