Clay Type

Clay type identification A plot of thorium versus potassium will indicate what type of clay is present. The thorium/potassium ratio can also be used. 

Soils are commonly named and classified according to the general size range of their particulate matter. Thus sandy, sih and clay types dwive their names from the predominant size range.of inorganic cons tiiuents. Particles between 0 07 and about 2 mm are classed as sands. SUt particles range from 0-005 mm to 0-07, and clay particle Size ranges from 0-005 mni mean diameter down to colloidal matter. 

The clay ion-exchange model assumes that the interactions of the various cations in any one clay type can be generalized and that the amount of exchange will be determined by the empirically determined cation-exchange capacity (CEC) of the clays in the injection zone. The aqueous-phase activity coefficients of the cations can be determined from a distribution-of-species code. The clay-phase activity coefficients are derived by assuming that the clay phase behaves as a regular solution and by applying conventional solution theory to the experimental equilibrium data in the literature.1 2 3... 

Sandy soils are easiest to extract and analyze, while clay soils are the hardest. Drying, crushing, and sieving will aid in extraction and analysis, although it may not be necessary to crush very sandy soils. Clayey soils may retain small amounts of contamination even after extensive extraction (see Figure 1.1). In all cases, extraction and analysis procedures must be robust enough to handle all textures containing all clay types [4],... 

Chatteijee, A. 2005. Application of localized reactivity index in combination with periodic DFT calculation to rationalize the swelling mechanism of clay type inorganic material. J. Chem. Sci. 117 533-539. 

Analysis of the minerals detected using SEM-EDS was effective with simple minerals, however, determination of clay types was difficult and it was not possible to determine whether a mineral species was anhydrous or hydrated. 

The EiAD technology works most effectively on clay-type soils where the hydraulic permeability is small. Results indicate that the EiAD technology can remove inorganic contaminants such as zinc and cadmium from clay sods. Soil contaminants may be cations, such as cadmium, chromium, and lead, or anions, such as cyanide, chromate, and dichromate. 

Electrokinetic treatment can be used to remediate soils, sludges, and sediments contaminated with heavy metals and organic hydrocarbons. Electrokinetic treatment works well on clay-type soils with low hydraulic permeability, which are difficult to treat using other in sitn technologies. Electrokinetic permeabilities for aqueous systems in clays have been demonstrated to be up to 1000 times greater than normal hydraulic permeabilities, and some heavy metals have exhibited removal efficiencies of up to 100%. 

Cost information comes from a vendor-supplied comparison of ACT and clay-type products. The example used was a 55-gal spill (440 lb). A spill of this size would require 880 lb of clay or 7.3 lb of ACT. At 0.10/lb for clay, the material cost would be 88, while ACT costs 9.50/lb with a total material cost of 85.50. Transportation cost of the materials was estimated by Landmark to be 1.50/lb. Once the materials have absorbed the 440 lb of contaminant, the weights increase to 1320 lb (clay and contaminant) and 447.3 lb (ACT and contaminant), and therefore respective shipping costs become 1980 and 670.95 to transport the Ml absorbents. Adding the material and shipping costs required for this 55-gal spill, total costs for clay-type absorbents is 2878 and ACT is 1026.45. These prices are based on 1996 information (D16319J, p. 9). 

Clay type Tensile strength (MPa) Elongation at break (%)... 

The superiority of synthetic catalyst over the natural clay type for the production of aviation gasoline from a yield and octane standpoint is shown in the following comparisons ... 

A number of other catalysts of both synthetic and natural clay types have been developed. Some of these catalysts have shown improvement in product distribution, but none have given appreciable octane benefit. For this reason, they have not been used commercially in fixed- or moving-bed units. 

Figure 1. Palestinian clay types, in lower row, reading right to left, Kaolin (Negev), red field clay, yellow limestone clay. Upper row, four pieces from Gaza, all made from red field clay. Pottery fragment in lower row Hebron, made from mix of red and yellow clays with salt added to give a white surface to the red paste.

