The feed to the mill is 100tons per hour. The ore comprises 10% Magnetite (Sg 5.3) and the rest is silica (Sg 2.7). Assu

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The feed to the mill is 100tons per hour. The ore comprises 10%Magnetite (Sg 5.3) and the rest is silica (Sg 2.7). Assume that themill product is 100% liberated after milling. The mill product isfed to a double screen mill with an upper screen having an apertureof 100m. The lower screen aperture is your choice as you seek tooptimise product quantity and quality. The work index of the ore is10kwh/t and the feed size distribution is given by the equationPf(d)=1-exp(-0.693(d/6000)). The resulting product sizedistribution is described by this equation Pp(d)=0.8(d/d80) .5(note that all dimensions are in microns and 0 ≤ P(d) ≤ 1). Themill product is screened on a double decker screen where productabove 100m goes to customer A and the screen middlings product isprocessed in a hydrocyclone for customer B. The screen undersize isdiscarded. You are required to maximise profitability from thisplant knowing that the value of the product to customer A is R100/twhile to customer B is R500/t provided the Magnetite produced hasless than 70% Silica contamination. Electricity costs 250cents perunit (1kwh=1 unit). Note that the classification function is Rui=1-exp(-0.693(d/d50c) 2 ) for both components, but the d50c isbased on a 50um silica particle settling in water under stokesconditions (Your Tsv value should always be equal to this referencevalue). Assume slurry density to be 40% solids slurry and viscosityto be 1.5X that of water.
1. Your main objective is to set-up your system to produce thementioned end-products. Refer to your class notes for any furtherinformation and you are welcome to make any necessary assumptions(20).
2. Plot on the Rosin-Rammler graph provided the feed and theproduct of the ball mill(4)
3. calculate the settling ratio of the two components in theslurry (2)
4. If this was separated using water with an upward velocity toget a pure magnetite product, calculate the aperture of the lowerscreen required (2)