Abstract: A molding material in a powder-fixing lamination method includes an aggregate and a powdery precursor of a binder that binds the aggregate mutually. The aggregate is a casting sand, and the powdery precursor contains a hardening component and a hardening accelerating component. A molded product is manufactured using the molding material.

Abstract: A molding material in a powder-fixing lamination method includes an aggregate and a powdery precursor of a binder that binds the aggregate mutually. The aggregate is a casting sand, and the powdery precursor contains a hardening component and a hardening accelerating component. A molded product is manufactured using the molding material.

Abstract: To provide a high zirconia fused cast refractory having high durability, which hardly has cracks at the time of production of the refractory, during the heating, by temperature changes during use and during the cooling at the time of suspension of operation. A high zirconia fused cast refractory which has a chemical composition comprising from 88 to 96.5 mass % of ZrO2, from 2.5 to 9.0 mass % of SiO2, from 0.4 to 1.5 mass % of Al2O3, from 0.07 to 0.26 mass % of Na2O, from 0.3 to 1.3 mass % of K2O, from 0 to 0.3 mass % by outer percentage of Li2O, at most 0.08 mass % by outer percentage of B2O3, and at most 0.08 mass % by outer percentage of P2O5, and contains B2O3+P2O5 in a content of at most 0.1 mass % by outer percentage.

Abstract: To provide a high zirconia fused cast refractory which has high corrosion resistance to molten glass and which is scarcely susceptible to cracking during its production. A high zirconia fused cast refractory which has a chemical composition comprising from 96.5 to 98.5 mass % of ZrO2, from 0.8 to 2.7 mass % of SiO2, from 0.04 to 0.35 mass % in a total amount of Na2O and K2O, and from 0.02 to 0.18 mass % of B2O3, wherein contents of Na2O, K2O and B2O3 satisfy the relation of the following formula (1) at the same time: 0.03?CB2O3?(CNa2O+CK2O)??(1) wherein CNa2O is the content of Na2O, CK2O is the content of K2O, and CB2O3 is the content of B2O3, and each of these contents represents mass % in the refractory.

Abstract: To provide a high zirconia fused cast refractory having high durability, which hardly has cracks at the time of production of the refractory, during the heating, by temperature changes during use and during the cooling at the time of suspension of operation. A high zirconia fused cast refractory which has a chemical composition comprising from 88 to 96.5 mass % of ZrO2, from 2.5 to 9.0 mass % of SiO2, from 0.4 to 1.5 mass % of Al2O3, from 0.07 to 0.26 mass % of Na2O, from 0.3 to 1.3 mass % of K2O, from 0 to 0.3 mass % by outer percentage of Li2O, at most 0.08 mass % by outer percentage of B2O3, and at most 0.08 mass % by outer percentage of P2O5, and contains B2O3+P2O5 in a content of at most 0.1 mass % by outer percentage.

Abstract: To provide a high zirconia fused cast refractory which has high corrosion resistance to molten glass and which is scarcely susceptible to cracking during its production. A high zirconia fused cast refractory which has a chemical composition comprising from 96.5 to 98.5 mass % of ZrO2, from 0.8 to 2.7 mass % of SiO2, from 0.04 to 0.35 mass % in a total amount of Na2O and K2O, and from 0.02 to 0.18 mass % of B2O3, wherein contents of Na2O, K2O and B2O3 satisfy the relation of the following formula (1) at the same time: 0.03?CB2O3?(CNa2O+CK2O)??(1) wherein CNa2O is the content of Na2O, CK2O is the content of K2O, and CB2o3 is the content of B2O3, and each of these contents represents mass % in the refractory.

Abstract: The present invention provides a method for identifying a glass defect source, whereby a glass defect source can directly be identified without using a mathematical simulation. The method for identifying a glass defect source, which comprises a step of constructing a glass melting furnace by using, as lining furnace material, a fusion cast refractory containing at least one tracer component selected from Cs2O, SrO, BaO and ZnO, a step of melting a glass material by the glass melting furnace and forming the molten glass material to produce glass products, and a step of extracting one having a glass defect from the glass products and analyzing its component composition to determine the position of a glass defect source in the glass melting furnace.

Abstract: To provide a process for producing high-purity highly oxidized refractory particles easily with good productivity by treating a spent refractory containing ZrO2 and Al2O3 to reduce components other than ZrO2 and Al2O3 to levels unproblematic for practical use as raw material for electrofused refractories and to increase the content of the ZrO2 and/or Al2O3 component. A process for producing refractory particles, which comprises introducing to and melting in a melting furnace both a spent refractory which contains, by mass % as chemical components, from 75 to 97% of ZrO2 and/or Al2O3, from 2 to 25% of SiO2, from 0.4 to 7% in total of Na2O, K2O and Li2O(Na2O+K2O+Li2O), at most 2% of CaO and at most 2% of MgO, and carbon particles in an amount of from 1 to 8% by outer mass percentage based on the spent refractory, and after the melting, tapping the melt while blowing compressed air against the melt to form refractory particles having the content of ZrO2 and/or Al2O3 increased.

Abstract: To provide a process for producing high-purity highly oxidized refractory particles easily with good productivity by treating a spent refractory containing ZrO2 and Al2O3 to reduce components other than ZrO2 and Al2O3 to levels unproblematic for practical use as raw material for electrofused refractories and to increase the content of the ZrO2 and/or Al2O3 component. A process for producing refractory particles, which comprises introducing to and melting in a melting furnace both a spent refractory which contains, by mass % as chemical components, from 75 to 97% of ZrO2 and/or Al2O3, from 2 to 25% of SiO2, from 0.4 to 7% in total of Na2O, K2O and Li2O(Na2O+K2O+Li2O), at most 2% of CaO and at most 2% of MgO, and carbon particles in an amount of from 1 to 8% by outer mass percentage based on the spent refractory, and after the melting, tapping the melt while blowing compressed air against the melt to form refractory particles having the content of ZrO2 and/or Al2O3 increased.

Abstract: A method for evaluating internal quality of fused cast refractories including the steps of: emitting electromagnetic wave pulses from sending and receiving antennas moving vertically in the vicinity of a side face of a refractory sample through the side face to an inner portion of the sample electromagnetic waves reflected by the sample via by the sending and receiving antennas, thereby obtaining crude reflected wave images; and evaluating an internal structure of the sample based on the picture of reflected wave images. By the present method, an entire inner structure of a fused cast refractory may be evaluated by emitting electromagnetic wave pulses through only by one side face toward a symmetry plane of said fused cast refractory about which the fused cast refractory is symmetrical, and receiving electromagentic waves reflected from an inner surface of the fused cast refractory sample.