Powder processing apparatus for classifying and degassing

A method of treating a powder material, the method comprising:

• providing a vessel that includes an interior chamber, a porous bottom wall, a divider wall that extends from the porous bottom wall and defines first and second sub-regions that are bottom-bound by the porous bottom wall, a top region extending above the divider wall, and first and second gas manifold regions below the porous bottom wall;
• providing a powder material into the first sub-region of the vessel;
• increasing a gas flow from the first gas manifold through the porous bottom wall and into the first sub-region such that the gas flow entrains smaller particles of the powder material and carries the smaller particles upwards from the first sub-region into the top region and over the second sub-region;
• slowing a velocity of the smaller particles in a diffusion zone in the top region such that the smaller particles dis-entrain and fall into the second sub-region thereby classifying the powder material by separating the smaller particles from larger particles of the powder material that do not become entrained and remain in the first sub-region;
• and
• degassing the smaller particles and the larger particles within the vessel by heating and fluidizing the smaller particles and the larger particles.