Kaolin Minerals Research Articles

Geochemical and mineralogical study of bauxite deposit of Mainpat Plateau, Surguja District, Central India

Bauxite deposits of Mainpat Plateau Surguja District, India, are composed of kaolinite, gibbsite, goethite, anatase, and bohemite. Quartz and micas are absent in the samples. The presence of boehmite and goethite are evidences of intense weathering during the formation of the bauxite deposits. The Mainpat Plateau is a mesa landform, at an elevation of around 1,060 m from msl in comparison to the general elevation of 580, consisting of Archaeans (granite−gneisses, phyllite, etc.) at the base, Gondwanas and Deccan basalt, and at the top having a cover of laterite and bauxite. The extremely high values of the chemical index of alteration, and the low values of the alkali metals and alkali earth metals, support an intense weathering origin for the bauxite deposit. There is evidence of deposition in the deposits based on the presence of pisoids in the bauxite samples and the composition of the parent rock. Kaolin minerals were first produced by the hydrolytic weathering of aluminous sediments and then gibbsite was formed as early kaolin was desilicated. The bauxite is having high TiO2 up to 17 %. The Mainpat laterite/bauxite deposits are characterized by having 50−58 % average Al2O3 and 10−30 % Fe2O3.

The Influence Factors of Compressive Strength and Production of Mineral Polymer of Aluminum Rocks in Xiuwen County, Guizhou Province, China

Aluminous rocks from Xiuwen County, Guizhou are the main raw materials, mixed some kaolin mineral. Water glass and alkaline activators are used to product polymer materials, the main experimental indicators are the compressive strength. Here, the studies on amount of water glass and alkaline activator, solid-liquid ratio, amount of kaolin and effects on compressive strength of Geopolymer have been proceeded respectively. The result shows that: the highest compressive strength of geopolymers is17.94 Mpa, with aluminous rock 40g, solid-liquid ratio 2.2, water glass12g and alkali activator 2.01g, as well as kaolin 18.02g.

Mapping Kaolinite and Dickite in Sandstone Thin Sections Using Infrared Microspectroscopy

AbstractA method to characterize and map both kaolinite and dickite polytypes in sandstone thin sections using infrared microspectroscopy (IRMS) was developed. Minerals identification using IRMS can be performed using the hydroxyl-stretching band of most clay minerals (3500–4000 cm−1) in spite of infrared (IR) interferences caused by the embedding resin and glass substratum. Emphasis was placed on determining the optimum analytical conditions for IR data acquisition. The best data-acquisition parameters for Fourier-transform infrared (FTIR) measurements (i.e. spectra quality as a function of beam size and the number of scans) were obtained from a series of single spectra. Then, spatial resolution was explored as a function of the IR beam size (from 50 μm × 50 μm to 15 μm × 15 μm) and the step-scan interval (i.e. the distance between two successive analysis points). The IRMS measurements were performed on thin sections of materials characterized previously using scanning electron microscopy (SEM) and chemical analysis. Using IRMS, locations on the thin sections containing nearly pure dickite or kaolinite polytypes were identified and mapped. Most spectra collected using IRMS represented kaolin mineral aggregates rather than individual crystals, however, and mixing of kaolin polytypes was common at the spatial resolution of the IR beam size used. The spatial resolution of the IRMS was comparable to optical petrography and made possible the identification of areas on the thin section for further ‘in situ’ investigation using other methods (e.g. microprobe, Laser Ablation Inductively Coupled Plasma Mass Spectrometry — LA-ICP-MS, etc.). Also, the use of blocky crystal morphology to identify dickite was questioned, as kaolinite with blocky habit was identified. Mineral mapping using IRMS seems particularly suited for investigating petrographic relationships between kaolinite and dickite in sandstone diagenesis, but could also be used for clay minerals in other rock types or soils.

