An evaluation of the general composition and critical raw material content of bauxite residue in a storage area over a twelve-year period

AbstractFunctionality and appearance are key aspects of good footwear. Developments in recent science and technology offer a wider scope of innovations, contributing to diversity and higher complexity of the production concept of footwear. Contemporary industrial footwear market offers a practically limitless number of new design and fashion solutions, often of quite similar appearance, but with significant differences in quality level, both regarding manufacture, raw material content, durability, and in some special functional finishes. The materials for footwear manufacture are functionalized for functional protective purposes, such as antimicrobial, waterproofing, fire resistant, wear and tear resistant, and recently for some therapeutical purposes. Novelties in material functionalization for the materials built in the footwear are most often promoted and presented on tags and labels and are used as advertisement issues, while some functionalities have become a logo for some brands.

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Preliminary Characterization of Three Metallurgical Bauxite Residue Samples

Materials Proceedings ◽

10.3390/materproc2021005066 ◽

2021 ◽

Vol 5 (1) ◽

pp. 66

Author(s):

Panagiotis Angelopoulos ◽

Maria Georgiou ◽

Paschalis Oustadakis ◽

Maria Taxiarchou ◽

Hakan Karadağ ◽

...

Keyword(s):

Low Cost ◽

Bauxite Residue ◽

Raw Material ◽

Morphological Observation ◽

Critical Metals ◽

Alumina Production ◽

Preliminary Characterization ◽

Fine Grained ◽

Extraction And Separation ◽

Bulk Chemical

Bauxite Metallurgical Residue (BR) is a highly alkaline and very fine-grained by-product of the Bayer process for alumina production. Its huge global annual production has resulted in increasing accumulation of BR, causing deposition problems and serious environmental issues. RM contains oxides and salts of the main elements Fe, Al, Ca, Na, Si, Ti, and rare earths—REEs (Sc, Nd, Y, La, Ce, Ds)—many of which have been categorised by EU as critical metals (CMs). The valorisation of BR as a low-cost secondary raw material and metal resource could be a route for its reduction, introducing the waste into the economic cycle. REEScue constitutes a research project that aims to instigate the efficient exploitation of European bauxite residues, resulting from alumina production from Greece (MYTILINEOS SA), Turkey (ETI Aluminium), and Romania (ALUM SA), containing appreciable concentrations of scandium and REEs, through the development of a number of innovative extraction and separation technologies that can efficiently address the drawbacks of the existing solution. The consortium consists of three alumina producers from Greece (MYTILINEOS SA), Turkey (ETI Aluminium), and Romania (ALUM SA) and two academic partners from Greece (National Technical University of Athens) and Turkey (Necmettin Erbacan University). We present preliminary characterization results of three different BR samples that originate from the three aluminium industries, in respect of bulk chemical analysis (XRF, ICP), mineralogical investigation (XRD), and morphological observation through microscopy.

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Study on the Preparation and Properties of Impervious and Breathable Sand Based on Hydrophobic Theory

Materials ◽

10.3390/ma14195613 ◽

2021 ◽

Vol 14 (19) ◽

pp. 5613

Author(s):

Xiao Li ◽

Xiong Zhang ◽

Hao Ren

Keyword(s):

