President Hideaki NISHIO

Xiangchong ZHONG and Fangbao YE

In the past 25 years in China, to meet with the rapid increase in steel production accompanied by adoption of advanced metallurgical technologies, there has been fast development of China's refractories industry in production capacity, in quality improvement and in development of new products.
Sophisticated high performance refractory materials mainly based on our rich reserves of magnesite, bauxite and flake graphite have been developed, such as carbon-bonded products, high purity oxide products, bauxite-based low creep and high strength high alumina bricks and LC, ULC and ZC castables.
They have been used in blast furnaces,BOFs,EAFs,secondary refining and continuous casting with considerable improvement in service performance.

Jialin SUN and Yanruo HONG

Si-Al2O3-SiC and Si-Al2O3-Si3N4 bricks were newly developed according to a concept called "metal plastic phase-containing oxide-nonoxide composite materials" , which are being applied widely for blast furnace linings for their good price performance ratio in China.
Si3N4-containing gunning mix, iron trough castable and taphole mud all also show excellent physical properties and corrosion resistance.
Utilizing domestic cheap minerals such as Jiaobo-stone, low creep bricks were developed for hot-blast stove.

Y.KUBOTA

Production of unshaped refractories now accounts for 64.5% of the total refractory production in Japan.
A maximum production of 946 thousand tons of unshaped refractories was recorded in 1974.
Prior to that, unshaped refractories technology was still in a rapid development period.
Under a progressively worsening economy since 1991, unshaped refractories have been developed and improved in various fields, and have contributed both to a reduction in total unit consumption of refractories and an improvement in working conditions.
New technologies such as self-flow castables and shotcreting have been developed since 1990.
Environmental improvement technology such as technology such as recycling used refractories has also been developed.
So, the amount of unshaped refractories produced has remained steady against a continuing trend of decreasing total refractory production.

M.OGATA , M.NAKAMURA and S.INOUE

The structure of the submerged entry nozzle (SEN) is important in controlling the flow pattern of molten steel in the mold.
Even though the nozzle structure is optimized to achieve the desirable flow pattern, slide gate valve throttling tends to cause uneven flow of molten steel in the nozzle and the mold.
We developed the "annular step SEN" to prevent the uneven flow, and it has come to be widely used at many casters since 1992.
Additionally, we developed the "MOGUL" SEN,which has many spherical convex projections in the nozzle bore.
Water model experiments and practical use confirmed that the "MOGUL" SEN has a drastic effect on preventing uneven flow in the nozzle and mold.

T.KAGEYAMA , M.KITAMURA , and D.TANAKA

Taphole mix contains much liquid binder, so we believe that the characteristics of binder influence the properties of taphole mix greatly.
In this study we examined four different types of binders for taphole mix.
We believe that with good understanding of the characteristics of the taphole mixes the performance of taphole mix can be improved by changing the binder to suit the occasion.

S.HORITA and S.HARA

Taphole mix is considered to be a refractory which helps maintain the stable blast furnace operation.
Our new taphole mix was developed with the advanced technology of Shinagawa Refractories Co.,Ltd. Good performance results were obtained under the intimate steel works with our company.

M.KITAMURA and K.ENOKI

We developed a new castable with high corrosion resistance and spalling resistance by increasing the total carbon content while maintaining good workability and creep properties.
In actual use, the wear rate decreased to two thirds that of ordinary castable.
Moreover, cracks and peeling were significantly reduced by the application of the new castable.

H.SASAKI , M.MORIGICHI and T.WAKAE

We investigated the effect of densifying Alumina-Magnesia castable by either modifying the grain size distribution or reducing the mixing water content.
Both densification methods had the effect of improving the physical properties and slag resistance.
These new dense castables are being used in the impact area and well blocks in actual ladles, and excellent performance is contributing to ladle life improvement.

Y.TAKAKURA , H.SASAKI and K.KOMATSUBARA

Recently, the repair process has become more important for the BOF process.
But, reducing repair time is required by steel plants in order to improve production efficiency.
We have developed new hot casting repair mixes, which harden quickly and give excellent performance.

Lance Pipe for Iron and Steel Making

Many customers have responded very favorably to our lance pipe technology.
The lance pipe has a composite structure consisting of a steel pipe core with a castable coating.
We describe our lance pipe design and technology in this article.

M.OGATA , K.MORIWAKI and H.MORII

Improvement of spalling resistance has an effect on both the edge damage and sliding surface damage for SV plate because it suppresses both edge breakage and peeling caused by spalling cracks.
We developed high spalling resistancce SV plate with low thermal expansion and low modulus of elasticity.
As a result of field trial of the new material for ladle SV plate, the rate of edge damage decrease and the new plate life became 1.5 times as many as the conventional material.

E.IIDA , M.OGATA and T.OMOTO

Heat loss from molten steel surface through the carbon-containing nozzle affects steel quality and operating efficiency in the continuous casting with small sized molds.
The combination of the fused-silica nozzle and ultra-high viscosity mold powder can minimize the heat loss from molten steel in the molds without diminishing nozzle performance.

T.OMOTO and Y.IWAMOTO

Conventional fine type mold powders were black.
We developed white fine type mold powders which made by except carbon black.
This white powder is effective to prevent dirt.
It is possible to make white about all mold powders and to keep same property to black mold powders.