The influence of kaolin filler on thermal and spectral characteristics of rubberizing components without rubber

The current trend is to use clay minerals as nanofillers in polymer blends. Kaolin is a hydrated aluminum silicate of a group of natural clays and it is one of the most important kaolin mineral fillers. The interactions between vulcanizing ingredients such a zinc oxide (ZnO), stearic acid (SA), CBS (N-cyclohexyl-2-benzothiazolesulfenamide), and sulfur (S) with kaolin (K) filler were studied in this work. We prepared systems of two and three components with kaolin at 1:1 ratio by mass, without rubber matrix. The second step was heating samples containing ZnO, SA, and CBS with kaolin at 140 °C. The interactions between vulcanizing components were investigated by thermal analysis (DTA, TG, and DSC), X-ray analysis, and Fourier transform infrared spectroscopy (FT-IR). Zinc stearate was formed in the presence of ZnO and SA as expected, which was confirmed by X-ray analysis.

Distribution and mineralogy of radioactive Cs in reservoir sediment contaminated by the Fukushima nuclear accident

This study investigated the distribution and mineralogy of radioactive Cs in a core sample from reservoir sediment affected by the Fukushima Daiichi Nuclear Power Plant accident. The sample was obtained 19 months after the accident from a reservoir in Iitate-mura, Fukushima Prefecture. The vertical concentrations of radioactive Cs in the sediment core varied little from the surface to 9 cm depth: 20-30 Bq/g for 137Cs. The concentration decreased abruptly at depths greater than 9 cm. The radioactive Cs concentrations were particle-size dependent: finer particles exhibited higher concentrations of radioactive Cs. X-ray diffraction analyses of the size-fractionated sample revealed that the contribution of clay minerals (14 Å minerals, kaolin mineral and mica) increased concomitantly with the decrease of particle size, implying a close relation between radioactive Cs concentration and clay mineralogical compositions. Periodical airborne monitoring showed that the 137Cs inventory in the reservoir catchment area decreased significantly with time after the accident. Results of a 137Cs inventory in the reservoir sediment were almost identical to those for the catchment area immediately after the accident, but were significantly higher than those in the core sampling period. Results might indicate that the reservoir sediments serve as a sink for radioactive Cs.

The key role of micromorphology in studies of the genesis of clay minerals and their associations in soils and its relevance to advances in the philosophy of soil science

Micromorphological observations from 3 different published works have been studied to aid understanding of aggregation and of colloids, both unique to soils. Saprolites in Hong Kong included ‘veins’ of different thicknesses and colours. Optical mineralogy identified them as infill from the neogenesis of clays in rock fractures. The common thicker infills resulted from weathering. Dark infill contained comminuted primary minerals whereas thin pale infill originated hydrothermally. Scanning electron microscopy (SEM) showed that the size, shape, and mineralogy of the kaolin minerals formed in infill depended on the types of cracks in the saprolites and on drying. Energy-dispersive X-ray spectroscopy analyses showed Fe and/or Mn in dark-coloured infill from comminution of primary minerals upon brecciation, or else beside pale infill in tuff, showing seasonal drying in tuff but not in granite. Pale infill gave predominantly large tubular halloysite in granite but large platy kaolinite in tuff, except that hydrothermal kaolin gave small particles. In dark infill, kaolin particles were also small and were kaolinite and halloysite mixtures. The effect of impurity Fe and Mn in constraining kaolin mineral crystallinity in infills simulates some of the effects of impure soil environments. Long-term cultivation of soils in Australia led to environmental scanning electron microscope images of large microaggregates indicating their breakdown and loss. Transmission electron micrographs of ultrathin sections showed that microaggregates of clay size, comprising clay minerals and oxides covering other materials, including organic matter, were predominant in virgin soil but were broken down to fine clay particles that blocked pores in cultivated soils. SEM showed a web of biological origin in long-term irrigated sandy New Zealand soil that surrounded macroaggregates but only became closely attached on drying. The nature of the macroaggregates was affected strongly by their history of drying, even during preparation for analyses. Micromorphology is especially useful for indicating the nature of aggregates in situ in soils.

