Solid-liquid mixing operations requiring

Is there a chemical reaction of the solid with the liquid Sohd-liquid mixing operations involving chemical reactions often require a high relative velocity between the solid particle and the liquid—high local shear rate or agitation intensity—to minimize the thickness of the boundary layer for mass transfer. This is also due for the dissolution of a sparingly soluble solid, as discussed further in Chapter 13. 

In agitated tank leaching systems, finely ground ore must be mixed with the lixiviant until the reaction is complete. Liquid/solid separation processes are used to recover the solution and prepare the waste for disposal in a tailing impoundment. Unlike percolation leaching operations, these operations require a large impoundment area to not only handle the solids, but also to neutralize the chemistry and pH of the solutions used to extract the metal value. 

In the GAS (SAS) process, the OS-HC solution is first loaded into the autoclave, and then the pressure is increased by feeding the SCF up to the value required for precipitation. At this point, three phases are present in the vessel the solid product, the liquid mixed-solvent and a vapor phase, essentially SCF. GAS (SAS) batch is a completely batch operation, very simple to carry out. However, as the system undergoes all pressure conditions, between the initial and final, the product obtained depends also on the pressure profile during pressurization. 

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