Treatment of clays

Abstract

Abstract Process and system for improving the brightness of clays to a point where the reflectance of light from the clay in dry form reaches a predetermined selected value. The process involves the formation of an agitated reaction mixture comprising an aqueous slurry of the clay and a decolorizing agent reactive with the impurities in the clay. The reaction mixture is maintained at a temperature sufficient to initiate and sustain the reaction and, as the reaction proceeds, at least a portion of the mixture is passed into a light reflectance measuring zone. Visible light is directed onto the mixture in the measuring zone and the magnitude of its reflectance from the mixture is measured. The measured value of reflectance is increased by reacting the decolorizing agent with the clay impurities until the measured value reaches a value representative of the predetermined selected value of the reflectance desired in the clay in dry form. Dry clay is then recovered from the reaction mixture having the desired brightness value. The system of the invention also provides means responsive to the magnitude of the reflectance of light from the clay slurry to regulate the rate of addition of the decolorizing agent into the reaction mixture. The invention provides a rapid, efficient means for monitoring and controlling the progress of the clay beneficiation reaction by measuring the light reflectance of the slurry, and avoids the time consuming steps of sampling, dewatering and drying of clay to obtain a sample for a brightness determination while the beneficiation process is being conducted, as was heretofore necessary in the prior art.

Inventors

• 👤 T Baak
• 👤 D Harris

Bibliographic Details