Contact Angle ◽

Hydrostatic Pressure ◽

Air Permeability ◽

Coating Material ◽

Raw Material ◽

Sustainable Utilization ◽

Land Resources ◽

Nano Structure ◽

Material Content ◽

Pressure Resistance

Land desertification, a severe global ecological and environmental problem, brings challenges to the sustainable utilization of land resources in the world. The purpose of this research is to use hydrophobic theory to prepare impervious and breathable sand, and to solve the problems of sandy soil that seeps easily and makes it difficult for vegetation to survive in desertified areas. The influences of coating material content, first-level and second-level rough structure on the impermeability and air permeability of impervious and breathable sand were studied. The research showed that, with the increase in coating material content, the impervious performance of the sample increased firstly and then decreased, and the air permeability rose continuously. The hydrostatic pressure resistance of the sample can reach an extreme value of 53 mm. The first-level rough structure of micron structure can greatly improve the hydrophobic performance, thus improving the impervious performance. The addition of micron calcium carbonate would improve the hydrostatic pressure resistance height of the sample to 190 mm. The sample would reach a superhydrophobic state in the condition of a first-level rough structure of a nano structure built by nano silica, and the contact angle was up to 152.0°, so that the hydrostatic pressure resistance height can rise to 205 mm. The best performance would be achieved under the condition of relatively less raw material with a second-level rough structure of micro–nano. At this point, the contact angle of the sample reached 152.8° and the hydrostatic pressure resistance height was up to 205 mm. At the same time, the air permeability index of the above four kinds of impervious and breathable sand met all planting requirements. The sample prepared can satisfy the demands of different degrees of impermeability and air permeability, and can be widely used in desertification control.

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Sustainable products in the leather industry

10.24264/icams-2020.iv.3 ◽

2020 ◽

Author(s):

Olga Ballus ◽

Anna Bacardit

Keyword(s):

Carbon Footprint ◽

Raw Materials ◽

Raw Material ◽

Low Carbon ◽

Leather Industry ◽

Material Content ◽

Sustainable Products ◽

Short Lifespan ◽

Renewable Raw Material ◽

Lower Carbon

Protecting the environment is one of the three objectives of sustainability. One way to achieve this is to preserve natural resources by using renewable or residual raw materials. These products have a shorter lifespan and a lower carbon footprint, are highly biodegradable, and are therefore considered to be sustainable products. In this paper, three retanning agents and two oils classified as sustainable products were studied. First, biobased carbon content (an indicator of renewable raw material content) was determined. Then, the physical and organoleptic properties of the leathers treated with each product (degree of softness, firmness and fullness) were evaluated. The COD of residual baths was also determined in oils. The products presented in this paper meet the sustainability requirements, i.e., high renewable raw material content, short lifespan, and low carbon footprint. In addition, these products show high fixation and therefore have a low COD in residual baths, thus also contributing to their sustainability.

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The Potential for REE and Associated Critical Metals in Karstic Bauxites and Bauxite Residue of Montenegro

Minerals ◽

10.3390/min11090975 ◽

2021 ◽

Vol 11 (9) ◽

pp. 975

Author(s):

Slobodan Radusinović ◽

Argyrios Papadopoulos

Keyword(s):

Raw Materials ◽

Bauxite Residue ◽

Raw Material ◽

Late Triassic ◽

Critical Metals ◽

Critical Elements ◽

Secondary Raw Material ◽

Increasing Demand ◽

First Time ◽

Critical Raw Materials

Research for critical raw materials is of special interest, due to their increasing demand, opulence of applications and shortage of supply. Bauxites, or bauxite residue after alumina extraction can be sources of critical raw materials (CRMs) due to their content of rare earth elements and other critical elements. Montenegrin bauxites and bauxite residue (red mud) are investigated for their mineralogy and geochemistry. The study of the CRM’s potential of the Montenegrin bauxite residue after the application of Bayer process, is performed for the first time. Montenegrin bauxites, (Jurassic bauxites from the Vojnik-Maganik and Prekornica ore regions from the Early Jurassic, Middle Jurassic-Oxfordian and Late Triassic paleorelief) are promising for their REE’s content (around 1000 ppm of ΣREE’s). More specifically, they are especially enriched in LREEs compared to HREEs. Regarding other CRMs and other elements, Ti, V, Zr, Nb, Sr and Ga could also be promising. In bauxite residue, the contents of Zr, Sr, V, Sc, La, Ce, Y, Ti and Nb are higher than those in bauxites. However, raw bauxites and bauxite residue as a secondary raw material can be considered as possible sources of CRMs.

