Bauxite potential of guinea whatever concepts and definitions used, it appears from all studies that guinea is the country the most endowed with bauxite in the world. Initially, the residue is washed, to extract as much valuable caustic soda and dissolved alumina as possible. Researchers from csiros mineral resources flagship have developed a process that lowers the cost of refining bauxite aluminium ore to alumina aluminium oxide by treating the waste product generatedred mudto recover a costly ingredient, caustic soda. Red mud in an liquid state causes harmful effects to human skin. Grey mud as a product overcomes certain implementation barriers in which red mud struggles, i. Bauxite residue is the ironoxide rich mine waste from the processing of bauxite ore for the extraction of alumina through the bayer process. Red mud or red sludge is a solid waste product of the bayer process, the principal industrial means of refining. Chemical analysis shows that red mud contains silicon, aluminum, iron, calcium, titanium, sodium as well as an array of minor elements namely k, cr, v, ba, cu, mn, pb, zn, p, f, s. Red mud is a waste material derived as residual from the bayer process by the caustic digestion of crushed bauxite at elevated temperature. Generally ferric oxide is the major constituent of red mud and gives it its characteristic brick red colour. Ncu scientist points to recognised solution for alumina dumps. Red mud rm is a solid waste byproduced formed after alumina production from bauxite following the bayer process. Thus, in this work, the modeling of the bauxite processing process to reduce quantity of red mud produced and with low alumina content was envisaged. Depending on the quality of bauxite, the quantity of red mud generated varies from 55 to 65% of the.
This letter is an invitation to the 2nd bauxite residue valorisation and best practices conference that will take place in athens, may 2018. In addition to iron, the other dominant components include silica, unleached residual alumina, titanium oxide, and caustic. The effects of composition proportions of lime, red mud, fly ash, bauxite and gypsum, firing temperature and duration on the properties of cements produced were studied in detail. Decreasing yield and alumina content of red mud by. Fe 2 o 3 2060 wt%, al 2 o 3 1030 wt%, sio 2 0220 wt%, tio 2 028 wt%, na 2 o 210 wt% and cao 28 wt%. Red mud direction volume note 1 sintering combined process building and construction materials 200250 kta use red mud directly 2 high iron red mud from gibbsite and diaspore building materials bricks 0 kta use the sand separated from red mud cement 800 kta iron ore separated from red mud. Preparation of special cements from red mud journal article. Red mud is produced during the bayer process for alumina production. Dr mark harris has a tried and proven formula that could transform the islands potentially harmful bauxitealumina red mud. Methods for utilization of red mud and its management. These trace elements are characterized at the ppm level, i. Its composition depends upon its parent material from which it is produced liu and wu, 2012. Red mud is toxic for the environment due to high alkalinity, salinity and trace metals.
The chemical composition of the two kinds of red mud determined by xrf analyzer is given in table 1. Successes and challenges in the management and use of bauxite residue ken evans iai consultant october 2015. Red mud rm is a byproduct of extracting of alumina from bauxite. Bauxite processors recycle the caustic soda and pump the residual red sludge into huge settling ponds. The bayer process uses caustic soda, high pressure, and high temperature to leach alumina from ferruginous residue slurry bauxite residue or red mud. More than 120 million tons of rm is generated annually all over the world and about 4 million tons is in india. Pdf neutralization and utilization of red mud for its. The only difference in the operations generating the two varieties of mud is that red muds at alcoa bauxite are sintered and leached to recover. Unfortunately, for each ton of aluminum produced, around 12 tons of red mud are also produced, creating a massive amount of industrial waste to manage.
Efthymios balomenos, studied mining and metallurgical engineering at national technical university of athens and received his phd degree in thermodynamics in the same school in 2006. Recovery of al2o3, fe2o3 and tio2 from bauxite processing. In addition to iron, the other dominant components include silica, unleached residual alumina, and titanium oxide. Bauxite is not a mineral, but rather a group of aluminum oxides. Apr 06, 2018 an emerging technology has the potential to turn toxic red mud into useful soil, combatting the expensive rehabilitation of red mud dams across australia. Chemical composition of red mud generated in alumina plants in various countries. Table 1 chemical composition range % for bauxite residue for main components. The composition, recycling and utilisation of bayer red mud. New technologies to rehabilitate dams into useful land. The disposal of red mud leads to a serious environmental threat because of its tiny particle size and high alkaline value. In some plants, red muds are further processed to produce aluminum oxides.
