Determination of semi empirical kinetic model for ...
Sulfuric acid was used to investigate the dissolution of bauxite ore. It was found that the dissolution rate increased with an increase in the acid co…
Sulfuric acid was used to investigate the dissolution of bauxite ore. It was found that the dissolution rate increased with an increase in the acid co…
In the standard Bayer Process for refining bauxite to produce alumina, the dissolution of the alumina in the ore to form sodium aluminate is accomplished in autoclaves under high pressures varying from 70 to 200 pounds per square inch. However, some lateritic bauxite ores are readily soluble in caustic, making it possible for them to be leached ...
Bauxite residue is a highly alkaline waste containing soluble alkaline anions, which can cause environmental concerns. The optimal leaching conditions, distribution of alkaline anions, types of pivotal alkaline anions and their dissolution behaviors were investigated based on the combination of single factors-orthogonal experiments and leaching stage experiment.
Dissolution of the bauxite residue slurries in water at different L/S ratios appears to be straightforward and easy to predict in most cases. Fig. 5 a and b shows clearly that the liquid phase of the sample is mainly responsible for providing the water-soluble sodium under the applied conditions.
The dissolution of aluminum hydroxides from bauxite ores constitutes a key process in the aluminum industry. Generally, aluminum minerals in bauxites are present in the form of gibbsite, boehmite or diaspore. Usually, these mineral forms are mixed in bauxite as a boehmite-diaspore or a gibbsite-boehmite mixture with different weight ratios.
For the dissolution of low-grade bauxite ore, Hulbert and Huff used mineral acid and the results indicated that the rate of calcined bauxite dissolution was fastest with hydrochloric acid, slower with sulfuric acid, and slowest with nitric acid. In the case of sulfuric acid, the results also showed that the rate-controlling step was the ...
Kinetics model was developed for aluminum dissolution of West Kalimantan bauxite based on shrinking core model. A series of digestion tests was carried out to study aluminum dissolution from the ore sample with particles size distribution of passing 60 mesh in 129 gpL of NaOH. The digestion tests were conducted at 140; 150
bauxite dissolution caustic Prior art date Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Withdrawn Application number EP97911968A Other languages German (de) French (fr) Other versions ...
Bauxite is a sedimentary rock with a relatively high aluminium content. It is the world's main source of aluminium and gallium.Bauxite consists mostly of the aluminium minerals gibbsite (Al(OH) 3), boehmite (γ-AlO(OH)) and diaspore (α-AlO(OH)), mixed with the two iron oxides goethite (FeO(OH)) and haematite (Fe 2 O 3), the aluminium clay mineral kaolinite (Al 2 Si 2 O 5 (OH) 4) and small ...
such as podsolization, transfer of Al to Al-rich minerals (as bauxite under lignite in Ar-kansas), or recombination with Si to yield kaolin minerals (as in German kaolins via the Moorverwitterung process) may be attributed to dominant dissolution efiects of organic acids. INrnorucuoN Dissolution of minerals and rocks in aqueous solutions has ...
This is due to dissolution of aluminum and silicon from the sodium aluminosilicates. Download : Download high-res image (118KB) Download : Download full-size image; Fig. 7. Effect of nitric acid concentration on dissolution of major elements in the bauxite residue sample (T: 25 °C, L/S: 50, t: 24 h).
Trans. Nonferrous Met. Soc. China 25(2015) 4151âˆ'4159 Dissolution kinetics and mechanism of gibbsitic bauxite and pure gibbsite in sodium hydroxide solution under atmospheric pressure Hui-bin YANG1,2, Xiao-lin PAN1, Hai-yan YU1, Gan-feng TU1, Jun-min SUN2 1.
Jeje 1983). It is believed that the dissolution of the lime- This investigation seeks to determine the effects of re- stone left residues in the downfaulted enclosures (Hill and moval, storage, and replacement, on soil organic matter Ostojic 1984) resulting in diagenesis of red bauxite.
The dissolution process of bauxite is one of the main technologies during the Bayer process. PAN et al [13] and LI et al [14] studied the dissolution process Foundation item: Projects (51104041, 51174054, 51374065) supported by the National Natural Science Foundation of China; ...
The soluble phosphate concentrations of 30 exploration bauxite samples taken from a hematite-rich mining area and 104 from the goethite-rich deposits that will be mined in the future are plotted against their total PO 4 3− concentrations in Fig. 1.The upper straight line (mg PO 4 3− /L = 0.091 mg PO 4 3− /kg) gives the PO 4 3− concentrations expected if crandallite is the only ...
such as podsolization, transfer of Al to Al-rich minerals (as bauxite under lignite in Ar-kansas), or recombination with Si to yield kaolin minerals (as in German kaolins via the Moorverwitterung process) may be attributed to dominant dissolution efiects of organic acids. INrnorucuoN Dissolution of minerals and rocks in aqueous solutions has ...