The ore grade is important in determining the metallurgical route for mineral recovery. Aqua regia is one of the classical analytical methods used to determine ore grade. You are tasked to apply the technique to the copper-bearing ore to determine the head grade. The optimized method is to digest a sample corresponding to 3% wt/v of pulp (solid + aqua regia solution) aqua regia solution at 60℃ for 1 hour. a) Define the following: (a) aqua regia, (b) head grade. b) Show the preparation of the aqua regia solution step by step, knowing that the digestion should be done in 150 mL of the aqua regia solution and the concentration of the reagents must be 3.0 M. The available chemicals in the storeroom with their characteristics are listed here below: • HCl; Molecular mass: 36.46 g/mol; Density: 1.28 Kg/L; Purity: 35% • HNO3; Molecular mass: 63.01 g/mol; Density: 1.54 Kg/L; Purity: 60% • H2SO4; Molecular mass: 98.08 g/mol; Density: 1.84 Kg/L; Purity 98% • NaOH (Atomic mass of Na= 22.9 and O= 15.9, and H=1 [g/mol] and Density of NaOH: 2,13 g/cm³). • CuSO4⋅5H2O (Atomic mass of Cu= 63.5, S=32, O= 15.9, and H=1 [g/mol]) c) After digestion, the solution was analyzed for Cu. Results revealed that the solution contains 1500 ppm of the analyte. What is the value of the head grade in %?
