利用弱碱性阴离子交换树脂从硫化后的钨酸钠溶液中吸附除钼

摘要

Thiomolybdate ( --24MoO xS x ) has high affinity to alkalescent anion exchange resin (primary amine), and can be striped with NaOH solution easily, but the adsorption capacity of Mo is very low when Mo content in Na2WO4 solution is low. To increase the adsorption capacity of Mo, the effects of Na2WO4 composition of solution and the kind of sulfurizing reagent on the adsorption behavior of Mo were studied. The results show that the adsorption rate and adsorption capacity of Mo increases with increasing Mo concentration for Na2WO4 solution containing 93 g/L WO3. The sulfurizing reagent NaHS, as a alternative to Na2S, lowers the equilibrium pH value of solution and favors sulfurizing and adsorbing of Mo. The Na2WO4 solution containing 85 g/L WO3, 7.6 g/L Mo, 100 g/L Na2CO3 sulfurized with NaHS is adsorbed by means of column test, and mass ratio of WO3 to Mo of the elution before breakthrough reaches 1970:1, the removal ratio of Mo is 99.4%, the loss rate of WO3 is 1.5%, and the adsorption capacity of Mo is 31 mg/mL. The stripping ratio of Mo is 97.3%when the loaded resin stripped with 1 mol/L NaOH solution.%弱碱性阴离子交换树脂(伯胺型)可从钨酸盐溶液中优先吸附--24MoO xS x ，且负载树脂易于用NaOH解吸，但当钨酸钠溶液中钼含量较低时其对钼的吸附容量很小。为提高其对钼的吸附容量，研究钨酸钠溶液成分及硫化剂种类对钼吸附行为的影响。结果表明：对于含93g/L WO3的钨酸钠溶液，钼的吸附率和吸附容量随料液中钼浓度的增加而增大；相对于Na2S，以NaHS作为硫化剂可明显降低溶液的平衡pH值，显著改善钼的硫化效果，从而更有利于钼的吸附；对于含85 g/L WO3、7.6 g/L Mo、100 g/L Na2CO3的钨酸钠溶液，以NaHS作为硫化剂硫化后，经动态吸附得到的钨酸钠溶液中，WO3与Mo的质量比达到1970：1，除钼率达99.4%，钨损失率仅为1.5%，钼的吸附容量(单位体积的湿树脂吸附的钼的质量)达31 mg/mL。经1.0 mol/L NaOH溶液解吸后，钼的解吸率达97.3%。