Study On Flotation Behavior And Electrochemistry Of Major Sulfide Minerals In Nickel Sulfide Ore With Low-grade

Jinchuan Mine Area is one of the most famous polymetallic extra large Cu-Ni sulphide deposits in the world. The proven ore reserves are above 520 million tons, which are ranked the third largest deposit of its kind in the world. The main sulphide minerals are pyrrhotite, pentlandite, chalcopyrite, violarite, pyrite and so on. There is not effective treatment of lean ores in Jinchuan Mine Area. It is well known that the ore properties is complex of poor nickel—copper sulfide ore and it has poor separability ,it is illogical to use the techniques presently to treatment exploiting poor ores at the angle of economy and technology, and made the low grade crude ore unable to treat which accounted for more than 67%.In order to make a breakthrough in technique and beneficiation index, to develop technical research on lean ores especially of the research on basic theory is demand. In this thesis, the flotation performance and interact mechanism of regeats with minerals of pyrite, pentlandite, pyrrhotite, nickel ( 1.55% ) bearing pyrrhotite were investigated and the main conclusions were obtained as follows:Flotation aspects:(1) Under the condition of self-induced flotation, floatability order of the four sulfide minerals was indicated as follows: pentlandite > nickel (1.55%) bearing pyrrhotite > pyrrhotite >pyrite. Pulp potential range of synchronous flotation was 285-360 mV and pulp pH range was 5-8.(2) Under the condition of sulfur-induced flotation, floatability order of the four sulfide minerals was indicated as follows: pyrrhotite≈nickel (1.55%) bearing pyrrhotite> pentlandite > pyrite. Pulp potential range of synchronous flotation was 50-300mV and pulp pH range was 2.6-11.(3) Under the condition of collector-induced flotation, floatability order of the four sulfide minerals was indicated as follows: pyrrhotite≈nickel (1.55%) bearing pyrrhotit≈pentlandite > pyrite. Pulp potential range of synchronous flotation was 130-400mV and pulp pH interval was 2.6-11.6.(4) The pH range of these sulfide minerals' synchronous flotation was not the same as each others,and followed the trend of self-induced flotation>sulfur-induced flotation> collector- induced flotation.Electrochemical aspects:(5) Cyclic voltammetry was used to study the electrochemistry behavior (anode production) of these four sulfide minerals in different solution pH. It has been shown that neutral sulphur was the primary hydrophobic entity on the surface of these minerals in the condition of collectorless flotation.(6) In the collectorless flotation, the hydrophobic production was characterized as sulphur to all the four sulphide minerals. From the Eh-pH diagram, we could conclude the pulp potential and pH range that caused the collectorless flotation, and the results of thermodynamic calculations coincided with the flotation results.(7) Under the conditions of collector-induced flotation, the Open Circuit Potential of all these sulfide minerals were higher than the equilibrium potential of dixanthogen Ex-/x², so dixanthogen would be the oxidative production of sulfide minerals. The results demonstrated that the oxidative product of sulfide minerals (pyrite,pentlandite,pyrrhotite,nickel (1.55%) bearing pyrrhotite) were dixanthogen.(8) The electrochemistry and the mechanism of pentlandite, nickel(1.55%) bearing pyrrhotite with Na₂S and PAX in the paper have not been reported and the study blazes new trails.