Ten metric tons per hour of dry seashore sand containing 1%w NaCI is to be washed by 10 metric tons per hour of NaCl- free water running countercurrent to the sand through 2 classifiers in series. This operation is carried out 24 hours per day. Assume that perfect mixing of the sand and wash water occurs in each classifier. The sand is discharged from the classifiers with 50% liquid (dry sand basis) 

a. If the exit sand is dried in a rotary kiln drier, what percentage of NaCl will it retain? 

b. What hourly wash water rate would be needed in a single classifier to wash the sand equally as well as in (a)?

Answer rating: 100% (QA)

Solution To do a mass balance around two stages Classifier I and II Basis 10 metric tons per hour 27... View the full answer