A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
The anion exchange properties of AFm (hydrocalumite-group) minerals defined from solubility experiments and crystallographic information
Abstract Solubility experiments with binary series of OH-, Cl-, SO4- and CO3-AFm were re-examined with a non-ideal, multicomponent solid solution model. The electrical double layer on the mineral's outer surface, which neutralizes about 5% of the anionic charge, can be included. The choice of the end-members in the solid solution and the reaction formulation can help to eliminate the ‘non-ideality’ for OH-SO4 and Cl-OH exchange. CO3-Cl-OH exchange is not ideal in the solubility experiments, nor can it be, because the mineral volume is not a linear combination of the end-members. The solubilities of the end-members are related to the anion charge and inversely to the anion-layer thickness. OH is part of the anion-charge, even when a pure, other anion form is the target of the synthesis. Pure OH-AFm is unstable and converts into hydrogarnet and portlandite, depending on the precipitation rate of hydrogarnet.
The anion exchange properties of AFm (hydrocalumite-group) minerals defined from solubility experiments and crystallographic information
Abstract Solubility experiments with binary series of OH-, Cl-, SO4- and CO3-AFm were re-examined with a non-ideal, multicomponent solid solution model. The electrical double layer on the mineral's outer surface, which neutralizes about 5% of the anionic charge, can be included. The choice of the end-members in the solid solution and the reaction formulation can help to eliminate the ‘non-ideality’ for OH-SO4 and Cl-OH exchange. CO3-Cl-OH exchange is not ideal in the solubility experiments, nor can it be, because the mineral volume is not a linear combination of the end-members. The solubilities of the end-members are related to the anion charge and inversely to the anion-layer thickness. OH is part of the anion-charge, even when a pure, other anion form is the target of the synthesis. Pure OH-AFm is unstable and converts into hydrogarnet and portlandite, depending on the precipitation rate of hydrogarnet.
The anion exchange properties of AFm (hydrocalumite-group) minerals defined from solubility experiments and crystallographic information
Appelo, C.A.J. (author)
2020-10-16
Article (Journal)
Electronic Resource
English
Solubility of chromate hydrocalumite (3CaOAl2O3CaCrO4nH2O) 5-75degreeC
| British Library Online Contents | 2001
Solubility of chromate hydrocalumite (3CaO.Al2O3.CaCrO4.nH2O) 5-75(degree)C
| Online Contents | 2001
Hydrogenolysis of glycerol over Cu-substituted hydrocalumite mediated catalysts
| Online Contents | 2015