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Selective Scandium (Sc) Extraction from Bauxite Residue (Red Mud) Obtained by Alkali Fusion-Leaching Method

Materials ◽

10.3390/ma15020433 ◽

2022 ◽

Vol 15 (2) ◽

pp. 433

Author(s):

Andrei Shoppert ◽

Irina Loginova ◽

Julia Napol’skikh ◽

Aleksey Kyrchikov ◽

Leonid Chaikin ◽

...

Keyword(s):

Red Mud ◽

Inductively Coupled Plasma ◽

Bauxite Residue ◽

Product Layer ◽

Raw Material ◽

X Ray ◽

Inductively Coupled ◽

Leaching Process ◽

Alkali Fusion ◽

Shrinking Core

Bauxite residue, known as “red mud,” is a potential raw material for extracting rare-earth elements (REEs). The main REEs (Sc, Y, La, Ce, Nd, Nb, and Sm) from the raw bauxite are concentrated in RM after the Bayer leaching process. The earlier worldwide studies were focused on the scandium (Sc) extraction from RM by concentrated acids to enhance the extraction degree. This leads to the dissolution of major oxides (Fe2O3 and Al2O3) from RM. This article studies the possibility of selective Sc extraction from alkali fusion red mud (RMF) by diluted nitric acid (HNO3) leaching at pH ≥ 2 to prevent co-dissolution of Fe2O3. RMF samples were analyzed by X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), electron probe microanalysis (EPMA), and inductively coupled plasma mass spectrometry (ICP-MS). It was revealed that Sc concentration in RMF can reach up to 140–150 mg kg−1. Sc extraction was 71.2% at RMF leaching by HNO3 at pH 2 and 80 °C during 90 min. The leaching solution contained 8 mg L−1 Sc and a high amount of other REEs in the presence of relatively low concentrations of impurity elements such as Fe, Al, Ti, Ca, etc. The kinetic analysis of experimental data by the shrinking core model showed that Sc leaching process is limited by the interfacial diffusion and the diffusion through the product layer. The apparent activation energy (Ea) was 19.5 kJ/mol. The linear dependence of Sc extraction on magnesium (Mg) extraction was revealed. According to EPMA of RMF, Sc is associated with iron minerals rather than Mg. This allows us to conclude that Mg acts as a leaching agent for the extraction of Sc presented in the RMF in an ion-exchangeable phase.

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The Effect of Time and H2O/CTAB Ratio in Synthesis of Mesoporous Alumina from Bauxite Residue

Malaysian Journal of Fundamental and Applied Sciences ◽

10.11113/mjfas.v15n2019.1003 ◽

2019 ◽

Vol 15 (1) ◽

pp. 93-98

Author(s):

Omita Riski ◽

Didik Prasetyoko ◽

Dwi Kumala Febrianti ◽

Yatim Lailun Nikmah ◽

Vita Nur Iftitahiyah ◽

...

Keyword(s):

Surface Acidity ◽

Bauxite Residue ◽

Textural Properties ◽

Mesoporous Alumina ◽

Raw Material ◽

Molar Ratio ◽

Crystallization Time ◽

Irregular Shapes ◽

Sem Micrograph ◽

Adsorption Desorption

Mesoporous alumina has been successfully synthesized from bauxite residues (red mud) as raw material and cetyltrimethylammonium bromide (CTAB) as template at room temperature. The effects of crystallization time and molar ratio of H2O/CTAB on structural and textural properties of mesoporous alumina were investigated. The synthesized product was characterized by XRD, FTIR, SEM-EDX, TEM, N2 adsorption-desorption and acidity test using pyridine adsorption. The XRD pattern and SEM micrograph showed that the synthesized product possessed an amorphous phase and irregular shapes. From obtained results, it could be observed that crystallization time and H2O/CTAB ratio influenced the surface acidity of mesoporous alumina.

