Bauxite residue, also known as red mud, is an abundant byproduct produced during the alumina production process from bauxite ore. As the demand for ecofriendly construction materials grows, researchers are exploring the potential of bauxite residue as a binding agent in cementitious composites. ... Thermally treated calcium carbide residue ...
WhatsApp: +86 18838072829In this study, bauxite residue was directly leached using the Brønsted acidic ionic liquid 1ethyl3methylimidazolium hydrogensulfate. Stirring rate, retention time, temperature, and pulp density have been studied in detail as the parameters that affect the leaching process. Their optimized combination has shown high recovery yields of Sc, nearly 80%, and Ti (90%), almost total dissolution ...
WhatsApp: +86 18838072829Bauxite residue is a kind of strong alkaline waste produced in the production of alumina. Its longterm storage poses a potential threat to the environment. With the tightening of environment policies in various countries, the strong alkalinity of bauxite residue has become a bottleneck restricting .
WhatsApp: +86 18838072829The starting material used in this work is a slag that was produced from a smeltingreduction process of lowgrade bauxite from our previous work (Azof et al., 2018).The lowgrade bauxite was mixed with lime in a mass ratio of CaO/Al 2 O 3 equals to The ratio was chosen so that the produced slag would have leachable phases in a sodium carbonate solution, as claimed in the literature ...
WhatsApp: +86 18838072829In addition, slaked lime (Ca(OH) 2) is typically added within the Bayer process to enhance extraction of the available alumina from bauxite and this can lead to the formation of many solid phase calcium hydroxides, carbonates and aluminates, such as TCA (tricalcium aluminate — Ca 3 Al 2 (OH) 12). These solids act as an alkalinity store and ...
WhatsApp: +86 18838072829The production of aluminum from bauxite is a twostep process: refining bauxite to obtain alumina and smelting alumina to produce aluminum. Bauxite contains a number of impurities, including iron oxide, silica, and titania. ... calcium, and silicon materials. The slurry then proceeds through the remaining steps of the Bayer process.
WhatsApp: +86 188380728291. Introduction. The characteristics of Chinese bauxite are high alumina, high silica, low ferrite, and middle and lowgrade diasporic bauxite (Niu, 2003, Yang, 2006).Consequently a combination process (Gu, 2004, Ai and Cheng, 2002) is mainly used to produce alumina in China, in which the flow is complicated and the energy consumption is Bayer process is an economical process with ...
WhatsApp: +86 18838072829The sinter process is widely used to process the poorgrade diasporic bauxite ores with A/S below 7, in China and Russia, by sintering the bauxite ore with sodium carbonate and limestone to form sodium aluminate and calcium silicate. In the process, the sinter is then leached with water, caustic soda solution, and recycled liquor to dissolve ...
WhatsApp: +86 18838072829Calcium was introduced to bauxite residue to form leachable calcium aluminate phases with the existing alumina in bauxite residue. This involved the addition of either CaCO 3 or a mixture of CaO ...
WhatsApp: +86 18838072829Overall, the bauxitebased defluoridation process described here offers a method that is potentially (1) effective at remediating fluoride contaminated groundwater, (2) affordable to impoverished households, (3) easy to operate and maintain without skilled labor, (4) culturally appropriate, and (5) widely available in fluorideaffected regions w...
WhatsApp: +86 18838072829A typical calcination process involves the conversion of calcium carbonate to calcium oxide. (begin{array}{l}CaCo^{3}overset{Delta h}{rightarrow} CaO+ Coend{array} ) ... Calcination of bauxite and gypsum involving the removal of water of crystallisation in the form of water vapour.
WhatsApp: +86 18838072829In the lime sinter process the additive is a calcium salt (usually calcite — ... Based on the stability field of silica gel formation, a stepwise acid leaching process for bauxite residue is proposed to facilitate downstream processing of the critical metals. Extraction of scandium from bauxite residue by highpressure leaching in sulfuric ...
