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Preparation of NiNb 2 O 6 columbite ceramics by a reaction-sintering process has been investigated. The mixture of raw materials was pressed and sintered into ceramics without any calcination stage involved. Columbite NiNb 2 O 6 ceramics were obtained after being sintered at 1250-1450 o C for 2 h and 4 h from mixture of Nb 2 O 5 and 50%Ni(NO 3 ) 2 -50%NiO (NN1). In pellets from mixture of Nb 2 O 5 and NiO (NN2), columbite NiNb 2 O 6 ceramics were obtained after being sintered at 1150-1350 o C for 2 h and 4 h. A density of 4.47 g/cm 3 was obtained in NN1 for 2 h sintering at 1400 o C. For NN2, a higher density 5.62 g/cm 3 (99.8% of the theoretical value) was obtained for 2 h sintering at 1300 o C. The reaction-sintering process has proven to be a simple and effective method in preparing columbite NiNb 2 O 6 ceramics. A higher density could be obtained at lower sintering temperature by using NiO instead of 50%Ni(NO 3 ) 2 -50%NiO in the reaction with Nb 2 O 5 .