Molecular Design And Properties Of Choline Deep Eutectic Solvents

Zinc-bearing dust sludge is an important source of recycled zinc raw materials.However,the traditional zinc leaching process has become the bottleneck of its industrial application because of its low efficiency,poor leaching selectivity,and high energy consumption.Therefore,this paper takes choline chloride as the matrix,calculates the relationship between the structure and properties of choline chloride with different substituents using quantum chemical method,and designs and synthesizes a deep eutectic solvent suitable for highly selective zinc leaching of zinc-bearing dust sludge so as to realize the efficient recovery of metal minerals that are difficult to separate.According to the frontier molecular orbital and charge population analysis,choline chloride lost electrons in choline deep eutectic solvents and hydrogen bond donors got electrons.Binding energy analysis showed that choline chloride was more likely to react with carboxylic acid hydrogen bond donors,and choline chloride oxalic acid（1:2）eutectic solvent was the most stable.As revealed by the density of states analysis,Zn in ZnO（001）plane was more active than O,Fe and O in Fe₂O₃（001）plane were similar,and O in Al₂O₃（001）and Ca O（001）was more active than Al and Ca.Molecular dynamics indicated that the interaction between ChCl-2OA,ChCl-2MA and ZnO was mainly chemical,and the interaction between ChCl-2MA and ZnO was strong.The interaction between Fe₂O₃ and Al₂O₃ and the two eutectic solvents was mainly intermolecular hydrogen bond.However,the O-H bond energy formed by the interaction between Ca O and two eutectic solvents is much smaller than that of Cl-Zn bond.According to the test results,under the conditions of temperature 90℃,leaching time15 min and liquid-solid ratio 10:1,the leaching rates of ChCl-2OA and ChCl-2MA for ZnO were more than 90%,while the leaching rates of the other three metal oxides were about 10%.Therefore,it could be concluded that ChCl-2OA and ChCl-2MA had certain selectivity for zinc in zinc-bearing dust sludge.ChCl-2MA has better selectivity.Figure 34;Table 20;Reference 113...