Abstract: The present invention provides: a method for drying compacts containing water so as not to cause explosion and powdering; a method for reducing the compacts after being dried with great efficiency in a rotary-hearth-type reducing furnace; and a rotary-hearth-type metal reducing furnace. In the present invention, when compacts comprising powder containing metal oxide and carbon are dried, the critical value of a water evaporation rate, beyond which explosion occurs, is determined from the size and porosity of the compacts, then the water evaporation rate is controlled to a value not exceeding the critical value and, by so doing, the increase in the internal pressure of the compacts caused by the generation of water vapor is prevented. By the method, the explosion and cracking of the compacts are prevented.

Abstract: The present invention provides: a method for drying compacts containing water so as not to cause explosion and powdering; a method for reducing the compacts after being dried with great efficiency in a rotary-hearth-type reducing furnace; and a rotary-hearth-type metal reducing furnace. In the present invention, when compacts comprising powder containing metal oxide and carbon are dried, the critical value of a water evaporation rate, beyond which explosion occurs, is determined from the size and porosity of the compacts, then the water evaporation rate is controlled to a value not exceeding the critical value and, by so doing, the increase in the internal pressure of the compacts caused by the generation of water vapor is prevented. By the method, the explosion and cracking of the compacts are prevented.

Abstract: A continuous hot rolling mill with a metal block conveying apparatus and a metal block joining apparatus which moves with the metal blocks along the metal block conveying apparatus to conform a joining operation. The metal block conveying apparatus uses rollers supported by cylinders with a common hydraulic circuit which allows the cylinders to follow guide rails on the metal block joining apparatus and lower out of the path of the metal block joining apparatus and then return to a metal block support position after the metal block joining apparatus' passage without individual control circuits and valves for each of the cylinders.

Abstract: The invention comprises a continuous hot rolling method in which a rear end portion of a preceding metal block and a fore end portion of a succeeding metal block are cut and the metal blocks are joined to each other by heating and pressing followed by a finish rolling. A region of each metal block is restrained from a clamping position to the end portion thereof in order to prevent a change in level of the metal blocks in heating and pressing the piece. The end portions of the metal blocks can be thus prevented from deformation.

Abstract: Assuming that the processes of joining, rolling, coiling, etc. of a material is evaluated by a preset speed pattern after the extraction from a heating furnace, the required time is predicted and calculated for both of a preceding material and a following material. At the time when the following material can catch up with the preceding material at an aiming position on the line, the following material is extracted from the heating furnace according to the result of the above prediction calculation. Control is carried out so that both of the preceding material and the following material finish the process at a preset speed. Also, the traveling speed of the following material is controlled according to the position and the speed of the tail edge of the preceding material in a section close to the catch-up position so that a distance between the tail edge of the preceding material and the leading edge of the following material be closed.

Abstract: There is herein disclosed a method for preparing high-purity aqueous hydrogen peroxide by bringing aqueous hydrogen peroxide into contact with a strongly basic anion exchange resin, said method comprising the step of using the strongly basic anion exchange resin which is converted into a form of an exchange group at the time of the purification of aqueous hydrogen peroxide by bringing the strongly basic anion exchange resin into contact with a liquid agent passed through a filter having an average pore diameter of 1.0 .mu.m or less.According to the present invention, aqueous hydrogen peroxide containing inorganic impurities such as metals and metallic compounds can be purified to prepare extremely high-purity aqueous hydrogen peroxide.

Abstract: A process for purifying an aqueous solution of hydrogen peroxide comprising bringing the aqueous solution of hydrogen peroxide into contact with a cation exchange resin or an anion exchange resin, aging the obtained intermediately purified aqueous solution of hydrogen peroxide by standing alone for 1 hour or more, and bringing the aged aqueous solution of hydrogen peroxide into contact with an ion exchange resin of the same type.The process provides a high purity aqueous solution of hydrogen peroxide and can advantageously be used in the field of production of semiconductors.

Abstract: In a method of continuously annealing steel strip comprising a heating step (A), a soaking step (B), a primary cooling step (C) including a rapid cooling step at least in a second half thereof, an overaging step (D), and a final cooling step (E), inert atmosphere gas containing H.sub.2 gas in the concentration of 30-60% is employed as cooling gas for use in the rapid cooling step, the blowoff temperature of the cooling gas is 30.degree.-150.degree. C., and the blowoff speed of the cooling gas is 100-150 m/sec. The primary cooling method in continuously annealing steel strip provides the primary cooling step (C) including the rapid cooling step which can be carried out with a high efficiency and a low cost.

Abstract: The invention comprises a continuous hot rolling method in which a rear end portion of a preceding metal block and a fore end portion of a succeeding metal block are cut and the metal blocks are joined to each other by heating and pressing followed by a finish rolling. A region of each metal block is restrained from a clamping position to the end portion thereof in order to prevent a change in level of the metal blocks in heating and pressing the piece. The end portions of the metal blocks can be thus prevented from deformation.

Abstract: An apparatus for pulling up a single crystal according to Czochralski method is provided with a cylindrical first screen and a second screen. The first screen is arranged in the periphery of the zone of pulling up the single crystal, said screen being constituted by a heat absorbing body at the side facing a quartz crucible and by a heat insulator at the other side and being provided with respective outward and inward annular rims at the upper and lower ends thereof, the corner of said screen facing the crucible being formed in a curved or polygonal structure, and said annular rim at the lower end being positioned in the vicinity of filling the melt in the crucible. The second screen forming a parabolic shape in the section opening at its center while enclosing the crystal pulling-up zone and being provided at its upper end with an outward annular rim.

Abstract: A single crystal pulling apparatus using Czochralski method includes a first screen in the shape of a hollow round cylinder. One side of the first screen facing a quartz crucible is made of a heat absorbent material and another side of the first screen is made of a heat insulator material. The upper and lower ends of the first screen have an outwardly extending flange and an inwardly extending flange, respectively. The first screen surrounds a single crystal pulling zone such that its lower flange is positioned near a melt charged zone in the crucible. The apparatus also includes a second screen positioned inside the first screen. The vertical section of the second screen has the shape of a substantially parabola and the center of the bottom of the second screen is open and surrounds the single crystal pulling zone. The upper end of the second screen has an outwardly extending flange.

Abstract: A process for making hydrogen peroxide by catalytically reacting oxygen with hydrogen in a liquid reaction medium, which comprises(a) filling a reactor with a liquid reaction medium containing a catalyst,(b) dissolving oxygen and hydrogen in the liquid reaction medium by contacting the gases separately and simultaneously with the liquid reaction medium in the reactor,(c) thus forming hydrogen peroxide in the liquid reaction medium containing the catalyst,(d) while maintaining the reactor at such condition that a gaseous phase containing a combination of both oxygen and hydrogen is substantially absent during the reaction, and(e) separating the catalyst from the resulting reaction mixture containing hydrogen peroxide.