Bauxite Beneficiation Electrostatic

The most widely used chemical process of refining bauxite into alumina, tsarin aikin Bayer, involves dissolving the Al2O3 out of the bauxite rock with caustic soda (NaOH) at elevated temperature and pressure. The Al2O3 fraction of the bauxite is dissolved into solution, to later be precipitated out as alumina. Duk da haka, a high-grade bauxite contains up to 60% Al2O3, and many operating bauxite deposits are well below this, lokaci-lokaci kamar yadda low kamar yadda 30-40% Al2O3. Because the desired product is a high purity Al2O3, sauran oxides a haƙar (Fe2O3, SiO2, TiO2, Organic material) are separated from the Al2O3 and rejected as alumina refinery resides (arr) or red mud. a general, ƙananan ingancin haƙar (ie lower Al2O3 content) the more red mud is generated per ton of alumina product. Bugu da kari, even some Al2O3 bearing minerals, musamman irin kaolinite, produce un-desirable side reactions during the refining process and lead to an increase in red mud generation, kazalika da asarar tsada caustic soda sinadaran, a manyan m kudin a haƙar refining tsari.

Red laka ko arr wakiltar babban kuma a kan-faruwa kalubale ga aluminum masana'antu. Red laka ƙunshi gagarumin saura caustic sinadaran ragaggen daga refining tsari, kuma shi ne sosai alkaline, sau da yawa tare da PH na 10 - 13. It is generated in large volumes worldwide – according to the USGS, kiyasta duniya alumina samarwa ya 121 ton miliyan a 2016. This likely resulted in more than 150 ton miliyan na ja laka generated lokacin daidai wannan lokacin. Duk da gudana bincike, ja laka a halin yanzu yana da 'yan kudi ne mai yiwuwa hanyoyi don amfani sake amfani. An kiyasta cewa, sosai kadan na ja laka ne beneficially sake amfani a duniya. Instead the red mud is pumped from the alumina refinery into storage impoundments or landfills, inda aka adana da kuma kula a manyan kudin.

A asarar tsada caustic soda (NaOH) and the generation of red mud are both related to the quality of the bauxite used in the refining process. a general, the lower the Al2O3 content of the bauxite, da ya fi girma da girma na ja laka cewa za a generated, as the non-Al2O3 phases are rejected as red mud. Bugu da kari, the higher the kaolinite or reactive silica content of the bauxite, da mafi ja laka za a generated. The reactive silica content not only increases the volume of red mud, but also consumes caustic soda reagent and reduces the yield of Al2O3 recovered from the bauxite. Saboda haka, there is both an economic and environmental argument to be made for improving the quality of bauxite prior to refining.

A STET bushe rabuwa aiwatar tayi haƙar kera ko haƙar refiners wata damar yin pre-Bayer-aiwatar da haɓaka na haƙar tama don inganta ingancin. Wannan dabarar yana da yawa amfanin:

• Raguwa a aiki da kudin na matata saboda ƙananan amfani da caustic soda ta rage shigar amsawa silica.
• Savings in energy during refining due to lower volume of inert oxides (Fe2O3, TiO2, Non-reactive SiO2) shigar da haƙar. Smaller mass flow of bauxite to refinery results in less energy to heat and pressurize.
• Reduction in red mud generation volume (ie – ja laka to alumina rabo) by removing reactive silica and inert oxides.
• Tighter control over input bauxite quality to refinery reduces process upsets and allows refiners to target ideal reactive silica level to maximize impurity rejection.
• Improved quality control over bauxite feed to refinery reduces process upsets, maximizes uptime and productivity.
• Reduction in red mud volume translates into less treatment and disposal costs and better utilization of existing landfills.
• Ba kamar ja laka, tailings daga wani bushe electrostatic tsari dauke da wani sunadarai, kuma kada ku wakiltar wani dogon lokacin da muhalli ajiya alhaki.
• Ba kamar ja laka, dry by-products/tailings from a bauxite processing operation can be utilized in cement manufacture as there is no requirement to remove the sodium, wanda shi ne detrimental zuwa ciminti yi. a gaskiya – Bauxite is already a common raw material for Portland cement manufacturing.
• Extend operating life of existing bauxite mine by improving quarry utilization and maximizing recovery.
• STET is a low operating cost, high throughput continuous process. No water or chemicals required.