Binding of vapour-phase mercury (Hg0) on chemically treated bauxite residues (red mud)

2008 ◽  
Vol 5 (4) ◽  
pp. 281 ◽  
Author(s):  
Nick D. Hutson ◽  
Brian C. Attwood
Keyword(s):  
Red Mud ◽  
Waste Product ◽  
Bauxite Residue ◽  
Anthropogenic Sources ◽  
Great Effort ◽  
Entrained Flow ◽  
Mercury Capture ◽  
Sorbent Materials ◽  
Control Technologies ◽  
Flow Experiments

Environmental context. Mercury (Hg) is a toxic, persistent pollutant that accumulates in the food chain. Atmospheric Hg is a global problem with many sources of emissions, of which anthropogenic sources are estimated to account for approximately one-third. Stationary combustion (coal combustion, municipal waste incinerators, etc.) are the largest worldwide sources of anthropogenic Hg emissions, and great effort has been taken to develop control technologies for capture of mercury from these sources. In the present study, Hg capture using bauxite residue (red mud) – a waste product from the aluminium industry – is evaluated and compared with other, more conventional sorbent materials. Abstract. The development and testing of novel control technologies and advanced adsorbent materials continue to be active areas of research. In the present study, Hg capture using adsorbent material derived from the bauxite residue (red mud) from two North American refineries was studied. The red mud, seawater-neutralised red mud, and acid-treated red mud were evaluated for their mercury adsorption capacity and compared with other, more conventional sorbent materials. Two different seawater-neutralised red mud (Bauxsol) samples were treated with HCl and HBr in an effort to increase the mercury sorption capacity. In all cases, the acid treatment resulted in a significant increase in the total surface area and an increase in the total pore volume. The fixed-bed mercury capture experimental results showed that the HBr activation treatment was very effective at increasing the mercury capture performance of both Bauxsol samples whereas the HCl treatment had no effect on the mercury capture performance. Entrained-flow experiments revealed that the Br-Bauxsol was not effective for in-flight mercury capture. This indicates that the mechanism of mercury capture is likely mass-transfer-limited in the entrained-flow experiments.

The liming effect of bauxite processing residue (red mud) on sandy soils

Soil Research ◽  
2004 ◽  
Vol 42 (3) ◽  
pp. 321 ◽  
Author(s):  
K. E. Snars ◽  
R. J. Gilkes ◽  
M. T. F. Wong
Keyword(s):  
Red Mud ◽  
Waste Product ◽  
Bauxite Residue ◽  
Sandy Soils ◽  
Titration Curves ◽  
Incubation Experiments ◽  
Soil Liming ◽  
Red Muds ◽  
P Leaching ◽  
Water Repellence

Bauxite residue (red mud) is produced in large amounts in alumina refineries as a waste product of the Bayer process. This material has the potential to be used as a soil liming agent due to its high pH and high acid neutralisation capacity. Soil incubation experiments compared red mud from several Australian and overseas refineries to estimate its liming effect relative to lime (CaCO3). Two acid (pH 4.3, 4.6) sandy soils were mixed with 8 rates of 17 red muds, 3 limes, and NaOH. Values of EC and pH were measured at 1, 4, and 16 weeks incubation. Each red mud produced a different buffering curve when added to soil, although the shapes of curves could be classified into 5 behavioural groups. The liming equivalent of red mud decreased with increasing target soil pH. For a target pH of 6 the lime equivalent of the red muds was 11–42% for soil 1 and 13–50% for soil 2. No single characteristic of red mud could be used to accurately predict the liming equivalent, as its liming effect is due to several, variable constituents (e.g. free caustic, sodalite, calcite). The pH reached for a certain rate of addition of red mud to soil can be estimated from a comparison of the buffering (titration) curves of both the soil and the red mud. In every case, CaCO3 had a much larger liming capacity than red mud and red mud may not be an economical alternative to lime except where other benefits are associated with its use (e.g. lower cost, decreased P leaching, reduced water repellence).

