Abstract: The disclosure is directed to a method for purifying metals, which can very efficiently and inexpensively eliminate impurity elements included in various metallic or semiconductor materials, or more specifically included in metallurgical grade silicon.

Abstract: A method for purifying a metal, which includes: a first step of holding a first molten metal containing impurities in a first crucible; a second step of immersing a first cooling body in the first molten metal held in the first crucible while letting a cooling fluid flow in the interior of the cooling body to crystallize a first purified metal on a surface of the cooling body; a third step of taking out the first cooling body with the first purified metal crystallized thereon from the first molten metal; a fourth step of holding in a crucible a second molten metal having an impurity concentration less than that of the first molten metal of the first step; a fifth step of melting the first purified metal crystallized in the second step and holding the molten metal in a second crucible together with the second molten metal held in the fourth step; a sixth step of immersing a second cooling body in the second molten metal held in the fifth step while letting a cooling fluid flow in the interior of the cooling bo

Abstract: Method capable of preparing silicon having purity of about 6N applied to a solar cell efficiently at a low cost. Raw silicon containing boron and a slag are melted and a shaft is rotated by a rotating/driving mechanism for stirring the molten silicon. The molten slag is dispersed in the molten silicon, thereby accelerating the boron removal reaction. It is further effective to use a slag containing at least 45 percent by mass of silicon oxide or to blow gas mixed with water vapor into the molten silicon for refining reaction.

Abstract: A first aluminum brazing alloy for cold brazing, comprises 70 to 90% by weight of zinc and 0.05 to 5% by weight of titanium with the balance consisting of aluminum and impurities. A second aluminum brazing alloy for cold brazing, comprises 30 to 70% by weight of zinc, 1 to 7% by weight of silicon, and 0.05 to 5% by weight of titanium with the balance consisting of aluminum and impurities. Brazing alloys having these compositions have a low melting point and can well wet a base metal. Further, use of the above aluminum brazing alloy for cold brazing enables a low-melting aluminum material to be well brazed at 400 to 550° C.

Abstract: A brazing material that has a low melting point and can braze aluminum materials at a low temperature with a good wetting property is disclosed. The brazing material can include a matrix composed of Zn, a Zn--Al alloy or a Al--Zn--Si alloy having a low melting point each preferably containing 0.001 to 3.0 wt % of rare-earth element. When such a brazing material is used, aluminum materials can be brazed at a temperature of 580.degree. C. or below.

Abstract: A process for brazing a die-cast aluminum material, wherein a die-cast aluminum material produced at a gate speed of 20 m/s or higher is used to be brazed at a brazing temperature of 500.degree. C. or lower. Further, it is preferred that the die-cast aluminum material is produced under a casting pressure of 600 kgf/cm.sup.2 or lower, or that the die-cast aluminum material is produced while depressurizing a mold. Brazing may as well be conducted using a brazing filler metal material composed of 6 to 24 wt. % of Al and the balance consisting of Zn and impurities. In the foregoing manner, the die-cast aluminum material can be brazed by heating it to a high temperature.

Abstract: Objects of the present invention are to provide a brazeable aluminum alloy cast material which can be manufactured brazeable products without lowering the productivity and the method of brazing a cast material.The cast material is composed of: 0.5-4.5% by weight of Mn; 0.5-3% by weight of Si; 0.5-1% by weight of Fe; and the balance composed of aluminum and impurities. In the method of brazing the cast material, a brazing agent and/or flux are used, the brazing agent is composed of: 25-65% by weight of Zn; 2-7% by weight of Si; and the balance composed of aluminum and 0.1% or less of Fe as one of impurities. The flux is a mixture of: 0.5-5% by weight of LiF; 1-10% by weight of ZnCl.sub.2 ; 1-5% by weight of K.sub..alpha. AlF.sub..alpha.+3 (.alpha. is an integer not less than 1.); and the balance composed of BaCl.sub.2 -KCl-NaCl.

