Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Thermal transformation of illite and smectite group clay minerals was studied using X-ray diffraction and transmission electron microscopy, and the results were compared with those of kaolinite. Differences were observed in the types and sizes of crystals formed at temperatures between 800° and 1400°C. Spinel-type phases were formed after 3 h at 1000°C in all three clays, but the morphology and composition of the spinel crystals varied. Mullite crystals reached greater sizes in the illite (>10 μm needles) and smectite (>1 μm) materials than in the kaolinite (0.5 μm). Iron-rich crystals formed in the illite and smectite materials, and feldspars present as impurities in these clays, along with interlayer cations, resulted in large quantities of liquid being formed above 1000°C. Similar thermal breakdown and phase development schemes are proposed for all three materials, with the major differences observed ascribed to the presence or absence of interlayer cations, substitutional impurities, and accessory minerals. These results provide a basis for predicting phase development on firing a given clay mineral, if its characteristics and impurity levels are known.

Microstructural Development on Firing Illite and Smectite Clays Compared with that in Kaolinite

With abundant bauxite mineral as starting material, a low-cost alumina-mullite composite hollow fiber ceramic membrane (HFCM) was fabricated via phase-inversion method followed by high temperature sintering. Process parameters, including bore fluid flow rate and air-gap distance, which affect structure and properties of the HFCM were systematically explored. A low bore fluid flow rate would lead to the deformation of inner walls of the HFCM as a result of insufficient solidification, while a large air-gap distance would induce the distortion of finger-like voids. Effects of sintering on the microstructure, pore size distribution, nitrogen gas flux and mechanical properties were investigated in details. Acid-base titration was first proposed to quantitatively determine concentration of surface active sites of membrane surface after sintering. An increase in sintering temperature leads to significantly enhancing strength but almost linearly reduces concentration of active surface hydroxyl sites. Compared with its alumina counterpart, this low-cost composite membrane can be sintered at lower sintering temperature, and exhibits higher mechanical strength and active surface hydroxyl site concentration.

A low-cost alumina-mullite composite hollow fiber ceramic membrane fabricated via phase-inversion and sintering method

Algerian kaolinite used for mullite formation

Phase Transformation of Kaolinite Clay

http://thaiceramicsociety.com/download/Mullite_from_clay-reactivity_alumina_for_substrate.pdf

V. Viswabaskaran

Papers

Mullite from clay–reactive alumina for insulating substrate application

Mullitisation behaviour of calcined clay-alumina mixtures

Effect of MgO, Y2O3 and boehmite additives on the sintering behaviour of mullite formed from kaolinite-reactive alumina

Mullitisation behaviour of south Indian clays

Effect of MgO on mullitization behavior of clays