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      Practical example                
        A sampling campaign gives the following results:            
        These laboratory results are the percentage of passing cumulated of separator feed,    
        fines (product) and rejects (tails).              
        Calculation of the circulation factor on each sieve with the formula:        
        And we get:                  
        We adopt the average of these values and we have:           
        If the mill production is 100 t/h, we have            
        the following flow rates:                
        Mill entrance: 100 t/h of fresh feed + 82,3 t/h of separator rejects        
        Mill outlet: 182,3 t/h                
        Separator feed: 182,3 t/h                
        Separator fines: 100 t/h                
        Separator rejects: 82,3 t/h           
        Calculation of the separation efficiency on each sieve with the formula:
        We observe that the efficiency is decreasing with higher sieves, it is absolutely normal.    
        Calculation of the Tromp Curve with the formula:
        We define the fraction sizes, here:              
        between  0 and 8µ, between 8µ and 16µ, between 16µ and 32µ, between 32µ and 64µ,    
        between 64µ and 90µ and finally between 90µ and 212µ.          
        For all these fraction sizes, we calculate the percentage of passing.        
        For example, for separator feed, between 0µ and 8µ, we have 23,5% of passing,      
        between 8µ and 16µ, we have 33,8 - 23,5 = 10,3% of passing...etc        
        After, we calculate Vfaverage with the formula:             
        Now, for each value of T, we have to calculate the average size of the fraction size.      
        It means, for example, we choose (0+8)/2 = 4µ for the 0-8µ fraction size.        
        We will have:                  
        The next step is to plot the chart with the dimension (µ) in x-axis        
        and the T values in y-axis, like that:              
        Remark: x-axis has a logarithmic scale              
        Separator evaluation                
        Cut size (D50%): 37µ this is a good estimation          
        D limit: < 3µ this is a rough estimation          
        by-pass: ± 13% this is a rough estimation          
        with the formula:
        we have to estimate D75% and D25%:               
        D75%: 58µ                
        D25%: 18µ                 
        In conclusion, this separator has a bad imperfection but the D limit and the by-pass are satisfactory.  
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