Chemical Composition Of Clay Research Articles

A cost-effective way to utilize low-grade Ti-rich clay: Preparing cordierite-mullite composite ceramics for thermal storage

Cordierite-mullite composite ceramics were prepared by solid-state method using Panzhihua low-grade Ti-rich clay, talc, and alumina. Influences of cordierite/mullite ratio, sintering temperature, and the chemical composition of clay on the phase composition, microstructure, physical properties, and thermal properties were investigated in detail. The results showed that the impurity oxides inside the Ti-rich clay had a great ability of forming liquid. Above 1300 °C, the reaction between TiO2 of the clay and Al2O3 produced stable Al2TiO5, which was conducive to decreasing the coefficient of thermal expansion (CTE). At 1300–1350 °C, the secondary mullitization caused the volumetric expansion, decreasing the bending strength and increasing the CTE. The optimum ratio of cordierite to mullite ranged from 90:10 to 80:20, and the sample fired at 1400 °C exhibited the lowest water absorption and porosity (0.64 % and 1.56 %, respectively), optimal bulk density, and bending strength (2.59 g cm−3 and 87.79 MPa), as well as better CTE, thermal conductivity, and thermal storage density (2.91 × 10−6 °C−1, 4.11 W/(m⋅K) (30 °C), and 1181 kJ kg−1, respectively). Compared with the reported values of cordierite-based thermal storage ceramics prepared by using the high-grade clay or minerals, the obtained samples showed the advantages such as lower costs for raw materials, higher bending strength, higher thermal conductivity (1.63–2 times higher), low CTE, and high thermal storage density. This study demonstrated that the low-grade Ti/Fe-rich clay has excellent cost-effective potential for the preparation of thermal storage ceramics.

Assessment of clay raw materials of western Kazakhstan

The article presents the results of the estimated assessment of the clay raw materials of the West Kazakhstan Pogodaevsky and Taskalinsky fields. The calculation was made by the chemical composition of clays, focusing on the formation of low-melting triple aluminosilicate eutectics. Based on the calculated data, the melt formation dynamics curves were built, from which the possible sintering degree, sintering intervals and the recommended firing temperature were determined. A forecast was made for a change in the properties of clay raw materials with the introduction of 2% alkaline oxides. The optimal directions of use of these clays and firing parameters are determined.

Natural Clays of the Kazakhstan Deposits for Catalysts of Cracking

Presented paper is devoted to the construction of cracking catalysts based on H-form zeolite Y, modifying by heteropolyacids of 12 row decationzed forms of natural clays of Tagan and Narynkol deposits. Conditions of acid activation were compared for Tagan clay. Chemical composition of clays before and after activation was detected by optical emission spectral method; phase composition was detected with X-ray<br />diffraction. It has been shown that activities of composite catalysts are related to the concentration and sequence of HPA adding. From the results the conclusion was drawn that amount of adding HPA influenced the activity and thermal stability of catalysts prepared on the base of Tagan and Narynkol clays deposits. The synthesized catalysts were studied in a laboratory microimpulse catalytic set by the model reaction of isopropylbenzene cracking at temperature 350-500 °C. The optimum compositions of zeolite containing contacts served as the base of creation of cracking catalysts for real raw (kerosene-gas-oil fraction) into quartz reactor with a fixed catalyst bed. These prepared catalysts have demonstrated enhanced thermal<br />stability and high activity. Stronger cracking activity of catalysts prepared on the base of Narynkol clay has been shown.

Instrumental neutron activation analysis (INAA) of Nok sculptures in I. P. Stanback Museum

The purpose of this research is to conduct provenance study of the Nok sculptures in the I.P. Stanback Museum via instrumental neutron activation analysis (INAA). Several samples at different points on the sculptures were collected and then irradiated with thermal/epithermal neutrons from the PULSTAR reactor. INAA results indicate that (1) ceramic samples from the sculptures have different elemental concentrations from those of soil samples in which the sculptures may have been buried; (2) ceramic samples of the two different Nok sculptures share similar elemental concentrations; (3) ceramic firing processes cannot change the chemical composition of clay significantly.

Технология получения и исследование свойств микродисперсного гидрофобного адсорбента на основе бентонитовой глины для ликвидации аварийных разливов нефти и нефтепродуктов

В статье представлены результаты разработки технологии получения и исследований эксплуатационных и физико-химических свойств микродисперсного гидрофобного адсорбента на основе бентонитовой глины Острожанского месторождения, применяемого для ликвидации аварийных разливов нефти и нефтепродуктов.

Pore-Forming Additives for Ceramic Gravel Production Made of Technogenic Materials

The purpose of the research is to determine the possibility of producing claydite gravel using the technogenic waste - wastewater treatment sludge – as the raw material. In this paper the titrimetric, spectrophotometrical, atomic absorption methods of research are used, the chemical composition of clay and wastewater treatment sludge has been determined. The possibility of using this waste material as an additive for claydite gravel production has been proved. The optimal amount of the wastewater treatment sludge being added to the basic raw stuff has been identified. The negligible extent of heavy metals leaching from the obtained building material has been researched and experimentally proved. The article can be of interest for the specialists in the sphere of obtaining new building materials based on industrial waste and wastewater treatment.

