(中南大學(xué) 資源加工與生物工程學(xué)院，長沙 410083)
摘 要: 開發(fā)一種處理高鋁褐鐵礦的新工藝。采用鈉化還原−磁選法對一種鐵品位為48.92%(質(zhì)量分數(shù))、Al2O3含量為8.16%(質(zhì)量分數(shù))的高鋁褐鐵礦進行鋁鐵分離研究。結(jié)果表明：當(dāng)硫酸鈉添加量為12%(質(zhì)量分數(shù))，還原焙燒溫度為1 050 ℃，焙燒時間為60 min時，焙燒產(chǎn)物磨至粒度小于0.074 mm的占98%；在磁場強度為0.675 T的條件下，可獲得鐵品位91.00%，Al2O3含量1.36%的金屬鐵粉，鐵的回收率為91.58%，鋁的脫除率為90.47%。XRD研究結(jié)果表明，在鈉鹽焙燒過程中，鐵氧化物被還原成金屬鐵，大部分鋁、硅礦物與硫酸鈉反應(yīng)生成非磁性物質(zhì)鋁硅酸鈉，經(jīng)磁選后進入非磁性物，從而實現(xiàn)鋁鐵的高效分離。
關(guān)鍵字: 褐鐵礦；鈉鹽；鋁；還原焙燒；磁選
(
（School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:A novel process was developed to treat the high-aluminum limonite ores. Al-Fe separation from a high-aluminum limonite ore with total iron grade of 48.92% and Al2O3 content of 8.16% (mass fraction) was studied by reduction roasting with addition of sodium salt followed by magnetic-separation. The results show that metallic iron powder with total iron grade of 91.00% and Al2O3 content of 1.36% is obtained when the sodium sulfate dosage is 12% (mass fraction), the roasting temperature is 1 050 ℃ and time is 60 min, and the grinding fineness is 98% ores less than 0.074 mm and the magnetic field intensity is 675 mT, then the iron recovery is 91.58%, and the removal of Al2O3 is 90.35%. The XRD results indicate that the iron oxides are transformed into metallic iron, most of the aluminiferous mineral and silicic mineral reacts with the sodium sulfate during the reduction roasting and forms sodium aluminosilicates, which enter into the nonmagnetic materials during the magnetic separation, then Al-Fe separation is realized.
Key words: limonite ores; sodium salt; aluminum; reduction roasting; magnetic separation