Red mud tanrai alumina processing plant contains a big content of oxides, such as. Red mud is a toxic byproduct of the industrial process that refines bauxite, raw aluminum ore, into aluminum oxide, or alumina. Bauxite residue generation balance between aluminous content of the bauxite, type of aluminium containing compound, local energy cost, transport cost, silica content reactive more important than crystalline when plants located very distant from the bauxite source, they tend to use high alumina bauxite. Preparation and characterization of red mud derived from. Composition and properties of red mud in the world have been presented by many researchers in their publications. The red mud waste dries to a very fine, powdery solid and contains significant amounts of iron, aluminum, calcium and sodium. Phytoremediation of bauxitederived red mud by giant reed. However, the production of alumina from bauxite is associated with serious environmental problems. Iron is a major constituent in most of the worlds reserves of bauxite residue 3 billion tons.
Mineral compositionof the red mud depends on the mineral composition of the source material bauxite. Summer school zerowaste valorisation of bauxite residue red mud summer school 2931 august 2016, leuven, belgium. The red colour arises from iron oxides, which comprise up to 60% of the mass. The high concentration of iron compounds in the bauxite gives the byproduct its characteristic red colour, and hence its common name red mud. A major challenge going forward is to reconcile mans activities on earth with the key pillars of environmental stewardship, sustainability and safeguarding life forms. This applies not least in the manufacturing industries and one example from the global aluminium sector is the issue of bauxite residue otherwise termed red mud. Pdf chapter 2 red mud polymer composites in red mud. Red mud is a byproduct of aluminum production, in which alumina is extracted from bauxite ore via the bayer process. Lancashire, bauxite and aluminium production, education in chemistry, may 1982, pps 6264. Jul 08, 2003 red mud is a byproduct of bauxite processing via the bayer process. As the percentage of silica increases so does the amount of red mud. We would be honoured if you would like to be part of it and help us collectively organise a conference that will be successful. A typical chemical composition is shown in table 1 and a typical mineralogical composition is shown in table 2. Red mud production, composition and impact, publisher.
Particle size distribution in red mud showed a fine physical texture of solid sludge. Johannes vind goes in search of the sources of red mud. Making the most of red mud february 24, 2014 issue vol. Red mud is the caustic material left over after aluminum is extracted from bauxite.
The fifth facility, alcoa in bauxite, arkansas, generates a residual that is different in color and is commonly called brown mud. Grey mud composition is affected by the modelling of both the solidification of the slag and the leaching operations. Red mud project site dedicated on the valorisation and. The output, composition and characteristics of red mud vary with the type of bauxite and the. Dealing with red mud by product of the bayer process for. However, a lot of ironrich bauxite and bayer red mud resources have not been timely and effectively recycled, resulting in serious problems of environmental pollution and wastage of resources. As to the recovery of valuable metals from ironrich bauxite and red mud, there are a lot. The actual composition of red mud depends on the type of bauxite, the mining location and the process parameters of the bayer process40. The aluminum mineral bauxite information and pictures. The jbi labs analyses a range of sampletypes for chemical and mineralogical composition for a fee eg. Described herein is a process that converts the red mud into mineral products that can be used for commercial applications. The chemical composition of the red mud samples expressed as distribution of oxides. Br 2018 conference red mud bauxite residue valorisation and best practices conference.
