Extraction Problem Solving Drill

Leaching Problem Solving Drill Leaching  1. A slurry of flaked soybeans weighing a total of 100 kg contains contains 75 kg of inert solids and 25 kg of  solution with 10 wt % oil and 90 wt % solvent hexane. This slurry is contacted with 100 kg of pure hexane in a single stage so that the value of N for the outlet underflow underflow is 1.5 kg insoluble solid/kg  solution retained. Calculate the the amounts and compositions compositions of the overflow V1 and the underflow L1, leaving the stage. 2. A treated ore containing inert solid gangue and copper sulfate is to be leached in a countercurrent multistage extractor using pure water to leach the CuSO4. The solid charge rate per hour  consists of 10 000 kg of inert gangue (B), 1200 kg of CuSO4 (solute A), and 400 kg of water  (C). The exit wash solution is to contain 92 wt % water and 8 wt % CuSO4. A total of 95% of the CuSO4 in the inlet ore is to be recovered. The underflow is constant at N = 0.5 kg inert gangue solid/kg aqueous solution. Calculate the number of stages required. Ans. 9 stages, LN = 20000kg/h, YAN = 0.0030, V1= 14250kg/h

3. Soybean flakes containing 22 wt% oil are to be leached in a countercurrent countercurrent multistage process to contain 0.8 kg oil/100 kg inert solid using fresh and pure hexane hexane solvent. For every 1000 kg  soybeans, 1000 kg hexane hexane is used. Experiments Experiments give the following retention of of solution with the solids in the underflow, where N is kg inert solid/kg solution retained and yA is the wt fraction of oil in solution: N 1.73 1.52 1.43  yA 0 0.20 0.30 Calculate the exit flows and compositions and the number of theoretical stages needed.

4. It is desired to extract e xtract benzoic acid from toluene using water as the extracting solvent. Data: Analysis 0f feed: benzoic acid = l0% toluene = 90%

Assumptions: 1. All flow rates are steady 2: Toluene and water are immiscible

Rate of feed = 120 kg/minute

3. Feed concentration remains constant

Rate of solvent = 20 kg/minute

4. Two streams leaving each stage are in equilibrium with each other and k =0.125

Calculate the % of the acid extracted ext racted with a single stage system and also for two stage st age countercurrent extraction system.

5. The distribution coefficient of solute A between solvents solv ents B and S is given by Y = 3X where Y and X are mass ratios of A to solvent in extract and in raffinate, raffinate, respectively. B and S are mutually insoluble to each other. One hundred kg of a 30% solution of A and B is to be successively treated in two batch contacts with 60 kg of solvent s olvent each time. Calculate the overall percent recovery of A .

Study Principles involve in Leaching Liquid--L Liquid iquid Extraction . Leaching and Liquid -L