Solid solution phase diagram

Fig. 11. Solid solution phase diagram for iron/carbon.

Procedures for the design of industrial fractional crystallization processes for multicomponent systems, utilizing appropriate eutectic and solid solution phase diagrams, have been described by Fitch (1970, 1976), Chang and Ng (1998), Cisternas (1999), Cesar and Ng (1999) and Wibowo and Ng (2000). 

FIGURE 7.23 A more complicated solid solution phase diagram. This is for the Na/K system. This phase diagram shows the existence of a stoichiometric compound, NajK. Source Adapted from T. M. Duncan andj. A. Reimer, Chemical Engineering Design and Analysis An Introduction, Cambridge University Press, 1998. 

FIGURE 7.24 A more complicated solid solution phase diagram, in this case describing the system Fe/C. 

Ideal and real solid solutions, phase diagrams... 

It can be seen in Fig. 1.5 that the higher the heats of fusion the broader the width between the liquidus and solidus lines of an ideal system. Furthermore, the difference between the heats of fusion determines the asymmetric shape of the phase diagram. In Section 1.3.1 the consequences of the shape of the solid solution phase diagrams on the segregation behavior in normal freezing growth processes will be discussed. 

The Pd-Rh alloy system provides a convenient test case for application of the methodology because of its particularly simple phase diagram, which consists of only the liquid and a fee solid solution phases. 

Figure 8.21 gives the ideal solution prediction equation (8.36) of the effect of pressure on the (solid + liquid) phase diagram for. yiC6H6 + xj 1,4-C6H4(CH3)2. The curves for p — OA MPa are the same as those shown in Figure 8.20. As... 

Figure 8.22 (Solid + liquid) phase diagram for. vin-CiaHut +. viCsHs. The circles are the experimental melting temperatures and the lines are the fit of the experimental results to equation (8.31). The dashed lines are the ideal solution predictions from equation (8.30).

Figure 8.23 (Solid + liquid) phase diagram for (. 1CCI4 +. yiCHjCN), an example of a system with large positive deviations from ideal solution behavior. The solid line represents the experimental results and the dashed line is the ideal solution prediction. Solid-phase transitions (represented by horizontal lines) are present in both CCI4 and CH3CN. The CH3CN transition occurs at a temperature lower than the eutectic temperature. It is shown as a dashed line that intersects the ideal CH3CN (solid + liquid) equilibrium line.

Figure 5.4. The niobium-hydrogen system. A small part (from 40 to 50 at.% H) of the diagram is shown in the low- and very-low-temperature region. Notice the complex equilibria and the high number of intermediate solid solution phases. Other phases are formed in the composition ranges not shown in figure the q (11 to 39 at.% H) and 0 (21 to 41 at.% H) solid solutions in the Nb-richer part and the nearly stoichiometric 6 phase ( NbH2, cF12-CaF2-type).

Rh and Ir alloys. A choice of formulae, composition ranges and structure types observed in selected intermediate phases of the Rh and Ir alloys is shown in Table 5.48b. Notice in the Rh (Ir) regions of the systems, several CaCu5-, AuCu3-, Cu2Mg-type phases and, in the central parts of the diagrams, CsCl-type (andNiAs-and AuCu-type) solid solutions phases. 

Considering for instance the formation of compounds, several variants may be observed due to the possible existence of binary (point or line) phases and/or of ternary, stoichiometric or solid solutions phases. Notice that true ternary phases may be formed (that is phases corresponding to homogeneity regions placed inside the diagram and not connected with the components or any binary phases). However within the ternary composition fields, phases are observed which contain all the... 

Other two-component systems may exhibit either limited solubility or complete insolubility in the solid state. An example with limited solubUity is the silver-copper system, of which the reduced-phase diagram is shown in Figure 13.5. Region L represents a liquid phase, with F = 2, and S and 5s represent solid-solution phases rich in Ag and Cu, respectively, so they are properly called one-phase areas. S2 is a two-phase region, with F= 1, and the curves AB and DF represent the compositions of the two solid-solution phases that are in equilibrium at any... 

Fergusson et al. pointed out that the X-ray powder diagram of the product was characteristic of their solid solution phase II indicating y-sulfur structure and cyclic eight-membered molecules. Recently Weiss confirmed it by determining... 

Figure 7.14. Phase diagram of a substance of (A. B) composition. In this system, one homogeneous solid-solution phase with composition is formed at high temperature. As the temperature decreases, it is energetically more stable for (A, B) to be separated into two phases (A) and (B). A solid-solution with composition will coexist as phases and at in equilibrium, and, on lowering the temperature further, phases C + C at T will be in equilibrium.

Fig. 2. Phase diagram describing lateral phase separations in the plane of bilayer membranes for binary mixtures of dielaidoylphosphatidylcholine (DEPC) and dipalmitoyl-phosphatidylcholine (DPPC). The two-phase region (F+S) represents an equilibrium between a homogeneous fluid solution F (La phase) and a solid solution phase S presumably having monoclinic symmetry (P(J. phase) in multilayers. This phase diagram is discussed in Refs. 19, 18, 4. The phase diagram was derived from studies of spin-label binding to the membranes.

I believe that Dr. Mathot has raised the question of phase equilibration in our phase diagrams. If we consider a simple solid solution, fluid solution phase diagram for a binary mixture, there are two limiting consequences of lowering the temperature from above the fluidus curve (Tj) to below the solidus curve (T2). The solid phase may or may not have... 

Fig. 2. Logarithmic activity diagram depicting equilibrium phase relations among aluminosilicates and sea water in an idealized nine-component model of tire ocean system at the noted temperatures, one atmosphere total pressure, and unit activity of H20. The shaded area represents (lie composition range of sea water at the specified temperature, and the dot-dash lines indicate the composition of sea water saturated with quartz, amotphous silica, and sepiolite, respectively. The scale to the left of the diagram refers to calcite saturation foi different fugacities of CO2. The dashed contours designate the composition (in % illite) of a mixed-layer illitcmontmorillonitc solid solution phase in equilibrium with sea water (from Helgesun, H, C. and Mackenzie, F T.. 1970. Silicate-sea water equilibria in the ocean system Deep Sea Res.).

Figure 10 Solid-liquid-phase diagram with sohd solution formation.

Figure 2 Solid-liquid phase diagram for a solution of salt and water.

Solid compounds and solid solutions have different physical properties and behaviors from the original compounds. Figure 2-20 is a generic solid-liquid phase diagram in which compounds A and B form an adduct solid compound, C, in the presence of solvent. As shown in... 

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