Conoco Inc.

Consolidation Coal Company

Thomas D Sandbrook

Michael G Nelson

Hayward B Oblad

Roy O Scandrol

A method and apparatus for determining the reflectivity of the tailings from a coal flotation cell to optimize the cell operation. A photoelectric detector determines the coal content of the tailings and through a process controller; frother and collector addition to the cell is monitored. An ultrasonic energy vibration is periodically transmitted to the detector to remove deposits on the detector to optimize detector operation.

Method and apparatus for controlling a flotation cell

A method of controlling the separation of coal from a mixture of coal and refuse in a froth flotation device by measuring the differential back pressure between two gas bubbler tubes immersed to different depths into the body of pulp in the device to produce a first control signal representative of the pulp density, and adjusting the rate of addition of a froth enhancement additive to the froth flotation device responsive to changes in said first signal; a second signal, produced by measuring back pressure of a single bubbler tube and representative of the pulp level in said device, can be corrected for changes in density by combining it with said first signal and then utilized to control liquid level in the cell by adjusting the rate of withdrawal of refuse therefrom.

Growing community of inventors

Eighty Four, PA, United States of America

Thomas D Sandbrook