Fireclay deposits occur in Latah County, Idaho, as residual weathered products, and as lacustrine sediments comprising part of the Miocene Latah formation. The residual deposits were developed upon granitic (granodioritic, gneissic) masses by surface weathering. The lacustrine fireclays were derived dominantly from weathered residuum and to a minor extent from volcanic ash.

Mineral proportions in the residual clay are typically as follows: kaolin minerals, 65 percent; quartz, 20 percent; K-bearing micas, 12 percent; and montmorillonite-chlorite mixed-layer clay, trace.

The sedimentary fireclay deposits range widely in clay content, from some that are almost wholly kaolin to others containing as little clay as the residual material, or alternatively, to those meeting minimal requirements of fireclay. As the content of kaolin decreases in the deposits, there is a corresponding increase in content of quartz, K-bearing micas, and in the less abundant components orthoclase, mixed-layer illite— montmorillonite, and mixed-layer chlorite—montmorillonite.

In both the transported and residual clay bodies the kaolin minerals are, in order of decreasing abundance, halloysite, endellite, and fireclay mineral.

The lake deposits also contain seams of poorly crystallized kaolin that is inferred to have been derived from volcanic ash because (1) it contains minor quantities of tridymite, sanidine, and volcanic glass, and (2) it contains notably more endellite and allophane (amorphous and relatively soluble in NaOH) than is present in the other kaolin deposits. Endellite seemingly has developed in two separate geologic environments: as an alteration product of granodiorite gneiss by surface weathering and as an alteration product of volcanic ash deposited and altered in a fresh-water lake. It is postulated that endellite is a relatively common product of weathering.

A 1–0·2 μm fraction from a soil in the Dominican Republic was studied by X-ray diffraction combined with solvation, cation saturation, and heat treatments. I.R., thermal (DTA, TGA) and chemical analyses were also made. This soil is saline and alkaline and its mineral composition is greatly influenced by the lacustrine parent material and poor drainage.

In addition to swelling chlorite, illite, kaolinite, carbonates and quartz are present in the 1–0·2 μm fraction. The swelling chlorite expanded to over 18 Å when Mg saturated and solvated with glycerol or water. Lower spacings with other cations and ethylene glycol were observed. 1 N HCl treatment partially removed the interlayer hydroxides in the chlorite and 6 N HCl destroyed the mineral. The mineral gave a reflection close to 14 Å up through 600°C but collapsed at higher temperatures to 10·2 Å.

Acid clays prepared by electrodialysis or by treatement with dilute (< about 0.1N) mineral acid solutions were largely Al-saturated, and had little catalytic effect on ester hydrolysis and sucrose inversion. On the other hand, clays exhaustively treated with cold 1N HCl were largely H-saturated, and served as effective H-ion catalysts. When various quantities of clay were used as catalysts, reaction rates were proportional to the concentration of H-ions in the system.

H-montmorillonites prepared from Plymouth, Utah bentonite and from Volclay bentonite were from 50 to 200 percent more effective catalysts for ethyl acetate hydrolysis than was HCl. For sucrose inversion, <2 μ H-clays had a somewhat greater catalytic effect than did HCl, while clay aggregates were much less effective catalysts. For ester hydrolysis, the degree of dispersion of the clay made little difference in its catalytic activity.

Clays are used in the ceramics industries largely because of their contribution to the moulding and drying properties of the wares being produced; many clays, such as the flint clays, are used because of favorable behavior during firing or because they produce favorable properties in fired ware.

To assure the most effective use of a clay, the ceramic technologist must meet problems of purification, aging, bacterial action, and the improvement of the working properties of clays and bodies through additions of non-plastic materials or chemicals. He deals with flocculation and deflocculation, thixotropy, and related phenomena in casting slips. Control of drying behavior is important. Finally, the ceramist is concerned with the influence of the clay content of ceramic bodies on their behavior during firing.

The most potent and significant polyphenolic molecule from tea catechins is epigallocatechin gallate (EGCG); it has potential anti-cancer and anti-inflammatory properties. Methods are needed to mitigate its presence in the environment and protect humans from exposure. The objective of the present study was to investigate a functionalized, low-cost clay mineral as an adsorbent for the tea polyphenol EGCG. Hydrophilic bentonite (Bn) was functionalized using Aliquat 336 (A336) and isobutyl(trimethoxy)silane (IBTS). The degree of clay functionalization depended on the extent of introduction of alkyl linkages between the superimposed clay layers. Results revealed that Aliquat 336 functionalized clay (A336-Bn) exhibited maximum thermal stability at 500°C and it is a promising adsorbent for ECGC with a maximum adsorption capacity of 196.26 mg/g at equilibrium. Experimental data were analyzed using pseudo-first order and pseudo-second order models. Adsorption isotherms were interpreted from the Freundlich adsorption isotherm.

