High Temperature Structural Modifications of Intercalated Montmorillonite Clay Mineral with OH-Al Polymers

AbstractTwo montmorillonitic clays were put into contact with a solution containing inorganic OH-Al polymers and subsequently washed and dried. The obtained solid (i.e.the clays with the OH -Al species in the montmorillonite interlayer) which was called the precursor, was subjected to a thermal treatment up to 1000 ¡ C using DTA-TG for analysis at low temperature. Additionally, the structural changes of the precursor by heating at 1030, 1100 and 1200 ¡ C for 2hours and that of the natural clays were examined. The crystallinity and formation of new phases was followed by x-ray diffraction analysis. Mullite and cordierite were originated depending on the different contents of aluminium and magnesium in the structure of natural montmorillonite, respectively, accompanied with other phases. The intercalated OH-Al species in both clays favored the increase in the mullite content in the final products. However, the transformation to this phase was directly related to the octahedral aluminium of the natural clay and thus mullite was found to be the dominant phase from montmorillomite containing higher octahedral Al

Smart thinking on co-creation and engagement: Searchlight on underground built heritage

This paper aims to explore public participation for activating underground built heritage (UBH). It describes and analyses practices of stakeholders’ engagement in different UBH assets, based on experiences gathered in the scope of the European COST Action ‘Underground4value’. It brings together five inspiring cases from Italy, Portugal, Spain, Switzerland and the United Kingdom, in which digital and mobile technologies were used as tools to improve community experiences in UBH. Thus, the paper discusses ‘smartness’ from the perspective of people and communities around cultural assets, where ‘smartness’ becomes a new connotation and a pathway to advance (local) knowledge and know-how. Therefore, this paper takes on the challenge to define a smart city as an ecosystem for people’s empowerment and participation, and, in particular, to explore social tools for creating new values in heritage placemaking—where sharing knowledge becomes a fundamental principle.info:eu-repo/semantics/publishedVersio

Imaging of the Inner Zone of Blast Furnaces Using MuonRadiography: The BLEMAB Project

The aim of the BLEMAB project (BLast furnace stack density Estimation through online Muons ABsorption measurements) is the application of muon radiography techniques, to image a blast furnace’s inner zone. In particular, the goal of the study is to characterize the geometry and size of the so-called “cohesive zone”, i.e., the spatial region where the slowly downward-moving material begins to soften and melt, which plays such an important role in the performance of the blast furnace itself. Thanks to the high penetration power of natural cosmic-ray muon radiation, muon transmission radiography could be an appropriate non invasive methodology for the imaging of large high-density structures such as a blast furnace, whose linear dimensions can be up to a few tens of meters. A state-of-the-art muon tracking system is currently in development and will be installed at a blast furnace on the ArcelorMittal site in Bremen (Germany), where it will collect data for a period of various months. In this paper, the status of the project and the expectations based on preliminary simulations are presented and briefly discussed

The BLEMAB European project: Muon radiography as an imaging tool in the industrial field

The European project called BLEMAB (BLast furnace stack density Estimation through on-line Muons ABsorption measurements), provides for the application of the muon radiography technique in the industrial environment. The project represents a non-invasive way of monitoring a blast furnace and in particular aims to study the geometric and density development of the so-called “cohesive zone”, which is important for the performance of the blast furnace itself. The installation of the detectors is expected in 2022 at the ArcelorMittal site in Bremen (Germany). This paper describes the status of the project, the experimental setup and the first results obtained with preliminary simulations. © 2022 Societa Italiana di Fisica. All rights reserved

Retention of chromium by modified Al-Bentonite Retenção de cromo por Al-bentonita modificada

Retention of chromium (III) from a tanning wastewater by modified Al-bentonites was studied. One bentonite from San Juan province, Argentina, was used. Al-bentonite was prepared by contact of bentonite with hydrolyzed OH-Al solutions (0.10 M in Al) for 24 hours. The modified Al-bentonites were obtained by: a) treatment with 0.5 M sodium chloride; b) with 0.5 M sodium chloride adjusted at pH 8; and c) treatment with an hexametaphosphate solution after sodium addition. Then, the samples were dried at 100 °C and heated at 500 °C. The chromium (III) retention by samples was carried out in batch system putting in contact the material with a 2000 ppm Cr tannery waste at different times. The retained chromium was characterized by analyzing the supernatant using UV-visible spectroscopy. The different chromium retention was correlated with structural characteristics of the solids.<br>Foi estudada a retenção de cromo (III) de águas residuais por meio de Al-bentonitas modificadas. Foi usada uma bentonita da província de San Juan, Argentina. As bentonitas-Al forma preparadas colocando-as em contato com soluções (0,10 M Al) hydrolizadas de OH-Al durante 24 horas. As bentonitas-Al modidicadas foram obtidas por meio de: a) tratamento com cloreto de sódio 0,5 M; b) com cloreto de sódio 0,5 M sodium com pH ajustado para 8; e c) tratamento com uma solução de hexametafosfato após a adição de sódio. As amostras foram então secas a 100 °C e aquecidas a 500 °C. A retenção do cromo (III) pelas amostras foi feita em lotes colocando o material em contato em diferentes tempos com um resíduo contendo 2000 ppm de cromo. O cromo retido foi caracterizado por meio de análise do sobrenadante usando espectroscopia UV-visível. As diferentes retenções de cromo foram correlacionadas com características estruturais dos sólidos