钨酸盐溶液中季铵树脂吸附除钼的应用基础研究

钨酸盐溶液中高含量钼难以高效除去是钨冶炼面临的新问题。季铵树脂吸附法处理高钼溶液潜力大，无废渣产生，但目前须用强氧化剂辅助解吸，造成树脂氧化降解，严重缩短其使用寿命。针对该技术瓶颈，本项目提出实现负钼树脂无氧化剂解吸的关键是调控硫代钼酸根和解吸剂对树脂的亲和力，并由此提炼亟需解决的科学问题：Mo-W-S-H2O体系物种与季铵树脂的相互作用规律。为此，本项目拟测定季铵树脂对Mo-W-S-H2O体系物种的选择性系数，明确其与树脂亲和力的强弱程度；测定吸附等温曲线，建立热力学模型，求得吸附反应的热力学参数；在透明离子交换柱中，采用前沿色层法和淋洗色层法分别研究物种的动态交换和洗脱行为，建立树脂吸附除钼和负钼树脂无氧化剂解吸的调控机制，最终形成系统的季铵树脂吸附除钼的基础理论。研究所得结果将有助于突破负钼季铵树脂无氧化剂解吸的技术瓶颈，推动树脂吸附法除钼的工业应用，从而解决高钼溶液除钼的难题。

Removal of high-content molybdenum from tungstate solution becomes a new challenge for extractive metallurgy of tungsten. However, the adsorption method using quaternary ammonium resin (QA resin) has great potential to remove the high-content Mo without the production of residue, but the desorption of tetrathiomolybdate must be performed with the help of strong oxidant at present, which lead to oxidative degradation of the resin and shorten its service life. Aiming at such technical problem, a key measure, which is to regularize affinities of thiomolybdate and desorption reagent to the QA resin, is proposed in this project for desorbing Mo form Mo-loaded resin without the use of oxidant. Thus, it is necessary to solve an urgent scientific problem: the interaction between the QA resin and species of Mo-W-S-H2O system. For this purpose, selectivity coefficients of the QA resin to the main species of Mo-W-S-H2O system will be determined to clarify the degree of affinity of a species to the resin. Furthermore, adsorption isotherms of the main species will also determined, and then adsorption model could be established to calculate thermodynamic parameters of the adsorption reactions. On the other hand, frontal chromatography and elution chromatography performed in transparent ion-exchange column will be employed to study dynamic ion-exchange behaviors and elution behaviors, respectively. Based on such researches, regulatory mechanisms of both removing Mo with the QA resin and desorbing Mo form the Mo-loaded resin without the use of oxidant will be established. Finally, a systematic and basic theory for removing Mo by the adsorption method with the QA resin could be form. All above researches will help to through the bottleneck of the desorption of Mo without the use of oxidant, promote commercial application of the adsorption method and thus solve the problem for the removal of high-content Mo.