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In the coal and mineral beneficiation industries, screening is one of the crucial physical separation methods carried out to separate the undersized fine particles from the oversize coarse particles. The vibratory screener is a relatively advanced screening technology applied for coal and iron ore beneficiation. This paper deals with the experimental investigation for assessing the efficiency of screening coal and iron ore in the vibratory screener. Furthermore, a comparative study between the test performance of screening coal and iron ore was carried out depending on moisture and density variation. Test results show that the vibratory screener can provide a high recovery of fines and increased efficiency for screening iron ore than coal material. The maximum efficiency of iron ore was attained at a higher angular position, such as 3 and 5 degrees in an upward slope, whereas the maximum efficiency of coal was attained at 1 degree in an upward slope. [ABSTRACT FROM AUTHOR]

The present research work evaluates the influential process parameters such as moisture content, angle, and frequency for separating coal in the vibrating screen. The design of the experiment for three factors with three levels was obtained using Taguchi's and Response surface methodology's (RSM) method. Taguchi's L27 and RSM Box–Behnken design (BBD) method was used to conduct the separation experiment on a vibrating screen. The main effect plot of Taguchi's L27 and BBD method was used to evaluate the optimized condition for obtaining the highest separation efficiency of the vibrating screen. The optimized condition obtained was lower moisture content (4%), lower angle (1 degree in upward slope), and medium frequency (9 Hz). The interaction plot of Taguchi's L27 and BBD method was used to evaluate the interaction between the process parameters. From the interaction plot and ANOVA results, it was clear that the moisture content is the most significant parameter compared with the angle and frequency parameter for separating coal in a vibrating screen. From the prediction results, it was also clear the regression coefficient of Taguchi's L27 was higher when compared with the RSM BBD method. This shows that Taguchi's L27 is the most suitable optimization method compared with RSM. [ABSTRACT FROM AUTHOR]

The availability of low-grade coal with a high amount of ash has urged the improvisation of separation equipment with minimal or no water utilization. The present work addresses the study on the separation equipment performance with different moisture coal. The experimental results were obtained in terms of separation efficiency. After obtaining the experimental results, the mathematical modeling results were obtained using different techniques. The cubic regression and cascade neural network models were considered to study the mathematical correlation with experimental results. The R-squared value of each mathematical modeling technique was correlated with the model fitting to check the model's validity. The results clearly showed that the cubic model fitting for the experimental condition had provided an excellent R-squared value varying from 92% to 99%. The cascade model fitting for the experimental condition has provided a higher R-squared value, i.e., more than 99%. Results show that for all experimental conditions, the cascade model fitting of the neural network technique provides the significant mathematical modeling technique suitable for predicting the separation equipment's performance compared to the cubic model of the regression technique. [ABSTRACT FROM AUTHOR]

Coal separation was usually carried out using the wet coal beneficiation technique. The waste generated by this technique pollutes the environment. So, in this work, a new mechanism of screening machine for dry coal beneficiation was developed. Dry coal screening removes ash impurities from the coal and improves its energy productivity. Hence, a new screening machine was developed with flexibility in changing the screen mesh, screen angle, and frequency of vibration. In this work, coal feed of less than 6 mm were divided into three groups of −6 + 4 mm, −4 + 2 mm, and −2 + 0.5 mm size fractions. Each size fraction was screened individually in the new screening machine by changing the screen mesh to the required perforation. The screening efficiency was determined for each size fraction by varying operational variables such as screen angle and frequency of vibration. This new screening machine provides maximum screening efficiency of 87.36%, 80.52%, and 66.42% for screening coal feed of 6 + 4 mm, −4 + 2 mm, and −2 + 0.5 mm size fractions, respectively. Highly efficient screening and higher removal of ash from coal were obtained due to the design and operational flexibilities of the screening machine. [ABSTRACT FROM AUTHOR]

