海藻酸钠强化油酸钠浮选分离白钨矿与方解石的第一性原理研究

First−principles Study on Sodium Alginate Enhanced Sodium Oleate for Flotation Separation of Scheelite and Calcitee

白钨矿与方解石的浮选分离一直是研究热点。考察了油酸钠体系下海藻酸钠对白钨矿与方解石浮选分离的影响,采用密度泛函理论,分别建立水-矿物、海藻酸钠-矿物、油酸钠-矿物三种吸附模型,比较了吸附能的差异。研究结果表明,加入海藻酸钠作为抑制剂后,当油酸钠用量为50 mg/L、海藻酸钠用量为10 mg/L、矿浆pH=9时,白钨矿和方解石回收率分别为83.20%、5.20%,分选效果良好。计算结果表明,在水体系中,海藻酸钠和矿物表面均发生吸附,但在方解石表面的吸附强于在白钨矿表面的吸附,海藻酸钠作用后油酸钠在方解石表面的吸附能为43.20 kJ/mol、在白钨矿表面的吸附能为-136.32 kJ/mol,这说明海藻酸钠在油酸钠体系下能够选择性抑制方解石,而白钨矿不受影响,原子力显微镜(AFM)观察结果同时也证实了大量海藻酸钠吸附在方解石表面。研究结果可为白钨矿、方解石的浮选分离提供理论指导。

Flotation separation of scheelite and calcite has been a hot research topic.The effect of sodium alginate on the flotation separation of scheelite and calcite in a sodium oleate system was investigated,Density functional theory was used to establish three adsorption models of water−mineral,sodium alginate−mineral,and sodium oleate−mineral,respectively compared the differences in adsorption energy.The results of the study showed thatwhen the dosage of sodium oleate was 50 mg/L,sodium algina was 10 mg/L,and the pH=9,the recovery of calcite could be controled to 5.20%,while the recovery of scheelite could reach to 83.20%,which showed a significant effect.The molecular simulation results indicated that sodium alginate adsorped on both surface,but the adsorption energy of calcite was stronger than scheelite.After adsorption of sodium alginate,the adsorption energy of sodium oleate on calcite was 43.20 kJ/mol,the adsorption energy of sodium oleate on scheelite was−136.32 kJ/mol.The results demonstrate alginate can selectively inhibit calcite in sodium oleate without affecting scheelite,The AFM image observed also confirmed that a large amount of sodium alginate was adsorbed on the surface of calcite,also provided constructive advice for the separation of scheelite and calcite.