a) Sketch a generic process flow diagram for a typical hydrometallurgical process and discuss the various unit operations associated with each step. Start with freshly excavated ore that contains valuable metal A as well as impurities and end with a finished product (metal or pure compound). Show liquid, solid, recycle and bleed streams, as well as effluents and residues produced. [15] b) Discuss the major environmental challenges associated with the hydrometallurgical extraction of metals from mineral ores