Kobe Steel, Ltd.

Sumitomo Metal Industries, Inc.

Nippon Paint Compnay, Ltd.

Isao Fujita

Mamoru Onoda

Takeshi Sugiyama

Shoji Shirouchi

Nobuyuki Imanishi

Fumikazu Kawaguchi

Tadao Tsutaya

Ryo Watanabe

Yoshimichi Takenaka

Osamu Tsuchiya

Tetsuzo Arai

Kazumasa Taguchi

Mitsuyuki Raijo

Yoshimichi Takenake

Takao Kawai

Masaharu Kitajima

Atsuko Yamashita

Tsutomu Nishida

Kan Aketa

Yasushi Yamamoto

An actinic radiation-curable, rust-preventive coating composition suitable for use in temporary protection of steel products from rusting and having improved rust preventing property even in the presence of oil on the steel surface is disclosed. The coating composition comprises: (A) from 10 to 50 parts by weight of a vinyl polymer having a glass transition temperature of not lower than 5.degree. C. and a solubility parameter in the range of 9 to 11.5; (B) from 50 to 90 parts by weight of one or more polymerizable compounds having at least one unsaturated group capable of initiating reaction by actinic radiation; and (C) from 0.1 to 20 parts by weight of an organic phosphate of the formula: ##STR1## wherein R.sub.1 is hydrogen or methyl; Y is a straight or branched chain alkylene having 2 to 20 carbon atoms which may be interrupted by one or more ester or oxy linkages and/or aromatic rings; and n is an integer of 1 to 3.

Actinic radiation-curable rust-preventive coating compositions for steel

Iron ore pellets containing coarse ore particles, having a particle size distribution consisting of 25-40 wt % of coarse ore having a particle size greater than 0.1 mm, less than 21 wt % of medium ore having a particle size of 0.1-0.04 mm, and more than 39 wt % of fine ore having a particle size smaller than 0.04 mm.

Iron ore pellets containing coarse ore particles

Fired iron-ore pellets are prepared which have at least two precipitated slag phases of different chemical compositions which appear among the iron-oxide grains of the pellets. The pellets each contain not less than 4% by weight of CaO+SiO.sub.2 so that the resulting pellets have the characteristic of forming large cracks which are formed in the course of reduction of the pellets. The cracks which form cause each pellet to split into several pieces. The fired iron-ore pellets exhibit excellent reducibility.

Fired iron-ore pellets having at least two different precipitated slag

Iron ore pellets having superior reduction and load softening properties in blast furnace operations. The pellets are prepared from a raw material to which is added an amount of magnesia or a MgO feeding source such as that the ratio of MgO to the SiO.sub.2 content of the raw material is at least about 0.5 and the CaO content in the raw material is adjusted so that the ratio CaO/SiO.sub.2 is less than about 0.05.

Iron ore pellets containing magnesium oxide

The present invention discloses a blast-furnace operation method which comprises selecting three factors, i.e. the oxygen volume in blast, the ore/coke and the reducibility of the burden materials as control factors from among these which participate in the variation of heat input and heat output of blast furnace, plotting values of these three factors obtained from the practical operation of efficient blast furnaces on a graph consisting of three parallel axes indicating the three factors, evaluating the conditions of furnace heat with reference to a balanced state of the three plotted factors and adjusting one or more of the three factors in the furnace so all will lie within a suitable range thereby balancing the furnace heat.

Blast-furnace operation method

Fired iron-ore pellets are disclosed which are prepared by crushing iron ore to be pelletized, mixing a carbonaceous material of grain sizes ranging from 0.1 to 3 mm in diameter to the crushed iron ore in an amount of up to 4% by weight, pelletizing the mixture thus prepared, and firing the resulting pellets; thereby providing pellets throughout each of which is dispersed macro-pores of sizes ranging from 0.1 to 3 mm in diameter at a ratio of up to 25% relative to all pores contained in each pellet.

Fired iron-ore pellets having macro pores and process for producing the

Fired iron-ore pellets having macro pores

In the present invention, after a powdered iron ore has been subjected to granulation and firing into spherical pellets, a further crushing is applied while adjustment of the particle size of the crushed pellets is made so that the outer surface of the pellets is composed of spherically formed surfaces and crushed surfaces. By doing so, improvements are made in the angle of repose and in the reducing characteristic of iron ore pellets, and eventually an efficient and highly economical blast furnace operation is attained.

Iron ore pellet having a specific shape and a method of making the same

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Kobe, Japan

Isao Fujita