The Study Of Flotation Of Lead Oxide By Using Xanthate And Its Molecular Structure And Property

Oxidized lead mineral is very difficult to be flotated due to its various, complicated composition and high content of fine slime and soluble salt. Cerusite is one of main oxidized lead minerals. Sulfiding-xanthate is the most effective and the most popular for flotating lead oxide. The paper researched the effect of different structures and length of xanthate collector on flotation behaviors of cerusite by means of single minerals and ores flotation experiments. And researched the relationship between xanthate molecular structure and its property by adsorption test, adsorption free energy calculation, inductive effect index of alkyl, group electronegativity and quantum chemical calculation.At different dosage of sodium sulfide and pH values, the paper tested the effects of 7 kind of different structures and length of xanthate collector which were ethyl xanthate, propyl xanthate, isopropyl xanthate, butyl xanthate, isobutyl xanthate, amyl xanthate and isoamyl xanthate on the floatability of cerusite. The results showed that the flotation efficiency of isomer to cerusite was better than normal. The flotation efficiency of isopropyl xanthate to cerusite was better than propyl xanthate. The flotation efficiency of isobutyl xanthate to cerusite was better than butyl xanthate. But the flotation efficiency of isoamyl xanthate to cerusite was not better than amyl xanthate. With the increasing of carbon chain, the flotation efficiency of xanthate to cerusite was more and more better. The flotation efficiency of amyl xanthate to cerusite was better than butyl xanthate. The flotation efficiency of butyl xanthate to cerusite was better than propyl xanthate. The flotation efficiency of propyl xanthate to cerusite was better than ethyl xanthate.The flotation of cerusite oxidized lead ore were tested on the basis of single mineral flotation results and ore property. The grinding fineness was 90.1%. The dosage of sodium sulfide was 10kg/t. The dosage of collector is 450g/t. Using 7 kind of xanthate to test, the results was in conformity with the single mineral flotation results. The flotation efficiency of isomer to cerusite was better than normal. But the flotation efficiency of isoamyl xanthate to cerusite was not better than amyl xanthate. With the increasing of carbon chain, the flotation efficiency of xanthate to cerusite was better.The relationship between xanthate molecular structure and its property were discussed from the adsorption free energy calculation, the inductive effect index of alkyl, the group electronegativity and the quantum chemical calculation. The results showed that with the increasing of solubility product of xanthate and the number of carbon atoms of isomer xanthate, the adsorption of xanthate on the oxidized lead was increasing. With the increasing of carbon chains of xanthate, the inductive effect index of alkyl was increased and the group electronegativity was decreased. This made charge distribution of sulfur atom in polar group of xanthate to increase and the action of sulfur atom and mineral to enhance. Except amyl xanthate, the inductive effect index of isomer xanthate was more than normal xanthate and the group electronegativity of isomer xanthate was less than normal xanthate. So the flotation efficiency of isomer to cerusite was better than normal. For the effects of isolation, isoamyl xanthate was anomalous. The paper calculated the charge distribution of sulfur atom in polar group of xanthate by I_p of different alkyl and quantum chemical HMO. Theresults showed that: with the increasing of length of carbon chain, charge distribution of sulfur atom in polar group of xanthate was increased. Theorder was: q_ethyl < q_propylisopropyl< q_butyl < q_isobutyl < q_isoamyl < q_amyl·This order was in conformity with the mineral flotation results. The interaction of xanthate with oxidized lead depended greatly on charge distribution of sulfur atom in polar group of xanthate. The bigger charge distribution of sulfur atom was, the greater the flotation efficiency of xanthate was.