2) Lithium is one of the critical metals needed to reduce dependence on fossil fuels. An important source of Li in Canada is the aluminosilicate mineral spodumene ( LiAlSi2O6). The following represents a simplified general diagram for a spodumene concentrator. Suppose that the ore entering the grinding circuits at 400 tonnes/ h (on a dry basis) is processed with water addition. The freshwater addition to the overall process is 800 tonnes/h. The tailings produced represent most of the mass in its slurry with the greatest potential for water recovery and recycling. As marked on the diagram, 320 tonnes of this ore end up as tails that go to a thickener at 38% solids. The discharge of the same tonnage of solids from the thickener is the underflow (TUF) at a density of 68% solids (by weight). The thickener overflow (TOF) with no solids is recycled as process water. The concentrate stream having 80 tonnes/h goes to its own thickener for additional water recovery for recycling, but this smaller portion is ignored for simplicity. a) If the feed enters the process at an equivalent grade of 1.64%Li2O and the tails leave the plant at 0.24%Li2O for disposal, what is the percent recovery and grade of the concentrate for Li2O ? b) Based on the data given, what is the \%water recovery from the thickener feed? How much water is recycled in percentage relative to the freshwater input to the process? (33 marks)