Hao Haiqing, Li Lixia, Somasundaran Ponisseril, Yuan Zhitao
School of Resources & Civil Engineering , Northeastern University , Shenyang 110819 , China.
Langmuir Center for Colloid and Interface Science , Columbia University , New York , New York 10027 , United States.
Langmuir. 2019 May 28;35(21):6878-6887. doi: 10.1021/acs.langmuir.9b00669. Epub 2019 May 13.
Pregelatinized starch (PS) was used for the selective flocculation and flotation of fine siderite in a carbonate-containing iron ore. With PS, the flotation of fine siderite was improved. The repulsive forces between fine siderite particles and the attractive forces between siderite and hematite or quartz were decreased after treatment with PS, indicating that the aggregation of siderite was enhanced and the aggregations of mixed minerals were weakened. An analysis of the changes in X-ray photoelectron spectra showed that coordination bonds were formed when PS was adsorbed on siderite and hematite. However, PS could not adsorb on quartz. Moreover, the molecular simulation showed that the main mechanism for PS adsorption on siderite was confirmed as a "tail model" with end -OH coordinated with Fe. The bridge connection of PS enhanced the flocculation of fine siderite. The flotation of fine siderite was also enhanced. For hematite treated with PS, the combination of coordination bond and hydrogen bond resulted in the "loop model" and "train model" as the main adsorption mechanisms of PS. The molecules covered the hematite surface and prevented the adsorption of the collector. The flotation of hematite was depressed. As a result, the selective flocculation and flotation of fine siderite were realized.
预糊化淀粉（PS）用于含碳酸盐铁矿石中细粒菱铁矿的选择性絮凝和浮选。使用PS后，细粒菱铁矿的浮选效果得到改善。用PS处理后，细粒菱铁矿颗粒之间的排斥力以及菱铁矿与赤铁矿或石英之间的吸引力降低，这表明菱铁矿的团聚增强，混合矿物的团聚减弱。对X射线光电子能谱变化的分析表明，PS吸附在菱铁矿和赤铁矿上时会形成配位键。然而，PS不能吸附在石英上。此外，分子模拟表明，PS吸附在菱铁矿上的主要机制被确认为“尾模型”，即末端-OH与Fe配位。PS的桥连作用增强了细粒菱铁矿的絮凝。细粒菱铁矿的浮选也得到增强。对于用PS处理的赤铁矿，配位键和氢键的结合导致“环模型”和“链模型”成为PS的主要吸附机制。分子覆盖了赤铁矿表面，阻止了捕收剂的吸附。赤铁矿的浮选受到抑制。结果，实现了细粒菱铁矿的选择性絮凝和浮选。