Abstract: A metal purifying apparatus comprises a closed melting furnace equipped with a heater, molten metal holding crucible disposed within the furnace, a vertical hollow rotary shaft penetrating through a top wall of the furnace, a packing sealing off a clearance in the shaft penetrating portion of the top wall around the shaft, rotary drive means for rotatingly driving the shaft, a hollow rotary cooling body fixedly provided at a lower end of the shaft and having an interior space communicating with an interior space of the shaft, and a cooling fluid supply source for supplying a cooling fluid to the interior of the cooling body. The rotary shaft has disposed therein a cooling fluid discharge pipe with a lower end positioned below the top wall of the furnace.

Abstract: An aluminum alloy for heat exchangers, the alloy, comprising a base compostion selected from a group consisting of Al-Mg-Si composition containing 0.1 to 0.8 wt % of Mg, 0.2 to 1.0 wt % of Si and 0.3 to 1.5 wt % of Mn; pure-Al composition; Al-Mg composition containing 0.05 to 1.0 wt % of Mg; and a Al-Zn composition containing 0.05 to 2.0 wt % of Zn. The alloy further comprises 0.01 to 0.3 wt % of Fe and/or 0.01 to 0.3 wt % of Ni, wherein the balance are aluminum of purity of 99.9% or higher and unavoidable impurities contained therein, and content of Cu as one of the impurities is controlled to be 0.05 wt % or less.

Abstract: A corrosion-resistant clad material is made of aluminum alloys, and in a preferable mode, comprises: a core which is either formed of an Al-Mn alloy containing 0.5-1.5% by weight of Mn; or alternatively formed of an Al-Mg-Si alloy containing 0.05-1.0% by weight of Mg and 0.05-0.3% by weight of Si. The Al-Mn alloy and Al-Mg-Si alloy further contain, as additional components, 0.05-0.3% by weight of Ti and/or 0.05-0.4% by weight of Zr. The clad material further comprises a skin layer which is formed of an Al-Zn alloy clad onto at least one surface of the core. In another preferable mode, the clad material comprises: a core formed of an Al-Mn alloy containing 0.5-1.5% by weight of Mn; and a skin layer clad onto at least one surface of the core and formed of an aluminum alloy containing 1.3-5.0% by weight of Zn, with or without 0.2-1.0% by weight of Mg, and a balance of aluminum and unavoidable impurities. Cu content as one of the impurities is controlled to 0.

Abstract: A heat exchanger comprises tubular elements and fin members. The tubular elements are made of an aluminum alloy containing 0.05 to 1.0 wt % of Mg, 0.2 to 1.2 wt % of Si, 0.2 to 1.5 wt % of Mn, 0.01 to 0.5 wt % of Fe, as necessary components, and further containing at least one of 0.05 to 0.3 wt % of Cr and 0.01 to 0.05 wt % of Ti, as optional auxiliary components, and 0.05 or less wt % of Cu as a controlled impurity, the balance being aluminum and unavoidable impurities. The fin members are made of another aluminum alloy containing 0.05 to 1.0 wt % of Mg, 0.2 to 1.2 wt % of Si, 0.2 to 1.5 wt % of Mn, 0.01 to 0.5 wt % of Fe, and further containing at least one of 0.01 to 0.1 wt % of In and 0.1 to 2.0 wt % of Zn as necessary components, and still further containing at least one or of 0.05 to 0.3 wt % of Cr and 0.01 to 0.05 wt % of Ti as optional auxiliary components, and 0.05 wt % or less of Cu as a controlled impurity, the balance being aluminum and unavoidable impurities.

Abstract: A metal having a high purity is prepared by immersing a hollow rotary cooling member in a molten metal containing eutectic impurities and rotating the cooling member while supplying a cooling fluid to the interior of the cooling member, whereby the high-purity metal is caused to crystallize out on a metal deposition area of the peripheral surface portion of the cooling member present under the surface of the molten metal, the metal deposition area being the peripheral surface of at least a part of the entire portion, present under the melt surface, of the member. When the purified metal is caused to crystallize but by rotating the cooling member, a flow of molten metal having a downward velocity component is produced in the vicinity of an upper part of the entire portion, present under the melt surface, of the cooling member.