The two above examples illustrate that not only is the Sc/Fe ratio remarkably consistent within a group representing a given area but that it varies significantly from area to area and from clay type to clay type. For example, our data on the Palestinian red and yellow clays show that the former have Sc/Fe — 3.74 0.09 while the latter have Sc/Fe = 5.46 0.29. Of course, in cases where clays of different types were mixed (either by the potter or by natural forces), intermediate Sc/Fe ratios would be obtained. 

To aid in grouping the materials, methods were worked out using ratios between the concentrations of pairs of elements and by computer-produced correlation plots between such pairs. Scandium and iron were highly correlated and of a distinct ratio for a given geographic area and clay type. 

BC Italy Vitruvius describes the different clay types used for making bricks. 

In most cases water molecules and ions occur between the layers. Especially the water is responsible for the elastic behaviour of a clay type. 

Is the clay composition within a certain range A clay whose composition deviates only little from the desired composition, i.e. the clay with the desired properties can be made suitable for production purposes by mixing it with a different clay type and / or other additives. 

In 1999 I visited the Westerwald, an area in Germany with approximately 25 clay quarries, which is discussed in chapter 12. In one of these quarries I received documentation on analysis data of 28 different clay types which can be supplied. In the table below the analyses of three of those types are presented to give you an impression of the large variety in composition and properties. 

In The Netherlands locally found clay is almost exclusively used as main raw material. The most important clay deposits for (paving) bricks are found along the river banks of Holland s main rivers. River clay from the polders is mostly fat to very fat and deficient in lime consequently it is used in the production of e g. roof tiles. We call a clay type fat when it contains a high percentage of minute particles. The Dutch coarse-ceramic clay is a sediment, appr. 45 % of whose particles have a diameter of < 10 pm. The coarser sand and silt fractions... 

The specific area is measured in m2/gramme. Its value can vary from 1-5 m2/g in the case of, for example, coarse kaolin to about 100 m2/ g for certain plastic clay types. The measurement for example takes place by adsorption of gases like nitrogen. The adsorbed amount is measured as a function of the pressure. At a certain N2 pressure nitrogen molecules at the surface of the solid particles are adsorbed and pressed into the pores. Consequently, this method is also suitable for measuring porosity and pore size distribution. 

Humic Clay types acid [M2+], mM pH % sorbed pH % sorbed... 

The type of clay present in a soil influences triazine sorption (Brown and White, 1969). Furthermore, variations in surface properties among different samples of the same clay type greatly influence sorption. For instance, sorption of atrazine on 13 clay samples, of which smectite was the dominant mineral, ranged from 0% to 100% of added atrazine (Figure 21.7), and was inversely correlated to the surface charge density of the smectites (Laird et al., 1992). Such data illustrate the complexity of sorption processes and the reason why simple predictive models relying on % OC, % clay, or surface area normalizations may fail to predict accurately the sorption of triazine by a particular soil. 

Ronov, A.B. and Khlebnikova, Z.V., 1957. Chemical composition of the main genetic clay types. Geokhimiya, 6 449-469. (Translation in Geochemistry, 6 527-552.)... 

The inherent limitations of the use of zeolites as catalysts, i.e. their small pore sizes and long diffusion paths, have been addressed extensively. Corma reviewed the area of mesopore-containing microporous oxides,[67] with emphasis on extra-large pore zeolites and pillared-layered clay-type structures. Here we present a brief overview of different approaches to overcoming the limitations regarding the accessibility of catalytic sites in microporous oxide catalysts. In the first part, structures with hierarchical pore architectures, i.e. containing both microporous and mesoporous domains, are discussed. This is followed by a section on the modification of mesoporous host materials with nanometre-sized catalytically active metal oxide particles. 

FIGURE 11.32 (See color insert following page 530.) Effect of clay type on MLR of PP (84.6%)/PPgMA... 

---