Mishra said about four billion tons of the waste material is stored globally in ponds where aluminum production plants are based, primarily in canada, australia, greece, and southeastern united states. The types and concentrations of minerals present in the muds depend on the composition of the ore and processing conditions. Apart from iron oxide, other primary substances within red mud include titanium oxide, residual aluminum oxides, and silica. It is a mixture of hydrous aluminum oxides, aluminum hydroxides, clay minerals, and insoluble materials such as quartz, hematite, magnetite, siderite, and goethite. Bauxite industry in guinea and value opportunities of the. The sodium hydroxide reacts with the aluminous minerals of bauxite to form a saturated solution of sodium aluminate. Therefore, red mud may contain technologically enhanced naturally occurring radioactive material tenorm. Rare earth elements in red mud jamaica bauxite institute. It is the insoluble product after bauxite digestion with sodium hydroxide at elevated temperature and pressure. Alumina is put through a separate process, electrolysis, to make. Unless managed properly, red mud poses significant risks to the local environment due to its extreme alkalinity and its potential impacts on surface and ground water quality. Red mud is the tailings generated from the production process of aluminum industry and is mainly stacked in openair at present, so how to ensure the stability of red mud stockpile is very important.
This variation has been responsible for conflicting reports about the damage caused by dumping red mud at sea. Production figures on bauxite from victoria in australia are available at the national resources and environment website under minerals and petroleum. The best bauxite ores have the highest ratio of alumina to silica and the lowest quality bauxite, vice versa. The exact composition depends on the composition of the original bauxite, but none of the minerals are known to be environmentally hazardous. Red mud is mostly collected from the bayer process which uses sodium hydroxide to dissolve the aluminium silicate.
The specific conditions depend on the quality of bauxite used i. In red mud the total rees composition is known to be approximately 900ppm. The utilization and value addition of iron in red mud is a critical measure for economically valorizing the waste and it eases the process of extracting. It must not damage, indeed should support, individual companies and research teams own innovations and new technologies towards ameliorating red mud retaining diversity and avoid lock in 3 allow the more rapid uptake of adaptive best. Typical chemical composition and metal content of bayer process red mud are. Ree content in red mud has been shown to double as a result of the bayer process11 and this is consistent in both jamaican.
Red mud bauxite residue is a byproduct generated during the bayers processing of bauxite. Alo oh, mixed with the two iron oxides goethite feo oh and haematite fe 2 o 3, the aluminium clay mineral. As the temperature and pressure increases, the solubility of red mud decreases with sodium hydroxide nie et al. The mud is highly basic with a ph ranging from 10 to. Physical and chemical properties of sintering red mud and. Wang and liu, 2012 measured by using xray diffractometer. Chemistry of seawater neutralization of bauxite refinery residues red mud article pdf available in environmental engineering science 212. Also red mud has been used as building materials 3, catalyst 4, inorganic substrate 5, removal agents 68 and absorbent 911, but all these applications use low amounts of generated red mud.
It is a mixture of compounds originally present in the parent mineral, bauxite, and of compounds formed or introduced during the bayer cycle. Red mud is composed of minerals such as hematite, gibbsite, calcite, quartz, goethite, diaspore, rutile, kaolinite, etc. Survey of bauxite resources, alumina industry and the prospects of. Mar 19, 20 bauxite residue is often referred as red mud due to the colour of the bauxite ore and iron oxides. The exact composition of red mud depends on the source of the bauxite and its treatment during production.
Rm is mainly made up of oxides of iron, aluminum, silicon and titanium. Analysis on physical and mechanical properties of red mud. Pdf red mud or bauxite residue is a solid waste generated from. Survey of bauxite resources, alumina industry and the.
Apr 26, 2015 bauxite residue red mud is produced in alumina plants by the bayer process in which alcontaining minerals are dissolved in hot naoh. The appropriate management of bauxite residue is becoming a global environmental concern following increased awareness of the. This red mud, or bauxite residue, represents a significant challenge to the industry due to its highly caustic nature and the. Pdf the composition, recycling and utilisation of bayer red mud. Bauxite, reserve, alumina, red mud, residue, product. The utilization and value addition of iron in redmud is a critical measure for economically valorizing the waste and it eases the process of extracting.
Bauxite residuevalorisationandbestpracticesleuven5 77102015355improved efficiency. This paper describes the basic characteristics and mineral compositions of rm. This paper describes the production and characterization of bauxite and red mud in view of world and indian context. The red mud bauxite residue is the major waste material. Dealing with red mud by product of the bayer process. Thus there is wide variation in chemistry of red mud, as follows. Red mud is composed of a mixture of solid and metallic oxides.
