矿物浮选过程的耗散结构分析

Analysis of Dissipative Structure in Mineral Floating Process

利用耗散结构理论分析了矿物浮选过程热力学和动力学特征．结果表明,进行浮选的矿浆体系是一个开放系统,矿浆处于湍流状态,系统的熵较大．随着浮选药剂和空气的不断输入,系统从环境吸入负熵流,悬浮矿粒与浮选药剂作用,使系统的熵降低,最后稳定在新的有序状态,形成耗散结构,有利于提高矿物回收率．以回收某镍尾矿为例,由于层流态的浮选柱有效泡沫层厚,底部的旋流力场赋予颗粒动能,能够容易地克服颗粒与气泡间的能垒,形成耗散结构．与浮选机相比,利用浮选拄回收的镍尾矿精矿品位提高0．29％,回收率提高3．02％．

The characteristics of thermodynamics and dynamic systems in mineral floating process were analyzed using a dissipative structure theory. The results show that the slurry floating process is an open system. When the slurry is in the state of onflow, the entropy value is bigger. The system absorbs minus entropy flow with the feed in of flotation agent and air, and the mineral particles react with flotation agent, which result in the decreasing of entropy value. Finally, the system stabilizes in a new order state and forms a dissipative structure, which can effectively enhance the recovery efficiency of mineral. For example, when the valuable metals were recovered from nickel tailings using a cyclonic static micro-bubble flotation column, the nickel concentration grade was increased by 0.29% and the recovery was increased by 3.02% compared with that using a flotation machine. The flotation column can form laminar flow and thicker effective foam layer. The cyclonic force in the bottom of the flotation column gives the particles kinetic energy to overcome the energy obstacle between particles and bubbles and form easily a dissipative structure.