Bauxite Beneficiation Electrostatic

The most widely used chemical process of refining bauxite into alumina, ilana 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. sibẹsibẹ, a high-grade bauxite contains up to 60% Al2O3, and many operating bauxite deposits are well below this, lẹẹkọọkan bi kekere bi 30-40% Al2O3. Because the desired product is a high purity Al2O3, awọn ti o ku oxides ni bauxite (Fe2O3, SiO2, TiO2, Organic material) are separated from the Al2O3 and rejected as alumina refinery resides (ARR) or red mud. Ni Gbogbogbo, isalẹ didara awọn bauxite (ie lower Al2O3 content) the more red mud is generated per ton of alumina product. Ni afikun, even some Al2O3 bearing minerals, paapa kaolinite, produce un-desirable side reactions during the refining process and lead to an increase in red mud generation, bi daradara bi a isonu ti gbowolori caustic omi onisuga kemikali, kan ti o tobi ayípadà iye owo ni awọn bauxite refining ilana.

Red pẹtẹpẹtẹ tabi ARR o duro kan ti o tobi ati lori-ti lọ ipenija fun awọn aluminiomu ile ise. Red pẹtẹpẹtẹ ni significant péye caustic kemikali ajẹkù ti lati refining ilana, ati ki o jẹ gíga ipilẹ, igba pẹlu kan pH ti 10 - 13. It is generated in large volumes worldwide – according to the USGS, ifoju agbaye alumina gbóògì wà 121 milionu toonu ni 2016. This likely resulted in more than 150 milionu toonu ti pupa pẹtẹpẹtẹ ti ipilẹṣẹ nigba ti akoko kanna. Pelu ti nlọ lọwọ iwadi, pupa pẹtẹpẹtẹ Lọwọlọwọ ni o ni diẹ lopo le yanju ototo to anfani ti tun-lilo. O ti wa ni ifoju-wipe gan kekere ti pupa pẹtẹpẹtẹ ni beneficially re-lo ni agbaye. Instead the red mud is pumped from the alumina refinery into storage impoundments or landfills, ibi ti o ti wa ni ti o ti fipamọ ati ki o ni abojuto ni o tobi iye owo.

Awọn isonu ti gbowolori caustic omi onisuga (NaOH) and the generation of red mud are both related to the quality of the bauxite used in the refining process. Ni Gbogbogbo, the lower the Al2O3 content of the bauxite, ni o tobi iwọn didun ti pupa pẹtẹpẹtẹ ti yoo wa ni ti ipilẹṣẹ, as the non-Al2O3 phases are rejected as red mud. Ni afikun, the higher the kaolinite or reactive silica content of the bauxite, awọn diẹ pupa pẹtẹpẹtẹ yoo wa ni ti ipilẹṣẹ. 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. nitorina, there is both an economic and environmental argument to be made for improving the quality of bauxite prior to refining.

Awọn STET gbẹ Iyapa ilana ipese bauxite ti onse tabi bauxite refiners ohun anfani lati ṣe ami-Bayer-ilana Igbegasoke ti bauxite irin lati mu awọn didara. Yi ona ni o ni ọpọlọpọ awọn anfani:

• Idinku ninu awọn ọna iye owo ti refinery nitori kekere agbara ti caustic omi onisuga nipa atehinwa input ifaseyin yanrin.
• Savings in energy during refining due to lower volume of inert oxides (Fe2O3, TiO2, Non-reactive SiO2) titẹ awọn pẹlu bauxite. Smaller mass flow of bauxite to refinery results in less energy to heat and pressurize.
• Reduction in red mud generation volume (ie – pupa amọ to alumina ratio) 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.
• Ko pupa pẹtẹpẹtẹ, tailings lati kan gbẹ electrostatic ilana ni ko si kemikali ati ki o ko soju kan gun-igba ayika ibi ipamọ layabiliti.
• Ko pupa pẹtẹpẹtẹ, dry by-products/tailings from a bauxite processing operation can be utilized in cement manufacture as there is no requirement to remove the sodium, eyi ti o jẹ bonkẹlẹ si simenti manufacture. Ni pato – 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.