用Fe2O3与Na2CO3制备铁酸钠用于脱除含硫铝酸钠溶液中的硫，采用氧化焙烧及水浸方式对铁基脱硫渣(NaFeS2?2H2O)进行再生，研究了其循环脱硫效果. 结果表明，铁基脱硫渣于950℃下在氧化性气氛中焙烧1 h，可除去脱硫渣中70%的硫；将焙烧渣水浸，硫含量降至0.2%以下，总硫去除率达99%. 将除硫后的浸出渣再制备铁酸钠用于循环脱硫，脱硫率可达67.65%，与初始脱硫剂的脱硫率(69.09%)相当，可实现铁基脱硫剂的再生循环. 焙烧时渣中硫主要以SO2气体排出，剩余可溶性Na2SO4则在水浸过程中进入溶液而被除去.
Along with the increasing scarcity of high quality bauxite and the gradual growth of alumina capacity, resource is crucial for restricting alumina industry development in China. As for there are large amount of refractory diasporic bauxite with high sulfur content in many regions of China, it is significant to investigate the efficiently utilization method of high sulfur bauxite. There are some related research showed that sodium ferrite was used to remove the sulfur in sulfur bearing sodium aluminate solution and the desulfurization effect was verified, which was prepared by Fe2O3 and Na2CO3. For the purpose of sodium ferrite regeneration, this dissertation presented a roasting-leaching process of sulfur removal from desulfurization residue. The process entailed roasting of desulfurization residue in oxidizing atmosphere and the roasted product was leached with water subsequently. Iron-based desulfurization residue (NaFeS2?2H2O) was a solid phase product from the sodium ferrite after removed the S2? in sodium aluminate solution. The regeneration and cyclic desulfurization of iron-based desulfurization residue (NaFeS2?2H2O) by oxidizing roasting and water leaching were investigated by DTG and XRD. The results indicated that oxidizing atmosphere was beneficial to the decomposition of NaFeS2?2H2O and the separation of sulfur and iron in the roasting process. The desulfurization rate was 70% by roasting the iron-based desulfurization residue under oxidizing atmosphere at 950℃ for 1 h. The sulfur content in roasted residue can be further reduced to less than 0.2% after leaching by water and the total sulfur removal rate could reach 99%. The sodium ferrite was prepared by the leaching residue and the cyclic desulfurization rate was up to 67.65%, which was very close to the initial desulfurization rate (69.09%). This conclusion indicated that the iron-based desulfurization residue can be regenerated and cyclic desulfurized. The sulfur in the desulfurization residue was discharged in the form of SO2 during the roasting process, while the rest sulfur was removed in form of Na2SO4 by water leaching. These results will contribute to the purification of the sulfur containing sodium aluminate solution and the utilization of the high-sulfur bauxite.
[1] Xue S G, Zhu F, Kong X F, et al. A review of the characterization and revegetation of bauxite residues (Red mud) [J]. Environmental Science and Pollution Research, 2016, 23(2): 1120?1132.
[2] 彭 欣, 金立业. 高硫铝土矿生产氧化铝的开发与应用[J]. 轻金属, 2010, (11): 14?17.
Peng X, Jin L Y. Development and application of bauxite containing high sulfur[J]. Light Metals, 2010, (11): 14?17.
[3] Xie Q, Chen W, Xie Q, et al. Corrosion behavior of 16Mn low alloy steel in sulfide-containing Bayer solutions[J]. Corro Sci, 2014, 86(10): 252?260.
[4] Kuznetsov S I, Grachev V V, Tyurin N G. Interaction of iron and sulfur in alkaline aluminate solutions[J]. Zh. Prikl. Khim, (Leningrad), 1975, 48(4): 748?750.
[5] 王晓民, 张廷安, 吕国志, 等. 高硫铝土矿浮选除硫药剂的选择[J].东北大学学报(自然科学版), 2010, 31(4): 555?558.
