A NEW METHOD FOR EVALUATION OF GRAVITY SEPARATION PROCESSES

Abstract

Over the years, different methods have been used to evaluate separation efficiency of gravity separation processes. In this paper, all these methods are reviewed and then critically evaluated for their application in the industry. Methods based on recovery of minerals are better than the other available methods. Among the recovery-based methods, those proposed by Lincoin and Gaudin probably addressed most of the important aspects of efficiency calculation. However, in these two methods, the separation efficiency value is also a function of feed characteristics. Therefore, to evaluate the role of process efficiency without the influence of feed characteristics, a new method is proposed for gravity separation processes. The method has its application in process optimization.

Keywords:

• gravity separation
• new method
• separation efficiency

I am thankful to the Raw Material and Coke Making Research Group (of R&D Division, Tata Steel) for their keen interest in this subject and constant encouragement. My sincere thanks are also due to the plant engineers, quality control managers, and geologists from mines and collieries who have raised valid queries time and again, and who inspired me to understand the subject every time I revisited it.

I am grateful to Dr. A. I. A. Salama of CANMET for providing me useful information on methods for calculation of separation efficiency. Prof. Tim. J. Napier-Munn of JKMRC, Australia, enriched my knowledge on the subject during his visit to Tata Steel. Finally, I thank Mr. Arijit Das for sharing his plant trial data of West Bokaro washery—II and the Geological Department, Noamundi, for providing me with the trial data of the jigging plant.

Notes

Note: The Lincoin and Gaudin methods measure actual separation efficiency. It should be noted that the method used to measure the actual separation efficiency in the proposed method is the same as that followed in the Gaudin method.