Biotechnological trends and market impact on the recovery of rare earth elements from bauxite residue (red mud) – A review

2021 ◽  
Vol 171 ◽  
pp. 105645
Author(s):  
Sandeep Panda ◽  
Rachel Biancalana Costa ◽  
Syed Sikandar Shah ◽  
Srabani Mishra ◽  
Denise Bevilaqua ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Red Mud ◽  
Bauxite Residue ◽  
Market Impact

scholarly journals An Alternative to Clay in Building Materials: Red Mud Sintering Using Fly Ash via Taguchi’s Methodology

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Suchita Rai ◽  
Dilip H. Lataye ◽  
M. J. Chaddha ◽  
R. S. Mishra ◽  
P. Mahendiran ◽  
...  
Keyword(s):  
Fly Ash ◽  
Construction Industry ◽  
Red Mud ◽  
Morphological Analysis ◽  
Building Materials ◽  
Sintering Temperature ◽  
Bauxite Residue ◽  
Significant Parameter ◽  
Alkaline Waste ◽  
Free Caustic Soda

“Red mud” or “bauxite residue” is a highly alkaline waste generated from alumina refinery with a pH of 10.5–12.5 which poses serious environmental problems. Neutralization or its treatment by sintering in presence of additives is one of the methods for overcoming the caustic problem as it fixes nearly all the leachable free caustic soda present in red mud. In the present study, feasibility of reducing the alkaline nature of red mud by sintering using fly ash as an additive via Taguchi methodology and its use for brick production, as an alternative to clay, is investigated. The analysis of variance (ANOVA) shows that sintering temperature is the most significant parameter in the process. A pH of 8.9 was obtained at 25–50% of red mud and 50–75% fly ash with water and temperature of . Alternatively 50% of red mud can be mixed with 50% of fly ash with water at temperature of to get a pH of about 8.4. The mechanism of this process has been explained with also emphasis on chemical, mineralogical, and morphological analysis of the sintered red mud. The results would be extremely useful in utilization of red mud in building and construction industry.

Deactivation of Red Mud by Primary Aluminum Production Wastes

2021 ◽  
Vol 1040 ◽  
pp. 109-116
Author(s):  
V.Yu. Piirainen ◽  
A.A. Barinkova ◽  
V.N. Starovoytov ◽  
V.M. Barinkov
Keyword(s):  
Carbon Dioxide ◽  
Red Mud ◽  
Negative Impact ◽  
Waste Product ◽  
Primary Aluminum ◽  
Raw Material ◽  
Aluminum Production ◽  
Environmentally Safe ◽  
Primary Aluminum Production ◽  
Knowledge Intensive

Current global environmental challenges and, above all, global warming associated with a change in the carbon balance in the atmosphere has led to the need for urgent and rapid search for ways to reduce greenhouse gas emissions into the atmosphere, which primarily include carbon dioxide as a by-product of human activity and technological progress. One of these ways is the creation of industries with a complete cycle of turnover of carbon dioxide. Aluminum is the most sought-after nonferrous metal in the world, but its production is not environmentally safe, so it constantly requires the development of knowledge-intensive technologies to improve the technological process of cleaning and disposal of production waste, primarily harmful emissions into the atmosphere. Another environmental problem related to aluminum production is the formation and accumulation in mud lagoon of huge amounts of so-called highly alkaline "red mud," which is a waste product of natural bauxite raw material processing into alumina - the feedstock for aluminum production. Commonly known resources and technological methods of neutralizing red mud and working with it as ore materials for further extraction of useful components are still not used because of their low productivity and cost-effectiveness. This article describes the negative impact of waste in the form of "red" mud and carbon dioxide of primary aluminum production on the environment. The results showed that thanks to carbonization of red mud using carbon dioxide, it is possible to achieve rapid curing and its compact formation for safer transportation and storage until further use. Strength tests of concrete samples filled with deactivated red mud were also carried out, which showed the prospects of using concrete with magnesia binder.

