Metallurgy Of Cast Iron

3-20 .MKTALLT K< 1Y < U-1 I'AST IRON.
iron I consider is likely to occur in any heat, the quantity escaping with the slag" being" dependent on the pressure of the blast and the size of the slag hole.
A short time after the difficulty with foamy slag I gave considerable attention to iron in slags, and had analyses made by Mr. Mac Shiras, who found the following weights of iron to be lost through slags: In a heat of forty tons, March 15, 1894, we had slag coming from the slag-hole weighing 1,700 pounds. The analysis showed this slag to contain 3.34 per cent, of shot iron and oxide of iron equivalent to 17.25 per cent, metallic iron, a loss of 350 pounds of iron in the i, 700 pounds of slag, and to the total weight of iron charged the percentage of loss would be thirty-nine one-hundredths of one per cent.
Another heat of forty tons on March 19, 1X94, which we followed up, showed the slag weighed 1,630 pounds. The analysis of this gave 2.70 percent, shot iron and an equivalent of 15.69 percent, of metallic iron, a loss of 300 pounds in 1,630 pounds of slag, and to the total weight of iron charged the percentage of loss would he thirty-three onc-hundi edt hs of one percent., which, figuring the iron at $12 per ton, would show a loss of $1.58, or a little less than four cents per ton. One factor which it will be profitable to dwell upon before proceeding further is the reason fur the <ii if ere. nee. of loss in the two forty-ton heats. As our metal is carried away from the cupola by a five-ton ladle, and there are often lulls in getting back with the, crane ladle, I permitted the practice of leaving the slag-hole open all the time, so as to make sure that the slag or metal did not reach the tuyeres. Feeling1 satisfied we u the heavier or sandless gray roll iron. While this is shown as such, it doeslate obtained. . , ' S<> Ibs, sy Ibs <jl Ibs f»i Ibs