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Full text of "Metallurgy Of Cast Iron"

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MKTAU.r K<;Y  oi«   CAST  IKON*.
allayed when \ve discovered  it was less  than  one-half of one per cent.
In the year 1893, we found a total loss of iron through the slag, oxidation in the cupola, and other sources, in the way of line scrap mixed with simp dirt, and also wheeled out with the cinder and tumbling barrel refuse, of three and one half per cent, all told. We can look to oxidation in remelting iron for the greatest percentage of a shop's loss of iron. There is little doubt but that a great part of the loss by oxidation or lk burning of the metal," as it is commonly termed, is done above the tuyeres, as the metal is dropping from the melting point through the fuel down past the tuyeres to the bath of metal in the bottom. Also, from the surface of the solid metal, at or above the melting point, as it exposes a semi-molten surface to the effects of the blast and heat; and the more surface we expose to the effects of blast and heat the faster the oxidation, hence, with light sera}), we must expect the greater loss. There are reasons why one founder should lose 10 percent, and another only 3 per cent., in remelting cast iron. It will pay any founder to closely investigate his losses, and if found
heavier than he thought  he may lessen them by intel-
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ligently studying the cause.s; and ('onnells-villecoke for fuel, of which .v»uo pounds were use<l for the bed ami .150 pounds between charges. The pi*.»- on bed was S,ooo pounds and between cliaj'^'es 6,000 pounds. We used limestone for a, ilux; for every three tons we used about 90 pounds, placed on top of ever}1 charge. There is no doubt that one or two hundredweight. <»f slai.^ could be added to the totals iMven above, whi«'h eouM be ;«;ather«Ml from the. skim-mini;-of ihf ladh- and tin- droppint-, of the bottoms. Our «Mj)pnrheii.sion as to loss of iron through slai;" was	r> ">'••	I I   O/..