Bentonite Clays Related to Volcanosedimentary Formations in Southeastern Spain: Mineralogical, Chemical and Pozzolanic Characteristics

IF 2.2 4区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

Minerals Pub Date : 2024-08-11 DOI:10.3390/min14080814

Elena Crespo, Domingo A. Martín, Jorge L. Costafreda

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引用次数: 0

Abstract

The volcanism that took place during the Neogene in the southeastern Iberian Peninsula caused a large accumulation of volcanosedimentary materials, which were subsequently altered and transformed into bentonite deposits. The mineral composition and technical quality of these deposits have been demonstrated and established in this work. The main object of this research is the mineral, chemical and thermal characterization of the bentonites that lie in the southeastern region of Spain and to demonstrate their technical capabilities to be used as pozzolans. The first phase of characterization of the samples was carried out by X-ray diffraction (XRD), oriented aggregates (OAs), X-ray fluorescence (XRF) and thermogravimetric analysis (TGA). In the second phase, a chemical‒technical quality test (CTQT) was carried out, aimed at determining reactive SiO2 and reactive CaO, whereas in the third phase, a chemical pozzolanicity test (CPT) was carried out to establish the pozzolanic behavior of the samples over two test periods: 8 and 15 days. The XRD and OA analyses showed that the bentonite samples are made up of a main phase formed by montmorillonite, quartz, plagioclase-albite and chabazite‒Ca. The results obtained by XRF on the bentonite samples indicated that the SiO2 contents are high and vary between 43.33 and 64.71%, while Al2O3 ranges between 15.81% and 17.49%. The CTQT established that more than 80% of the SiO2 and CaO present in the samples are reactive, which was confirmed by the results of the chemical pozzolanicity test (CPT). The results obtained show that the bentonites in this study present technical qualities that are undoubtedly reinforced by their mineral constitution and chemical composition. These tests could become a practical guide for the selection of eco-efficient materials in the production of pozzolanic cements and environmentally friendly ceramic products.

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与西班牙东南部火山沉积层有关的膨润土粘土：矿物学、化学和滑石特性

伊比利亚半岛东南部新近纪时期的火山活动造成了大量火山碎屑物质的堆积，这些物质随后被改变并转化为膨润土矿床。这些矿藏的矿物成分和技术质量已在这项研究中得到证实和确定。这项研究的主要目的是对西班牙东南部地区的膨润土进行矿物、化学和热学特征描述，并证明其用作胶凝剂的技术能力。样品表征的第一阶段是通过 X 射线衍射（XRD）、定向聚集（OAs）、X 射线荧光（XRF）和热重分析（TGA）进行的。在第二阶段，进行了化学技术质量测试 (CTQT)，旨在确定活性 SiO2 和活性 CaO，而在第三阶段，进行了化学抗热性测试 (CPT)，以确定样品在 8 天和 15 天两个测试期间的抗热性。XRD 和 OA 分析表明，膨润土样品是由蒙脱石、石英、斜长石-闪长岩和茶褐铁矿-钙组成的主相。对膨润土样品进行 XRF 分析的结果表明，SiO2 含量较高，在 43.33% 到 64.71% 之间，Al2O3 在 15.81% 到 17.49% 之间。CTQT 确定，样品中超过 80% 的 SiO2 和 CaO 具有活性，这一点也得到了化学热解性测试 (CPT) 结果的证实。所得结果表明，本研究中的膨润土无疑因其矿物结构和化学成分而具有更高的技术质量。这些试验可以成为在生产胶凝水泥和环境友好型陶瓷产品时选择生态高效材料的实用指南。

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来源期刊

Minerals MINERALOGY-MINING & MINERAL PROCESSING

CiteScore

4.10

自引率

20.00%

发文量

1351

审稿时长

19.04 days

期刊介绍： Minerals (ISSN 2075-163X) is an international open access journal that covers the broad field of mineralogy, economic mineral resources, mineral exploration, innovative mining techniques and advances in mineral processing. It publishes reviews, regular research papers and short notes. Our aim is to encourage scientists to publish their experimental and theoretical results in as much detail as possible. There is no restriction on the length of the papers. The full experimental details must be provided so that the results can be reproduced.