# Process Calculations GATE-2005

**Q 1:** A metal recovery unit (MRU) with an intake capacity of 5000 kg/hr treats a liquid product from a plant and recovers 90 % of the metal in its pure form. The unrecovered metal and its associated liquid are sent to a disposal unit along with the untreated product from the plant (see figure below). Find the flow rate (m6) and the weight fraction of the metal (w6). The liquid product flow rate is 7500 kg/hr of composition 0.1 (wt. fraction). Assume a steady state.

**Q 2: **A feed stream (S1) at 100 kg/hr and containing only A mixes with recycle stream S5 before entering the reactor (see figure below), where the reaction A→B takes place. The operation is at a steady state. The stream S3 leaving the reactor is separated, without either phase or composition change, into two streams S4 and S5. If the mass fraction of B in S4 is 0.95 and the total rate of S5 is 10 kg/hr, then the ratio of flow rates of streams (S3/S5), and the flow rate of A in S3 are, respectively.

**Q 3: **The relation between the stress τ and the strain rate (du_{x}/dy) for the rapid flow of a granular material is given by

Where B is a constant. If M, L, and T are the mass, length, and time dimensions respectively, what is the dimension of the constant B?