| Tailings are the waste of ore extracted from useful components after beneficiation operation,which not only pollutes the environment but also wastes resources.The Guiding Opinions on the Comprehensive Utilization of Bulk Solid Wastes in the Fourteenth Five-Year Plan period clearly points out that it is necessary to accelerate the comprehensive development and utilization of associated mineral resources,step by step recovery of valuable components,and strengthen the utilization of residual waste residue after extraction of valuable metals.In this paper,the process mineralogy study of a gold tailings in Shandong Province is carried out.It is found that the main chemical composition of the tailings is:Si O2 73.69%,Al2O3 12.32%,Na2O 6.64%,K2O 1.05%and TFe 0.7%.The main mineral composition of the tailings is quartz and albinite,with a small amount of potassium feldspar,mica and magnetite.In order to recover quartz and feldspar from the tailings,this paper mainly carried out experimental research from three aspects:pure mineral flotation test,gold tailings grinding and magnetic separation test,and actual mineral flotation test.At the same time,Materals Studio 7.0 software was used to conduct molecular simulation and analyze the interaction mechanism between reagent and mineral and test the contact Angle.The flotation test of pure minerals shows that when the pulp p H is 5 and the molar ratio of dodecylamine and sodium oleate is 2:1,the maximum absolute value of the floating difference between quartz and feldspar is 63.24%,and the feldspar recovery is 88.98%at this time.When the pulp p H value is 12,the maximum absolute value of floating difference between quartz and feldspar is 14.16%and the recovery of quartz is 19.52%by using the anion-cation mixed collector with the molar ratio of laurylamine and sodium oleate of 2:1.The grinding test showed that the grinding time was 15min and the particle size of-0.074mm accounted for 80.6%.The magnetic separation test shows that the magnetic field intensity is 1.0T,and the iron removal rate reaches 94.72%.The actual mineral flotation test showed that when the pulp p H was 5,the albinite with11.23%Na2O content was firstly exposed by using the mixed collector of dodecylamine2×10-4mol/L,sodium oleate 1×10-4mol/L and the quartz inhibitor sodium hexametaphosphate0.6×10-4mol/L.When the pulp p H=13,quartz with Si O2 content of 95.98%was floatated by using the mixed collector of dodecylamine 2×10-4mol/L and sodium oleate 1×10-4mol/L.The geometric modeling optimization and adsorption molecular dynamics simulation of quartz,albinite crystal and cation collector were performed using Materals Studio 7.0 software.The results show that the valence band of the quartz cell is mainly composed of 2s and 2p orbital of oxygen atom,the conduction band is mainly composed of 3s and 3p orbital of silicon atom,and the Fermi level is mainly occupied by 2p orbital of oxygen atom.The valence band of albinite crystal cell is mainly composed of 2s and 2p orbital of oxygen atom,the conduction band is mainly composed of 3p and 3s orbital of sodium atom and 2s and 3p orbital of silicon atom,and the Fermi level is mainly occupied by 2p orbital of oxygen atom.The adsorption of dodecyl amine cation,sodium oleate anion and sodium dodecyl sulfonate on the dissociation surface of quartz and albite(001)is physical adsorption,in which there may be chemical adsorption between dodecyl amine cation and albite crystal.According to the analysis of the interaction mechanism between reagent and mineral,the adsorption form of dodecylamine collector on the surface of quartz and feldspar mineral is the same,both of which are mainly physical adsorption.Sodium oleate exists chemical adsorption on the surface of albite and sodium hexametaphosphate can play a desorption role on the collector on quartz surface.The contact Angle test results show that both quartz and feldspar are hydrophilic minerals.When the collector is added,the surface wettability of the two minerals will be weakened,and the hydrophobicity will be enhanced and it is easy to float.The paper has 65 pictures,22 tables and 87 references. |
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