The development of nanoparticles incorporating Gd3+ has attracted interest in the field of contrasting nanomedicine for magnetic resonance (MR) and computed tomography (CT). In order to achieve an effective contrasting performance, the amount and stability of Gd incorporated as well as particle-size control of the nanoparticles should be considered simultaneously. In the current study, Gd-diethylenetriaminepentaacetate(Gd-DTPA) was incorporated into layered double hydroxide (LDH) to meet the physicochemical properties required for MR-CT dual contrasting nanomedicine. Strategically, the particle size and nanometer incorporation of Gd-DTPA into LDH (GL-R hybrid) were controlled homogeneously using the reverse micelle method. X-ray diffraction showed that the hybrid obtained possessed a hydrotalcite phase. Dynamic light scattering and electron microscopic analyses showed that the hybrid had a controlled size of <200 nm with significant homogeneity. Fast Fourier-transform of transmission electron microscopy confirmed that the platelets of the GL-R hybrids were oriented randomly to form inter-particle space, enabling the Gd-DTPA moiety to be encapsulated stably. The encapsulation efficiency of Gd-DTPA was 20.8%, which was sufficiently high compared with other Gd-DTPA-incorporatedLDH. According to X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy, Gd-DTPA incorporated in the hybrid preserved its structure intact. Its potential as a dual modal contrast agent was demonstrated by measuring the concentration-dependent Hounsfield unit and magnetic resonance relaxivity, which were determined to be 230 at 2 mg/mL and 5.8 in the range ~0.2–1 mM-Gd, respectively.

X-ray diffraction has been used to study the sorption of water by multilayer films containing ordered stacks of alternating layers of an organic polyelectrolyte and individual platelets of a smectite. The position and shape of the 001 reflections due to the ordered polyelectrolyte/platelet stacks were essentially the same when in air at low relative humidity (23–25% RH) and under water. These data indicate that swelling occurs exclusively in X-ray amorphous regions within the film, and that the ordered polyelectrolyte/clay domains themselves are not ‘swellable’ by water.

The intercalation of kaolinite through the insertion of ions or molecules amongst the structural aluminosilicate layers is a vital process in numerous clay-based applications and products. Layer neutrality and hydrogen bonding limits direct intercalation into kaolinite, other than for small molecules. Synthesizing zirconia-intercalated kaolinite is not a straightforward matter. To overcome this barrier, raw Egyptian kaolin (UnK) or its acid-activated product (HK) was sonicated and impregnated in aqueous ZrOCl2·8H2O solution followed by thermal treatment at various temperatures (100, 200, 300, and 500°C). The intercalation process was confirmed using various spectroscopic and analytical techniques. The direct intercalation of ZrO2 into the kaolinite layers was observed even through a mild thermal treatment (100, 200, and 300°C). The mechanism of intercalation was suggested to occur by binding ZrO2 to the Si/AlO groups with a preference for the acid-activated HK, causing variable enlargements of the basal spacing and producing very perturbed layers. Interestingly, the surface area increased by 250% as a result of zirconia intercalation. Scanning electron microscopy (SEM) images showed a remarkable improvement in the stacking order of the kaolinite particles. The impact of ZrO2 intercalation into kaolinite also enhanced its adsorption efficiency for Pb2+, Cu2+, and Cd2+ ions. Preliminary investigations showed that the zirconia-intercalated HK demonstrated a removal efficiency, which is three times greater than that of pristine HK. The adsorption tendency toward Pb2+ ions was greater than those of Cu2+ and Cd2+ and followed the order: Pb2+ >> Cu2+ > Cd2+. The study suggests that the chemical modification of kaolin by zirconia via a direct intercalation technique, which greatly improves its functionality as demonstrated by the selective sorption of heavy metal ions, is worthy of further study.

Altered perthites from a weathered pegmatite in the Spruce Pine District, North Carolina, were characterized by electron microprobe as a K-rich microcline host with lesser Na-rich plagioclase having a lamellar morphology. Light-optical and transmission electron microscopy (TEM) show microtextural elements such as phase boundaries, holes and microfractures that could serve as potential nucleation sites for alteration to clay minerals.

The host microcline contains albite and pericline twinning textures that vary in character; the amount of each twinning type and/or the size of twin individuals changes on a μm scale. Plagioclase ranges from large lamellar vein and film albite (visible in the light microscope) to cryptoperthite whose size ranges from μm to perhaps 100 Å. The smallest-scale albite appears to be a late-stage phase of exsolution in which lamellae have nucleated heterogeneously on albite-twin composition planes in the microcline.

