Patent ID: 7338624

Claim:
A method of producing a green form for use in manufacturing a composite, ceramic ion transport membrane, said method comprising: forming a first layer from a first ceramic powder mixture having coarse particles in a coarse particle size range of between about 30 microns and about 150 microns and the fine particles having a fine particle size of no greater than about 15 microns, said first layer being used to form the anode of an electrolytic cell; forming a second intermediate layer on said first layer from a second ceramic powder mixture having a second particle size in a second particle size range of between about 0.1 microns and about 5 microns, said second intermediate layer being thinner than said first layer; the first ceramic powder mixture and the second ceramic powder mixture having a binder and at least the first ceramic powder mixture also having a pore forming material; the second ceramic powder mixture formed at least in part by material used in forming a dense layer and having a particle size less than that of particles of said first ceramic powder mixture to decrease surface roughness and to allow formation of pores in the second layer of smaller size than those of the first layer; heating the first and the second intermediate layer to remove the binder and pore forming material and to form the pores in the first and the second intermediate layer while not sintering the first layer and the second intermediate layer; after heating, the pores of said first layer are large pores having a large size range of between about 20 microns and about 100 microns end small pores having a small size range of between about 1 micron and about 10 microns and a porosity is produced of between about 20 percent and about 45 percent and said second intermediate layer has second intermediate layer pores no greater than about 5 microns and a second intermediate layer porosity of no greater than about 45%; and forming a layer of dense layer material, on said at least one second intermediate layer after the removal of the binder and the formation of the pores front the first layer and the second intermediate layer, the dense layer material containing dense layer particles capable of conducting ions and forming an electrolyte layer of the electrolytic cell, the first layer, the at least one second intermediate layer and the layer of dense layer material all not being sintered during production of the green form.