Transactions of the Australasian Institute of Mining Engineers Volume 12

Transactions of the Australasian Institute of Mining Engineers Volume 12

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1907 edition. Excerpt: ...but, if the sample be black and not so crystalline, there is too much antimony still, and another skimming is necessary. The life of the furnace is about four weeks, when the bricks which have been slagged (mostly at the litharge level) must be renewed. The weight of skimming is about one ton, and will be dealt with under "Treatment of By-Products." The zincking kettles, before receiving their charge, must be washed and heated up by means of fires underneath; the lead must also be cooled back in the antimony softener, so that, when run in, there is no appreciable difference of temperature between the two, which would cause the pan to strain, and perhaps crack. The kettle itself is a circular cast-iron pan of 9 ft. diameter and 3 ft. 9 in. depth. This will hold, approximately, 45 tons of metal. The 6-in. flange of the kettle forms the support on which it rests, being supported above the fire-box by a circular brickwork structure cappei with 1%-in. plate of cast-iron, and on this rests the shoulder of the kettle. The firing is done from the next floor, grate area being 2 ft. x 8 ft. A step hearth is used, so that the flames must go within a foot of all parts of the kettle when the hearth is clean. As the working TRANsACTIoNs Ans. I.M.E, VoL. XII ON Rnrmmo Bass BvLmon. PLATE XI. goes on, however, the hearth gets choked up with ash till this space is greatly diminished. If the space is not uniform all round the kettle this will produce unequal heating, andl severe strains in the iron. The principle upon which the separation of gold, silver, and lead is based is that these first two metals form an alloy with zinc more readily than with lead; this alloy is both more infusible and lighter than lead, consequently it rises as a...show more

Product details

  • Paperback | 48 pages
  • 189 x 246 x 3mm | 104g
  • Rarebooksclub.com
  • United States
  • English
  • black & white illustrations
  • 1236778618
  • 9781236778611