钙离子对红柱石浮选的影响及作用机理

Effect and mechanism of calcium ion on flotation of andalusite

通过单矿物浮选试验,考察钙离子在pH为3~9的浮选条件下对十二胺浮选红柱石的影响。通过对钙离子溶液化学分析和采用波耳兹曼理论计算红柱石表面捕收剂离子浓度变化,探讨钙离子对红柱石浮选的抑制机理。结果表明:3≤p H≤7时,钙离子对红柱石具有较强的抑制作用;7<p H≤9时,钙离子的抑制作用逐渐减弱;3≤p H≤7时,钙离子主要以Ca^(2+)组分形式存在,在红柱石矿物表面吸附后降低了其表面负电性,使十二胺的静电吸附力减弱,此时界面层内RNH_+~3的浓度均小于液相内部RNH_+~3的浓度,钙离子对红柱石具有较强的抑制作用;7<pH≤9时,CaOH^+组分浓度较低,活化作用并不强烈,只是在一定程度上减弱了Ca^(2+)组分的抑制作用,此时界面层内RNH_+~3的浓度大于液相内部RNH_+~3的浓度,钙离子的抑制作用逐渐减弱。

Through single mineral flotation test, the effect of calcium ion on flotation system of andalusite-dodecylamine was studied under the flotation conditions of p H=3-9. Through solution chemical analysis of calcium ion and the use of Boltzmann theory calculating the collector ion concentration in andalusite surface, the inhibition mechanism of calcium ion to andalusite flotation was discussed. The results show that calcium ion has a strong inhibition to andalusite when the p H is in rage of 3-7 and inhibition of calcium ion is waning when the p H is in rage of 7-9. When the p H is in rage of 3-7, the major component of calcium ion is the form of Ca^（2＋）, after adsorption in andalusite mineral surface, its surface potential decreases, the electrostatic adsorption force of dodecylamine decreases, at this time, the RNH_3^＋ concentration in interfacial layer is less than the RNH_3^＋ concentration inside liquid, calcium ion has a strong inhibition to andalusite. When the p H is in rage of 7-9, the component concentration of CaOH^＋ is lower, and the activation is not strong, only the inhibition of Ca^2＋ component is reduced, at this time the RNH_3^＋ concentration in interfacial layer is more than the RNH_3^＋concentration inside liquid, the inhibition of calcium ion is waning.