Bauxite as a natural raw material is of great importance for the refractory industry. Despite its essential role and its use in further fields of application, such as aluminum production and the chemical, cement, and abrasives industries [], the designation "bauxite" is not uniformly defined [2,3,4].Thus, different bauxites can display vast …

The activation energy of the dissolution celestite in nitric acid solutions was calculated to be 42.22 kJ/mol. ... Z.I. Zafar, Determination of semi empirical kinetic model for dissolution of bauxite ore with sulfuric acid: Parametric cumulative effect on the Arrhenius parameters, Chem. Eng. J., 141(2008), ...

Bauxite residue (BR) is a well promising resource for critical metals, especially scandium (Sc), a rare and expensive metal with increasing applications in advanced technology. Greek BR seems to significantly favor a commercially viable recovery of Sc combining optimized leaching and advanced separation techniques. Leaching with mineral acids …

kinetics of a Cu-Co ore in the sulfuric acid and hydrogen peroxide system followed the shrinking core model, of which the controlling factor is the diffusion of the reac-tants through a product layer. Wang et al. [29] applied the sulfuric acid leaching process to recover the copper from the otation tailings and showed that under optimal

Fig. 1, Fig. 2 show the results of the reactions carried out between the two phosphate rocks and H 2 SO 4 at different concentrations. Each reaction was carried out for a fixed time: 5; 10; 20; 30; 40 and 50 min.It can be noted that regardless the type of phosphate, when using more concentrated sulfuric acid (80 wt% and 96 wt%), the …

The bauxitic claystone samples calcined at 600 °C were leached with different sulfuric acid concentrations at 80 °C for 60 min with a liquid-solid ratio of 5:1 mL/g. As shown in Fig. 4, the leaching of metals increases with increasing sulfuric acid concentration. The leaching rate of lithium reaches 86.23% when the sulfuric acid …

"Bauxite Residue" (BR) refers to the insoluble solid material, generated during the extraction of alumina (Al 2 O 3) from Bauxite ore using the Bayer process.When bauxite ore is treated with caustic soda, the aluminum hydroxides/oxides contained within, are solubilized, with approximately 50% of the bauxite mass being transferred to the …

In this regard, metals recovery from red mud by selective leaching has been reported mostly by sulfuric acid 11 – 17, hydrochloric acid 9, 18 – 20, nitric acid 11, 21, phosphoric acid 11, 22, 23, and oxalic acid 24 – 27. Pepper et al. 11 examined the selectivity of HCl, HNO 3, H 2 SO 4, and H 3 PO 4 in red mud extraction experiments. …

Determination of semi empirical kinetic model for dissolution of bauxite ore with sulfuric acid: Parametric cumulative effect on the Arrhenius parameters ... The dissolution of iron in the bauxite ore including diasporite mineral from Kayaderesi region in Mugla-Milas city, Turkey was investigated in hydrochloric acid solution. The bauxite …

Scattered bauxite crystals made free pores for passage of solutions enhancing leaching conditions. Al, Ti, Fe, Si, Cu and Zn were identified as significant components; out of which, Al and Ti have the highest concentration. ... Zafar ZI (2008) Determination of semi empirical kinetic model for dissolution of bauxite ore with …

Determination of semi empirical kinetic model for dissolution of bauxite ore with sulfuric acid: Parametric cumulative effect on the Arrhenius parameters

A new process of Al2O3 production from low-grade diasporic bauxite based on the reactive silica dissolution and stabilization in concentrated NaOH-NaAl(OH)4 solutions is proposed and proved feasible. NaOH and Al2O3 concentrations and leaching temperature were found to be the main factors affecting the leaching process of reactive silica. The A/S (mass …

Semantic Scholar extracted view of "Dissolution of iron oxide using oxalic acid" by Sung Oh Lee et al. ... hydrochloric acid is used to remove iron impurities in the bauxite ore contained in the diasporite mineral located in the Sari region. ... Drum leaching tests in iron removal from quartz using oxalic and sulphuric acids.

