铁矿石浮选过程中氢键的形成及其作用机理研究

It was discovered from our extensive researches on the structure of iron ore flotation reagent molecules that N, O, and F atoms in the polar groups of the reagents turned out to be the main active sites, such as O in the -COO- of oleic acid (a typical iron ore flotation collector), N in the -NH2 of dodecylamine, N and O in the hydroximic acid and 8-hydroxyquinoline（a typical iron ore flotation depressor), O in the -SO3- of thioetherification sulfonic acid salt, and F in the NaF，HF, and Na2SiF4（typical iron ore flotation depressors). The generality of these three atoms is that they are the atoms which all are able to form the hydrogen bond. Therefore，it is from this novel perspective of hydrogen bond formation conditions and hydrogen bond intensity measurement that the mechanisms of interactions between flotation reagents and iron minerals (plus associated gangue) are investigated.The intensities of hydrogen bonds between polar groups of flotation reagents and atoms of the active site on the surface of the minerals are measured by FTIR and AFM. The corresponding relationship between the intensities of hydrogen bonds and flotation effect is observed, which established the position and role of hydrogen bond in the interactions between polar groups of flotation reagents and atoms of the active site on the surface of the minerals. Besides hydrogen bonding, traditional static adsorption, bonding adsorption, solubility product theory, and crystal field theory of coordination compounds are also used to investigate chemical essence existing in the process of interaction between polar groups of flotation reagents and atoms of the active site on the surface of the minerals. The research can not only reveal the key factors effecting flotation reagent performance but also establish a mechanism of new type of flotation reagent technology development, which will lay the theoretical foundation for the new flotation reagent preparation of iron ore in Anshan area.

从各类铁矿浮选药剂分子结构的研究中发现，浮选药剂分子极性基团中的N、O、F原子为主要活性位点，而这三个原子均为能形成氢键的原子；因此首次从氢键形成条件及其氢键强弱检测角度重新审视浮选药剂与矿物表面的相互作用机理。采用红外光谱、X射线衍射、电子和中子衍射和原子力显微镜等手段检测药剂极性基团与矿物表面活性位点原子之间氢键作用的强弱，考察相互作用过程中氢键的强弱与浮选效果的对应关系，从而确定氢键在浮选机理中的地位与作用；再结合静电吸附、键合吸附、溶度积理论及晶体场理论研究铁矿石浮选药剂与矿物相互作用的物理化学本质，建立浮选药剂与铁矿物及其脉石矿物相互作用新的理论体系。该理论体系的建立不仅可以揭示影响浮选药剂性能的关键因素、建立新型浮选药剂研发机制，而且对阐明矿物颗粒在新型浮选药剂分子溶液中弥散、浸润、静电吸附、氢键形成、分子间缔合、化学键结合等现象的物理化学本质具有重要意义。

从各类铁矿浮选药剂分子结构分析中发现，浮选药剂分子极性基团中的N、O原子为主要活性位点，而这两种原子均为能形成氢键的原子；因此首次从氢键形成条件及其氢键强弱检测角度重新审视捕收剂与矿物相互作用机理。采用红外光谱、量子力学及分子动力学MS软件计算能量等手段检测药剂极性基团与矿物表面活性位点原子之间氢键作用的强弱，考察了氢键的强弱与浮选效果的对应关系，从而确定了氢键在浮选机理中的地位与作用；再结合价键理论、晶体场理论、离子晶体晶格能计算、离子半径比定则、离子球体最紧密堆积原理等，采用量子力学和分子动力学MS软件模拟，重点研究了捕收剂的极性基与磁铁矿、菱铁矿、赤铁矿、石英、白云石等矿物表面的键合作用机理，提出了“捕收剂极性基团中活性原子的价层电子密度（态密度）与矿物表面活性原子的价层电子密度（态密度）匹配关系（类似于“钥匙与锁”的齿间咬合互补关系）才是捕收剂对某种矿物具有高效选择性的本质关键所在”，结合氢键形成条件及氢键强度检测分析，发现了氢键吸附在药剂极性基与矿物表面活性原子之间不可忽视的重要作用，创造性地提出了“氢键耦合多基团协同”的捕收剂分子结构组装新理论。该理论体系的建立揭示了影响浮选药剂性能的关键因素、建立了新型浮选药剂研发机制，对阐明矿物颗粒在新型浮选药剂分子溶液中弥散、浸润、静电吸附、氢键形成、分子间缔合、化学键结合等现象的物理化学本质具有重要意义。. 基于该捕收剂分子结构组装新理论，根据浮选药剂分子设计原理及鞍山具体矿石的性质，合成并研制出了DTSY、DWD等系列高效、低温捕收剂。在鞍山钢铁集团东鞍山烧结厂、河北钢铁集团司家营研山铁矿现场进行了工业化应用试验。通过大量的实验室试验及工业试验使常温浮选药剂成功应用于矿山生产现场，将浮选矿浆温度降低15℃，有效地解决了需要给成吨的矿浆加热、浪费能源的实际问题，实现了铁矿石的低碳化浮选，节能降耗、低碳环保、降本增效、成效显著。