Wang X M, Zhang T A, Lv G Z, et al. Selection of Flotation Desulfurization Collector for High-Sulfur Bauxite[J]. Journal of Northeastern University(Natural Science), 2010, 31(4): 555?558.
[6] Hu X L, Chen W M, Xie Q L. Sulfur phase and sulfur removal in high sulfur-containing bauxite[J]. Trans. Nonferrous Met. Soc. China. 2011, 21(7): 1641?1647.
[7] 吕国志, 张廷安, 鲍 丽, 等. 高硫铝土矿的焙烧预处理及焙烧矿的溶出性能[J]. 中国有色金属学报，2009,19(09): 1684?1689.
Lv G Z, Zhang T A, Bao L, et al. Roasting pretreatment of high-sulfur bauxite and digestion performance of roasted ore[J]. The Chinese Journal of Nonferrous Metals, 2009, 19(09): 1684?1689.
[8] Lv A J, Shen Y Q, Gong X Z, et al. Effects of electrolyte recycling on desulfurization from bauxite water slurry electrolysis[J]. Trans. Nonferrous Met. Soc. China. 2016, 26(6): 1714?1720.
[9] Liu Z W, Li W X, Ma W H, et al. Conversion of sulfur by wet oxidation in the bayer process[J]. Metall. Mater. Trans. B, 2015, 46 (4): 1702?1708.
[10] Lewis A E. Review of metal sulphide precipitation[J]. Hydrometallurgy, 2010, 104(2): 222?234.
[11] Lewis A, Hille V R. An exploration into the sulphide precipition method and its effect on metal sulphide removal[J]. Hydrometallurgy, 2006, 81(3-4): 197?204.
[12] Liu Z W, Li W X, Ma W H, et al. Research on Digestion Behavior of Sulfur in High-Sulfur Bauxite[C]//Light Metals 2015. Shenyang: Springer International Publishing, 2015: 39?43.
[13] Li X B, Li C Y, Peng Z H, et al. Interaction of sulfur with iron compounds in sodium aluminate solutions[J]. Trans. Nonferrous Met. Soc. China, 2015, 25(2): 608?614.
[14] 李重洋，拜耳法处理高硫铝土矿铝酸钠溶液中硫铁控制原理及技术 [D]. 长沙：中南大学, 2014.
Li C Y, Theroy and Technology for Sulfur and Iron Controlling in Aluminate Solution of Treating High-sulfur Bauxite by Bayer Process [D]. Changsha: Central South University, 2014.
[15] Li X B, Niu F, Tan J, et al. Removal of S2? ion from sodium aluminate solutions with sodium ferrite[J]. Trans. Nonferrous Met. Soc. China, 2016, 26(5): 1419?1424.
[16] 谭杰，铝酸钠溶液中S2?的铁酸钠沉淀脱除 [D]. 长沙：中南大学, 2014.
Tan J, Removal of S2? from Sodium Aluminate Solution with Sodium Ferrite [D]. Changsha: Central South University, 2014.
[17] 胡鹏举, 彭志宏, 周秋生,等. 铁基脱硫渣的再生循环[J]. 过程工程学报, 2017, 17(6): 1227-1232.
Hu P J, Peng Z H, Zhou Q S, et al. Regeneration and Cyclic Utilization of Iron-based Desulfurization Residue[J]. Chin. J. Process Eng., 2017, 17(6): 1227-1232.
[18] 李小斌, 王一霖, 周秋生,等.铁酸钠对含铁矿物碳热还原过程铁粒形成的影响[J].中国有色金属学报, 2016, 26(05): 1129?1135.
Li X B, Wang Y L, Zhou Q S, et al. Effect of sodium ferrite (Ⅲ) on iron grain formation in carbothermal reduction of iron minerals[J]. The Chinese Journal of Nonferrous Metals, 2016, 26(05): 1129?1135.
