A pregnant solution produced from heap leaching of a low grade nickeliferous laterite ore with sulfuric acid contains the following metal ions. Aluminium(III) ions can be extracted using Cyanex 272 in Exxsol D-80 with 5% TBP at 40C. The loading isotherm for the extraction of aluminium(III) from a feed solution of pH3 by Cyanex 272 is shown below. Loading on to Cyanex 272(20%v/v in Exxsol D-80, pH=3.0,T=40C (Aqueous feed flow rate =20.5mL/min, organic flow rate =8.2mL/min ) (i) Construct a McCabe-Thiele diagram to determine the number of extraction stages required to extract aluminium (>99%) from the leach liquor using a counter current operation. (ii) What is the concentration of Al (III) in the loaded organic? [10 marks] [2 marks]