Rehabilitation of Degraded Tropical Rainforest Using Dipterocarp Trees in Sarawak, Malaysia

To develop rehabilitation planting techniques in tropical degraded forests, we investigated (1) basic soil characteristics and light conditions; (2) growth and survival of seven dipterocarp seedlings over 81 months; and (3) the effect of environmental factors on the survival of seedlings grown in three degraded vegetations (grassland, secondary forest, and logged forest) in Sarawak, Malaysia. The soil was weakly acidic, and kaolin minerals dominated. The amount of exchangeable bases in surface soils, soil temperature (>35°C), and relative light intensity were all highest in the grassland. Seedling growth was also highest in the grassland, whereas many seedlings died there over 81 months. Growth and survivability were very similar in secondary and logged forests. The death of the seedlings in the grassland was attributable to an extremely high light intensity for all species. In contrast, the seedling growth rate in all species was also enhanced by light intensity. In conclusion, dipterocarp seedlings can be planted on highly degraded land such as grassland, although high light intensity limits their survival. Planting under nurse trees such as regenerated pioneer trees may be an effective method to enhance seedling survival under open conditions such as grassland.

통가국 라우분지 TA 26 해저산의 열수변질작용

통가국 라우분지(Lau Basin)의 해저열수광상 개발을 위한 해저열수광상 분포 및 산상에 관한 특성을 규명하기 위하여 X선 회절분석을 통하여 해저열수광상 해저퇴적물 및 열수변질대의 광물조성을 연구하였다. 연구에 사용된 시료는 TA 26 해저산 주변에서 채취된 코어 시료, 기반암 및 해저퇴적물 시료이고, 벌크 시료와 점토 부분을 분리한 정방위 시료를 제작하여 X선 회절분석을 실시하였다. TA 26 해저산에서 채취된 기반암은 대부분 사장석과 석영으로 이루어져 있는 데 반하여, 표층퇴적물은 대부분 카올린광물과 스멕타이트로 구성되어 있다. 열수구 퇴적물은 대부분 석고, 중정석, 섬아연석, 황철석 등 황산염광물과 황화광물로 구성된다. 기반암과 해저퇴적물의 광물조성으로 미루어 보아, TA 26 해저산의 열수광화대는 주변에 스멕타이트 또는 카올린광물을 형성시키는 정도의 이질변질작용을 일으켰음을 알 수 있다. MC08H-06 시추 코어 시료는 상부는 비변질대, 하부는 스멕타이트와 카올린광물로 구성된 이질변질대에 해당한다. 다양한 황화광물과 황산염 광물의 존재, 이질변질작용에 해당하는 열수변질대의 존재는 TA 26 해저산 내에 해저열수광상이 존재하고 있음을 지시하는 것으로 판단된다. We have researched the distribution and characteristics of seafloor hydrothermal deposits for the development of economic mineral deposits in the Lau Basin, Tonga since 2009. In this study, we interpreted hydrothermal alteration around TA 26 seamounts of the Tofua volcanic arc using X-ray diffraction analysis for bulk sample and preferred-oriented specimen of clay fraction. We used 2 core samples and several surface samples. Plagioclase and quartz are dominant mineral in the basement rock, whereas kaolin mineral and smectite are superior in marine surface sediments. Especially sulfate and sulfide minerals such as gypsum, barite, sphalerite, and pyrite are predominant in the vent sediments. When we compare the mineral composition between basement rock and sea surface sediments, argillic alteration zone composed of kaolin mineral and smectite could be produced by hydrothermal fluids. Based on the downcore variation of mineral assemblages, most portion of MC08H-06 core could be interpreted as argillic alteration zone composed of kaolin mineral and smectite except top 2 cm area. Various sulfate or sulfide minerals and argillic alteration zone suggest a high probability of massive sulfide deposits in the seafloor of the TA 26 seamount.

The Study on Preparation of Kaolin-Acrylic Super Absorbent Polymer and its Internal Curing Effect in the Hydration Procedure of Cement Materials

In this paper, a new kind of superabsorbent polymer (SAP) is designed and prepared. Using sodium persulfate as initiator and N,N’-methylene bisacrylamide as Crosslinker, monomer of acrylic acid can be grafted into the skeleton of natural mineral kaolin with the method of microwave irradiation. The performance of water adsorption for SAP is tested in saturated Ca(OH)2 solution. Also, the internal curing effect of SAP to hydration procedure of cement paste is studied. The result shows that the compressive properties and flexural strength of cement paste specimens in early stage have significant improvement in contrast to those without superabsorbent polymer or excessive or a small amount of superabsorbent polymer, when superabsorbent polymer is accounted for 0.3% to 0.5% of the total cement.

