Research On Flotation Separation Of Complex Lead-Zinc-Sliver Sulfide Ore And Its Practice

Located in Mengzi county,Yunnan province,Bainiuchang deposit is a super-large poly-metal deposit with lead,zinc,silver and indium.It is one of the three large deposits in tin-zinc-copper-silver-lead-tungsten poly-metal metallogenetic belt at the east-south part of Yunnan province.In this thesis,the flotation separation of complex lead-zinc-sliver sulfide ore was studied.The flow was designed,revised,and practical experiments were carried out.Based on the flotation theory of sulfide minerals,the mechanism of sulfide flotation and its practical application were studied.The flotation tests of galena,sphalerite,pyrite and pyrrhotite were performed.The relationship among pulp potential,the pulp pH value and the concentration of collector is the crux factor of flotation.The relationship between pH value and concentration of collector(C)and floatability of forth sulfide minerals,which include galena,sphalerite, pyrite and pyrrhotite,were discussed.In this paper,the electrochemical behaviors of sulfide minerals in flotation system were studied and relationship between potential and floatability of sulfide mineral was discussed.Practical application of the technology of potential control flotation was studied with pulp potential(Eh),pH value and concentration of collector(C)as the primary parameters..Lime is used as a pH regulator and it also acts as a stabilizer of the pulp pH and potentials. The stable pulp pH and potentials are very beneficial to the selective flotation of galena from sphalerite,pyrite and pyrrhotite.Because the solubility of lime is not higher,the pulp pH and potentials in galena flotation process can maintain stable under a higher dosage of lime (14kg/t).The dominant parameters of sulfide mineral floatation system were ascertained.Effective recovery of the valuable minerals can be achieved by processing the Mengzi complex lead-zinc-sliver Sulfide from Duimenshan and 1750 Ore Body using the new flotation flowsheet.In the new flowsheet,the flotation separation of galena from sphalerite,pyrite and pyrrhotite is conducted in the strongly alkaline pulps of pH=12.3,with DDTC as collector and without the additions of ZnSO₄ and Na₂SO₃.The new flowsheet can improve the results of Pb and Zn flotation and decreases the types and consumption of flotation reagents.The flotation plant of Mengzi Lead-Zinc Mine has a treatment capacity of 4000 t ores per day.The flotation operation is carried out in two separate systems,with each treating 2000 t ores per day.It can be seen that the lead concentrate of high quality is produced;assaying about 54-65%Pb,and the flotation recovery of lead in the Cu concentrate is up to 82%,and the zinc concentrate of high quality is produced;assaying about 44-47%Zn,and the flotation recovery of zinc in the Zn concentrate is up to 83%.We obtain a very important discovery in the plant practice that the flotation rate of galena in the new separation system is much faster than that in the original.This means that the flotation time of galena can be shortened and the numbers of galena flotation machine can be reduced or the same numbers of the machine can treat more amounts of ores.The potential controlled flotation technology has made the Mengzi Lead-Zinc Mine obtain more profits because of the improvement of flotation results and the simplification of flotation separation system.Mengzi Lead-zinc Mine is a super-large poly-metal deposit with lead, zinc,which is rich of Ag and In.In order to improve the ratio and technologies of the comprehensive recovery of scattered metals(Ag and In)to a new level,this paper studies emphatically the characteristics of the resources of the scattered metals of Mengzi Mine and the beneficiation behavior of Ag and In in the recovery of the concentration. Studies on the beneficiation behavior of Ag and In during the concentrate processing show that sphalerite is the main supporter mineral of In,and galena is the main supporter mineral of Ag which beneficiate in the concentrate.While the lost shape of In in the sulphur concentrates and tailings is mainly the intergrowth of Pb,Zn and Pyrite.On the other hand, occupancy ratio of In in the zinc concentrate is up-grated obviously with the large size of the concentration apparatuses and the processes which are gradually improved,but the quantity of Ag and In in the sulphur concentrates and tailings is obviously degraded.Through the thermodynamic calculation,the Eh—pH equilibrium of galena,sphalerite,pyrite and pyrrhotite in the absence or presence of collector were set up.The Voltammogram measurement showed that the products formated by the surface oxidation of sulfide minerals were different,and the processes of the reaction were in keeping with the calculation results of the E—pH equilibrium.