FREE BOOKS

Author's List




PREV.   NEXT  
|<   76   77   78   79   80   81   82   83   84   85   86   87   88   89   90   91   92   93   94   95   96   97   98   >>  
EZ, Hoerde. If in the acid and the basic Bessemer processes the molten pig iron is taken direct to the converter from the blast furnace, there is the disadvantage that the running of the individual blast furnaces can hardly ever be kept so uniform as it is desirable should be the case in order to secure regularity in the converter charges. In the manufacture of Bessemer steel the variable proportions of silicon and of carbon here come chiefly under consideration, while in the basic process it is chiefly the varying proportions of silicon and of sulphur; and in cases where either ores containing variable percentages of phosphorus, or puddle slags, are treated, the varying proportion of phosphorus has also to be considered. This disadvantage of the irregular composition of the individual blast furnace charges is obviated in a simple and effective manner by W.R. Jones's mixing process. In this as much pig iron from the various blast furnaces of a works as is sufficient for a large number of Bessemer charges, say from seven to twelve charges, or, in other words, from 70 to 120 tons of pig iron, is placed in a mixing vessel. Only a portion of pig iron placed in the mixer is taken for further treatment for steel, while new supplies of pig iron are brought from the blast furnace. In this way homogeneity sufficient for practical purposes is obtained. In the treatment of phosphoric pig iron, which is employed in the production of basic steel, it is, however, not sufficient merely to conduct the molten pig iron in large quantities to the converter in a mixed condition, but the problem here is to render the proportion of sulphur also independent of the blast furnace process to such an extent that the proportion of sulphur in the finished steel is so low that the quality of the steel is in no way influenced by it. The question of desulphurization has, especially of late years, become of the utmost importance, at any rate for the iron industry of the Continent. By the great strike of 1889, the German colliers have succeeded in greatly improving their wages; and with this increase in wages not only is there a distinct diminution in the amount of coal wrought, but, unfortunately, the coal produced since then is raised in a much less pure condition than was formerly the case. Consequently the proportion of sulphur in the coke has considerably increased. Whereas formerly this proportion did not exceed one per cent., it has now in
PREV.   NEXT  
|<   76   77   78   79   80   81   82   83   84   85   86   87   88   89   90   91   92   93   94   95   96   97   98   >>  



Top keywords:

proportion

 
furnace
 

charges

 

sulphur

 

process

 

sufficient

 

converter

 

Bessemer

 
chiefly
 

variable


proportions

 

silicon

 

varying

 

mixing

 

condition

 
phosphorus
 

disadvantage

 

individual

 
furnaces
 

molten


treatment

 

importance

 

utmost

 

independent

 
extent
 

render

 

problem

 

conduct

 

quantities

 

finished


industry

 

desulphurization

 
question
 
quality
 

influenced

 

diminution

 

Consequently

 

raised

 

considerably

 

exceed


increased

 
Whereas
 

produced

 

colliers

 

succeeded

 

German

 

strike

 

greatly

 
improving
 
amount