Bauxite Beneficiation Electrostatic

The most widely used chemical process of refining bauxite into alumina, usoro 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. Otú ọ dị, a high-grade bauxite contains up to 60% Al2O3, and many operating bauxite deposits are well below this, mgbe ụfọdụ dị ka ala dị 30-40% Al2O3. Because the desired product is a high purity Al2O3, ndị fọdụrụ oxides na bauxite (Fe2O3, SiO2, TiO2, Organic material) are separated from the Al2O3 and rejected as alumina refinery resides (ARR) or red mud. N'izugbe, ala àgwà ndị bauxite (ie lower Al2O3 content) the more red mud is generated per ton of alumina product. Na mgbakwunye, even some Al2O3 bearing minerals, Ichi kaolinite, produce un-desirable side reactions during the refining process and lead to an increase in red mud generation, nakwa dị ka a ọnwụ nke dị oké ọnụ caustic soda chemical, a nnukwu agbanwe na-eri na bauxite n'usoro nnụcha.

Red apịtị ma ọ bụ ARR na-anọchi anya a buru ibu ma na na-aga ihe ịma aka maka aluminum ụlọ ọrụ. Red apịtị nwere ịrịba mmapụta caustic chemical fọdụrụ afọdụ n'usoro nnụcha, na bụ ukwuu alkaline, mgbe mgbe na a onye Onyenwe anyị + nke 10 - 13. It is generated in large volumes worldwide – according to the USGS, atụmatụ zuru ụwa ọnụ alumina mmepụta bụ 121 nde tọn na 2016. This likely resulted in more than 150 nde tọn red apịtị eme n'otu oge. N'agbanyeghị na-aga n'ihu research, red apịtị ugbu a nwere ole na ole commercially viable ụzọ ka bara uru re-eji. Ọ na-eme atụmatụ na ihe dị nnọọ nta nke red apịtị bụ bara uru re-na n'ụwa nile. Instead the red mud is pumped from the alumina refinery into storage impoundments or landfills, ebe ọ na-echekwara na ekwu na nnukwu na-eri.

Ọnwụ nke dị oké ọnụ caustic soda (NaOH) and the generation of red mud are both related to the quality of the bauxite used in the refining process. N'izugbe, the lower the Al2O3 content of the bauxite, ibu olu nke red apịtị na a ga-eme, as the non-Al2O3 phases are rejected as red mud. Na mgbakwunye, the higher the kaolinite or reactive silica content of the bauxite, ndị ọzọ red apịtị ga-eme. 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. Ya mere, there is both an economic and environmental argument to be made for improving the quality of bauxite prior to refining.

The STET akọrọ nkewa usoro rịọ bauxite emepụta ma ọ bụ bauxite refiners ohere ịrụ tupu Flo Rida feat-usoro upgrading nke bauxite ore iji melite ogo. Nke a na obibia nwere ọtụtụ uru:

• Mbelata ke arụ ọrụ na-eri nke refainari ruru ala oriri nke caustic soda site na mbenata input reactive silica.
• Savings in energy during refining due to lower volume of inert oxides (Fe2O3, TiO2, Non-reactive SiO2) abanye na bauxite. Smaller mass flow of bauxite to refinery results in less energy to heat and pressurize.
• Reduction in red mud generation volume (ie – red apịtị alumina ruru) 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.
• N'adịghị ka red apịtị, tailings si a akọrọ electrostatic usoro nwere dịghị Chemicals na-adịghị na-anọchi anya a ogologo oge na gburugburu ebe obibi na nchekwa liability.
• N'adịghị ka red apịtị, dry by-products/tailings from a bauxite processing operation can be utilized in cement manufacture as there is no requirement to remove the sodium, nke bụ detrimental ka simenti rụpụta. N'ezie – 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.