English

Although, soil properties of tropical rainforest in Southeast Asia have been characterized by several researchers, limited information exists on soil characteristics due to conversion of natural forest into various land use types such as oil palm plantation, rubber plantation, forest plantation and secondary forest. A study was conducted to characterize the soil properties under various land use types of logged-over forest (LF), rehabilitation forest (RF), oil palm (OP) and rubber plantation (RP) at Universiti Putra Malaysia, Bintulu, Sarawak, Malaysia. Soil profiles were dug up to 100 cm depth and 50 cm width and were followed by soil sampling according to soil horizon. Soil morphology was determined in the field while soil physico-chemical properties were determined in the laboratory using standard soil analysis. The soils at RF, LF, OP and RP were derived from sandstone intercalated with shale which gives silty loam and sandy clay loam texture. The soils are acidic to weakly acidic with pH increases with depth. The Cation Exchange Capacity (CEC) and Total Carbon (TC) of soils tend to decrease with depth and it seems to be higher under OP and RP as compared to RF and LF. The Alo, Ald, Feo and Fed increased with depth in all of the profiles. The values of Point Zero of Salt Effect (PZSE) and σp are low in all sites with dominated by kaolin minerals and sesquioxide properties indicating that the soils are highly weathered and low soil fertility status.   Key words: Forest rehabilitation, logged-over forest, oil palm and rubber plantation, charge characteristic.

Microstructural properties and pozzolanic activity of calcined kaolins as supplementary cementing materials

In this study, the utilization of unprocessed kaolins calcined at various temperatures as supplementary cementing material was investigated experimentally. The current work deals with four kaolin deposits existing in the western region of Turkey that have not yet been investigated for this purpose. Thermal properties of the unprocessed kaolins were examined by means of differential thermal and thermo gravimetric analysis. After determination of the thermal behavior, pozzolanic activity indices of the kaolins were determined according to ASTM C311. Based on the pozzolanic activity test results, calcination temperatures were assigned for kaolins and the changes in the mineralogical composition and the formation of amorphous structures were examined by X-ray diffraction analysis. The changes in particle size and specific surface area of the calcined kaolin minerals were observed through, particle size analysis with laser diffractometer, Scanning electron microscopy image analysis, and Brunauer-Emmett-Teller specific surface area measurement. The results showed that a complete kaolinite to metakaolinite conversion was achieved by the calcination procedure adopted.

Adsorption- and desorption-controlled magnesium isotope fractionation during extreme weathering of basalt in Hainan Island, China

Magnesium isotopic compositions of a set of clay-rich saprolites developed on the Neogene tholeiitic basalt from Hainan Island in southern China have been measured in order to document the behavior of Mg isotopes during continental weathering. Compared with unaltered basalts (δ26Mg=−0.36‰), the overlying saprolites are strongly depleted in Mg (i.e., τTh,Mg=−99.1% to −92.9%), and display highly variable δ26Mg, ranging from −0.49‰ to +0.40‰. Magnesium concentration and δ26Mg value of the saprolites display a general increasing trend upwards in the lower part of the profile, but a decreasing trend towards the surface in the upper part. The variations of Mg concentration and isotopic composition in this weathering profile can be explained through adsorption and desorption processes: (1) adsorption of Mg to kaolin minerals (kaolinite and halloysite), with preferential uptake of heavy Mg isotopes onto kaolin minerals; and (2) desorption of Mg through cation exchange of Mg with the relatively lower hydration energy cations in the upper profile. Evidence for adsorption is supported by the positive correlation between δ26Mg and the modal abundance of kaolin minerals in saprolite of the lower profile, while negative correlations between δ26Mg and concentrations of lower hydration energy cations (e.g., Sr and Cs) in the upper profile support the desorption process. Our results highlight that adsorption and desorption of Mg on clay minerals play an important role in behavior of Mg isotopes during extreme weathering, which may help to explain the large variation in Mg isotopic composition of river waters.

