SOME CONSIDERATIONS ON THE MANUFACTURE OF LOW CARBON PIG IRON WITH BLAST FURNACE

Recently, it has been accomplished to manufacture low silicon pig iron for basic open hearth furnace by blast furnace in Japan. And so the next important problem on this line is turned to reduce further its carbon content as possible, because in our country, for want of steel scrap, the open hearth furnace works in future have to be operated mainly with pig iron and ore for their materials, and it is necessary to reduce carbon content of molten pig iron-the chief materials of the above operation-as low as possible.At the beginning of this study the author discussed on the equilibrium relation between iron and carbon at high temperature as in blast furnace; and then explained theoretically in details on the course of carbon absorption into iron during the charge traveled from top to bottom of the furnace with many data; and also stated on the influence of other elements upon the absorption of carbon into iron. Then the author studied closely on melting zone of blast furnace to find that the socalled concentrated melting method should be adopted for blast furnace operation in future, that is the total thickness of melting zone should be kept possibly thin but width and thickness of the highest temperature oxidized part in it must be enlarged and brought below in hearth as possible. And when the combution in furnace is rationalized by the further study of tuyres, and also adequate forehearth is established, this problem will be solved to a certain extent.Finally the author explains that he has now constructing a large experimental blast furnace for this object, and soon will begin the study witn it to solve this interesting and important problem.