Effects of sodium salts on reduction roasting and Fe-P separation of high-phosphorus oolitic hematite ore
Effects of sodium salts on reduction roasting and Fe-P separation of high-phosphorus oolitic hematite ore
复制标题
钠盐对高磷鲕状赤铁矿还原焙烧及Fe-P分离的影响
DOI：
10.1016/j.minpro.2013.07.006
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发表时间：
2013-11-14
影响因子：
--
通讯作者：
Jiang, Tao
中科院分区：
文献类型：
--
作者：
Li, Guanghui;Zhang, Shuhui;Jiang, Tao
研究了高磷鲕状赤铁矿在煤基直接还原后湿磁选过程中，钠盐对还原焙烧和铁磷分离的影响。考察了还原温度和还原时间、钠盐种类和用量、磁选原料磨矿细度和磁场强度等参数。添加硫酸钠和硼砂可显著提高铁磷磁选的还原效果和铁磷磁选效果。以铁品位为48.96%、磷品位为1.61%的鲕状赤铁矿为原料，在7.5%硫酸钠和1.5%硼砂的存在下进行还原，在适当条件下湿式磁选，可获得总铁品位为92.7%、总磷含量为0.09%的磁性精矿。还原球团的光学显微镜和x射线衍射（XRD）分析结果表明，在没有钠盐的情况下，还原球团存在10 ~ 20 μ m大小的金属铁颗粒，与脉石矿物密切相关。相反，当硫酸钠和硼砂存在时，金属铁晶粒明显长大，平均大小为50 μ m。钠盐能够通过与脉石反应破坏鲕状结构，增强氧化铁的还原，促进还原过程中金属铁颗粒的生长，有利于鲕状赤铁矿铁磷分离。(C) 2013 Elsevier B.V. All rights reserved。
Effects of sodium salts on reduction roasting and Fe-P separation of high-phosphorus oolitic hematite ore were studied in the process of coal-based direct reduction followed by wet magnetic separation. Various parameters, including reducing temperature and time, type and dosage of sodium salts, grinding fineness of magnetic separation feed and magnetic field intensity were investigated. The results of reduction and Fe-P magnetic separation are significantly improved by the addition of sodium sulfate and borax, in comparison with those in the absence of additives. A magnetic concentrate with total iron grade of 92.7% and phosphorus content of 0.09% was obtained from an oolitic hematite ore containing 48.96% iron and 1.61% phosphorus when reduced in the presence of 7.5% sodium sulfate and 1.5% borax and wet magnetic separated under the proper conditions. The results of optical microscopy and X-ray diffraction (XRD) analyses of reduced pellet reveal that metallic iron grains exist in sizes of 10-20 mu m and are associated with gangue minerals closely when reduced in the absence of sodium salts. By contrast, the oolitic structure is destroyed and metallic iron grains grow markedly to the mean size of 50 mu m when reduced in the presence of sodium sulfate and borax. Sodium salts are capable of destroying the oolitic structure via reacting with gangues, enhancing the reduction of iron oxide and promoting the growth of metallic iron grains during reduction, which is beneficial for Fe-P separation of the oolitic hematite ore. (C) 2013 Elsevier B.V. All rights reserved.