Abstract: A powdery or fine granular ore containing metal oxides is melted and refined by charging the ore and a part of a reducing gas discharged from a vertical type of melting and reducing furnace into a fluidized bed type of preliminary reducing furnace to preliminary reduce the ore therein, charging the preliminary reduced ore heated at a high temperature into the above described melting and reducing furnace and melting and reducing the ore by using a carbonaceous solid reducing agent and air or oxygen rich air heated at a high temperature and discharging the molten metal and the molten slag from the melting and reducing furnace. By using the preliminary reduction step, the pretreatment of the powdery or fine granular ore containing metal oxides, such as formation into pellets, sintered ores, briquets and the like can be omitted.

Abstract: A powder feeder, includes a cylinder body connected to a gas blow pipe for fluidizing a powder at its bottom portion; a porous plate crossing the lower portion of the cylinder body above a gas blow hole; a partition plate which divides the interior of the cylinder body into a powder supply side and a delivery side and has a slit for communicating the supply and delivery sides with each other at its upper portion; a powder supply pipe connected to the lower portion of the cylinder body at the supply side to be inclined downward toward a connecting portion; and a powder delivery pipe connected to the lower portion of the cylinder body at the delivery side to be inclined downward in a delivery direction.

Abstract: A method of producing amorphous mother alloy is disclosed, which comprises charging raw material, carbonaceous reducing agent and secondary material into a smelting furnace and then smelting to produce Fe-B-Si series molten metal having a B-Si composition range which lies within an area represented by the trapezoidal area abcd shown in FIG. 2 of the accompanying drawings. The amorphous mother alloy is used to produce an amorphous starting material by diluting with molten steel.

Abstract: Fe-B molten metal for producing amorphous alloys are produced in a low cost by using a vertical furnace wherein beds packed with a carbonaceous solid reducing agent are formed and two or three stages of tuyeres are provided in the lower portion of said furnace, feeding a preliminarily reduced powdery iron ore into the furnace through the upper stage of tuyeres together with hot air and feeding boron oxide or boric acid into the furnace through the lower stage of tuyeres together with hot air and, if necessary blowing hot air into the furnace through the lowest stage of tuyeres. In stead of the above described vertical furnace, a usual blast furnace provided with one or two stages of tuyeres at the lower portion of said furnace is used. In this case, sintered iron ore, pellet-formed iron ore or lump iron ore is fed from the top of the furnace and powdery boron oxide or boric acid is fed through the tuyeres.