3 3 3 The average copper grade of the ore is 0.7 %. The total pregnant solution flowrate from all the leach pads is 8 000 m²/hr, with an average concentration of 1.8 kg/m², with the concentration of copper in the lixiviant that is irrigated onto the heap being 0.2 kg/m (ignore any solution or copper losses to the environment in these calculations). What is the average copper recovery for the process?

10 ton/h of saturated aqueous solution of BaCl2 at 100ºC is fed into a crystallizer that can be simulated by the perfect mix model (MSMPR). The magma leaves the crystallizer to 20ºC, with dihydrate crystals. The volume of mother liquor in the crystallizer is 2.0 m3. The crystal growth determined on a pilot scale was 4 x 10-7 m/s and it is expected thatkeep in the crystallizer in question. The solubility of BaCl2 is 35.7 Kg/100 Kg H2O (20ºC) and 58.3 Kg/100 Kg H2O (100ºC). The density of the crystals produced is 3.097 g/cm3 and the density of a saturated solution of BaCl2 at 20ºC is 1.29 g/cm3. Calculate: a) the predominant size based on the mass of crystals. (Resp. 1.3 mm)b) the size that accumulates 30% of the size distribution (L). (Resp 154 μm)c) the required nucleation rate in the crystallizer (in nuclei formed h-1 m-3). (Ans.?=º9.02 x 108 cores / h m3

34. calculate the residence time of the methane stream in the porous absorber given the solar power of 2.3193 kW and a felt temperature of 1758 K. the methane flow rate is 12683.916793505834 cm^3/min. the porous carbon felt absorber has a porosity of 0.9 and a thickness of 3.2 mm.

If the slurry is filtered using a larger filter press with an area of 15 m2 at a constant rate of 450 L/h, calculate the volume of filtrate that will be recovered and the time it will take to reach a pressure of 1000 kPa.

•A homogeneous sludge forming a uniform incompressible cake is filtered through a batch leaf filter at a constant difference in pressure of 40 psi forming a ¾ inch cake in 1 hr with a filtrate volume of 1500 gal. 3 min. are required to drain the liquor from filter. 2 min required to fill the filter with water. Washing proceeds exactly as filtration using 300 gal. opening dumping and closing take 6 min. Assume the filtrate to have the same properties as water and neglect the resistances of the filter cloth and flow times. •How many gallons of filtrate are produced on the average per 24 hr.

A ball mill grinds a nickel sulphide ore from a feed size 80% passing size of 8 mm to a product 80% passing size of 200 microns. The ball mill discharge was reground in a Tower mill to increase liberation before re-cycling to the float circuit. The Tower mill has an installed power of 40 kW and produces a P80 of 30 microns from a F80 of 200 microns. What are the reduction ratios for the ball mill and tower mill, respectively? O A. 100: 15 O B. 25.5: 12.5 OC 73.5: 4.6 O D. 37.5: 6.4 OE. 40.0; 6.67