Influence of the pH on the accumulation of phosphate by red mud (a bauxite ore processing waste)

Red Mud is the solid residue generated from Alumina refinery during the process of bauxite ore processing through Bayer’s process. Typical generation of red mud is 1.5 tons of red mud per ton of alumina produced. The disposal and storage of red mud has been a concern for the alumina industry since its inception, more than a hundred years ago. With the increase in alumina production, the magnitude of the problem is getting multiplied. Its alkaline nature (Na2O ~ 3-7%) and fine size make red mud unsuitable for many applications; a limited utilization is reported in cement industries as one of the raw mix components for cement. The present work deals with the utilization of red mud in geopolymer based paving blocks. Alumina, silica and alkali are the essential items required for geopolymer preparation. Having all these in red mud, the current study attempted to use the same in geopolymer based products. The focus has been on bulk utilization of red mud; target strength of 20 MPa after 28 days of curing (M20 grade) has been the goal as this strength is sufficient for many applications. The study focused on optimizing the red mud content, alkali concentration, fly ash content, etc. The samples are tested for its compressive strength and leachability. The study reveals that significant amount of red mud incorporation is possible with products conforming to USEPA 1311 norms.

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Study of sorption processes and FT-IR analysis of arsenate sorbed onto red muds (a bauxite ore processing waste)

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2009.09.145 ◽

2010 ◽

Vol 175 (1-3) ◽

pp. 172-178 ◽

Cited By ~ 55

Author(s):

Paola Castaldi ◽

Margherita Silvetti ◽

Stefano Enzo ◽

Pietro Melis

Keyword(s):

Processing Waste ◽

Ore Processing ◽

Ft Ir ◽

Bauxite Ore ◽

Ir Analysis ◽

Red Muds

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Assessment of Naturally Occurring Radioactive Materials (NORM) in Mining Residues and Environmental Material from Sefwi, Awaso Bauxite Mine

10.21203/rs.3.rs-551561/v1 ◽

2021 ◽

Author(s):

Matjele Moipone ◽

Oscar K. Adukpo ◽

Joseph B. Tandoh

Keyword(s):

Effective Dose ◽

Water Samples ◽

Red Mud ◽

Gamma Ray ◽

Gamma Ray Spectrometry ◽

Activity Levels ◽

Environmental Material ◽

Bauxite Ore ◽

Mining Residues ◽

Bauxite Mine

Abstract Gamma ray spectrometry was used to quantify level of NORM in mining residues sampled at Awaso bauxite mine and surrounding communities. The radionuclides of interest were 238U, 232Th and 40K and the radioactivity levels were determined in soil, bauxite ore, red mud and water samples from wells. The radioactivity concentrations in soil, bauxite ore and red mud 238U, 232Th and 40K were 18.01±1.96 Bqkg-1, 19.07±2.12 Bqkg-1 and 103.21±1.74 Bqkg-1; 39.42±4.18 Bqkg-1, 97.32±10.63 Bqkg-1 and 14.68±1.82 Bqkg-1; 44.85±4.79, 64.23±6.58 and 125.30±18.72 Bqkg-1. The activity levels for both 232U and 232Th were above world-wide average values while Potassium-40 levels were lower. The mean activity concentration values of 238U, 232Th and 40K in water samples were 1.49±0.45 Bql-1, 3.68±0.69 Bql-1 and 15.69±0.28 Bql-1 respectively and were within the world average activity concentrations except for bauxite ore and red mud. The committed effective dose was 0.74 mSv and annual effective dose estimated to be 0.136 mSv which is below recommended dose limit of 1 mSvyear-1 for public exposure.

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Possibility of enrichment of ore processing waste from Karagaily and Zheskazgan mining plants by dry separation method

Bulletin of the Karaganda University Chemistry series ◽

10.31489/2020ch1/117-123 ◽

2020 ◽

Vol 97 (1) ◽

pp. 117-123

Author(s):

E.S. Mustafin ◽

◽

Kh.B. Omarov ◽

A.S. Borsynbaev ◽

D. Havlicek ◽

...

Keyword(s):

Separation Method ◽

Processing Waste ◽

Ore Processing

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Treatability of chromite ore processing waste by leaching

Waste Management & Research ◽

10.1177/0734242x0101900304 ◽

2001 ◽

Vol 19 (3) ◽

pp. 217-228 ◽

Cited By ~ 3

Author(s):

Kahraman ünlü ◽

Serkan Haskök

Keyword(s):

Processing Waste ◽

Chromite Ore ◽

Ore Processing

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Effect of Calcined Red Mud Addition on the Hydration of Portland Cement

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.1408 ◽

2012 ◽

Vol 727-728 ◽

pp. 1408-1411 ◽

Cited By ~ 2

Author(s):

Daniel Véras Ribeiro ◽

João A. Labrincha ◽

Márcio Raymundo Morelli

Keyword(s):

Portland Cement ◽

Red Mud ◽

Setting Time ◽

Cementitious Materials ◽

Adiabatic Calorimeter ◽

Hydration Process ◽

Early Hydration ◽

Bauxite Ore ◽

Calorimetric Studies ◽

Reference Mixture

The red mud (RM) is a solid waste derived from the processing of bauxite ore to produce alumina and it is considered a hazardous waste due to its high pH. This paper describes the use of mud untreated and after calcination at distinct temperatures (450, 650, and 1000°C) attempting to improve its reactivity. The Portland cement was replaced up to 30 wt% red mud, and its addition changed the hydration process, evaluated by calorimetric studies of early hydration and setting time. By comparing with the reference mixture (without red mud), the obtained results confirm the potential of the red mud to be used as pozzolanic additive to cementitious materials. Temperature of hydration was monitored by a quasi-adiabatic calorimeter (Langavant). The hydration temperature increases with RM addition, particularly if calcined in the same interval (450-650°C). In this condition, the hydration process is accelerated.

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Effect of red mud addition on the corrosion parameters of reinforced concrete evaluated by electrochemical methods

Revista IBRACON de Estruturas e Materiais ◽

10.1590/s1983-41952012000400004 ◽

2012 ◽

Vol 5 (4) ◽

pp. 451-467 ◽

Cited By ~ 9

Author(s):

D.V. Ribeiro ◽

J.A. Labrincha ◽

M.R. Morelli

Keyword(s):

Electrical Resistivity ◽

Reinforced Concrete ◽

Red Mud ◽

Corrosion Potential ◽

Corrosion Process ◽

Bayer Process ◽

Alumina Production ◽

High Ph ◽

High Electrical Resistivity ◽

Bauxite Ore

Red mud, the main waste generated in aluminum and alumina production from bauxite ore by the Bayer process, is considered "hazardous" due to its high pH. The high pH also provides greater protection of rebars, which is reflected in the low corrosion potential and high electrical resistivity (filler effect) of concrete. The corrosion potential was monitored by electrochemical measurements and the electrical resistivity was evaluated using sensors embedded in concrete test specimens. The results showed that the addition of red mud is beneficial to concrete, reducing its corrosion potential and increasing its electrical resistivity. Red mud proved to be a promising additive for concrete to inhibit the corrosion process.

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