Clay Minerals

Bentonite, a claystone formed from the devitrification of volcanic ash, demonstrates varying amounts of alteration in elemental concentrations through the transition from glass to clay. Many studies have sought to characterize and correlate bentonites using various elemental signatures, but the information garnered from this can be misleading since 1) volcanoes produce highly variable compositions during single events, making tephra classifications reliant on the position within the bed and the distance from the source, and 2) the elemental concentrations may vary significantly due to devitrification. Strontium and neodymium isotopic signatures offer a powerful dataset to supplement these efforts, but the extent to which the isotopic ratio is preserved during devitrification and post-depositional diagenesis is not well documented. Here we perform a detailed isotopic, geochemical, and mineralogical examination of sixteen bentonites preserved in Cenomanian and Campanian strata (Late Creta-ceous) from South Dakota in order to characterize the diagenetic factors that may influence the ash geochemistry, while checking for the fidelity of the isotopic signatures to the magmatic source. A mixing model between the isotopic composition of bentonite and seawater can be generated to determine the original endmember composition of each deposit, since Sr was likely derived from both sources during devitrification. Initial 87 Sr/ 86 Sr ratios from Cenomanian samples ranged higher than the Campanian, demonstrating a negative correlation with εNd values that point towards magmatic signatures with the influence of crustal assimilation. X-Ray diffraction was utilized to determine the speciation of the clay mineral and sedimentary input, displaying a complete lack of smectite illitization that would indicate the presence of a hydrothermal influence. Bentonite isotopic chemistry, therefore, is reliably traced to the magmatic source under the appropriate diagenetic conditions. With careful consideration for diagenesis, the isotopic composition of the Cretaceous bentonites can be used for provenance identification and points towards magmatic emplacement within an evolved crustal source on the Laurentian craton. This isolates the most likely provenance of Cenomanian bentonites as being the Idaho batholith, while Campanian bentonites were likely derived from the Elkhorn Volcanic complex.

The research was aimed at producing a cost-effective ceramic filter for the removal of bacteria in wastewater using locally sourced materials. Clay from several locations in Ekiti state, Nigeria was mixed with sawdust (combustible material) to form a ceramic filter. The results showed that the 50%-50% ratio of Igbara odo clay to sawdust was the most effective and optimum mix. This was in terms of a flow rate of 1.9 L/hour, removal effi-ciencies of 80% and 100% for coliform and E. coli bacteria respectively. Introduction Ceramic materials based on clay have been used in different parts of the world as a means of purifying and storing water at points of use. The application of ceramic filter isn't solely a brand new and trendy technique , but it reduces cost and the use of chemicals/coagulants in water treatment. The use of clay and sawdust from southwest Nigeria is worth researching upon for use as ceramic materials. Nigerian clay soils and sawdust had been used in previous studies for various waste containment purpose [1-3]. Methods Clay soils sampled from different locations (Ara, Igbara Odo, Ikere, Ire and Isan) in Ekiti State, Nigeria were pulverized and sieved through the 0.25 mm sieve size. Sawdust from a hardwood (Nesogordonia papaverifera of Danta Specie) was sieved through the 0.075 mm sieve size. The sieved samples of clay and sawdust were mixed in various ratios with water to form a mouldable paste. These were aged to cause physical changes in the material over time. The aged moulded paste materials firing process was carried out in a traditional kiln (made of low-cost heat resistant brick made of Ball clay, sand and sawdust) after an air drying stage had been completed. The air drying was to prevent material from cracking due to rapid drying or heating during the firing process. Atterberg limit tests [4] were carried out on the clay samples. The ceramic filters were tested for its flow rate and its bacteria removal efficiency. Results and conclusions The Atterberg limits values and colour of the Ekiti clay samples are listed in Table 1. The flow rates were measured based on the reduction in the water column height over a period of time (Table 2). The removal efficiency of Coliform and E. coli from the wastewater was 100% for some of the fabricated ceramic filter samples (Table 3). From the results, Igbara odo clay and sawdust in 50%:50% ratio had the highest performance level in terms of flow rate and bacteria removal efficiency.

is current article demonstrates how X-ray fluorescence spectroscopy (XRF) was employed to reveal the major constituents of a sample of natural grey Saudi kaolin. e XRF results showed that it contained 52.90 wt.% silica together with 14.84 wt.% alumina. Additionally, this paper presents a study on the effect of holding times (i.e., 6, 12, 18, and 24 h) using pyrrole adsorption and methylbutynol test reaction (MBOH) on the Saudi grey kaolin (raw material). Temperature-programmed desorption of pyrrole (pyrrole-TPD) results indicated that increases in thermal conductivity detector (TCD) signals are directly proportional to increases in the heat activation holding time. Notably, a raw Saudi grey kaolin sample heated at a holding time of twenty-four hours resulted in the most intense TCD signal. Further, the MBOH transformations produced 3-methyl-3-buten-1-yne (MBYNE), as the main product, indicating the dehydration of MBOH due to the acidic sites of Saudi grey kaolin. e basic catalysis route was operative at the beginning of the reaction as acetone was observed only during the initial thirty-five minutes of the reaction then later dispersed entirely. Its disappearance is attributed to the high silica content of the test sample.