Alteration is concentrated in vein and film albite, especially along grain boundaries with microcline. Powder X-ray diffraction (XRD) patterns of intensely altered pegmatite show halloysite. Holes, microfractures, vein albite/host microcline boundaries and microcline/halloysite boundaries trend parallel to the traces of (010) and {110}, suggesting that these directions are pathways along which fluids migrate. Cleavage and microfractures occur along, and holes are bounded by, these directions. Holes are associated with dislocations and the latter are observed at feldspar/clay boundaries. Twin domains and cryptoperthitic albite are less susceptible to alteration than coarse lamellar albite and regions containing negative crystals and microfractures. However, microtextures in some areas containing halloysite suggest that once fluids penetrate the crystal, alteration may proceed preferentially in more strongly twinned regions.

The cleavage of two single-crystal chlorites (a clinochlore and a penninite) has been studied using angle-resolved X-ray photoelectron spectroscopy (XPS). Both minerals cleaved in regions not typical of the bulk; the composition of the clinochlore was found to be especially non-uniform. The brucitic interlayer divided evenly between the pair of new surfaces exposed for two cleaves in the clinochlore, but was partitioned unequally in two cleaves in the penninite. The differences in apparent composition between the complementary pairs of surfaces are interpreted to show a marked preference of octahedral Al for the brucitic layer, in agreement with X-ray bulk structure refinements. For both chlorites, the layer charge was reduced in regions of easy cleavage, which also had a higher proportion of Si and less tetrahedral Al than the bulk chlorite. The percentages of tetrahedral aluminium deduced from the XPS surface analyses agreed satisfactorily with the percentages independently determined by consideration of the magnitude of anisotropy in the X-ray photoelectron diffraction (XPD) patterns. The XPD patterns from the clinochlore for rotation about axes parallel and antiparallel to the crystallographic a-axis were identical, showing that tetrahedral ordering was absent.

Kaolin waste dumps contain a huge volume of material that cannot be commercialized due to the presence of variable amounts of iron minerals, which impart a yellowish color to the kaolin. Elimination of iron from kaolin using either a chemical or a biological method was the aim of this study. The chemical leaching of iron from kaolin was carried out using response surface methodology to optimize the reaction conditions. Time was found to be the most influential variable, although oxalic acid must be present to leach 32% of the iron. Biological leaching was also assayed for 14 days using a Bacillus strain. The results of bacterial leaching of iron from kaolin showed <1% iron elimination.

A detailed study has been made of the dehydration of sepiolite. This work, together with other studies of dehydration in vacuo and over phosphoric anhydride, rehydration of samples heated to various temperatures, specific surface, water uptake, and x-ray examination of natural and heated samples (to be published later), lead us to certain conclusions regarding types of water in sepiolite. A comparison is made with attapulgite.

A carbonate rock silicification reaction has been defined and shown to be dependent on the presence of clay in the host rock. Introduction of silica in soluble form(s) serves to polymerize the clay fraction, forming a continuous three-dimensional network. This siliceous network (polymer) can be separated from the rock by leaching away the carbonate minerals. Laboratory silicification of argillaceous carbonate rocks under controlled conditions has served to define critical variables.

Early studies were limited to argillaceous carbonate rocks from the Devonian Cedar Valley formation in eastern Iowa. Similar results have been obtained with carbonate rocks from the Devonian Chaffee formation in south-central Colorado. Some of the rocks in the latter formation have been silicified in nature, and yield siliceous polymers on acid leaching identical to those formed by silicification in the laboratory.

The reaction defined is suggested to be common in natural diagenesis of argillaceous rocks, clay-rich sedimentary material, and soils.

In the case of argillaceous carbonates this reaction affects physical properties of the rock which control processes involved in petroleum migration, ore-metal transfer, rock leaching and all diagenetic reactions that involve solution transfer.

The heavy atom content and distribution in chlorite were estimated using the relative intensities of basal X-ray powder diffraction (XRD) peaks. For these peaks to be meaningful, however, corrections had to be made for the effects of sample thickness, sample length, and preferred orientation of the mineral grains, all of which are 2θ dependent. The effects of sample thickness were corrected for by a simple formula. The effects of sample length were accounted for by using rectangular samples and by ensuring that the sample intersected the X-ray beam through the range of diffraction angles of interest. Preferred orientation of mineral grains were either measured directly or estimated. Estimated values were quicker and easier to obtain and were within 5% of measured values. A comparison of the compositional parameters of chlorite estimated before correcting for these sample effects with those estimated after the corrections had been applied indicate that the uncorrected values differed from the corrected values by as much as 55% of the latter values. Mounts of a single sample prepared by different filter-membrane peel and porous-plate techniques yielded widely different compositions until the measurements were corrected for sample effects. Analyses in triplicate indicated that the XRD intensity ratio 003/001 is preferred for calculating heavy atom distributions and abundances in chlorite because of the relative strength of the 001 peak.

