Mining and Refining – Bauxite Residue Management
Bauxite residue is a by-product of the Bayer Process. It is primarily composed of the insoluble fraction of the bauxite ore that remains after extraction of the aluminium-containing components. Iron oxides (10 – 30%), titanium dioxide (2 – 15%), silicon oxide (5 – 20%) and undissolved alumina (0 – 20%) make up the residue…
Recovery of iron from bauxite residue using advanced ...
In the Bayer process, bauxite is digested with sodium hydroxide solution at high temperature and pressure producing alumina and generating the waste known as ‘red mud’ or ‘bauxite residue’ in large quantity. After the process, the residue which is alkaline in nature has pH of 10.5–13 and is disposed of in red mud ponds.
Local properties of bauxite residue filter cakes - Separation
Nov 24, 2017 · Solid-liquid separation of bauxite residue is a topical issue in the alumina industry, not least due to the great quantity and problematic properties of this highly alkaline residue. The objective of this contribution is to provide deeper knowledge about the solid–liquid separation of pH-adjusted (pH 11) bauxite residue by investigating the local filtration properties of filter cakes produced with a piston press.
Hidden values in bauxite residue (red mud): Recovery of ...
Bauxite residue (red mud) is a hazardous waste generated from alumina refining industries. 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.
THE IMPACT OF DESILICATION PRODUCT ON BAUXITE …
1.2 Bauxite residue fl occulation Achieving rapid solid-liquid separation between digestion and precipitation is critical, given the super-saturated state of the liquors. A large number of studies have sought to identify the causes of poor solid-liquid separation performance from bauxite residue fl occulation. From these it is known that
Sequestration of CO2 in Mixtures of Bauxite Residue and ...
The Carbonation capacity of bauxite residue/brine mixtures was considered over the full range of reactant mixture combinations in 10% increments by volume. A bauxite residue/brine mixture of 90/10 by volume exhibited a CO2 sequestration capacity of greater than 9.5 g/L when exposed to pure CO2 at 20 °C and 0.689 MPa (100 psig).
Recovery of scandium from leachates of Greek bauxite ...
Bauxite residue (red mud) is a waste residue that results from the production of alumina by the Bayer process. Since it has no large-scale industrial application, it is stockpiled in large reservoirs.
Mining and Refining – Process - World Aluminium
The bauxite residue sinks to the bottom of the settling tanks, then is transferred to the washing tanks, where it undergoes a series of washing stages to recover the caustic soda (which is reused in the digestion process). Further separation of the pregnant liquor from the bauxite residue is performed utilising a series of security filters.
Red mud – addressing the problem – Aluminium Insider
In the Bayer process, the alumina and the silicate clays initially dissolve in the caustic soda solution. Sodium in the caustic soda then combines with reactive silica to produce the residue red mud waste, which falls out of the solution taking the sodium with it. The loss of sodium represents a significant cost.
Iron Recovery from Bauxite Residue Through Reductive ...
Bauxite residue; Iron recovery; Magnetic separation; Roasting process Introduction Bauxite is an important ore that is widely used to produce metallurgical-grade alumina (the precursor for aluminum production) and chemical-grade alumina/aluminum hydroxide for many industrial applications through the Bayer process [ 1 ].
Classification of bauxite residue - PROMETIA
S/L separation, S/S separation (fractionation), selective ... • Bauxite residue is a waste of the Bayer process (invented in 1888) which refines bauxite into alumina • Depending on the quality of the bauxite processed, between 1 and 2.5 tonnes of bauxite residue is
Iron Recovery from Bauxite Residue Through Reductive ...
Jun 20, 2018 · The scope of this work is to develop and optimize a reductive roasting process followed by wet magnetic separation for iron recovery from bauxite residue (BR). The aim of the roasting process is the transformation of the nonmagnetic iron phases found in BR (namely hematite and goethite), to magnetic ones such as magnetite, wüstite, and metallic iron.
Recovery of Rare Earths and Other Valuable Metals From ...
Aug 11, 2016 · These complex processes can be divided into three types: (1) smelting of bauxite residue followed by slag leaching, (2) reduction roasting of bauxite residue followed by magnetic separation and water leaching followed by residue leaching, and (3) alumina removal from bauxite residue by leaching or roasting, followed by reduction or smelting and slag leaching (Figs. 8, 9, 10).
Bauxite - Wikipedia
The undissolved waste, bauxite tailings, after the aluminium compounds are extracted contains iron oxides, silica, calcia, titania and some un-reacted alumina. After separation of the residue by filtering, pure gibbsite is precipitated when the liquid is cooled, and …
Reduction of chlorine in bauxite residue by fine particle ...
Solid-liquid separation of bauxite residue is a topical issue in the alumina industry, not least due to the great quantity and problematic properties of this highly alkaline residue.
5 Aluminum Industry - The National Academies Press
Separation processes are an important part of the aluminum manufacturing process. The three basic processes used in making aluminum are the Bayer process, for the conversion of bauxite into alumina, the Hall-Heroult process, for the electrolytic smelting of alumina to aluminum, and the alloying, casting, forging, and fabrication processes for making products.
(PDF) Efficient separation of rare earths recovered by a ...
PDF | Bauxite residue (BR) contains substantial concentrations of rare-earth elements (REEs), but their recovery is a challenge. Acidic BR leachates... | Find, read and cite all the research you ...
World Aluminium — Images — Alumina
Combined heat & power plant, Aughinish alumina refinery, Ireland. Rusal Aughinish