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采用基于密度泛函理论的第一性原理,计算了理想白钨矿、萤石和方解石的电子结构,及水分子和聚丙烯酸钠在3种矿物表面吸附的吸附能,并采用单矿物浮选试验验证了水体系中聚丙烯酸钠在3种矿物表面的吸附能的关系。计算结果表明:白钨矿、萤石和方解石的优化都采用局域密度泛函近似(LDA)下的CA-PZ交换相关函数,截断能分别为277,270和275 e V;能带结构表明3种矿物均属于绝缘体,其Ca原子态密度组成很相似,因此化学活性非常相似,在浮选过程中表现出相似的浮选性能;Mulliken布居分析表明3种矿物Ca原子所带电荷大小顺序为方解石>白钨矿>萤石。在矿浆中聚丙烯酸钠排开矿物表面的水分子与矿物发生吸附,其吸附能均为负值,大小顺序为白钨矿>方解石>萤石,说明自然p H(未添加p H调整剂)条件下聚丙烯酸钠对3种矿物有抑制作用,抑制强弱为萤石>方解石>白钨矿。单矿物浮选试验结果表明,聚丙烯酸钠为抑制剂时,在自然p H条件下,白钨矿、萤石和方解石的回收率分别为76.03%,18.59%和33.68%,此时聚丙烯酸钠的抑制强弱顺序为萤石>方解石>白钨矿,与计算模拟结果相符。为进一步了解白钨矿、萤石和方解石可浮性的差异及含钙矿物浮选新药剂开发提供理论参考。
The electronic structure of ideal scheelite, fluorite and calcite, and the adsorption energy of water molecules and sodium polyacrylate adsorbed on three mineral surfaces were calculated by the first principle based on density functional theory. The single mineral flotation test The relationship between the adsorption energy of sodium polyacrylate on three mineral surfaces in water system was verified. The calculated results show that the scheelite, fluorite and calcite are optimized by CA-PZ exchange correlation function under local density functional approximation (LDA), the cut off energies are 277, 270 and 275 eV respectively. The band structure shows that the three minerals All belong to the insulator. The density of Ca atoms is very similar, so the chemical activity is very similar and shows similar flotation performance during the flotation process. The population distribution of Mulliken shows that the order of charge of Ca atoms in the three minerals is calcite> Scheelite> fluorite. The adsorption of water molecules and minerals on the surface of mineral deposits in the sodium polyacrylate mineral was negative, and the order of adsorption was scheelite> calcite> fluorite, indicating that natural p H (no p H modifier) Under the conditions of sodium polyacrylate inhibition of three kinds of minerals, the inhibition of the strength of fluorite> calcite> scheelite. The results of single mineral flotation test showed that the recoveries of scheelite, fluorite and calcite were 76.03%, 18.59% and 33.68%, respectively, under the natural condition of p H when sodium polyacrylate was used as inhibitor. At this time, the sodium polyacrylate The order of inhibition is fluorite> calcite> scheelite, which is consistent with the calculated simulation results. In order to further understand the difference between flotation of scheelite, fluorite and calcite and the development of new agents for calcium mineral flotation.