Solids Leaching

Dispersed-Solids Leaching Equipment for leaching fine solids... 

Forward and Halpem (F7) described extraction of uranium by generating sulfuric acid directly from the sulfide minerals present in the ore at elevated temperatures and pressures. The optimal conditions found for most of the ores studied are a grind of 50-65% — 200 mesh, a pulp density of 65% solids, leaching temperature of 130°C, and an oxygen partial pressure of 10 psi to give 90-95% uranium dissolution in 4-6 hr. This... 

Dispersed-Solids Leaching Equipment for batch leaching of fine solids in a liquid suspension is now confined mainly to batch tanks with rotating impellers. For a detailed discussion of all aspects of the suspension of solid particles in fluids, refer to agitation of particle suspensions at the beginning of this subsection. 

DISPEI ED-SOLID LEACHING. Solids that form impermeable beds, either before or during leaching, are treated by dispersing them in the solvent by mechanical agitation in a tank or flow mixer. The leached residue is then separated from the strong solution by settling or filtration. 

SCFs may be used in the same way as other ordinary solvents taking into account their different properties and behaviors. Supercritical fluids can replace liquids solvents in many processes, such as extractions from solids (leaching), countercurrent multistage separations, chromatographic separations, and others, provided the solvent properties of the SCFs are adequate. 

Liquid-solid leaching. This involves treating a finely divided solid with a liquid that dissolves out and removes a solute contained in the solid. 

In Chapters 10 and 11 gas-liquid and vapor-liquid separation processes were considered. The separation processes depended on molecules diffusing or vaporizing from one distinct phase to another phase. In Chapter 12 liquid-liquid separation processes were discussed. The two liquid phases are quite different chemically, which leads to a separation on a molecular scale according to physical-chemical properties. Also, in Chapter 12 we considered liquid-solid leaching and adsorption separation processes. Again differences in the physical-chemical properties of the molecules lead to separation on a molecular scale. In Chapter 13 we discussed membrane separation processes where the separation also depends on physical-chemical properties. 

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