Flow-Sheet Design

An extraction plant should operate at steady state in accordance with the flow-sheet design for the process. However, fluctuation in feed streams can cause changes in product quaUty unless a sophisticated system of feed-forward control is used (103). Upsets of operation caused by flooding in the column always force shutdowns. Therefore, interface control could be of utmost importance. The plant design should be based on (/) process control (qv) decisions made by trained technical personnel, (2) off-line analysis or limited on-line automatic analysis, and (J) control panels equipped with manual and automatic control for motor speed, flow, interface level, pressure, temperature, etc. 

Process planning, scheduling, flow sheet design, 1... 

MRR) to recover platinum. The extraction of palladium by the sulfide is slow with 2-3 hr to achieve equilibrium, which inhibits flow sheet design. However, it has been shown that tertiary amines can act as a kinetic accelerator, reducing equilibrium times to minutes, but no information has been published on the effect of these amines on palladium-platinum separation. High loading of the sulfides is possible, and stripping is easy with aqueous ammonia. The overall extraction and stripping equations are as follows ... 

High-temperature decomposition of sulphuric acid is a major step for sulphur-based thermochemical cycles such as hybrid sulphur and sulphur-iodine. It is generally also the most energy-intensive, so that the overall heat requirement for this step can determine whether a particular decomposition reactor or flow sheet design is practical. 

Flow-Sheet Design Thickener-sizing tests, as described earher, will determine unit areas, flocculant dosages, and underflow densities for the various stages. For most cases, unit areas will not vary significantly throughout the circuit similarly underflow concentrations should be relatively constant. In practice, the same unit area is generally used for all thickeners in the circuit to simplify construction. 

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