RECOVERY OF POTASH IX THE BLAST-FURNACE INDUSTRY. 15 
ESTIMATED LOSS OF POTASH IN 
INDUSTRY. 
THE BLAST-FURNACE 
Tables 8, 9, and 10 show that the potash content of the numerous 
samples of ore, coke, and limestone that were analyzed give an 
average about the same for each material of approximately 0.2 per 
cent. The average percentage of potash in the raw mix used in 
cement manufacture (0.67 per cent) is therefore over three times as 
great as that occurring in the raw materials consumed in the blast- 
furnace industry. 
Table 12. — Estimated loss of potash in blast-furnace industry. 
Material. 
Annual 
consump- 
tion. 1 
Average 
potash 
(K S 0) 
content. 
Total 
potash 
(K 2 0) 
content. 
Potash 
(KsO) per 
gross ton of 
pig iron. 
Ore 
Limestone . 
Coke 
' Short tons. 
.1 72,800,000 
. 18,400,000 
,| 38,700,000 
Per cent. 
0.17 
.16 
.18 
Short tons. 
123,800 
29,400 
69, 700 
Pounds. 
7.3 
1.7 
4.1 
Total in charge. 
222, 900 
13.1 
Material. 
Production, 
Average 
potash 
(K 2 0) 
content. 
Total 
potash 
(K 2 0) 
content. 
Potash 
(KgO) per 
gross ton of 
pig iron. 
Pig iron gross tons. . 33, 700, 000 
Slag short tons. . 23, 600, 000 
Per cent. 
Short tons. 
Pounds. 
0.59 
139, 200 
8.2 
Total lost by volatilization . 
83,700 
1 The figures for consumption and production of ore. limestone, coke, and pig iron are average values 
obtained from Annual Statistical Reports, American Iron and Steel Institute 1913 to 1920. The production 
of slag was calculated from the ratios of slag to pig iron for numerous blast furnaces throughout the country. 
In an investigation that was made some time ago by R. J. Wysor 6 
of the Bethlehem Steel Co., it was reported that the potash in the 
ore, coke, and limestone used at that plant amounted, respectively, 
to 10.3, 5.8, and 6.3 pounds per ton of pig iron, or to a total of 22.4 
pounds per ton. 
The results given in Table 12, which represent an average as 
applied to all the blast furnaces of the country, show corresponding 
values of 7.3, 4.1, and 1.7 pounds per ton of pig iron or a total of 
13.1 pounds. The average potash in the slags, on the other hand, 
was found to be almost twice as great as reported by Wysor for the 
Bethlehem Steel Co. It therefore follows, as Wysor himself Dre- 
dicted, that the potash volatilized per ton of pig iron must be less 
for the average plant than was found for the Bethlehem plant. 
According to our results this amounts to only 4.9 pounds per ton of 
iron as compared with Wysor's 17.9 pounds. 
That the potash lost at the Bethlehem plant is about three times 
greater than the average for the blast furnaces of the country as a 
whole is further indicated by the potash found in the dust collected 
8 Wysor, R. J. Potash as a By-Product from the Blast Furnace. Bui. Am. Inst. Mining Eng. No. 
121, pp. 1-32, 1917. 