T.OMOTO and K.NITTA

In order to increase stable casting operation and steel quality and reduce mold powder price, "VRP" series have been developed.
The characteristics of "VRP" series are low impurities, high insulation and good melting properties.
Basicity of mold powder can be adjust to under 1.2. and viscosity can be adjust low to high.
Also Melting speed can be controlled very strictly.

K.MORI and H.FUJIE

Most of the coke oven batteries currently operating in Japan have be used for long period and then the coke chamber wall and/or oven front suffered from extensive damage.
It is necessary to repair the damaged part to prolong the life of coke oven batteries.
Effective repairing method for the damage of older coke oven batteries is hot exchange repair.
We introduce the features of Hot Repair Silica "HRS" which is most appropriate for the method,and describe its recent performance and the outline one of the installation methods.

H.SHIKAMA and M.YOSHIDA

Torpedo cars transport pig iron and are storage containers.
As a wear refractory, commonly unburned Al2O3-SiC-C bricks are applied for the torpedo car.
However, the problem of decreasing torpedo car temperature and shell deformation,exists because the thermal conductivity of graphite is high.
We have developed a line of low thermal conductivity carbon containing refractories called "ECONOS" .
Actual service results proved that we were successful in decreasing shell temperature without decreasing durability.

E. IIDA and T.KOYAKE

Our newly developed magnesia-spinel bricks have low thermal conductivity which is comparable to that of ordinary magnesia-chrome brick.
They can replace ordinary magnesia- spinel bricks at the burning and transition zones.
Improved performance and decreased shell temperature can be expected.

R.NAKAMURA and M.PAULINE

Shinagawa Refractories Australasia, which is the largest refractory manufacturer in Australia, has been manufactured refractory bricks for the use in anode baking furnaces for 40 years.
Severe quality specification required for the furnace and quality control are briefly introduced.

S.UCHIDA

A change from a horizontal to an inclined lining at the BOF cone prevented wear lining bricks from dropping off. The structure analysis has used to simulate the lining behavior and it revealed that a problem of a bigger opening between bricks would occur with an inclined lining. A new inclined lining derived from studying many countermeasures is presented.

S.SUZUKI and K.NAKASHIMA

ISOLITE is a manufacturer of the Insulating Fire Bricks (IFB) and the Refractory Ceramic Fiber (RCF) used as insulating refractory material in higher temperature equipment.
The IFB has some kinds of the grade that are, lower, made from diatomaceous earth and, higher, made from fire clay and alumina.
So, they are used as insulating refractory in various kinds of industrial furnace.
The RCF is the inorganic fiber that is made from the molten silica and alumina in melting furnace with electrical heat.
The RCF has a resistance against more that 1000 degree C temperature, are used as insulating refractory too.
This document says the feature and usage of them below.

Y.KINOSHITA , K.SHIONO and H.SUZUKI

For more than 35 years, ISOLITE has been producing insulating material of alumina-silica based ceramic fiber applicable at higher temperatures than 1000oC.
We would like to introduce herein different applications of ceramic fiber other than insulation purposes.

H.ASAKURA and S.ARAI

CERATEX is a useful Refractories gasket which is cutable with Scissors.
It is used as gasket, expansion spacer,and cover material at the steel making plant,non-steel metal refining plants,chemical plants,and waste incineration plants.

H.ASAMI

SUKITOR is a special inorganic flocculant adaptable for waste water treatment.
Separation of liquid and solid phase is easily achieved by the addition of this flocculant and stirring.

Y.SASAI and J.OKUHARA

Most refractory linings are inspected with observation equipment in hot conditions.
An observation probe is inserted into a furnace during operation to estimate the remaining service life,either by direct observation or from images of damage.
However, a general observation probe can not provide precise images of the lining in hot conditions over 800oC.
We investigated the technology of various special optical filter combinations and found some effective filter combinations for 800oC to 1300oC.

Y.SASAI

This research has been carried out in order to construct an ultra‐high temperature furnace which uses a zirconia heating element.
We have redesigned the cylindrical zirconia heating element, preheating furnace and control system to attain ultra‐high temperatures in an oxidizing atmosphere.
We have developed a new, economical large-sized zirconia ultra‐high temperature furnace (ZRF-120) which is optimum for research and development.
We will give an outline, specifications,the electrical resistance change caused by repeated heatings from room temperature to 2000oC and applications in this report.

M.KOSAKA , H.NAGASHIO and Y.KOGISHI

Influenced by the Athens Olympic games, the demand for larger and flatter TV screens is becoming still greater, and the demand for large-sized display screens, such as LC- TV and plasma TV is showing rapid growth.
Mother glass board size is continuing to become larger in view of efficient production.
For these reasons, the size of alumina ceramic parts necessary for manufacturing for LCD equipment is growing at high-speed.
In order to meet the endless demands for enlargement, we adopted a new design concept of division structure and composite with metal.
We developed low cost and reliable large-sized products.
And our ONLY- NE commercialization was achieved by carrying out a market injection promptly.

K.WAKASUGI , T.MITSUBOSHI and H.MINAMIZONO

adsorbing characteristics.
Our company manufactures and sells various adsorbing products from Allophane that is mined from the Moka area of Tochigi prefecture as a raw material.
The characteristics of Allophane are discussed and a historical outline of products utilizing Allophane is introduced in this report.
Then, future development is also discussed.

K.IGAMI

The Ceraficoat series, which is new type of inorganic heat resistant shading paint for lamps, has excellent properties such as low-temperature hardening or paint workability.