Abstract: A gravity blending apparatus and methods of gravity blending involving an improved venting arrangement, by means of which an increase in the "thru-put" flow rate of a gravity blender apparatus is provided by venting the underside of an inverted cone within a collecting chamber to one or more low pressure zones. Advantageously, such venting may proceed progressively from the underside of an inverted cone within the collecting chamber to a low pressure zone within the upper portion of the collecting chamber, with venting continuing by way of auxiliary or further venting conduit means to the underside of a material distributing, inverted cone in the lower portion of the base of the main bin of the gravity blender.