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).

scholarly journals Hydrocarbon-Contamination of Soils: The Potential of Sodium Clays to Decelerate Soil Toxicants

2016 ◽  
Vol 8 (11) ◽  
pp. 193
Author(s):  
Mark Anglin Harris
Keyword(s):  
Red Mud ◽  
Spreading Rate ◽  
Hydrocarbon Contamination ◽  
Polluted Soils ◽  
Inorganic Particles ◽  
Clay Particles ◽  
Contamination Of Soils ◽  
Red Muds ◽  
Constant Head ◽  
Water Repellence

<p>Hydrocarbon-contamination can change hydraulic conductivity (HC) in soils, and hence increase the spreading rate of aqueous toxicants in the ground. A constant head permeameter used in the laboratory to measure HC of soils taken from near the Pitch Lake in Trinidad determined that the HC exceeded that of a reference soil having “normal HC” for a loam. Although water moved rapidly through it, the Pitch Lake soil (PLS) remained dry due to water repellence. Treatment consisted of either of two red mud bauxite wastes mixed at 25 and 50% w/w with PLS at air dry. One of the bauxite wastes had undergone treatment with gypsum several years before and hence contained a greater proportion of calcium ions compared to the other red mud which contained more sodium ions. At 25% w/w the non-gypsum-treated red mud waste decreased HC of the PLS by 50%, and at 50% w/w caused a 10-fold decrease of HC on the PLS. The gypsum-treated red mud waste had no effect on the HC of the PLS. The drastic decrease in HC of the hydrocarbon-contaminated soil implies blocking of hydraulic channels by inorganic particles. The high levels of Na<sup>+</sup> released in the Bayer beneficiation process dispersed and released fine &lt; 5 mµ clay particles from the non-gypsum-treated red muds. This suggests that the rapid movement of aqueous pollutants in such hydrocarbon-polluted soils could be similarly curtailed under field conditions.</p>

Possibility of using caustic residue from bauxite for improving the chemical and physical properties of sandy soils

1982 ◽  
Vol 33 (2) ◽  
pp. 275 ◽  
Author(s):  
NJ Barrow
Keyword(s):  
Physical Properties ◽  
Coastal Plain ◽  
Red Mud ◽  
Sodium Sulfate ◽  
Waste Product ◽  
Chemical Properties ◽  
Sandy Soils ◽  
Exchange Capacity ◽  
Good Growth ◽  
Western Australian

Large quantities of alkaline red mud are produced as a waste product from the extraction of alumina from bauxite. Its chemical and physical properties and the way that it could be modified to produce good growth of plants were investigated. The cation exchange capacity of the red mud increased with pH, the adsorption of phosphate decreased, and the adsorption of cadmium increased. A pH of just above eight seemed to provide a good combination of desirable properties. This could be achieved by exposing the red mud to air and mixing it with gypsum - also available as a waste product. Carbon dioxide was absorbed by alkaIi in the red mud, and then precipitated by the gypsum as calcium carbonate. This released sodium sulfate which could be leached from the mud. Medic species could then be grown, provided that phosphate, potassium and manganese were supplied. Residual sodium sulfate from incomplete leaching seemed to limit the growth of other species. There seemed to be a potential to use the amended red mud to improve the waterholding properties and the chemical properties of sandy soils of the Western Australian coastal plain.

Effect of application of bauxite residue (red mud) to very sandy soils on subterranean clover yield and P response

Soil Research ◽  
2001 ◽  
Vol 39 (5) ◽  
pp. 979 ◽  
Author(s):  
R. N. Summers ◽  
M. D. A. Bolland ◽  
M. F. Clarke
Keyword(s):  
Soil Ph ◽  
Red Mud ◽  
Close Contact ◽  
Bauxite Residue ◽  
Maximum Yield ◽  
Sandy Soils ◽  
Subterranean Clover ◽  
Yield Response ◽  
Lime Treatment ◽  
Pasture Production

Bauxite residue (red mud) is the byproduct from treatment of crushed bauxite with caustic soda to produce alumina. When dried the residue is alkaline and has a high capacity to retain phosphorus (P). The residue is added to pastures on acidic sandy soils to increase the capacity of the soils to retain P so as to reduce leaching of P into waterways and so reduce eutrophication of the waterways. This paper examines how red mud influences the effectiveness of P from single superphosphate for producing subterranean clover (Trifolium subterraneum) dry herbage, in the year of application and in the years after application (residual value). Red mud was applied at 0, 2, 5, 10, 20, and 40 t/ha and the P was applied at 0, 5, 10, 20, 40, 80, and 160 kg P/ha. In the year of application and the year after application of red mud, dry matter yields were doubled on the soil treated with 20 t/ha of red mud compared with the untreated control. Improvements in production were initially greater in the red mud treatments than in the lime treatment (2 t lime/ha). Red mud increased the maximum yield plateau for P applied in current and previous years. When P was applied to freshly applied red mud, more P needed to be applied to produce the same yield as the amount of red mud applied increased. Red mud increased soil pH, and the increases in yield are attributed to removing low soil pH as a constraint to pasture production. This initial need for higher amounts of fertiliser P when increasing amounts of red mud were applied may be due to increased P sorption caused by increased precipitation of applied P when the fertiliser was in close contact with the freshly alkaline red mud. When P was freshly applied to red mud that had been applied to the soil 12 months ago, yield response and P content increased. This was attributed to the reduction in sorption of P due to red mud being neutralised by the soil and because sorption of P already present in the soil reduced the capacity of the red mud to sorb freshly applied fertiliser P. Residues of P in the soil and pH were also increased with application of red mud. In the years after application of red mud and lime, relative to P applied to nil red mud and nil lime treatment, the effectiveness of fertiliser P applied to the red mud and lime treatments increased. This was so as determined using plant yield, P concentration in plant tissue, and soil P test.

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.

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.

Conversion of Red Muds into Pozzolans

1991 ◽  
Vol 245 ◽  
Author(s):  
Jean Pera
Keyword(s):  
Red Mud ◽  
Mineralogical Composition ◽  
Waste Materials ◽  
Strength Development ◽  
Blended Cements ◽  
Temperature Range ◽  
Lime Consumption ◽  
Red Muds ◽  
Mineralogical Compositions

ABSTRACTRed muds are waste materials obtained from the aluminium extraction industry. They consist mainly of clays, aluminium and iron hydrated oxides. Three muds were studied; they differed in chemical and mineralogical compositions. They were converted into reactive pozzolans by calcination in the temperature range 600–800°C for five hours. Pozzolanicity was investigated on calcined red mud-OPC mixes studying strength development and lime consumption as evaluated by DTA. The nature of hydrates formed during hardening was also identified.The mineralogical composition of the mud is the most important factor affecting its pozzolanicity. Blended cements containing 30% calcined red mud develop significant strengths.

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.

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