I-Bauxite Beneficiation Electrostatic

Inqubo esetshenziswa kakhulu yamakhemikhali yokuhlanza i-bauxite ibe yi-alumina, inqubo yeBayer, kufaka phakathi ukucibilika kwe-Al2O3 edwaleni le-bauxite nge-caustic soda (NaOH) emazingeni okushisa aphakeme nengcindezi. The Al2O3 fraction of the bauxite is dissolved into a solution, which is later precipitated out as alumina. Nokho, high-grade bauxite contains up to 60% Al2O3, futhi imali eningi esebenza nge-bauxite ingaphansi kwalokhu, ngezinye izikhathi njengoba low 30-40% Al2O3. Because the desired product is a high-purity Al2O3, the oxides ezisele bauxite (Fe2O3, SiO2, TiO2, Izinto eziphilayo) zihlukaniswe ne-Al2O3 futhi zenqatshwa njengokuhlala indawo yokuhlanza i-alumina (Fika) noma udaka obomvu. Ngenjwayelo, the lower the quality of the bauxite (okuyi, lower Al2O3 content), udaka obomvu xaxa lwenziwa ithoni ngayinye yomkhiqizo we-alumina. Ngaphezu kwalokho, even some Al2O3-bearing minerals, ephawuleka kaolinite, ukukhiqiza engathandeki ohlangothini ukusabela phakathi kucwengisiswa futhi kuholele ukwanda obomvu udaka isizukulwane, kanye nokulahlekelwa ezibizayo caustic soda chemical, a high variable cost in the bauxite refining process.

Red mud, or ARR, represents a large and on-going challenge for the aluminum industry. Red mud contains significant residual caustic chemical leftover from the refining process and is highly alkaline, ngokuvamile line-pH 10 - 13. It is ekhiqizwa kuleli lemiqulu emikhulu emhlabeni wonke - ngokuvumelana USGS, Kulinganiselwa ukukhiqizwa alumina global kwaba 121 amathani ayizigidi ezingu-e 2016. Lokhu kungenzeka kuholele kokunye 150 amathani ayizigidi ezingu udaka olubomvu elakhiwe phakathi nenkathi efanayo. Naphezu ucwaningo okuqhubekayo, udaka olubomvu okwamanje Imbalwa izindlela elizimele ukuba nenzuzo kabusha ukusetshenziswa. It is estimated that very little red mud is beneficially re-used worldwide. Kunalokho, odakeni obomvu akhishwa endaweni yokuhluza alumina kusitoreji impoundments noma landfills, where it is stored and monitored at a high cost.

Ukulahleka ezibizayo soda caustic (NaOH) kanye nesizukulwane sodaka obomvu kuhlobene nekhwalithi ye-bauxite esetshenziselwa inqubo yokucoca. Ngenjwayelo, engezansi okuqukethwe kwe-Al2O3 kwe-bauxite, elikhulu ivolumu udaka olubomvu ukuthi lizokhiqizwa, njengoba izigaba ezingezona i-Al2O3 zenqatshwa njengodaka obomvu. Ngaphezu kwalokho, ukuphakama kokuqukethwe kwe-kaolinite noma okusebenzayo kwe-bauxite, odakeni elibomvu ngaphezulu lizokhiqizwa. 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. Ngakho-ke, both an economic and environmental argument must be made to improve the quality of bauxite prior to refining.

The STET dry separation process offers bauxite producers or bauxite refiners an opportunity to perform pre-bayer-process upgrading of bauxite ore to improve the quality. Le ndlela kunezinzuzo eziningi:

• Ukuncishiswa kwezindleko zokusebenzisa ka femu ngenxa ukusetshenziswa aphansi of soda caustic ngokunciphisa okokufaka Silica esisheshayo.
• Savings in energy during refining are due to the lower volume of inert oxides (Fe2O3, TiO2, I-SiO2 engasebenzi) engena bauxite. A smaller mass flow of bauxite to the refinery results in less energy to heat and pressurize.
• Ukwehliswa kwevolumu yokudala udaka obomvu (okuyi, obomvu odakeni alumina isilinganiso) ngokususa i-silica esebenzayo kanye ne-inert oxides.
• Tighter control over input bauxite quality to the refinery reduces process upsets and allows refiners to target ideal reactive silica levels to maximize impurity rejection.
• Improved quality control over bauxite feed to the refinery reduces process upsets and maximizes uptime and productivity.
• Ukwehliswa kwethamo lodaka olubomvu kuhumusha ekuphathweni okuncane nezindleko zokulahla kanye nokusetshenziswa okungcono kokulahlwa komhlaba okukhona.
• Ngokungafani udaka olubomvu, tailings inqubo ezomile electrostatic awuqekethe amakhemikhali futhi ungameli wesikhathi eside kwemvelo isitoreji isibopho sezomthetho.
• Ngokungafani udaka olubomvu, dry by-products/tailings from a bauxite beneficiation operation can be utilized in cement manufacture as there is no requirement to remove the sodium, okuyinto elimaza usimende womshini. Empeleni, bauxite is already a common raw material used in Portland cement manufacturing.
• Extend the operating life of existing bauxite mines by improving quarry utilization and maximizing recovery through effective bauxite beneficiation.
• I-STET yindleko ephansi yokusebenza, inqubo ephezulu yokuqhubeka. No water or chemicals are required.