浮选固液系统的热力学理论及应用

Thermodynamic Theory of Flotation Solid-Liquid Systems and Its Application

浮选是发生在固液界面的物理化学行为,涉及多种物质组分之间的相互作用,是浮选理论研究的难题之一。同时,多种浮选药剂联合使用,提高矿物的浮选效果,是提高难处理矿产资源高效利用的有效手段。但对浮选固液复杂系统的研究极其困难,至今没有形成系统的理论,组合药剂提高浮选效果的物理机制也还没有获得统一的认识,这都限制了浮选理论的发展和浮选技术的进步。基于热力学基本方程,研究了浮选过程中药剂在矿物表面吸附的熵变和吉布斯自由能变化,构建了各种物质组分相互作用的热力学平衡方程组,提出了反映浮选药剂在矿物表面吸附能力的吸附平衡常数。应用浮选热力学平衡方程组,揭示浮选中各种矿物表面同质化效应的物理本质,推导出了浮选溶度积理论、双电层理论、吸附理论的数学表达式。建立了通过增加矿物表面吸附浮选药剂种类,提高浮选药剂的吸附熵变,减少吉布斯自由能变化,提高浮选药剂吸附的效率和稳定性,从而提高难处理矿物的浮选效果的高熵浮选理论和技术方法。

Flotation is a physicochemical behavior that occurs at the solid-liquid interface,involving interactions among various material components,and is one of the challenging issues in flotation theory research.Additionally,the combined use of various flotation agents to enhance the flotation effect of minerals is an effective approach for improving the efficient utilization of difficult-to-process mineral resources.However,research on complex flotation solid-liquid systems is extremely challenging,and to date,no systematic theory has been established.The physical mechanism by which combined reagents improve flotation effects has not yet reached a consensus,which limits the development of flotation theory and the advancement of flotation technology.Based on the fundamental equations of thermodynamics,this study investigates the entropy change and Gibbs free energy change during the adsorption of reagents on mineral surfaces in the flotation process.It constructs a set of thermodynamic equilibrium equations for the interaction of various material components,and proposes an adsorption equilibrium constant that reflects the adsorption capacity of flotation agents on mineral surfaces.By applying the thermodynamic equilibrium equation set in flotation,the physical nature of the homogenization effect on various mineral surfaces during flotation is revealed,and mathematical expressions for flotation solubility product theory,double layer theory,and adsorption theory are derived.A high-entropy flotation theory and technical method have been established,which enhance the flotation effect of difficult-to-process minerals by increasing the variety of flotation reagents adsorbed on the mineral surface,improving the adsorption entropy change of the flotation reagents,reducing the Gibbs free energy change,and thus improving the efficiency and stability of flotation reagent adsorption.