E/MJ : engineering and mining journal . and waste must lie handled with care to insure a cleanshipping product. As stated, dips in the cut vary from25 to 15°., and the amount mined per man will vary withthe dip. On the sleeper slopes, where the rock slide-easily, one man can bring down as much as 25 or 30 tonsof ore and waste per day. The proportion of this that canhe accounted for as ore will of course vary with the com-position of the section being mined. Including and cleaning the magnesite on both sides, 25 menand 1. teams produce 45 tons of shipping product perday ; so th
E/MJ : engineering and mining journal . and waste must lie handled with care to insure a cleanshipping product. As stated, dips in the cut vary from25 to 15°., and the amount mined per man will vary withthe dip. On the sleeper slopes, where the rock slide-easily, one man can bring down as much as 25 or 30 tonsof ore and waste per day. The proportion of this that canhe accounted for as ore will of course vary with the com-position of the section being mined. Including and cleaning the magnesite on both sides, 25 menand 1. teams produce 45 tons of shipping product perday ; so that, considering the thin seams, the frequent tiatdips, the careful breaking and handling necessary, themethod is not so expensive as it might seem. In order to reach those seams lying too deep for openeutwork a lxl-1t. shaft (with a gasoline hoist) has been sunkto a depth of 100 ft., at which point it meets an incline185 ft. long with an average pitch of 23°. About 550 ft. ofdrifting and erosscutting has been done from the shaft, and. SEDIMENTARY MAONESITE DEPOSIT OPERATED BY REX PLASTER CO. NEAR BISSKLL, KERN COUNTY, CALIF. as it is desirable to avoid the mixing of waste and ore asmuch as possible. The work is carried on by on the order of eoal mining, which can beaccomplished in the softer strata by the use of a pick cut is carried under the waste until a seam of goodmagnesite is reached. The waste above the undercut isthen broken by working upward and picking as much aspossible, pulled down and wheeled out of the way. leavingihe seam of magnesite exposed. The magnesite is usually found covered by a seam ofmagnesian clay, thin hut such as materially to detractfrom its quality. This is scraped off by hand, a broad-pointed pick resembling a small adze being used for thepurpose. The magnesite seam is then undercut, pickeddown and the underside cleaned of clay; after which it isready for shipment. This would perhaps appear to be a crude and expen
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Keywords: ., bo, bookcentury1900, bookdecade1910, booksubjectmineralindustries
