Abstract: Aerated bitumen froth containing bitumen, water, air and solids is the product of the hot water extraction process for recovering bitumen from oil sand. Measurements related to the water content of the froth can be obtained by measuring its resonant frequency in a calibrated output, open-ended microwave cavity. By also measuring the bulk density of the froth and assuming a constant relationship for the solids content, one can compute from the assembled data the output quality of the froth. The measurements can be taken repetitively at the vessel as the froth is produced and used to almost instantly provide froth quality information.

Abstract: An aperature is formed in the bottom wall of the launder. A downwardly extending container communicates with the aperture. A weir is positioned immediately downstream of the aperture. The container and weir combine to form a separator. In the launder, free water and solids contaminants settle and form a bottom layer of dirty water. The layer is diverted into the container through the aperture and the weir temporarily retains a small head of it. Temporary retention in the separator therefore generates a vertical fluid column comprising an upper layer of relatively clean froth and a lower layer of dirty water, said layers having an ascertainable interface. The elevation of the interface is monitored and contaminated fluid is withdrawn from the container as underflow at a rate controlled to keep the interface elevation substantially constant. The froth overflowing the weir is reduced in water and solids relative to the original froth issuing from the flotation vessel.