Of Removal Of Sio From Bauxite

percentage in bauxite through beneficiation methods such as flotation and dry milling before introducing the material to the Bayer process. Another approach involves incorporating …

The mineralogical characteristics of low SiO 2 bauxite in Guinea (SiO 2 <3%) are studied, and the results are presented in Fig. 3 [41]. The main minerals were boehmite, gibbsite, goethite, hematite, and Al-substituted goethite. ... and the iron removal rate was 85.32% in non-magnetic materials under a pre-roasting temperature of 750 °C for 30 ...

The most effective way to remove both kaolinite and goethite is by washing, followed by attrition scrubbing and desliming through removal of clay-rich super fines in hydro-cyclone.

For low-grade diasporic bauxite with an Al 2 O 3 to SiO 2 mass ratio of below 8, a sintering process (Jiang et al., 2002) or a combined sintering and Bayer process can be used (Zhao et al., 2004 ...

removal of sulfur from high-sulfur bauxite during the alumina production. Keywords: high-sulfur bauxite, Bayer process, removal of sulfur, zinc DOI: 10.3103/S1067821222010126 1. INTRODUCTION The rapid development of the alumina industry has challenged bauxite resources and made them scarce. There are about 0.56 billion tons of diasporic high-sul-

The removal of iron from the six bauxite samples was found to vary between 7% and 29% and the highest extraction corresponded to the sample containing the Fe(II) rich compound, chamosite.

According to Table 1, the total iron grade (TFe) in the non-magnetic material decreased greatly after pretreatment of the bauxite ore residue.However, the other components such as Al 2 O 3, SiO 2, CaO, Sc 2 O 3, and TiO 2 were enriched obviously. The recoveries of Sc 2 O 3 and TiO 2 in the non-magnetic material were 92.40% and 90.0%, respectively.. 2.1.2. …

As the mainstreams of bauxite desulfurization technologies, the bauxite pre-desulfurization (roasting, electrochemistry, biology, flotation, etc) and Bayer process desulfurization (oxidation and ...

In this section, the optimal phosphoric acid leaching conditions for the removal of SiO 2 and enrichment of La 2 O 3, Ce 2 O 3, Sc 2 O 3 and Y 2 O 3 from iron-removed BR …

High-silicon bauxite, as a potential resource for the industrial production of alumina, contains large amounts of Al 2 O 3 and SiO 2.It mainly exists as minerals of boehmite, diaspore, kaolinite and muscovite with fine-grained dissemination and high chemical inertness, which is difficult to be separated by the beneficiation method (Pandey et al., 2010).

Dissolution kinetics and removal mechanism of kaolinite in diasporic bauxite in alkali solution at atmospheric pressure Yan WU, Xiao-lin PAN, Yue-jiao HAN, Hai-yan YU ... bauxite, so all of the SiO2 are in the form of kaolinite in this bauxite. The calculated mineral composition is shown in Table 2. The A/S of the bauxite is 4.97, which

Characteristics of Bauxite ore Characteristics of bauxite used for the preparation of synthetic aluminate liquor. S no Characteristics Bauxite 1 Al 2 O 3 (t)% 44.56 2 Fe 2 O 3 % 24.83 3 Tio 2 % 2.02 4 SiO 2 %(t) 4.20 5 SiO 2 %(r) 3.05 6 ATH% 39.4 7 Na 2 O% - 8 Org.C% 0.086 9 Min C% 0.184 10 P 2 O 5 % 0.088 11 V 2 O 5 % 0.062 12 CaO% 0.018 13 ...

The Bayer process is a chemical process for refining aluminium hydroxide, Al(OH) 3 from bauxite; this aluminium hydroxide is subsequently calcined to produce alumina, Al 2 O 3.The basis of the Bayer process is an understanding of the characteristics of the sodium-hydroxide—sodium-aluminate solution relationship, namely its ability to keep sodium-aluminate in a dissolved state …

Beneficiation and removal of impurities in low alumina bauxites (<50% Al 2 O 3) is a common technique in order to attain good quality in abrasive, refractory and pottery products.As far as iron is concerned, many of these applications require that Fe 2 O 3 should be as low as 2%. Conventional methods, such as gravimetric and magnetic separation or differential flotation, …

The pyrite and sulfate digestion behaviors and sulfur removal of high sulfur bauxite during Bayer process were studied in this paper. The thermodynamic analysis shows that pyrite reacts with alkali solution to generate different valence sulfur (S 2-, S 2 O 3 2-, SO 3 2-, SO 4 2-), Fe 2 O 3, and Fe 3 O 4; the standard Gibbs free energy of these reactions is negative and …

The main mineral phases in high-iron bauxite were diaspore (AlOOH) and limonite (most of them are cryptocrystalline goethite (FeOOH)) together with a phase of quartz (SiO 2) and titanium dioxide (TiO 2). The mineral composition of raw ore was determined by identification of rock and minerals method according to the optical properties of the ...

