| At present,sulfide flotation is the most commonly used flotation technology for oxidized copper ore and mixed copper ores.The production practice has confirmed that the sulfide flotation of mixed copper,adding ammonium(amine)salt,can significantly improve the flotation index,indicating that ammonium(amine)salt can strengthen vulcanization oxidized copper ore and also eliminate or weaken the inhibitory effect of vulcanizing agent to copper sulphide ore.A large number of experimental studies have been carried out to study the mechanism of ammonium(amine)salt strengthening vulcanization of oxidized copper ore,but few studies have been done on how to eliminate or weaken the inhibition mechanism of vulcanizing agent to copper sulphide ore.Thesis comes from the project of national Natural Science Foundation that study on coupled sulphidization flotation mechanism of refractory copper ores,mainly to study the mechanism of ammonium(amine)salt to eliminate or weaken the inhibition of sulfide.Eight kinds of common ammonium(amine)salt are provided with activation to inhibited bornite by sodium sulfide,its activation effect from strong to weak order:ammonium sulfate>ammonium chloride>ammonium hydrogen carbonate>ammonium fluoride>ammonium nitrate>ammonium carbonate>ethylenediamine phosphate diammonium hydrogen phosphate.In addition diammonium hydrogen phosphate,single ammonium(amine)salt can completely eliminate the inhibitory effect of sodium sulfide on bornite.In the combination of ammonium(amine)salt,ethylenediamine phosphate and ammonium sulfate in combination with is the best effect.Ammonium(amine)salt can prevent S2-or HS-adsorption on the surface of bornite.Comparison of ammonium(amine)bornite surface salt and sodium sulfide after direct vulcanization after the EDS analysis shows that the S atom concentration bornite surface from direct sulfide 42.36%reduced to 38.55%;XPS analysis showed that the atomic concentration of S spot the copper surface is reduced,and adding ammonium sulfate less when a chemical state of sulfur;Zata potential test shows that bornite surface potential increased,close layer cations increased,decreased.The anionic ammonium(amine)salt can prevent S2-or HS-in bornite surface adsorption.Sulfur ion electrode determination showed that the vulcanization system in bornite,adding ammonium(amine salt),compared with a single system of pulp decreased pH,sodium sulfide,sulfur ion potential decreased,which reduced sulfur ion;sulfur ion potential stable time significantly shortened,reduced from 23min to 4min,which show that the addition of ammonium(amine)salt at the same time,to reduce the sulfur ion concentration,but also hinder the S2-or HS-adsorbed on the surface of bornite,eliminate the inhibitory effect of sodium sulfide on bornite.Ammonium(amine)salt promote isoamyl xanthate in bornite surface adsorption.In isoamyl xanthate dosage of 200mg/L,sodium sulfide dosage was 300mg/L,adding ammonium salt combination after adsorption test showed that isoamyl xanthate adsorption quantity on the surface of bornite from direct vulcanization of 6.3×10-2mg/g to 2.778×10-1mg/g,contact angle test results show that the contact angle of 35.64 degrees from the direct vulcanization increased to 52.78 degrees.It is indicated that the ammonium(amine)salt can promote the adsorption of iso amyl xanthate in the copper sulfide system,which can eliminate the inhibition effect of sodium sulfide on the copper deposit.Ammonium(amine)salt in bornite surface orientation arrangement hindered S2-or HS-adsorption on the surface of bornite.In the vulcanization system of bornite,adding ammonium(amine)salt treatment,EDS analysis showed that in bornite surface does not appear N,P elements,XPS analysis showed that in bornite surface N did not appear,the characteristic peaks of P,indicating that ammonium(amine)salt not has the characteristics of the solid-liquid interface in directional arrangement of bornite surface adsorption of.NH4+,Zata potential test shows that bornite surface potential increased,close layer cations increased,indicating that NH4+ in the surface layer of bornite directional arrangement,which makes the S2+ or HS-is difficult to directly contact with copper ion adsorption.Ammonium(amine)salt elimination mechanism of vulcanizing agent on the inhibition of bornite is ammonium(amine)salt or the combination of S2-or HS-in the salt block surface adsorption of copper sulfide,promoting the adsorption of collector on the surface,the copper sulfide surface contact angle increases,enhances its surface hydrophobicity,so as to improve the floatability of sulfide.When the dosage was 300mg/L,bornite recovery rate was 50.67%;adding ammonium salt after the combination,the recovery rate was 93.8%.For artificial mixed copper oxidation rate of 70%,adding ammonium amine combination the flotation recovery rate reached 77.02%when compared with the direct flotation,flotation,the recovery rate increased by 25.12 percentage points,to obtain a better flotation index. |
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