scholarly journals Red Mud-Blast Furnace Slag-Based Alkali-Activated Materials

2021 ◽  
Vol 13 (20) ◽  
pp. 11298
Author(s):  
Alessio Occhicone ◽  
Mira Vukčević ◽  
Ivana Bosković ◽  
Claudio Ferone
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Red Mud ◽  
Blast Furnace Slag ◽  
Bauxite Residue ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Waste Products ◽  
Furnace Slag ◽  
Alkali Activated

The aluminum Bayer production process is widespread all over the world. One of the waste products of the Bayer process is a basic aluminosilicate bauxite residue called red mud. The aluminosilicate nature of red mud makes it suitable as a precursor for alkali-activated materials. In this work, red mud was mixed with different percentages of blast furnace slag and then activated by sodium silicate solution at different SiO2/Na2O ratios. Obtained samples were characterized by chemical–physical analyses and compressive strength determination. Very high values of compressive strength, up to 50 MPa, even for high percentage of red mud in the raw mixture (70 wt.% of RM in powder mixture), were obtained. In particular, the higher compressive strength was measured for cubic samples containing 50 wt.% of RM, which showed a value above 70 MPa. The obtained mixtures were characterized by no or scarce environmental impact and could be used in the construction industry as an alternative to cementitious and ceramic materials.

scholarly journals A Study of the Potential Use of Red Mud to Obtain Compositions Based on Portland Cement

2020 ◽  
Author(s):  
Ekaterina Gerasimova ◽  
Elizaveta Gumirova
Keyword(s):  
Portland Cement ◽  
Red Mud ◽  
Waste Product ◽  
Cement Stone ◽  
Mathematical Planning ◽  
Alumina Production ◽  
Mineral Additive ◽  
Composition Properties ◽  
Planning Of Experiments ◽  
Potential Use

The paper deals with the problem of utilization of red mud which is a waste product from alumina production using the Bayer method. The principal possible use for the red mud of JSC “Bogoslovsky aluminum plant” (Sverdlovsk region) for the compositions based on Portland cement is shown. It was found that the mud introduction accelerates beginning of the cement paste setting and thickens the paste reducing its mobility. It is concluded that the introduction of red mud up to 30 % is justified in terms of strength indicators. The work is carried out using mathematical planning of experiments. Keywords: red mud, Portland cement, active mineral additive, composition, properties, bauxite, chemical composition, cement stone strength, mathematical planning of experiments

Red Mud (RM) and Soil Amelioration

2019 ◽  
pp. 151-167 ◽  
Author(s):  
Amit Kumar
Keyword(s):  
Red Mud ◽  
Sodium Hydroxide Solution ◽  
Bauxite Residue ◽  
Acid Soils ◽  
Large Area ◽  
Vegetation Growth ◽  
Ground Water Pollution ◽  
Trace Metal Content ◽  
Rich Material ◽  
Ph Range

Rapid growth in industrialization, which is necessary and inevitable for society progress, has also created negative encroachment. Red mud produced during alumina production has strong alkanity in a pH range of 10-13% because of the sodium hydroxide solution used in the refining process. The base is strong enough to kill plant and animal life, and due to finer particle and trace metal content, it creates soil contamination, ground water pollution, and suspension in ocean; hence, we need precautions while we use this waste to add with soil. Red mud occupies a large area or its deposition in it. Red mud has properties similar to sandy clay. Red mud has property similar to clay and sand, even if it does not contain quartz or clay mineral. Bauxite residue/red mud can be mixed with variant type of saline soils, acid soils organic rich material, and silicate soil suitable pH conditions were achieved to promote vegetation growth.

Cost Analysis as a Tool for the Development of Sc Recovery Processes from Bauxite Residue (Red Mud)

2018 ◽  
Vol 6 (4) ◽  
pp. 5333-5341 ◽  
Author(s):  
Remya P. Narayanan ◽  
Liang-Chih Ma ◽  
Nikolaos K. Kazantzis ◽  
Marion H. Emmert
Keyword(s):  
Cost Analysis ◽  
Red Mud ◽  
Bauxite Residue ◽  
Recovery Processes
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