scholarly journals Application of modified red mud in environmentally-benign applications: A review paper

2019 ◽  
Vol 25 (6) ◽  
pp. 795-806 ◽  
Author(s):  
Collin G. Joseph ◽  
Yun Hin Taufiq-Yap ◽  
Vigneswar Krishnan ◽  
Gianluca Li Puma

Red mud (RM) is a waste product that results from bauxite refining via the Bayer process. Its disposal remains an issue which raises significant environmental concerns, particularly if disposed on land or water bodies. Much research has been done on the use of red mud for environmentally-benign applications such as wastewater treatment, catalysis, the production of construction materials and glass ceramics, and for the recovery of metals. This paper reviews the current efforts made in the utilization of red mud as a valuable industrial by-product, which in turn should minimize its harmful impact on the environment. This detailed review compiles and highlights a variety of novel applications of modified red mud as a coagulant, an adsorbent for wastewater treatment, as well as, its use in catalytic processes and in building materials. The physico-chemical properties of red mud can be tuned by a range of treatment methods include acidification, neutralization and heat treatment. As revealed from the literature reviewed, modifications on red mud for the removal of various types of contaminants have shown promising results. However, further amendment and modifications on red mud are needed to utilize this industrial waste in many other industrial applications.

2021 ◽  
Vol 11 (8) ◽  
pp. 3545
Author(s):  
Fernanda Andreola ◽  
Isabella Lancellotti ◽  
Paolo Pozzi ◽  
Luisa Barbieri

This research reports results of eco-compatible building material obtained without natural raw materials. A mixture of sludge from a ceramic wastewater treatment plant and glass cullet from the urban collection was used to obtain high sintered products suitable to be used as covering floor/wall tiles in buildings. The fired samples were tested by water absorption, linear shrinkage, apparent density, and mechanical and chemical properties. Satisfactory results were achieved from densification properties and SEM/XRD analyses showed a compact polycrystalline microstructure with albite and wollastonite embedded in the glassy phase, similar to other commercial glass-ceramics. Besides, the products were obtained with a reduction of 200 °C with respect to the firing temperatures of commercial ones. Additionally, the realized materials were undergone to leaching test following Italian regulation to evaluate the mobility of hazardous ions present into the sludge. The data obtained verified that after thermal treatment the heavy metals were immobilized into the ceramic matrix without further environmental impact for the product use. The results of the research confirm that this valorization of matter using only residues produces glass ceramics high sintered suitable to be used as tile with technological properties similar or higher than commercial ones.


2018 ◽  
Vol 761 ◽  
pp. 181-188
Author(s):  
Ehud Cohen ◽  
Gabriela Bar Nes ◽  
Alva Peled

The main goal of our work is to develop an alternative building material based on “zero waste” objective, thus creating commercially valuable products from materials that are otherwise high-volume waste products. Fine dolomitic quarry dust is a waste product manufactured in several millions of cubic tons each year in the mining industry of Israel. Our study examines a sustainable and useful solution to use this quarry dust (QD) as a part of fly ash based geopolymeric systems. Mechanical, thermal and chemical properties were examined and analyzed.


2013 ◽  
Vol 346 ◽  
pp. 15-21
Author(s):  
Vsévolod A. Mymrin ◽  
Rodrigo E. Catai ◽  
Elena V. Zelinskaya ◽  
Natalia A. Tolmacheva

This paper is devoted to the development of valuable new construction materials based on various ecologically burdensome galvanic wastes, namely industrial sludge from the RENAULT plant and metal cleaning glass waste. The only natural component used is local clay. Both of the wastes need significant financial investment and efforts for neutralization and subsequent disposal while they can be recycled into glass-ceramics or red ceramics (tiles, bricks, blocks, etc.). Mechanical properties of the ceramics of various compositions are as follows: flexion resistances are 4.8-9.2, 7.6-11.5 and 11.1-14.9 MPa (after calcination at 800°C, 850°C and 900°C, respectively); the dilatation coefficient values are normally 6.6 to 9.5% (up to 10% for certain materials); the water absorption values are between 19.7 and 23.9%. These values meet the Brazilian standards for ceramics production. Physicochemical interactions of initial components and new materials structure formation processes have been studied. The XRD data show the formation of new minerals in the process of baking: Na-Anortite (Ca,Na)(Si,Al)4O8, Thenardite Na2SO4, Mullite Al6Si2O13, Tamarugite NaAl (SO4)2 6H2O. Only two minerals are identified both before and after baking: Quartz SiO2 and Hematite Fe2O3. High X-ray background clearly visible on the XRD-pattern is an evidence of a highly amorphous glassy structure resulting from founding processes during the mixtures heating. The SEM and EDS studies of the ceramics strongly confirm the XRD results demonstrating fields of almost glassy morphology within the new material. These new-crystalline and new-amorphous structures can explain all the mechanical and chemical properties of the ceramic materials developed. Leaching and solubility studies of the new ceramics with Atom Absorption Analysis demonstrate that a great excess of heavy metals (Sn, Zn and Ni) from the industrial wastes is decreased in the baked ceramics achieving levels that meet Brazilian sanitary standards.


