Effects of purification and heat treatment on pore structure and composition of diatomite

Abstract

treatment in HCl acidic solutions. 1 0 There are several important studies in the literature on aspects of diatomite T he eVects of sintering and puri cation processes on including its puri cation, sintering, and processing. 6 ,1 1 -1 4 the porosity and speci c surface area of diatomaceousThe Turkish material was found to be essentially earth, mined in the A nkara region of T urkey, were amorphous but also contained crystalline illite, investigated. T he material was studied in three forms,and a small amount of feldspar. as received, calcined, and puri ed. Changes in surface As is the case for most deposits in Turkey, it did not area occurred, with large diVerences between as consist only of diatom skeletons, and so is classi ed as a received, calcined, and puri ed materials. A s received low grade diatomite. The chemical composition (wt-%) material had very high pore volume, with a speci c was 74•4%SiO 2 , 14•55%Al 2 O 3 , 3•62%Fe 2 O 3 , 1•55%CaO, surface area of 204 m2 g -1. For puri cation, the raw 1•37%MgO, 2•44%K 2 O, and 0•72%Na 2 O. material was treated in H Cl solutions varying in concentration f rom 1 to 5N for several hours, with and without heating. T he puri cation treatment caused EXPERIMENTAL PROCEDURES reductions in BET surface areas, with minimum area Materials preparationafter treatment being 136 m2 g -1. A s received andThe material was studied in three forms, as received, puri ed samples were calcined at various temperatures.calcined, and puri ed. The as received material had an T he eVects of puri cation treatment and sintering on average particle size of 12 mm with a broad size distribution surface area and on the contents of undesirable aluminvarying from <0•2 to 140 mm, and with a BET area of ium, calcium, magnesium, iron, and alkaline impurities 204 m 2 g -1 . This material was calcined without ux at in the materials were characterised.BCT /501 several temperatures, selected with reference to the temperatures for maximum weight loss (700°C), decomposition of Dr Goren

Diatom frustule-filled epoxy: Experimental and numerical study of the quasi-static and high strain rate compression behavior

“…The potential engineering and medical applications of diatom frustules have also recently been proposed, including metal film membranes, pinpoint drug delivery and processing of nanopowder silica [7]. The surface area of diatomaceous earth was reported to be relatively high, 22 m 2 /g [8] and it was shown to decrease slightly as a result of heat-treatment [9].…”

Effect of Thermal Treatment on Textural Properties of Natural Montmorillonite

“…The effect of acid treatment on different forms of highly and purified Egyptian diatomite was performed [19]. The conclusion of the above study stated that the structure of diatomite changes depended on the treated temperatures.…”

“…From Other investigations [19] were performed on prepared silica nanoparticles. It has been found that from the XRD spectra no sharp peaks resulting the absence of ordering crystalline structure.…”

Easy and industrially applicable impregnation process for preparation of diatomite-based phase change material nanocomposites for thermal energy storage

“…No other treatments such as purification or heating was applied on received diatomite samples to avoid complicating the process although effects of purification and heat treatment on pore structure and composition of diatomite are known [17].…”