Study On The Mechanism Of Mixed Copper Ore Vulcanization Flotation

The mixed copper mine occupies a 3%proportion of copper resources,which is one of the raw materials for producing copper metal.The main beneficiation method is sulfuration-xanthate flotation method.The main problem of this method is:sodium sulfide is the copper oxide flotation activator and a strong inhibitor for copper sulfide;the insufficient dosage of sodium sulfide will lead to the recovery of copper oxide.However,the use of sodium sulfide is too large,which will suppress copper sulfide and sulfuration copper oxide.Therefore,it is of great practical significance to carry out the theoretical research on the sulfuration-xanthate flotation of mixed copper ore.On the one hand,it can enrich the flotation theory;on the other hand,it can provide the theoretical basis for the development of new flotation technology.The title of the paper is from:National Natural Science Foundation of Key Projects "Study on coupled sulfuration flotation mechanism of refractory copper"（No.51364017）.In view of the application of ammonium（amine）salt in the beneficiation of copper oxide and mixed copper ore,the pure mineral of malachite and chalcopyrite is used as the object of this thesis.The flotation behavior and action machine of these two minerals in the ammonium（amine）salt-sodium sulfide-xanthate system and effect of ammonium（amine）salt on flotation of artificial mixture copper oxide was investigated.Finally,the actual mixed copper test was used to verify.Ammonium（amine）salt on the malachite Sulfuration flotation test showed that Excluding diammonium phosphate,four inorganic ammonium salts（ammonium sulfate,ammonium carbonate,ammonium bicarbonate,ammonium chloride）and ethylenediamine phosphates have an activating effect on the sulfuration flotation behavior of malachite.The activation effect of combined ammonium-amine salt is more significant than that of single ammonium（amine）salt.The results of SEM-EDS analysis show that the content of mineral surface floc after the addition of ammonium-amine salt is significantly increased,and the mass concentration of S is increased from 2.3%to 15.16%,and the characteristic trace peaks of N,P elements are detected on the mineral surface,which are suggesting that the enhanced sulfuration effect is obvious.The results of XPS analysis show that the combination of ammonium-amine salt can reduce the electron bonding energy of Cu 2p on the surface of malachite,increasing the activity of copper atoms,and S is in the form of S2-and Sn2-form on the surface of mineral,and the characteristic peak of N is also detected on the surface of mineral suggesting[Cu（en）2]²⁺ being present on the surface and the P atom is not adsorbed on the surface of the malachite.Ammonium（amine）salt on the chalcopyrite flotation tests show that five kinds of inorganic ammonium salts can produce a slight activation effect on the flotation of chalcopyrite directly,and ethylenediamine phosphate does not play any role.It is found that the five kinds of inorganic ammonium salts and ethylenediamine phosphate could eliminate the inhibitory effect of sodium sulfide in chalcopyrite flotation treated with 150 mg/L sodium sulfide in different level.The effect of combination of ammonium-amine salt on the eliminating inhibition of sodium sulfide is different.The combination of ammonium chloride and ethylenediamine phosphate is the best,which can completely eliminate the inhibitory effect of sodium sulfide on chalcopyrite flotation.Ammonium（amine）salt can eliminate the inhibitory effect of sodium sulfide on chalcopyrite due to the fact that the divalent sulfur ions in the low-valent state are more susceptible to the catalytic action of transitional ions such as Cu²⁺,Cu-ammonium complex ions in the ammonium（amine）salt-sodium sulfide-chalcopyrite system,and are oxidized to oxygenates of high valence state.The fact that chalcopyrite is a semiconductor mineral;ammonium salts are strong electrolyte increasing the conductivity of the solution,can promote the S2-oxidation process.The results of dynamic tracking of sulfur ion showed that the ethylenediamine phosphate used alone had no effect on the S2-ion consumption;chalcopyrite,Cu²⁺,copper ammonium complex ions could promote the speed of the S2-ion consumption;ammonium chloride,combined ammonium-amine salt can make S2-ion consumption faster,faster decline in sulfur potential.The SEM-EDS results showed that ammonium chloride could clean the surface of the mineral,and the S element concentration decreased from 33.65%to 26.85%.After the addition of ethylenediamine phosphate,N and P were detected,and the content of P element was 2.46%,Phosphate ions can be adsorbed on the mineral surface,which also hinders the solution of S2-ions adsorbed on the mineral surface.The XPS analysis showed that ammonium chloride did not adsorb on the surface of minerals,owing to no new material formation;ethylenediamine phosphate and mineral surface have a certain role,owing to the surface detection of copper amine complex characteristic peaks,and sulfur elements appear a variety of form,indicating that sulfur is oxidized on the surface of the mineral.The effect of ammonium（amine）salt on the sulfuration flotation of mixed copper ore is that on the one hand,it can strengthen the sulfuration process of copper oxide and stabilize the sulfuration film on the surface of copper oxide to improve its hydrophobicity.On the other hand,it can weaken the inhibitory effect of sulfur ions on the chalcopyrite in the remaining sodium sulfide,and promote the oxidation of the sulfide ions into the sulphide ions to improve the floatability of the copper sulfide,and finally the total copper recovery rate is improved.The result of the recovery rate of chalcopyrite 59.36%,the recovery rate of malachite 47.58%,total copper recovery 65.82%is achieved when the dosage of sodium sulfide was 200mg/L in the 30%oxidation rate of artificial mixed copper sulfuration-xanthate flotation.When the combined ammonium-amine salt was added,the recovery rate of chalcopyrite can reach 91.32%and the recovery rate of malachite was about 41%with total copper recovery 76.23%.Compared with the direct sulfuration flotation method,the total copper recovery rate was improved by 10.41 percentage point.In the mixed copper ore sulfuration-xanthate flotation test with the oxidation rate of 27.42%,the addition of ammonium-amine salt can improve the recovery rate of copper by 4.79 percentage points and the recovery rate of copper oxide phase increased by 9.66 percentage points,the recovery rate of copper sulfide ore increased by 2.95 percentage points.The test results have further confirmed the conclusion of pure mineral flotation test.