Leaching composition diagrams

FIG. 18 81 Composition diagrams for leaching calculations a) right-triangular diagram (h) modified Ponchon-Savarit diagram,... 

Composition Diagrams In its elemental form, a leaching system consists of three components inert, insoluble solids a single non-adsorbed solute, which may be liquid or solid and a single solvent. Thus, it is a ternary system, albeit an unusual one, as already mentioned, by virtue of the total mutual insolubility of two of the phases and the simple nature of equilibrium. 

The first phase-equilibrium diagrams discussed are for two-component liquid-vapor systems. Next, three-component diagrams used in extraction, absorption, leaching, and ion exchange are developed. Finally, enthalpy-composition diagrams, which include energy effects, are constructed. 

The county landfill in the diagram was monitored to verify that toxic compounds were not leaching into the local water supply. Wells drilled at 21 locations were monitored over a year and pollutants were observed only at sites 8, 11. 12, and 13. Monitoring all 21 sites each month is very expensive. Suggest a strategy to use composite samples (Box 0-1) made from more than one well at a time to reduce the cost of routine monitoring. How will your scheme affect the minimum detectable level for pollutants at a particular site ... 

Equilibrium relations in leaching usually are simpler than in liquid-liquid equilibria, or perhaps only appear so because few measurements have been published. The solution phase normally contains no entrained solids so its composition appears on the hypotenuse of a triangular diagram like that of Example 14.8. Data for the raffinate phase may be measured as the holdup of solution by the solid, K lb solution/lb dry (oil-free) solid, as a function of the concentration of the solution, y lb oil/lb solution. The correspond-... 

Alloys are prepared commercially and in the laboratory by melting the active metal and aluminum in a crucible and quenching the resultant melt which is then crushed and screened to the particle size range required for a particular application. The alloy composition is very important as different phases leach quite differently leading to markedly different porosities and crystallite sizes of the active metal. Mondolfo [14] provides an excellent compilation of the binary and ternary phase diagrams for aluminum alloys including those used for the preparation of skeletal metal catalysts. Alloys of a number of compositions are available commercially for activation in the laboratory or plant. They include alloys of aluminum with nickel, copper, cobalt, chromium-nickel, molybdenum-nickel, cobalt-nickel, and iron-nickel. 

Figure 5 Pb profile in the Danish peat hog of Storelung Mose [48]. (a) Lithogenic Pb, anthropogenic Pb vs. depth (see Ref. [48] for calculation details as well as the isotopic composition summarized by the Pb/ Pb ratio), (b) Diagram Pb/ Pb vs. Pb/ Pb for the leached fraction of the Danish peat samples, also shown UK coal [49], UK leaded gasoline in 1997 [167] and the isotopic composition of a pre-anthropogenic sediment [165].

---