Comparison of microwave irradiation and oxidation roasting as pretreatment methods for modification of ilmenite physicochemical properties
Comparison of microwave irradiation and oxidation roasting as pretreatment methods for modification of ilmenite physicochemical properties
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DOI：
10.1016/j.jiec.2015.09.018
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发表时间：
2016-01
影响因子：
6.1
通讯作者：
A. Mehdilo;M. Irannajad
中科院分区：
文献类型：
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作者：
A. Mehdilo;M. Irannajad
比较了微波辐照和氧化焙烧（常规加热方式）对钛铁矿表面性质和浮选行为的影响。通过微观和实验室尺度的浮选试验、XPS、XRD、FTIR、SEM和微探针分析、zeta电位和接触角测量进行比较。微尺度浮选试验表明，微波辐照预处理和氧化焙烧预处理后，钛铁矿浮选回收率分别从73.5%提高到近94%和91%。这与XPS分析结果一致，微波辐照预处理后的Fe3+含量从48.5%提高到66%，氧化焙烧后的Fe3+含量提高到64.8%。FTIR分析、zeta电位和接触角测试表明，预处理后钛铁矿可浮性和疏水性的改善是由于更多的油酸离子进入亥姆霍兹层，增加了比铁更不溶的油酸铁铁的形成。两种方法预处理后，石英的表面性能和可浮性均无明显变化。在浮选试验中，对磨矿后的矿石进行微波辐照和氧化焙烧预处理，在浮选精矿tio2品位不发生明显变化的情况下，tio2回收率分别从65.4提高到76.2%和73.7%。未磨矿经微波辐照和氧化焙烧后，tio2的回收率分别达到79.8%和70.2%。两种方法预处理后，脉石矿物中铁含量的降低，提高了tio2品位和回收率。微波辐照预处理对tio2的回收率和分离效率的提高均大于氧化焙烧预处理。此外，微波辐照减少了活化剂和抑制剂的消耗。
The effect of microwave irradiation and oxidation roasting (as a conventional heating method) on ilmenite surface properties and its flotation behavior were compared. This comparison was performed by carrying out micro and laboratory scales flotation tests, XPS, XRD, FTIR, SEM and microprobe analyses, zeta potential and contact angle measurements. The micro scale flotation experiments indicated that the ilmenite flotation recovery improves from 73.5% to almost 94% and 91% after pretreatment by microwave irradiation and oxidation roasting, respectively. This is in good concordance with the results of XPS analysis showing the increase of Fe3+content from 48.5% to 66% after pretreatment by microwave irradiation and 64.8% after oxidation roasting. As evidenced by FTIR analysis, zeta potential and contact angle measurements, the improvement in ilmenite floatability and hydrophobicity after pretreatment is due to the entrance of more oleate ions into the Helmholtz layer and the increase of the formation of ferric iron oleate which is more insoluble than the ferrous one. The surface properties and floatability of quartz does not change significantly after pretreatment by both methods.In ore flotation experiments, when the grinded ore was pretreated by microwave irradiation and oxidation roasting, without significant changes in the TiO2grade of flotation concentrate, the recovery of TiO2improves from 65.4 to 76.2% and 73.7%, respectively. In the case of non-grinded ore, the recovery of TiO2increases up to 79.8% and 70.2% after microwave irradiation and oxidation roasting, respectively. The decrease of iron content in the gangue minerals increases the improvement of TiO2grade and recovery after pretreatment by both methods. Using microwave irradiation as a pretreatment process, the improvement in the recovery of TiO2and separation efficiency is more than those of oxidation roasting. In addition, microwave irradiation reduces the consumption of activation and depressant agents.