Abstract: A refining agent containing Al, MgO and CaO as main components, wherein dolomite is a MgO source and a CaO source. When the refining agent is supplied into molten iron, Mg vapor is produced due to a reaction in the molten iron, and causes a refining reaction by the Mg vapor.

Abstract: A refining agent contains Al, MgO, and CaO as main components, and uses dolomite as a MgO source and CaO source. When the refining agent is supplied into molten iron, it produces Mg vapor due to a reaction in the molten iron, and causes a refining reaction by the Mg vapor.

Abstract: Provided is a raw material for phosphate fertilizer having excellent fertilizer characteristics, which raw material consists essentially of a slag containing phosphate generated from dephosphorization reaction in molten iron, and is a method for manufacturing the raw material suitable for manufacturing the phosphate fertilizer. The raw material for phosphate fertilizer consists essentially of a slag containing phosphate generated from dephosphorization reaction in molten iron.

Abstract: An Fe--Ni alloy cold-rolled sheet excellent in cleanliness and etching pierceability prepared as specified in the claims, which consists essentially of: 30 to 45 wt. % nickel, 0.1 to 1 wt. % manganese, 0.003 to 0.03 wt. % aluminum and the balance being iron and incidental impurities comprising up to 0.4 wt. % silicon, up to 0.1 wt. % chromium, up to 0.005 wt. % carbon, up to 0.005 wt. % nitrogen, up to 0.005 wt. % sulfur, up to 0.010 wt. % phosphorus, up to 0.002 wt. % oxygen, and up to 0.002 wt. % as converted into oxygen for non-metallic inclusions. The non-metallic inclusions contain at least CaO, Al.sub.2 O.sub.3 and MgO, and the composition thereof is in a region of a melting point of at least 1,600.degree. C., which region is defined by the liquidus curve of 1,600.degree. C. in the CaO--Al.sub.2 O.sub.3 --MgO ternary phase diagram. The non-metallic inclusions have a particle size of up to 6 .mu.m.

Abstract: A method for manufacturing an Fe-Ni alloy cold-rolled sheet excellent in cleanliness and etching pierceability, comprising: preparing an Fe-Ni molten alloy, containing 30 to 45 wt. % nickel, and subjected to dephosphorization and decarburization; adding aluminum and flux to the Fe-Ni molten alloy in a ladle made of an MgO-CaO refractory containing 20 to 45 wt. %; strongly stirring the Fe-Ni molten alloy which contains the added aluminum and flux in the ladle to produce a CaO-Al.sub.2 O.sub.3 -MgO slag so as to react the Fe-Ni molten alloy with the CaO-Al.sub.2 O.sub.3 -MgO slag to deoxidize the Fe-Ni molten alloy while controlling a value of activity of SiO.sub.2 from 0.001 to 0.005 and a value of activity of Al.sub.2 O.sub.3 from 0.1 to 0.3 in the CaO-Al.sub.2 O.sub.3 -MgO slag, and the CaO-Al.sub.2 O.sub.3 -MgO slag having the following chemical composition: CaO and Al.sub.2 O.sub.3 : at least 57 wt. %, wherein the ratio of CaO/(CaO+Al.sub.2 O.sub.3) being at least 0.45, MgO: up to 25 wt. %, SiO.sub.

Abstract: Molten metal is put under pressure of up to 10 atmospheres in a covered ladle and a gas soluble in the metal is bubbled through the melt. Some gas goes into solution, while the remainder rises in bubbles and brings inclusions suspended in the molten metal up to the surface. Then the pressure is lowered, after which gas comes out of the solution in fine bubbles which also bring impurity inclusions up to the surface. In another method molten steel is refined at pressures not exceeding atmospheric pressure in a covered ladle equipped for evacuation and equipped for bubbling gas through the molten steel bath. Bubbling followed by pressure reduction can then be performed to form two stages of cleaning. Heat may be added for compensating the cooling effect of gas expansion.

Abstract: A method for economically manufacturing an iron-boron-silicon alloy through simple steps, which comprises the steps of: adding a boron raw material and a carbonaceous reducing agent to a molten iron received in a vessel; blowing oxygen gas into the molten iron to reduce the boron raw material in the molten iron by means of the carbonaceous reducing agent to prepare a boron-containing molten iron; continuing the blowing of oxygen gas to decarburize the boron-containing molten iron until the carbon content in the boron-containing molten iron decreases to up to 0.2 wt. %; and adding at least one of silicon and ferrosilicon to the boron-containing molten iron while stirring the boron-containing molten iron, thereby manufacturing an iron-boron-silicon alloy.