Implementing the planned execution of experiments will optimize the resources and time of a newly developed process or equipment. In the present work, the screening machine is newly developed equipment designed for the separation of coal. The present work was carried out to evaluate the performance of separation efficiency of the screening machine using generalized and forward selection fractional factorial experimental design. Further, the present work will also determine the significance of each operational variable, such as moisture content, angle, and frequency, for increasing separation efficiency. A cube plot was developed from the experimental design, which shows the highest and lowest condition of separation efficiency for each level of the operational variables. Further, a Pareto chart was developed to evaluate the significant operational variable for the screening machine. The results of the generalized method and forward selection method of fractional design show that the moisture content was the most significant operational variable, followed by angle and frequency. The results also show that the screen blinding of a screening machine plays an important role in reducing the separation efficiency of a screening machine. [ABSTRACT FROM AUTHOR]

In the present work, optimization of the newly developed vibrating screen's operational parameters was carried out to obtain a high response parameter. The operational parameters considered in the present work were moisture content, angle, and frequency. The Taguchi L27 design technique was used to optimize three different operational parameters to obtain high screening efficiency of coal in the vibrating screen. The maximization of screening efficiency was obtained by selecting the "larger the better" condition for developing the model. The regression coefficient of 99.6% shows the close relationship between the predicted and experimental values. The lower value mean error and standard deviation of normal probability indicate that the developed model has less error. From the optimization results, it was clear that the 4% moisture content (low level), 1-degree angle (low level), and 9 Hz frequency (medium level) yielded high screening efficiency. Further, a confirmation test was carried out with the optimized condition, which has yielded a screening efficiency of 84.40%. The results showed that the Taguchi technique could be applied to study the influential operational parameters for maximizing the vibrating screen efficiency. [ABSTRACT FROM AUTHOR]

In this paper, coal screening in vibrating screen was carried out with the size ranges of −6 mm + 4 mm, −4 mm + 2 mm, and −2 mm + 0.5 mm. The vibrating screen was newly designed with flexibility in angle and frequency. The vibrating screen experimentation was carried out by varying screen mesh, angle, and screen frequency. During the screening, the angle was kept constant, and frequency was varied to obtain each size range's screening efficiency. The experimental results of screening efficiency were evaluated for each size fraction range of coal. The maximum efficiency for screening coal with −6 mm+4 mm, −4 mm+2 mm, and −2 mm+0.5 mm size range obtained was 87.60%, 80.93%, and 62.96%, respectively. Further, the prediction model was developed for each size range using a feed-backward artificial neural network (ANN) to consider the back-propagation error technique. For each screening condition, 10 ANN models were developed with the variation in 1–10 different neurons. ANN has provided mathematical models with a 99.9% regression coefficient for predicting each size range's screening efficiency. Furthermore, the residuals of each optimal ANN model were analyzed using a normal probability plot and histogram. The ANN model's accuracy was obtained from the residual analysis by evaluating four different model conditions, i.e., independence, homoscedasticity, normality, and mean error. [ABSTRACT FROM AUTHOR]

Coal is one of the chief energy sources having significant applications in the iron and steel industry. This research investigates the screening efficiency of coal of different size range. The experiments on the screening of coal with different size range in the screening machine were carried out using different mesh sizes. The screening efficiency for different screen angles and frequency of vibration was carried out. After experimentation, regression modeling was carried out for each screening condition. The maximum efficiency of screening coal with size range +4 mm-6 mm, +2 mm-4 mm, and +0.5 mm-2 mm obtained was 87.60%, 80.93%, and 62.96%, respectively. The experimental results show that the screening efficiency decreases with the decrease in size range for screening from +4 mm-6 mm to +0.5 mm-2 mm. The reduction in screening efficiency was due to the clogging of coal to the screen mesh. Linear and quadratic modeling were performed to estimate the efficiency of all the experimental results. After prediction, the validation using residual analysis was carried out, and the results illustrate that the quadratic prediction modeling was accurate. [ABSTRACT FROM AUTHOR]