The reactivity and stability of the edge faces of swelling clay minerals can be altered by layer charge and the stacking structure; however, these effects are poorly understood due to experimental limitations. The structure and stability of the montmorillonite {110}, {010}, {100}, and {130} edge faces with a layer charge of either y = 0.50 or y = 0.33 (e−/Si4O10) were investigated using first-principles calculations based on density functional theory. Stacked- and single-layer models were tested and compared to understand the effect of stacking on the stability of montmorillonite edge faces. Most stacked layers stabilize the edge faces by creating hydrogen bonds between the layers; therefore, the surface energy of the layers in the stacked-layer model is lower than in the single-layer model. This indicates that the estimates of edge face surface energy should consider the swelling conditions. Negative surface energies were calculated for these edge faces in the presence of chemisorbed water molecules. A high layer charge of 0.50 reduced the surface energy relative to that of the low layer charge of 0.33. The isomorphic substitution of Mg for Al increased the stability of interlayer Na ion positions, which were stable in the trigonal ring next to the Mg ions. The lowest surface energies of the {010} and {130} edge faces were characterized by the presence of Mg ions on edge faces, which had a strong cation adsorption site due to the local negative charge of the edges. The coordination numbers of O atoms around cations adsorbed to these edge faces were small in comparison to interlayers without water.

Powder-type semiconductor photocatalysts are widely applicable but their defects (e.g. easy agglomeration during preparation and recyclability in the suspension system) limit their practical application. In the current study, perovskite oxide photocatalytic material was loaded onto a muscovite substrate to overcome the problems of low stability, easy agglomeration, and difficult recovery. A photocatalytically active LaNi0.95Fe0.05O3/muscovite composite material was synthesized by a sol-gel impregnation method. Phase composition, morphology, and interfacial interaction of the composites, denoted as LNFBY-x (x: mass ratio of LNF to muscovite), were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and other analytical methods. According to the results, the particle size of LNF nanoparticles was regulated effectively by compounding with muscovite, and the agglomeration of LNF decreased. LNF nanoparticles were distributed evenly and attached in dense fashion to the surface of muscovite, thereby increasing the contact area with the reaction medium. The nanoparticles were connected to the silicon-oxygen tetrahedral sheet of the muscovite via Si–O–La, Si–O–Ni, and Si–O–Fe bonds, which increased the bonding strength between the composite components and expedited the transfer of photogenerated charge. More highly active oxygen species were produced, and a growing number of chemically active moieties (٠O2- and ٠OH) was generated in the photocatalytic reaction. LNFBY-1.00 demonstrated the best photocatalytic activity. A degradation rate of methyl orange of 99.03% was achieved after visible-light irradiation for 120 min, which decreased to 75.75% after five repeated uses, thereby indicating high stability and recycling ability. The photocatalytic LaNi0.95Fe0.05O3/muscovite composite material exhibited potential for application in environmental remediation practices.

Exploratory experiments on irradiation of mixtures of polyethylene and organo-montmorillonites with gamma rays indicated that the polyethylene became crosslinked to the organoclays. Subsequently, 264 samples of 1:1 clay-polyethylene compositions were irradiated with 2 MeV electrons and tested for tensile strength and weight fraction extractable in toluene at 110°C. From statistical analysis of the variables of clay lattice, clay surface, polyethylene type and radiation dose it is concluded that: (1) polyethylene can be bonded directly to the clay surface by ionizing radiation, and (2) at least one organoclay bearing a “polyethylenelike” chain, polyvinyl alcohol, is more effective than wholly inorganic clay for the purpose of radiatively linking polyethylene to clay surface. The data below show the markedly increased solvent resistance of polyethylene radiatively bonded to clay over that of equivalently irradiated pure polyethylene.

Novel polymer-clay compositions were synthesized by neutralizing hydrogen montmorillonite and hydrogen kaolinite with amine-terminated polystyrene. The latter was obtained by the amide ion-initiated polymerization of styrene in liquid ammonia at −33°C. The neutralization reactions were carried out in methyl ethyl ketone, acetone, N,N-dimethylformamide and their aqueous solutions. As a result of their chemical modifications, the clays change from hydrophilic to hydrophobic, organophilic substances. Polystyrene-montmorillonite compositions containing about 50 per cent by weight of combined polymer formed dispersions in hydrocarbon oils which were similar to high temperature lubricating greases. The basal spacings of the organo-montmorillonites indicate the deposition of a polymer layer one molecule thick.