Abstract: A stave cooling device includes a double drawn steel tube cast-mounted in a castable metal main body, and the double tube includes an inner tube which serves as a passage for a coolant. The inner tube of the double tube contains 0.20 to 0.38% of equivalent carbon and an outer tube of the double tube contains 0.15 to 0.25% of equivalent carbon. The outer tube has on its outer surface an alumina coating of 0.08 to 0.25 mm thick, and the main body is formed by casting a spheroidal graphite cast iron. The double tube is cast-mounted in the main body such that the double tube and the main body are not welded together.

Abstract: A process for recovering and utilizing useful substances from a molten metal produced, when manufacturing a steel slag cement from a steel slag discharged from a top-blowing oxygen converter, during a reduction treatment of steel slag, which comprises the steps of: subjecting, in an acidic refining furnace, said molten metal to a primary oxidation refining treatment and a secondary oxidation refining treatment to recover a primary slag containing a large amount of TiO.sub.2 and SiO.sub.2 and a secondary slag containing a large amount of MnO and V.sub.2 O.sub.5, said primary slag being utilized as a blast furnace burden raw material serving as a TiO.sub.2 source, and said secondary slag being utilized as a raw material for producing ferromanganese and ferrovanadium; then, subjecting, in a basic Kaldo furnace, said molten metal to an oxidation refining treatment several times to recover a low-phosphorus high-quality steel and a slag, said slag being utilized as a Thomas phosphoric fertilizer.

Abstract: A steel slag cement manufactured by reducing a steel slag discharged from a steelmaking furnace such as a converter, an open-hearth furnace or an electric arc furnace, and then oxidizing the steel slag thus reduced, which consists of, in weight percentage:CaO : 68 to 72%,SiO.sub.2 : 22 to 26%,Al.sub.2 O.sub.3 : 1 to 3%,Fe.sub.2 O.sub.3 : 0.2 to 1.0%,P.sub.2 o.sub.5 : 0.1 to 0.6%,TiO.sub.2 : 0.4 to 0.9%,MnO : trace to 0.4%,MgO : 0.3 to 3.0%,CaF.sub.2 : 0.3 to 2.0%,and the balance incidental impurities.

Abstract: A plurality of different types of raw material coal fines are sieved to a size not exceeding 1.5 mm; said sieved raw material coal fines are blended so as to satisfy the following conditions:(a) AP index: 75 at the minimum,(b) Mean maximum reflectance: 1.20% at the minimum, and(c) A [dilatation] - [contraction] value of from -2 to +5% when carbonized under conventional conditions in a horizontal type coke oven battery at a heating rate of 5.degree. C/min. (350.degree. - 600.degree. C);said blended raw material coal fines thus obtained are mixed with a binder and formed to produce a formed coal; and then, said formed coal thus obtained is charged into a horizontal type coke oven battery and carbonized, whereby a high-strength formed coke for blast furnace is a slight mutual agglomeration is manufactured.

Abstract: With the use of low-fluidity blended raw material coal fines having a maximum fluidity of up to 20 d.d.p.m. as an inner core material, and coal fines having a maximum fluidity of at least 30 d.d.p.m. or a bituminous material having a C/H ratio of from 0.7 to 1.9 as an outer envelope material, green composite briquettes are formed by covering said inner core material with said outer envelope material. Said green composite briquettes thus formed are charged into a conventional coke oven battery and carbonized by an ordinary process, whereby a high-strength metallurgical formed coke in a slight mutual agglomeration is produced.

Abstract: A grain coke is packed in a vertical furnace between a pair of opposite electrodes for passing current through the coke, thus heating the same to a temperature of above 1400.degree. C, preferably 1500.degree. C for more than 10 minutes. Coke is loaded into the furnace from an upper portion and heat treated coke is cooled and then discharged from the bottom. Inert or reducing gas may be introduced into the lower portion of the furnace and discharged from the upper portion thereby cooling heat treated coke and preheating loaded coke.