抄録
It is a well known fact that the addition of a very small amount of vanadium improves the quality of stcel, increasing its strength as well as ductility.
Unfortunately, however, the occurrence of this precious element in its available forms of compounds is very scarce, and can not satisfy metallurgical demands.
The price of Ferro-vanadium, consequently, is very high, so that it forms an almost insurmountable obstacle in the course of developing the manufacture of vanadium steel.
The magnetic sand in Japan, without exception, contains certain quantities of V2O5, which sometimes exceed 0·6% in the original ore with a high iron content. Though the physical condition of the existence of V2O5 in the magnetic sand has not yet been cleared, when we apply the magnetic separation for the dressing of magnetic sand, nearly. all the content of V2O5 enters into the concentrate, resulting in a higher percentage of V2O5 in it than in the original ore.
From an economical point of view, the utilization of this element in the concentrate (or in the ore) affords a splendid prospect in the refining of magnetic sand, giving a superior quality to the product.
The author carried out several researches for reducing the V2O5 in magnetic sand with an electric furnace.
Naturally, varying degrees of reduction of V2O5 into the iron from the sand might give remarkable variations on the quality of the product. as well as their composition, say, phosphorus, mangan, silicon, titan and carbon.
The results of the author's research are summarized as follows:-
(1). In the direct reduction of V2O5 from the fused mass in the electric furnace, the slag must have certain definite ratios of SiO2 and CaO to reduce the V2O5 as perfectly as possible. In this case, the TiO2 and Al2O3 are considered as neutrals, and the reduction of TiO2 must be excluded as much as possible.
(2). For the above purpose, the slag should preferably have a composition approximating Bisilicate slag.
(3). The absorption of carbon by the iron produced at certain temperature depends on the basicity of the slag and the length of time held in the furnace.
(4). The vanadium content will accelerate the absorption of carbon in the iron produced.