The primary component of red mud is iron oxide which gives the substance its red color. Jan 30, 2016 red mud is a waste product in the reduction of bauxite in the production of aluminium. However, the count depends on the quality of bauxite ore from which alumina is. Bauxite produces 60120 million tons of toxic red mud annually during its processing to alumina. Bauxite tailings, also known as bauxite residue, red mud, red sludge, or alumina refinery residues arr, is a highly alkaline waste product composed mainly of iron oxide that is generated in the industrial production of alumina aluminium oxide, the principal raw material used in the manufacture of aluminium metal and also widely used in the. The term is generally used to describe the economically important mixture of these minerals, which form a mass of the individually classified members of gibbsite, boehmite, and diaspore. In 2017, china was the top producer of aluminium with almost half of the worlds production, followed by russia, canada, and india. Recover iron from bauxite residue red mud iopscience.
The use of red mud as secondary resource to recovery of valuable. Proposal for resources, utilization and processes of red. Bauxite residue generation balance between aluminous content of the bauxite, type of aluminium containing compound, local energy cost, transport cost, silica content reactive more important than crystalline when plants located very distant from the bauxite source, they tend to use high alumina bauxite and high. Meet our keynote speakers br 2018 conference red mud. The global residue inventory reached an estimated 3. Red mud or bauxite residue is a solid waste generated from the bayer process. Red mud rm is a solid waste product obtained from aluminum industries which is reddish brown in color. As a general rule of thumb, processing the best bauxite generates about 2 tons of red mud per ton of alumina. Geotechnical characterization of bauxite residue red mud. There are a lot of utilization method to process red mud, but billion tons of red mud in worldwide should be utilized in an economic and innovative way.
Red mud consists of a mixture of compounds originally present in the parent mineral and those introduced during the bayer process 23,10. Redmud bauxite residue is a byproduct generated during the bayers processing of bauxite. Dec 19, 20 the bayer process for the production of alumina from bauxite ore is characterized by low energy efficiency and it results in the production of significant amounts of dustlike, high alkalinity bauxite residues known as red mud. The advancement and developing of red mud utilization in china. Red mud is a product of the bayer process during the production of alumina hairi et al.
Red mud a hazardous industrial solid waste red mud world. Chemistry of seawater neutralization of bauxite refinery. Red mud is a byproduct of bauxite processing via the bayer process. Characterization and applications of red mud from bauxite. The final red mud contains a residual level of caustic liquid or alkalinity, with a ph of approximately. Bauxite is a sedimentary rock with a relatively high aluminium content. Bauxite residue red mud is a hazardous waste generated from alumina refining industries.
Research has shown that bauxite tailings are made up of a combination of metallic and solid oxides. Bauxite residue, or red mud, is a solid waste produced from the alumina refining of bauxite ore. Red muds from bauxite refining are generated at four facilities. Since 2008 he has been working in the laboratory of metallurgy as a postdoc researcher focusing on sustainable process development, co 2 mitigation strategies, exergy analysis and resource utilization efficiency. Bauxite consists mostly of the aluminium minerals gibbsite al oh 3, boehmite. The chemical and mineralogical composition of red mud depends largely on the nature of bauxite ore and the extraction process. Australia is the largest producer of bauxite, followed by china.
Bauxite residue, also called red mud rm is a waste. Red mud is a hazardous waste generated from alumina refining industries. The production of 1 t of alumina generally results in the creation of 11. Although aluminium demand is rapidly increasing, known reserves of its bauxite ore are sufficient to meet the worldwide demands for aluminium for many centuries. The major chemical composition of red mud for selected countries over the world is presented in table 2. Oct 11, 2012 as red mud is generated by chemical extraction of alumina from bauxite it has typically twice the concentration of natural radionuclides found in bauxite. With the rapid development of iron and steel industry and aluminum industry, highquality iron ore and bauxite resources become increasingly tense.