Skip to main content

Full text of "Metallurgy Of Cast Iron"

See other formats

I.DSS   OK    IKON    I5\"    SS.Adl 1INC,    Ol'T   Cl I I'Ol.AS.            : 2 1
were losing" some metal by letting the bhist continually blow out of the shi;;1 hole, I decided to try, in the second heat quoted, to plui;' and tap the sla^-hole at intervals, or just a few minutes before tapping out. Ply doiii^-so we obtained, as shown, a, saving of six one-hum dredths of OIK* per cent, of the total weight of iron changed, or in oilier words, we saved 29 cents in the heat of 40 t MIS at the risk of letting the iron or sla^ fill up the/ tuyeres, and hence Imnij; up the cupola. .By such a met hod of retarding melting to save a little iron, we ini^ht' lost many dollars in castings through bad melting or dull iron.
Where conditions are favorable to tapping a sla^~ hole, at intervals, or just before tapping out the; iron, on account of having a greater distance between the
tuveres and slai'"~hole, then  we.  had, the above iivnires .                                 t                      ,*>
clearly demonstrate* the economy of such practice; and it is one/ that, as a general thin;;'can be safely followed; but in cases where the. tapping; out and pb lining up of a slaiL>"--l)ole would require a man solely to look after it, nothing is !< be saved bv this prael iee. \Ve used aJl pit;"; no scrap except iiii.; a few kk titles," which, fora 5o-ton h-at would w-ii.;h about two tons; and ('onnells-villecoke for fuel, of which .vuo 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 ;;atherMl 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/..