The effects of the additives, calcination and leach conditions for alumina production from red mud

Alp, Ahmet; Goral, M. S.

doi:10.1111/j.1600-0692.2003.00656.x

Cited by 17 publications

(4 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The soda sintering process is used for materials which are hardly digestible via the Bayer process and requires high temperatures of 800-1200°C, usually 1000-1200°C [13][14][15][16][17]. It is basically a "dry digestion" of aluminum oxides with soda (Na 2 CO 3 ) and employs the principle of the sodapot-ash digestion, but in this case without the use of K 2 CO 3 .…”

Section: Soda Sintering Processmentioning

confidence: 99%

Methods for Alkaline Recovery of Aluminum from Bauxite Residue

Kaußen

Friedrich

2016

J. Sustain. Metall.

View full text Add to dashboard Cite

Different ways for alkaline recovery of aluminum from bauxite residue are considered from the literature and examined in experiments. The advantages and disadvantages of a high-temperature digestion via Bayer process and soda-lime sintering process are elaborated and compared. As a hybrid process, bauxite residue undergoes a reductive smelting process with lime addition in an electric arc furnace in order to generate aluminaenriched slag. This slag is subsequently treated with highpressure caustic leaching at moderated (200-300 g/l) and high (572-762 g/l) sodium hydroxide concentrations. The aluminum extractions are related to phase transitions in mineralogy caused by the process parameter and are analyzed and proofed by x-ray diffraction. The results show moderate aluminum recoveries of 70 % in case of the use of Bayer process, extremely high aluminum extractions of 95 % in case of slag leaching at high NaOH concentrations, and even high recoveries of almost 90 % achieved by an optimized sinter process with subsequent leaching at 50°C with water. Special focus throughout all experiments is set on the dissolution of silicon as major impurity in the leachate.

show abstract

Section: Soda Sintering Processmentioning

confidence: 99%

Methods for Alkaline Recovery of Aluminum from Bauxite Residue

Kaußen

Friedrich

2016

J. Sustain. Metall.

View full text Add to dashboard Cite

show abstract

“…Zhang et al [83,84] were able to recover alumina by forming andradite-grossular hydrogarnet in a hydrothermal process. The pyrometallurgical recovery involves sintering with soda (25-70 wt.%) and lime (10-50 wt.%) in the temperature range 1000-1050 • C to form water-soluble sodium aluminate, followed by leaching in water/NaOH (1.5-2 M) achieving up to 76-90% aluminum extraction [85,86]. However, some of these processing methods could be quite expensive, time consuming and produce secondary waste products as well.…”

Section: Aluminiummentioning

confidence: 99%

Red Mud as a Secondary Resource of Low-Grade Iron: A Global Perspective

et al. 2022

View full text Add to dashboard Cite

Managing red mud (RM), a solid waste byproduct of the alumina recovery process, is a serious ecological and environmental issue. With ~150 million tons/year of RM being generated globally, nearly 4.6 billion tons of RM are presently stored in vast waste reserves. RM can be a valuable resource of metals, minor elements, and rare earth elements. The suitability of RM as a low-grade iron resource was assessed in this study. The utilization of RM as a material resource in several commercial, industrial operations was briefly reviewed. Key features of iron recovery techniques, such as magnetic separation, carbothermal reduction, smelting reduction, acid leaching, and hydrothermal techniques were presented. RMs from different parts of the globe including India, China, Greece, Italy, France, and Russia were examined for their iron recovery potential. Data on RM composition, iron recovery, techniques, and yields was presented. The composition range of RMs examined were: Fe2O3: 28.3–63.2 wt.%; Al2O3: 6.9–26.53 wt.%; SiO2: 2.3–22.0 wt.%; Na2O: 0.27–13.44 wt.%; CaO: 0.26–23.8 wt.%; Al2O3/SiO2: 0.3–4.6. Even with a high alumina content and high Al2O3/SiO2 ratios, it was possible to recover iron in all cases, showing the significant potential of RM as a secondary resource of low-grade iron.

show abstract

“…With each ton of primary produced aluminum, 1 -2.5 t red mud are generated [2,3]. The composition of red mud varies strongly dependent on the composition of the original bauxite and the employed process parameters (digestion temperature, caustic concentration, digestion time, etc.).…”

Section: Introductionmentioning

confidence: 99%

Reductive Smelting of Red Mud for Iron Recovery

Kaußen

Friedrich

2015

Chemie Ingenieur Technik

View full text Add to dashboard Cite

The reductive smelting of red mud is calculated and investigated regarding the necessary amount of reduction agents and the final composition of the pig iron phase and the mineral (slag) phase as products of the process. Liquidus temperatures of slags with three different compositions are calculated during the reduction process and in dependency of the remaining sodium content in the slag. All calculations were done with FactSage and the results are confirmed by smelting experiments in a lab scale electric arc furnace.

show abstract

The effects of the additives, calcination and leach conditions for alumina production from red mud

Cited by 17 publications

References 8 publications

Methods for Alkaline Recovery of Aluminum from Bauxite Residue

Methods for Alkaline Recovery of Aluminum from Bauxite Residue

Red Mud as a Secondary Resource of Low-Grade Iron: A Global Perspective

Reductive Smelting of Red Mud for Iron Recovery

Contact Info

Product

Resources

About