LOSS OF IRON BY OXIDATION IN CUPOLAS.*
The amount of Iron lost by melting is as important an item for consideration as that of any other material necessarily destroyed in the making of castings. Many founders endeavor to keep a close record of such losses, but there are many who cannot. Founders who can clean up each day's heat of castings and collect all their fine shot, scrap, and gates the day following each hunt are in the best position to obtain the greatest accuracy in such records, but shops where castings lie in the sand from one to six days or more before they can be removed or cleaned up find the task a much more difficult one. In buying pig iron the furnacetrian allows .»f>S pounds per ton for scale and sand on sand casi pig,and .r.jo pounds on chilled cast pig. How much <>f this is actual ivfuse is difficult to determine accurately. Wlu-n first studying the method of casting pig metal in chills, the author could sec-nothing unfavorable to the universal adoption of metal so cast for founders and steel makers. It was not until at a meeting of the Pittslmrg Poundrymen's Association, December 3, r«So,K, where a member made the claim that a greater loss \,ould be incurred by the use of chilled cast pig iron, in re-melting iron, than by having sand and scale on it which was said to afford
*This chapter is ;t tvvisr<l cxtnu't. of a paper presented by the author to the Pittslmry, FniinflrywcnV. Association, January, 1898.ity, see Chapters IX. and X.