Possible effects of irrigation with wastewater on the clay mineralogy of some Australian clayey soils: laboratory study

Potassium is common in a wide variety of wastewaters and in some wastewaters is present at several hundred to several thousand mg L–1. Potassium is taken up by expandable clays leading to its fixation and illitisation of smectitic and vermiculitic layers. Hence the addition of wastewaters to soils may lead to mineralogical changes in the soils that affect their physico-chemical properties. Winery wastewater was equilibrated with clay-rich soils from Southern Australia. X-ray diffraction patterns and chemical composition of clays extracted from untreated and treated soils were determined. In three of the four soils, shifts in peak positions occurred towards more illitic components along with increases in K and sometimes also Mg and Na contents of soil clays. Peak decomposition showed trends towards the formation of interstratifications of illite with smectite at the expense of smectite and an alteration of poorly crystallised illite into its more well-ordered forms. The results show that illitisation may occur as a result of the addition of K-rich wastewaters to clayey soils.

Химический состав глин как индикатор сырьевого источника

Химический состав глин как индикатор сырьевого источника

Valorization of wood sawdust in making porous clay brick

This paper studies the application of a variety of sawdust materials in the production of lightweight insulating bricks. First, the mineralogical and chemical composition of clays was determined. Next, ceramic bricks were fabricated with different quantities of materials (3 to 6 and 9 wt. % for sawdust, 65 wt. % for grey clay, 24 to 27 and 30 wt. % for yellow clay and 2 wt. % of tuff). These bricks were fired at 800 and 950°C. The effect of adding this sawdust on the technological behaviour of the brick was assessed by drying and firing shrinkage, water absorption, porosity, bulk density and compressive strength. The results have shown that the optimum sintering temperature is 950°C. Below this temperature, at 950°C, increased open porosity was observed, which decreased the compressive strength of the bricks. Based on the results obtained, the optimum amounts of waste were 9 wt. % sawdust of eucalyptus, 24 wt. % shaping moisture and 1.6 particle size diameter. These percentages produced bricks whose mechanical properties were suitable for use as secondary raw materials in ceramic brick production. Key words: Clay brick, absorption, porosity, sawdust, mechanical properties.

Evaluation methods for ceramic suitability of raw clays

Ceramic suitability of kaolinitic-illitic and chloritic-illitic raw clays was assessed by methods involving microstructure investigation and ceramic properties measurements, some reported diagrams and response surface methodology (RSM). Results of the former method showed that all clays are suitable for red stoneware tiles. The stoneware manufacturing is facilitated by the marked reduction of porosity due to the flow of melt, mainly originated from the breakdowns of illite. This result was partially supported by the use of a diagram involving the chemical composition of clays as well as by the RSM results. According to the later method, bricks may be manufactured under restricted firing conditions and stoneware tiles could be prepared at temperatures as low as 950°C.

Final report on CCQM-K57: Chemical composition of clay

After the successful completion of the pilot study, CCQM-P65 [1], the Inorganic Analysis Working Group of CCQM agreed to conduct key comparison CCQM-K57, Chemical composition of clay, in Paris, April 2006. The natural mass fraction levels of five elements—Si, Ca, Fe, Al and Mg—were measured and reported as oxides in clay. Six national metrology institutes participated in CCQM K57, and CENAM (Querétaro, Mexico) coordinated.The methods employed were isotope dilution mass spectrometry (IDMS), inductively coupled plasma–mass spectrometry (ICP-MS), inductively coupled plasma–optical emission spectrometry (ICP-OES) using the dehydration method and condensation method, gravimetric analysis, neutron activation analysis (NAA), prompt gamma activation analysis (PGAA) and x-ray fluorescence spectrometry (XRF) with the reconstitution method and external calibration.This final report presents the capability of the participant institutes, based on the KCRV, which was approved at the IAWG spring meeting in 2008, and the equivalence statements regarding the KCRV, approved at its autumn meeting.Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

A method for determining the CEC and chemical composition of clays via XRF

AbstractA new method for determining the cation exchange capacity (CEC) of clays is proposed. The method is based on X-ray fluorescence analysis of natural and Ba-exchanged clays following the analytical procedure suggested by Franzini et al. (1975). This procedure, which utilizes powder pellets and is based on a full matrix correction method, is frequently applied in Earth Sciences laboratories for the routine analysis of minerals and rocks. For the analysis of Ba-exchanged clays, Franzini's procedure has been modified slightly to account for the contribution of Ba to matrix effects.The new method, which furnishes both the CEC and the chemical compositions of the whole natural clay samples, has been tested on the eight ‘Source Clays’ of The Clay Minerals Society. The results compare well with data reported in the literature and confirm the accuracy and precision of the method and make it a valid alternative to techniques based on wet chemistry, execution of which is usually more time-consuming and which often requires greater analytical skill.

Clay Minerals in Evaporite Host Rocks, Palo Duro Basin, Texas Panhandle

ABSTRACT The mineralogy and chemical composition of clays in evaporite strata of the Palo Duro Basin, Texas Panhandle, were investigated to determine the type and extent of alteration and to explore the preservation of diagenetic clays in changing geochemical environments. The coarse clay-size fraction (2-8 µm equivalent settling diameter (ESD)) contains predominantly illite and irregularly interlayered chlorite/vermiculite, whereas the fine-clay-size fraction (< 0.5 µm) contains predominantly illite and irregularly interlayered chlorite/smectite. Detrital illite, biotite, chlorite, and smectite are the probable parent clays. Electron microprobe analysis of clay-size flakes shows that the diagenetic clays are enriched in magnesium relative to detrital clays. Chemical composition , the geologic history of the Palo Duro Basin, and comparison to clays from other Paleozoic marine evaporites suggest that alteration occurred syndepositionally in the presence of hypersaline marine evaporite brine. Mineral assemblages of clays encased in primary marine halite, clays from regions where halite has been dissolved, and clays from strata approximately 300 m beneath the salt section are structurally and chemically similar, suggesting that these clay minerals record paleohydrologic and paleoenvironmental conditions.