Patent GB-431329-A (GB)
Title: Improvements in or relating to the manufacture of iron alloys
IPC: C21C7/06
Filed: 1933-10-27
Abstract: A process for the manufacture of iron alloys comprises violently intermixing a molten fluid slag other than a deoxidizing slag which has been exhausted by a violent intermixing with oxidized steel, the slag containing one or more oxidic compounds of alloying substances, with a molten ferrous metallic bath capable of reducing the said oxidic compounds of the slag, the violence of the intermixing being such that the slag is finely divided and dispersed in the metal, the slag being separated from the molten alloy after the turbulence has subsided.  The violent intermixing may be produced by rapidly pouring the ferrous metallic bath upon the molten fluid slag, e.g. in a thick jet and from a height of 2 1/2 to 3 metres, or by rapid simultaneous pouring of the bath and slag or by movement of a receptacle containing them.  For producing iron-nickel, iron-molybdenum and iron-copper alloys, the ferrous bath itself acts as the reducing agent, the slag containing, for example, nickel silicate, calcium molybdate, or copper oxide, respectively.  Reducing agents, such as carbon, calcium, carbide, aluminium, silicon, manganese, ferro-titanium, calcium, titanium, aluminium silicide, or calcium silicide, may be added to the bath, e.g. for the reduction of chromium ores contained in the slag.  For the production of alloys containing reducing agents such as silicon, aluminium, manganese, or titanium excess of such agent is added to the ferrous bath, the excess being calculated to correspond to the amount of oxides to be reduced in the slag.  The ferrous bath may be of deoxidized iron, steel which has been deoxidized by violent intermixing with very fluid non-reducing slags capable of extracting the oxides dissolved therein, or iron alloys, the alloying element or elements being that or those to be reduced from the slag or some other element or elements: such alloys may have been produced by the present process. Basic, neutral, or acid slags may be used, e.g. slags containing silica, lime, alumina, titanic acid, magnesia, alkali, iron oxide, or manganese oxide.  For example, a slag may contain silica, alumina, magnesia, and lime; in this case, by the use of silica-aluminium and silico-calcium as reducing-agents, it is sufficient to add magnesia to the slag to compensate for losses due to manipulation. Specification 423,048 is referred to.  The Specification as open to inspection under Sect. 91 comprises also a process for the regeneration of slags loaded with oxides by violently intermixing the fused slag with a reducing agent in a solid finely divided condition or in a fused condition.  The reducing-agent may be placed in a casting ladle, super-imposed, if desired, on a thin layer of slag, and the slag poured violently thereon: or simultaneous pouring may be effected.  Alternatively, reducing agents, slag and deoxidized steel may be poured violently into a receptacle or added to a receptacle capable of mechanical movement.  Further, a silicon-manganese steel alloy may be produced by using a silicious slag to which is added manganese oxide, aluminium being, used as the reducing-agent in a steel bath which may have been previously deoxidized by use of the silicious slag.  A slag containing silica, alumina, magnesia, lime, 9,6 per cent of manganese oxide, and 3,37 per cent of iron oxide is placed in a ladle and steel containing 0,43 per cent of carbon, 1,975 per cent of silicon and 0,50 per cent of manganese poured violently thereon: the resulting slag is used to deoxidize mild oxidized steel. Also, oxides may be removed from steel by violent intermixing with a slag and the oxides then reduced in the body of the slag by a second violent intermixing with the steel to which a reducing-agent has been added.  This subject-matter does not appear in the Specification as accepted.