Si and Al removal from the bauxite by the metabolites of strains H19 and G21 is shown in Fig. 5. Compared to distilled water, ... Notably, the ratio of Al 2 O 3 /SiO 2 in the bauxite treated with these strains was more than nine, which met the requirement in the Bayer process for alumina production. These results may give us to better ...

The removal of SiO 2 reached 42.5%, and the A/S of the bauxite concentrate increased from 7.6 to 12. The roasting-alkali leaching process can also achieve good …

(mass ratio of Al 2 O 3 to SiO 2) of dis solved residues is increased to 8.55, while the A/S of the bauxite is only 4.97. Key words: Bayer process; kaolinite; pre-desilication; dissolution kinetic ...

In China, low grade diasporic bauxite with an Al 2 O 3 /SiO 2 mass ratio below 8 can be processed by sintering, or through a combination of sintering and the Bayer process (Liu et ... Reverse flotation for removal of silicates from diasporic-bauxite. Minerals Engineering, 17 (2004), pp. 63-68. View PDF View article View in Scopus Google Scholar ...

Iron loss and removal rate of quartz (SiO2), aluminum (Al2O3) and phosphorus (P), respectively, % : R loss/removal(%) = c c ×w c ×w t * 100 (2) c c* w c Where: C c is for Fe, SiO2, Al2O3 and P content in the original iron ore sample used in this study. C t is for Fe, SiO2, Al2O3 and P content in the product from fl otation and roasting-water ...

In addition, the biological methods demand a long cycle to desilication. According to the dissolving properties of diaspore and kaolinite under different reaction conditions, Yang et al.6 used sodium hydroxide solution to leach bauxite ore directly. The removal of SiO 2 reached 42.5%, and the A/S of the bauxite concentrate increased from 7.6 to ...

In addition, it has been illustrated that partial removal of other components of the ore such as Si, Ti, V is also possible [5, 6]. ... If the bauxite ore contains high amount of SiO 2, the aluminothermic reduction of SiO 2 may yield silicon ferroalloys, while a proper calcium aluminate slag for the hydrometallurgical Pedersen process is ...

a high content of Al2O3 and SiO2 and a low mass ratio of Al2O3 to SiO2 (m(Al2O3)/m(SiO2), usually 5−6) compared with gibbsite-bauxite and boehmite-bauxite in other countries[3]. Bayer process[4] to treat diasporic bauxite needs bauxite with m(Al2O3)/m(SiO2) larger than 8. The sintering process is extremely energy-intensive

Aluminum-silicates such as pyrophyllite, illite, kaolinite and chlorite are impurity minerals in diasporic-bauxite, it being necessary to remove these silicate minerals to improve …

The reverse-flotation process cannot achieve effective separation of Al 2 O 3 and SiO 2 from high-ferrous bauxite [13] because high-ferrous bauxite is characterized by a high content of Al 2 O 3 ...

0.7% is called high-sulfur bauxite. Such bauxite is mainly composed of alumina in middle-high proportion, silicon oxide in middle-low proportion, sulfur in high proportion (sulfur content is greater than 0.7%) and middle-high A/S (weight ratio of Al 2O 3 to SiO 2) bauxite [2]. FeS 2,asthe main sulfur-containing mineral of high-sulfur bauxite ...

with the above ingredients, bauxite tailings have the advan-tages of large output, free availability and nontoxic impurities. The bauxite tailings in China are generated from ota-tion before the Bayer process to produce alumina [31]. It is reported that 0.2 t of bauxite tailings are generated from every 1 t of bauxite ores processing [32].

The reactive silica (SiO 2) content (18.1%) of the bauxite was significantly (p < 0.05) higher than the threshold (8.0%) of high silica bauxites (Smith, 2009). Besides, the Al 2 O 3:SiO 2 ratio (3.36) of the bauxite was far below 9.0, suggesting that the bauxite was not suitable for the Bayer process for alumina production

The increasing of collector dosage at pH 10 gives a good result on Al 2 O 3 content is 62% and SiO 2 is 29.4% with 50.44% recovery of Al 2 O 3 obtained at dosage of collector at 500 g/ton. The Al 2 O 3 ontent which is higher in conditions without the addition of depressant is 66.8% while SiO 2 in 23.5%. While for the size fraction variation, it ...