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新型含钛矿物捕收剂TBC及其作用机理
The Role of TBC on Titanium Minerals Flotation
【作者】 李文军;
【导师】 孙伟;
【作者基本信息】 中南大学 , 矿物加工工程, 2010, 硕士
【摘要】 我国金红石资源储量不足、砂矿少、原生矿多,特别是金红石粒度嵌布细、分选难度大,尤其是重选抛尾难度大。浮选和浮选捕收剂的研究是解决我国金红石资源利用的关键。本论文研究寻找到一种有效的含钛矿物浮选捕收剂--TBC。从分子动力学模拟、配位化学、浮选溶液化学、光谱检测等各个角度探讨了捕收剂对矿物,特别是新型药剂TBC与金红石矿物的作用机理。主要内容和结果如下:试验表明:TBC具有更强的捕收性能和极高的选择性。在最佳的浮选条件下,金红石单矿物的浮选回收率可以达到97.5%;金红石与石英混合矿浮选精矿中金红石的品位>80%,回收率>97%;金红石与方解石混合矿浮选精矿中金红石的品位和回收率均达到80%。对钛铁矿和钛辉石单矿物的浮选,TBC同样具有较强的捕收能力和选择性。pH=7、TBC的用量为8×10-5mol/L时两种矿物的回收率分别为91%和47%,两种矿物的可浮性在pH=5-9时有明显的差异。以TBC为捕收剂浮选富集德兴铜尾中的金红石并取得了一定的效果。给矿二氧化钛品位11.18%时,TBC与油酸混合使用浮选的攀枝花钛铁矿一次精选的品位和回收率可以达到42.78%和56.95%。TBC作为一种新型的金红石捕收剂,可以为含钛矿物的浮选提供技术参考。量子化学计算的结果从TBC作为一种硬碱的角度说明了它对钛矿物的捕收能力,而Ti(Ⅳ)和Ca(Ⅱ)离子的性质可以影响TBC对金红石和方解石浮选的选择性。分子动力学模拟和吸附作用能的计算表明:TBC与金红石的作用要强于与石英的作用,从而实现了对金红石浮选的选择性。结合分子模拟、溶液化学分析及光谱检测可以推断TBC与金红石表面的作用机理:在浮选矿浆中,TBC可能首先以未解离的形式向金红石表面靠近和发生物理吸附,而后继续靠近并与金红石表面的Ti质点发生化学键合,形成五元环稳定螯合物,从而具有了较强的选择性捕收能力。
【Abstract】 Due to inadequate reserves of rutile, espeically the lack of placer deposits, the primary ore became the major rutile resources in China. And the separation of rutile from the other component minerals is difficult because the rutile grain size often appears very fine and it’s difficult to realize tailings discarding.T hus the development of flotation collectors is of vital importance for the utilization of the rutile resources in China.In this paper, a new effective, selective chelating collector, TBC, was developed for titaniium minerals flotation based on pure mineral flotation and the applicatin to process two kinds of titanium ores.The mechanism was them studied in aspects of molecular dynamics, coordination chemistry, solution chemistry and also spectra dertermination. The following are the main work and results:In the pure mineral flotation, both of single and the mixtures, TBC shows much higher performance for rutile, compared with SHA and BHA, and no activation was needed. Under the optimum condition, the recovery of single mineral flotation reached 97.5%.In the mixture flotation of rutle and quartz, the recovery and grade of rutile reached to 92% and 80%, respectively. The results for the mixture flotation of rutile and calcite were both 80%.For the single mineral flotation of Panzhihua ilmenite and a gangue mineral,titanaugite,the performace was still high and the selectivity still very good. With the pH=7 and the dosage at 8×10-5mol/L, recoveries of 91% and 47% were achieved for the two minerals respectively and the flotability difference was remarkable at the pH range of 5-9.TBC shows a limit performance in batch scale flotation of a copper ore taling while the resulta were much better for Panzhihua ilmenite ores.The HOMO and LUMO energy of the seven collectors were calculated to evalute the ability of them to compex Ti(IV).The differerce of the stcuture of Ti(Ⅳ) and Ca(Ⅱ)may lead to the selectivity of chelating collectors in flotation of rutile and calcite. Adsorption model of TBC onto the rutile(110) surface and thea-quartz(100) surface were established and optimized by Molecular Dynamics, and the adsorption energies were calculated to find the lowest energy adsorption form of TBC on of the two mineral surfaces.It turned out that molelular adsorption and the complete dissociation form were the best form for rutile and quartz, respectively.The tendcy of TBC to adsorp on rutile surface is much stronger than to quartz surface, which explains the selectivity of the collector for tutile.An interaction mechanism was finally proposed based on moleculaer dynamics, IR spectrum and further analysis.In the flotation process, TBC may first moves close to rutile surface in the molecular form.Then it moves closer until chemical bonds are formed and TBC chelates to Ti atom to form a 5-membered ring.
【Key words】 titanium minerals; flotation; collector; TBC; interaction mechanism;