ECKEL.] 
UTILIZATION OF IRON AND STEEL SLAGS. 
225 
Slag bricks are light in color, varying from light to dark gray; they 
weigh less than clay bricks of equal size, require less mortar in laying 
up, and are equal to clay bricks in crushing strength. The following 
analyses of slags used in slag-brick manufacture are fairly represent- 
ative : 
Analyses of slags used in slag-brick manufacture. 
Constituent. 
Si0 2 . 
A1 2 3 
FeO . 
MnO. 
CaO_ 
MgO. 
S ___ 
1. 
2. 
3. 
4. 
22. 5 
25. 8 
27.0 
33.0 
14.0 
17.3 
19.3 
18.67 
3.3 
1.5 
1.7 
1.0 
.0 
.0 
0.1 
4.25 
51.0 
51.4 
51.5 
40.0 
1.4 
0.4 
2.5 
2. 33 
0.3 
1.3 
1.8 
1.33 
35.0 
15.0 
1.1 
0.3 
45.0 
.0 
0.4 
FERTILIZERS. 
The highly phosphatic slags produced by basic Bessemer converters 
are valuable fertilizers, and are of great economic importance. In 
Germany, especially, large quantities are annually sold under the 
name of Thomas slag. In slags produced by this process the content 
of phosphoric acid usually runs from 10 to about 25 per cent. 
Analyses of basic Bessemer slags. 
Constituent. 
Si0 2 
A1 2 3 _ 
Fe 2 3 -.._ 
FeO ._.. 
MnO 
CaO 
MgO 
K 2 0, Na 2 
CaS 
S 
S0 3 
PA-- - 
H 2 0,etc_-_ 
7.38 
2.57 
8.54 
13.62 
3.79 
41.58 
6.14 
54 
14.36 
1.29 
4.1 
9.3 
4 
49.6 
4.7 
. 
2 
17.5 
5. 8 
1.5 
15. 42 
2.1 
3. 5 
45.04 
6.42 
4. 
.32 
18.1 
5. 76 
1.43 
2.07 
12.72 
3.43 
47. 34 
6.01 
5.10 
4.01 
2.49 
12 
5. 56 
45.26 
5.90 
.80 
8.19 
1.23 
61.02 
91 
19. 19 
1.19 
21.81 
27.35 
1. Redgrave, Jour. Soc. Arts, Vol. XXXVIII, p. 230. 
2. German. Phillips, Trans. Am. Inst. Min Eng., Vol. XVII, p. 86. 
3. English. Phillips, ibid., p. 86. 
4. Redgrave. Jour. Soc. Arts, Vol. XXXVIII, p. 230. 
5. Pottstown Iron Company , Pennsylvania. Morris, Trans. Am. Inst. Min. Eng. , Vol. XXI, p. 232. 
6. Bohemian. Phillips, Trans. Am. Inst. Min. Eng., Vol. XVII, p. 87. 
Bull. 213—03- 
•15 