Dissolution of iron decreased after 2 h, indicating precipitation of the dissolved iron, which can simultaneously adsorb scandium in the precipitate. ... The high-pressure acid leaching of the bauxite residue in sulfuric acid resulted in scandium recovery rates comparable to or even higher than the energy ... Elsevier; 2016. …

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 concentration, liquid/solid ratio, stirring speed and temperature along with a decrease in the particle …

Bauxite residue is a highly alkaline industrial solid waste generated through the alumina production process. Its high alkalinity causes serious environmental pollution. In this article, a fast, high-efficiency, low-cost dealkalization process was developed. Bauxite residue was dealkalized by sulfuric acid and CAM, a calcium-containing compound. …

During acid leaching of bauxite residue (red mud), the increase in dissolution of rare-earth elements (REEs) is associated with a substantial co-dissolution of iron; this poses problems in the downstream processing (i.e. solvent extraction or ion exchange). Six different slags generated by reductive smelting of the same bauxite …

characteristics of ammonium sulfate and sulfuric acid showed that they are equal in terms of their efficiency of the dissolution of sodium, calcium, iron, and …

Magnetite (Fe3O4) is a key economically valuable component in iron ore and is extracted by dissolution processes, but among the Fe (oxyhydr)oxides its solubility behavior is one of the least understood. ... The most important individual observation regarding the equilibrium state of the nitric- and sulfuric-acid systems seems to be that …

The experimental procedure proposed in this study is depicted in Fig. 1.The experimental procedure is composed of (1) oxalic acid leaching of red mud to separate iron and aluminum, (2) roasting the oxalic acid-leaching residue followed by dilute hydrochloric acid leaching to remove calcium, and (3) sulfuric acid leaching of the hydrochloric acid …

The process of dissolution the boehmite-kaolinite bauxite of Severoonezhsk bauxite deposit with hydrochloric acid, and the processes taking place at calcinations in the air were investigated in ...

Rare earth elements, such as yttrium, scandium, neodymium, and praseodymium, have been reported to be associated with minerals in bauxite and transferred to the refining residue when bauxite is refined to alumina (Al2O3) by Bayer Process. In terms of price, scandium is the most valuable rare-earth element in bauxite …

Zafar ZI (2008) Determination of semi empirical kinetic model for dissolution of bauxite ore with sulfuric acid: parametric cumulative effect on the Arrhenius …

As the volume of CO 2, one of greenhouse gases linked to global warming, in the atmosphere increases, there has been an increasing interest in CO 2 sequestration. Aqueous carbonation, which involves the extraction of Mg from serpentine minerals and the subsequent carbonation reaction with CO 2 to form the geologically stable mineral …

Xu et al. used sulfuric acid to leach zinc from a sulfide complex and a silicate-containing zinc ore, and 97% of zinc was leached after a reaction time of 150 min at 413 K, demonstrating that the ...

The thermochemical and kinetics study of the attack of a synthetic fluorapatite (Fap) by a 10 mass% H2SO4 sulfuric acid solution was performed first at 25 °C using C-80 SETARAM microcalorimeter with reversal cells. The results are repetitive only for few amounts of Fap and the global enthalpy of the attack equals − 401.4 ± 9.7 …

Dissolution kinetics of low-grade bauxite rock in sulfuric acid solution is studied. Using a known acid concentration and particle size of the sample, the influence …

the bauxite ore (Hector et al., 1997). Mostly clay has been ... (pfa) using dilute sulphuric acid, results in the co-dissolution of silica and the subsequent formation of an unfilterable silica ...

The Bayer process holds an exclusive status for alumina extraction, but a massive amount of caustic "red mud" waste is generated. In this work, three oxalate reagents: potassium hydrogen oxalate (KHC 2 O 4), potassium tetraoxalate (KHC 2 O 4 ·H 2 C 2 O 4), and oxalic acid (H 2 C 2 O 4) were investigated for the Al and Fe extraction …

Determination of semi empirical kinetic model for dissolution of bauxite ore with sulfuric acid: Parametric cumulative effect on the Arrhenius parameters. Chem. Eng. J., 141 (1–3) (2008), pp. 233-241. View PDF View article View in Scopus Google Scholar [14] A. Ghorbani, A. Fakhairyan.