Abstract: A metal having a high purity is prepared by immersing a hollow rotary cooling member in a molten metal containing eutectic impurities and rotating the cooling member while supplying a cooling fluid to the interior of the cooling member, whereby the high-purity metal is caused to crystallize out on a metal deposition area of the peripheral surface portion of the cooling member present under the surface of the molten metal, the metal deposition area being the peripheral surface of at least a part of the entire portion, present under the melt surface, of the member. When the purified metal is caused to crystallize out by rotating the cooling member, a flow of molten metal having a downward velocity component is produced in the vicinity of an upper part of the entire portion, present under the melt surface, of the cooling member.

Abstract: An apparatus for treating a molten metal comprises a vertical post, a treating container disposed at one side of the post and having an opening at its upper end for containing the molten metal, a horizontal suspending arm mounted at its base end on the post upwardly and downwardly movably and rotatable in a horizontal plane, a vertical rotary shaft suspended from the arm and having a treating gas channel internally extending therethrough longitudinally, a bubble releasing-dispersing rotor provided at the lower end of the rotary shaft and having in its bottom surface a treating gas outlet in communication with the gas channel, the rotor being movable into and out of the container through the opening, and at least one baffle suspended from the arm and movable into and out of the container through the opening for preventing eddying and waving.

Abstract: Hydrogen gas and non-metallic inclusions are removed from molten aluminum by a process comprising the steps of rendering the portion above the surface of molten aluminum in a treating vessel where the molten aluminum is placed, an atmosphere of air having a lower dew point than that of the atmosphere and maintaining it as it is, introducing a treating gas into the molten aluminum, and removing floating non-metallic inclusions and treating gas containing hydrogen gas from the surface of the melt.

Abstract: Crude silicon is purified by melting the crude silicon, maintaining the molten silicon above the solidification temperature thereof in an inert gas atmosphere, and rotating a hollow rotary cooling member as immersed in the molten silicon while introducing a cooling fluid into the cooling member to cause high-purity silicon to crystallize on the outer surface of the cooling member.

Abstract: A device comprising a rotary shaft to be disposed in a liquid substantially vertically and rotatable about its own axis, the rotary shaft having a gas channel extending therethrough axially of the shaft, and a rotor fixed to the lower end of the rotary shaft and having at its bottom surface a gas discharge outlet communicating with the gas channel. The rotor is formed in its bottom surface with radial grooves extending from the gas outlet to the peripheral surface of the rotor and each having an open end at the peripheral surface. A recess is formed in the peripheral surface between the open ends of immediately adjacent grooves and has an open lower end at the bottom surface. When the rotary shaft is rotated in a liquid while supplying a gas to the gas channel of the shaft, the gas flows out from the discharge outlet into the radial grooves and is released from the open ends of the grooves at the peripheral surface into the liquid in the form of finely divided bubbles.

Abstract: Hydrogen gas and non-metallic inclusions are removed from molten aluminum by a process comprising the steps of maintaining an atmosphere containing BF.sub.3 gas in a treating vessel above the surface of molten aluminum placed therein, introducing a treating gas into the molten aluminum, and removing floating non-metallic inclusions and treating gas containing hydrogen gas from the surface of the molten aluminum.

Abstract: To obtain a high-purity aluminum fraction from aluminum containing both eutectic impurities and peritectic impurities, the contents of these impurities in the original aluminum are reduced by melting the original aluminum to obtain molten aluminum, adding boron to the molten aluminum, and rotating a cooling body as immersed in the boron-containing molten aluminum while introducing a cooling fluid to the interior of the body to crystallize high-purity aluminum on the surface of the body. The peritectic impurities react with the boron to form metallic borides, which are centrifugally forced away from the cooling body by the rotation of the body without being incorporated into the aluminum crystallized on the surface of the body. The eutectic impurities are removed from the crystallized aluminum on the surface based on the principle of segregation.