WhatsApp: +86 18838072829Abstract The recovery of major components of bauxite residue by carbothermic reduction at °C and subsequent slag leaching in a Na3CO3(aq) solution is studied. Iron recovers primarily to pigiron and lime is added to tune the calcium aluminate slags towards the highly leachable mayenite phase. The concentration of aluminum in the leachate correlates well with the occurrence of ...
WhatsApp: +86 18838072829The main minerals in the reduction product from the ironaluminum symbiotic ore obtained by the lowcalcium reduction process are Fe, NaAlO 2, Na 2 CaSiO 4 and NaAlSiO 4, and the iron metallization efficiency, the leaching efficiency of Al 2 O 3 and the content of iron in the concentrate are %, % and % respectively under the ...
WhatsApp: +86 18838072829During the digestion process of the Bayer method, lithium and gallium in bauxite will enter into the sodium aluminate solution (Tang et al. 2020; Xu et al. 2018), which will return to the digestion process for recycling after the precipitation of aluminum hydroxide from the decomposition of crystal to a large amount of red mud discharge, most of the lithium and gallium in the ...
WhatsApp: +86 18838072829In general, a national acceptable synthesis method involves a twostep method where the bauxite, hydrochloric acid and calcium aluminate are used as raw materials to prepare liquid PAC [5,6]. And, in China, PAC is also based on those process to produce, however, which resulted in generation of large volumes of very acidic residue called ...
WhatsApp: +86 18838072829Aluminium ore bauxite can be found in a variety of applications. As calcined bauxite, this raw material is a central raw material in the refractory industry thanks to its highly refractory properties. This versatile mineral is also in demand in steel production as slag conditioner, in the production of refractory aluminium oxide cement, in road construction, in mineral wool production and as ...
WhatsApp: +86 18838072829The Pedersen process is a method to produce alumina from Alcontaining sources, and it is a more materialefficient method than the current commercial Bayer process, since the formation of bauxite ...
WhatsApp: +86 18838072829The hydrometallurgy process of the "calcificationcarbonation method" (CCM; process flowchart shown in Fig. 1) was proposed (Zhang et al., 2017; Zhang et al., 2013; Lu et al., 2014; Lu et al., 2017) to convert the hydrated sodium aluminosilicate phase in Bayer red mud to CaO·SiO 2 and CaCO the calcification process, siliconcontaining phases (such as kaolinite in bauxite) are ...
WhatsApp: +86 18838072829The Ca content in most bauxite ores was below the detection limit except in India bauxite, which contained % Ca. Fig. C shows the XRD patterns of the four bauxite ores. The main crystalline Al phase in all bauxites was gibbsite, and an additional crystalline Fe phase (hematite) was detected in Ghana, India, and Guinea bauxites.
WhatsApp: +86 18838072829The calcium ions enhance the ability of alkaline minerals to trap dissolved organic carbon, and the work highlighted the significance of organomineral associations in the microscopic mineral structure for the organic carbon sequestration in the revegetation process of bauxite residue disposal areas.
WhatsApp: +86 18838072829Jiannan Pei et al. (2021) proposed a recovering alkali process of lowcalcium sintered bauxite residue, and the final slag obtained contains % Na 2 O. However, bauxite residue treatment by sintering has the defects of high energy consumption and expensive cost, so it has not been used on a large scale. Guozhi Lu et al. (2019) studied the ...
WhatsApp: +86 18838072829This study investigates the properties of H2reduced calciumadded bauxite residue, selfhardened pellets, and the feasibility of iron recovery through electrostatic and magnetic separation methods. The oxide pellets are prepared via a mixing of bauxite residue, calcite, and quicklime. The selfhardened pellets are reduced at 1000 °C with hydrogen gas flow for 120 min.
WhatsApp: +86 18838072829The Utilization of Bauxite Residue with a CalciteRich Bauxite Ore in the Pedersen Process for Iron and Alumina Extraction Original Research Article Open access Published: 08 March 2021 52, ( 2021 ) Download PDF You have full access to this open access article Metallurgical and Materials Transactions B Aims and scope Submit manuscript
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