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Potential of Briquette Produced with Torrefied Agroforestry Biomass to Generate Energy

Forests ◽

10.3390/f11121272 ◽

2020 ◽

Vol 11 (12) ◽

pp. 1272

Author(s):

Gabriel Reis Portilho ◽

Vinicius Resende de Castro ◽

Angélica de Cássia Oliveira Carneiro ◽

José Cola Zanuncio ◽

Antonio José Vinha Zanuncio ◽

...

Keyword(s):

Energy Density ◽

Sugarcane Bagasse ◽

Compaction Pressure ◽

Calorific Value ◽

High Energy ◽

Raw Material ◽

High Energy Density ◽

Fixed Carbon ◽

Volatile Material ◽

Material Content

Agroforestry industries, such as sugar-alcohol, food, and logging, produce large quantities of waste, used to generate energy from direct burning. The application of other processes, such as torrefaction and briquetting, can increase the profits from the use of agro-industrial waste for energy generation. Briquetting is an alternative for using these wastes, allowing the compaction of the biomass, generating a biofuel with high energy density, and which is more homogeneous and easier to store and transport. The objective of this study was to evaluate the physical and chemical properties of four biomass types (wastes from sawed eucalypt and pine wood, coffee pruning wastes, and sugarcane bagasse) torrefied at 300 °C and compacted (briquetting) at pressures of 6.21, 8.27, and 10.34 MPa. The torrefaction increased the fixed carbon content, ash, and calorific value, and reduced the volatile material content and hygroscopic equilibrium moisture of the biomasses. The volatile material content was lower and the fixed carbon higher in the coffee pruning waste, the ash content higher in the sugarcane bagasse, and the calorific value higher in the pine and eucalypt wood. The briquetting and the torrefaction processes increased the biomass bulk density, and the useful calorific value, respectively, and consequently the energy density of the briquettes produced with torrefied raw material under high pressure. The mechanical properties of the briquettes produced with all materials increased with the compaction pressure. Torrefaction and briquetting increased the energy potential of the biomasses evaluated to produce energy from clean technology.

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Effects of Raw Material Content on Efficiency of TiN Synthesized by Reactive Ball Milling Ti and Urea

Chinese Physics Letters ◽

10.1088/0256-307x/26/7/078102 ◽

2009 ◽

Vol 26 (7) ◽

pp. 078102 ◽

Cited By ~ 4

Author(s):

Sun Jin-Feng ◽

Li Xiao-Pu ◽

Liang Bao-Yan ◽

Zhao Yu-Cheng ◽

Wang Ming-Zhi

Keyword(s):

Ball Milling ◽

Raw Material ◽

Material Content

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Diseño de un sistema de inventario computarizado para la rastreabilidad de partes reutilizables

Revista de Ingeniería Industrial ◽

10.35429/jie.2019.9.3.18.25 ◽

2019 ◽

pp. 18-25

Author(s):

Daniel Acosta-Hernandez ◽

Jorge De La Riva-Rodriguez ◽

Arturo Woocay-Prieto ◽

Rosa María Reyes-Martínez

Keyword(s):

The Other ◽

Raw Material ◽

Development Cost ◽

Manufacturing Costs ◽

It Impacts ◽

Considerable Impact ◽

Storage Area ◽

Production Areas ◽

Computerized System ◽

Inputs And Outputs

This article presents the design of a computerized system for the traceability and reuse of pieces, where it impacts on the reduction of manufacturing costs, contributing to the decrease in the consumption of natural resources. The components to be reused are recovered from a complete used equipment, starting from a list of all its parts. The system facilitates the traceability of the components that need to be recovered, reducing the time of location and supplying parts to the production areas. In addition, it avoids the saturation in the warehouse area of parts that are not required. This system will have data in real time and concise on the inputs and outputs of raw material, speeding up the reception of equipment, making the capture of input inventory. As a result, it will lead to better production planning, increasing the recovery rates of the required components, making the most of the storage area, decreasing equipment unloading times. In addition, it will allow a better costing of inputs and outputs of the company. On the other hand, the software development cost was minimal, and could have a considerable impact on the profits of the industry, ecology and the economy where it is implemented.

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