Microtexture and genesis of clay minerals from a turbiditic sequence in a Southern Pyrenees foreland basin (Jaca basin, Eocene)

AbstractA set of fine-grained samples from a turbiditic sequence in a Southern Pyrenees foreland basin (Jaca Basin, Eocene) were studied to determine the influence of tectonics (Pyrenean Orogeny) on phyllosilicate recrystallization and infer the grade and basin maturity. The samples from four different outcrops were examined by X-ray diffraction (XRD) and by scanning (SEM) and transmission electron microscopy (TEM) with special emphasis on clay-mineral characterization (e.g.illitic phases). The analysed samples have simple mineral assemblages and consist of detrital quartz, albite and calcite, scarce clay matrix (mainly illite with chlorite), and calcite and dolomite cement. The lack of other phyllosilicates such as mixed-layer illite-smectite (I-S), pyrophyllite, Na-micas, or kaolin minerals is quite remarkable. On the SEM scale, samples (with marl composition) have poorly sorted textures and high detrital contents. In many cases they show bedding and/or cleavage, and in some cases neither is observed. Most of the clay-sized illites show very similar crystallinity and b0 values (determined by XRD) and distributions of crystallite thickness (measured by TEM) in all the outcrops, which is typical of late-diagenesis illites forming under low-pressure conditions. These illites are parallel (or subparallel) to bedding or randomly orientated. They are also characterized by disordered polytypes and low K contents. In some TEM images, a second type of illite has been observed. This secondary illite occurs parallel to cleavage, with thicker crystals (25–35 layers), K contents in the interlayer, and a 2M1 polytype. The pole figure analysis shows that most of the clays have (00l) planes parallel (or subparallel) to bedding although there are abundant clays with random orientation. There is no trend in the clay orientation/disorientation from the south to the north of the basin. All the data indicate that the strain rate associated with the Pyrenean Orogeny has not been recorded in the turbidite sequence controlling the relative orientation of clays, although anchizonal clay crystallization is favoured as a minor process.

Improvement of performance of lubricating materials with additives of clayey minerals

The paper presents the results of comparative tests of serpentine and kaolin minerals using the criteria of wear, scuffing, and friction resistance properties. It is established that, irrespective of the silicate stock type, the structure of the appearing protective layer and the mechanism of subsurface chemical modification are quite similar. The possibility is established that kaolin can serve as an equivalent substitute for serpentine.

On Kaolin Minerals in Pliocene Clay Deposits around Nagoya City

On Kaolin Minerals in Pliocene Clay Deposits around Nagoya City

The dehydration of kaolin minerals at near 500°C

The dehydration of kaolin minerals at near 500°C

Kaolin Mineral Transformation during Weathering and Diagenesis

Kaolin Mineral Transformation during Weathering and Diagenesis

Mineralogy of Kaolin Minerals and Its Relation to the Genesis of Sedimentary Kaolin Deposits around Nagoya

Mineralogy of Kaolin Minerals and Its Relation to the Genesis of Sedimentary Kaolin Deposits around Nagoya

Identification methods of kaolin minerals and chlorite

Identification methods of kaolin minerals and chlorite

Geopolymers based on a coarse low-purity kaolin mineral: Mechanical strength as a function of the chemical composition and temperature

Abstract A coarse mineral with 70% kaolinite and 30% quartz was calcined and chemically activated by alkaline solutions of Na 2 SiO 3 and NaOH. The compressive strength evolution was investigated as a function of the curing temperature at 20 and 80 °C, and the molar ratios of SiO 2 /Al 2 O 3 (2.64–4.04) and Na 2 O/Al 2 O 3 (0.62–1.54). For curing at 20 °C, the best composition was SiO 2 /Al 2 O 3 = 2.96 and NaO/Al 2 O 3 = 0.62, reaching 85 MPa at 28 days. Curing at 80 °C had a positive effect on the strength development only in the first 3 days. X-ray diffraction of the geopolymeric formulations showed the formation of amorphous silicoaluminates of similar nature. The microstructure consisted of unreacted quartz and metakaolinite particles in a matrix of silicoaluminate polymer and condensed silica gel from the unreacted sodium silicate.