Prediction of Cleaned Coal Yield and Distribution Rate in Coal Gravity Separation Based on the Modified Hyperbolic Tangent Model

To accurately predict the gravity separation distribution rate and thus the product yield during the design and management of coal preparation plants, a modified hyperbolic tangent model was proposed to derive direct calculation formulas for heavy-medium and water-medium separation distribution rate. Four groups of coal samples from heavy-medium coal preparation plant and water-medium coal preparation plant were used to verify the accuracy of the derived direct formulas, and the prediction results of the direct formulas were compared with those of the approximate formula method (AFM). The results showed that the distribution rates predicted by the direct formulas were closer to the actual value, and the distribution curve fitted by these distribution rates was closer to the actual distribution curve. Under the condition that the cleaned coal ash content was basically the same, the cleaned coal yield predicted by direct formula was lower than that predicted by AFM, which was closer to the actual value. Thus, it is verified to be better and more reasonable than the usual AFM. The direct formula derived has reasonable theoretical basis, simple calculation process and accurate result, which will help to improve the design and management level of coal preparation plant