An open pit mine containing gold (Au) ore deposit at a wall slope angle of B has been proposed, having the ultimate pit limit base (DC), slope wall boundaries (AD and BC), and surface width (AB), as shown in Figure A2-Q2, and the data provided in Table A2 OPEN PIT C Figure A2-Q2. Open pit gold mine divided into square benches and blocks Table A2-Q2 - Ore deposit data Description Pit surface length (L), in out-of-plane (z axis) Pit surface width (AB) Pit base width (DC = 0.2*AB) Pit ore rock unit weight (y=pg) Cost to mine highlighted Block X Cost to process highlighted Block X Ore grade of Block X (g(Au)/t) Gold price (Pr) Metallurgical recovery (R) Value 119 119 0.2*119= 3.5 5.8 8.9 0.32 36.4 92 Unit m m m t/m $/t % g/t $/g % B Q2. (a) Assume square blocks, calculate the pit section area in square metre (m). (b) Calculate pit slope angle (3) and depth (d = vertical distance between surface plane AB and base plane DC). (c) Calculate the pit total volume in m, and calculate the pit rock tonnage in tonne (t). (d) Calculate the total number of blocks and sketch/discuss your appropriately designed pushbacks. (e) Calculate tonnage of Block X in tonne (t). (f) Calculate mining cost, processing cost, and total cost of Block X. (g) Calculate Value, Profit and Revenue of Block X. (h) Calculate the cut-off ore-grade for Block X. Identify each mining and processing cost contribution. (1) Determine and discuss that after mining Block X, whether it should be sent to waste dump or to the process plant by appropriate logic/discussion/calculation. (j) Calculate the excess excavation volume and tonnage when your calculated slope angle b had to change to B = 40.3 due to the slope stability requirements proposed by the site Geotechnical engineer.