2021 ◽  
Author(s):  
Juyoung Ha

Nanoparticles are assemblies of atoms in the size range less than 100 nanometers. At these length scales, the properties of particles may deviate significantly from those of the equivalent bulk material indicating that changes in physical and chemical properties of materials depend on the dimensions of the particle. The presence of mineral nanoparticles has been reported in a range of natural environments. Such nanoparticles can arise from a variety of mechanisms, including chemical weathering processes, precipitation from relatively saturated solutions in hydothermal and acid mine drainage environments, evaporation of aqueous solutions in soils, and biological formation by a variety of different microorganisms. Furthermore, recent increased applications of nanoparticles in different types of industries, including construction and building material manufacturing, have caused prevalent occurrences of different types of synthetic nanoparticles in the environment. In this chapter, a comprehensive reviews on occurrences and observations of naturally and anthropogeniccally generated nanoparticles in the environment and their characterization techniques will be discussed along with directions and suggestions for the future research topics and areas for nanomaterials.


The rapid increase of plastics waste produced worldwide today poses a danger to human health because of the pollution caused by the unsafe disposal and non-biodegradability of this waste combined with toxic gas emissions during incineration. Globally, PET (polyethylene terephalate) is commonly used for bottling water and other plastic containers. Recycling the waste would be an additional benefit. This study focuses some researchers on the forms, methods of recycling and various literature applications of PET wastes. Recycled PET can of course be used when combined with the sand aggregate to manufacture of various construction materials, such as tiles, bricks, paving stones etc. This research focuses on its application as it attracts substantial building materials such as the manufacture of various PET waste tiles and their unique mechanical , physical and chemical properties; There are some important studies discussed in relation to PET waste, recycling methods , and results from the study. Even various applications are described here. Its usefulness is further defined as roofing Composite concrete, floor tiling and other applications


2021 ◽  
Vol 13 (22) ◽  
pp. 12741
Author(s):  
Nathália C. G. Silveira ◽  
Maysa L. F. Martins ◽  
Augusto C. S. Bezerra ◽  
Fernando G. S. Araújo

About 120 million tons of red mud is produced worldwide each year. Due to its high basicity and potential leaching, its storage is a critical environmental problem. This material is typically stored in dams, which demands prior care of the disposal area and includes monitoring and maintenance throughout its useful life. Consequently, it is crucial to figure out an industrial solution able to consumes large volumes of this material. At this moment, there are several studies, the majority in metallurgical procedures, building materials, and in the chemical industry, discussing how to reuse red mud. This paper provides a review of the aluminium process, including metal importance, its global production, and the environmental impact due to its manufacture process. It presents a review of the potential application of red mud showing its overall generation, some relevant characterisation results collected from the literature, and its utilisation in diverse areas of engineering. The study aimed to highlight applications where red mud characteristics may be favourable.


2021 ◽  
Vol 36 (2) ◽  
pp. 182-191
Author(s):  
Ljiljana Kljajevic ◽  
Miljana Mirkovic ◽  
Sabina Dolenec ◽  
Katarina Ster ◽  
Mustafa Hadzalic ◽  
...  

