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 electrocast refractory in which occurrence of cracks in manufacture and occurrence of cracks in use as a furnace material is further reduced while maintaining extremely high corrosion resistance to molten glass. The high-zirconia electrocast refractory contains 96.7 to 98.5 mass % of ZrO2, 0.8 to 2.7 mass % of SiO2, 0 to 0.2 mass % of Na2O, 0.21 to 1 mass % of K2O, 0.1 to 0.4 mass % of Al2O3, and does not substantially contain B2O3, in terms of oxide, as a chemical composition, wherein contents of the Na2O and the K2O satisfy a relation of following Formula (1) 0.15 mass %?CK2O/2+CNa2O?0.6 mass %??(1) where CK2O is the content of K2O and CNa2O is the content of Na2O, and each of the contents is expressed by mass % in the refractory.

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 electrocast refractory in which occurrence of cracks in manufacture and occurrence of cracks in use as a furnace material is further reduced while maintaining extremely high corrosion resistance to molten glass. The high-zirconia electrocast refractory contains 96.7 to 98.5 mass % of ZrO2, 0.8 to 2.7 mass % of SiO2, 0 to 0.2 mass % of Na2O, 0.21 to 1 mass % of K2O, 0.1 to 0.4 mass % of Al2O3, and does not substantially contain B2O3, in terms of oxide, as a chemical composition, wherein contents of the Na2O and the K2O satisfy a relation of following Formula (1) 0.15 mass %?CK2O/2+CNa2O?0.6 mass %??(1) where CK2O is the content of K2O and CNa2O is the content of Na2O, and each of the contents is expressed by mass % in the refractory.

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 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 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.