The potential re-use of red mud in the building and construction industry has been the subject of research of many scientists. The presented research is a contribution to the potential solution of this environmental issue through the synthesis of potential construction materials based on red mud. A promising way of recycling these secondary raw materials is the synthesis of alkali-activated binders or alkali activated materials. Alkali-activated materials or inorganic binders based on red mud are a new class of materials obtained by activation of inorganic precursors mainly constituted by silica, alumina and low content of calcium oxide. Since red mud contains radioactive elements like 226Ra and 232Th, this may be a problem for its further utilization. The content of naturally occurring radionuclides in manufactured material products with potential application in the building and construction industry is important from the standpoint of radiation protection. Gamma radiation of the primordial radionuclides, 40K and members of the uranium and thorium series, increases the external gamma dose rate. However, more and more precedence is being given to limiting the radiological dose originating from building materials on the population these days. The aim of this research was to investigate the possible influence of alkali activation-polymerization processes on the natural radioactivity of alkali activated materials synthesized by red mud (BOKSIT a. d. Milici, Zvornik, Bosnia and Herzegovina) and their structural properties. This research confirmed that during the polymerization process the natural radioactivity was reduced, and that the process of alkali activation of raw materials has an influence on natural radioactivity of synthesized materials.


2021 ◽  
Vol 3 (1) ◽  
pp. 1-31
Author(s):  
Benjamin Gabriel Poulson ◽  
Qana A. Alsulami ◽  
Abeer Sharfalddin ◽  
Emam. F. El Agammy ◽  
Fouzi Mouffouk ◽  
...  

Due to their unique structural, physical and chemical properties, cyclodextrins and their derivatives have been of great interest to scientists and researchers in both academia and industry for over a century. Many of the industrial applications of cyclodextrins have arisen from their ability to encapsulate, either partially or fully, other molecules, especially organic compounds. Cyclodextrins are non-toxic oligopolymers of glucose that help to increase the solubility of organic compounds with poor aqueous solubility, can mask odors from foul-smelling compounds, and have been widely studied in the area of drug delivery. In this review, we explore the structural and chemical properties of cyclodextrins that give rise to this encapsulation (i.e., the formation of inclusion complexes) ability. This review is unique from others written on this subject because it provides powerful insights into factors that affect cyclodextrin encapsulation. It also examines these insights in great detail. Later, we provide an overview of some industrial applications of cyclodextrins, while emphasizing the role of encapsulation in these applications. We strongly believe that cyclodextrins will continue to garner interest from scientists for many years to come, and that novel applications of cyclodextrins have yet to be discovered.


2017 ◽  
Vol 32 (3) ◽  
pp. 261-266 ◽  
Author(s):  
Snezana Nenadovic ◽  
Gabor Mucsi ◽  
Ljiljana Kljajevic ◽  
Miljana Mirkovic ◽  
Milos Nenadovic ◽  
...  

The main goal of the presented research was the preliminary investigation of possibility of red mud - Hungarian dump sites Almasfuzito (sample A) and Ajka (sample B) - application as a pigment or as a raw material for use in the construction materials industry. Also, the aim of this work was the characterization of red mud as industrial waste generated by the Bayer process in the aluminum industry - which may cause environmental problems if appropriate treatment is not carried out. The main mineral phases of both red mud are hematite (Fe2O3), calcite (CaCO3), gibbsite (Al(OH)3) and they consists of particles of median particle size 2.1 mm (sample A) and 2.5 mm (sample B) and have a characteristic red color, which was the reason for its testing for use in the industry of building materials as a pigment for standard concrete mixtures. The radionuclides content in the samples was determined by gamma spectrometry, and the radiological hazards originating from 238U, 232Th, 40K in the samples, were assessed through the radium equivalent activity, and the external radiation hazard index. The absorbed dose rate and the annual effective dose were calculated in accordance with the UNSCEAR 2010 report and the results are presented in this paper.


2013 ◽  
Vol 11 (2) ◽  
pp. 127-136

This paper deals with the geopolymerization of the red mud generated in the primary aluminium production and the slag generated in the ferronickel production, in order to develop inorganic polymeric materials with advanced mechanical and physical properties. In particular, the effect of the main synthesis parameters of the inorganic polymeric materials on their mechanical strength and water absorption was investigated. Moreover, the structure of the inorganic polymeric materials was studied according to X-ray Diffraction analysis, Fourier Transform Infra Red spectroscopy and Scanning Electronic Microscopy. The inorganic polymeric materials produced by the geopolymerization of the red mud developed compressive strength up to 21 MPa and presented water absorption lower than 3 %, while the geopolymerization of the ferronickel slag resulted in materials with compressive strength higher than 110 MPa and extremely low water absorption (< 1 %). According to these results, the developed materials may be viewed as alternatives in the industrial sectors of construction and building materials.


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