Study On The Influence Of Different Depressants On The Flotating Separation Efficiency Of Copper-lead Sulphide Ore

The chalcopyrite and galena are associated severely and fine-grained.Besides,the same floatability of copper-lead results in the difficulty of the flotating separation between them.The existing depressants in copper-lead flotating separation are mainly odium cyanide and potassium dichromate,but sodium cyanide is highly toxic,and cyanide water is very difficult to be degraded,potassium dichromate is toxic too,and it can cause chromium pollution along with the water flows into the crops.Other depressants have some limitations too.XBL is a low-toxicity and small-molecule reagent,which is used for the gold leaching,but it has not been reported as a depressant for the flotating separation of sulphide minerals.In this paper,XBL,sodium thioglycolate,sodium cyanide and potassium dichromate were used as depressants,their effects on flotating separation of copper-lead sulphide minerals were compared and the depressing mechanism were discussed.The results of single mineral floatation test show that XBL can effectively depress the chalcopyrite but can not depress the galenais,the selectivity of XBL is better.The depressing effect of sodium thioglycollate on chalcopyrite is weaker,and it also has a certain depressing effect on galena,which results in a lower selectivity.Sodium cyanide has the best depression effect on chalcopyrite,but it also has a strong depressing effect on galena,which results in the low selectivity.The dosage of potassium dichromate is larger and with the increasing of dosage,it can depress not only chalcopyrite but also galenais,which results in it?s poor selectivity.Under the best conditions of the study,the relationship between the flotating recovery difference of chalcopyrite and galenais is as follow:XBL?69.80%?>sodium thioglycollate?58.48%?>Sodium cyanide?46.48%?>potassium dichromate?36.60%?.The single mineral floatation test also shows that Ca²⁺and Cu²⁺are beneficial to strengthen the depressing effect of XBL on the chalcopyrite,but it do not affect the floatability of galena.Fe²⁺has little effect on the floatability of chalcopyrite,but it can greatly reduce the floatability of galena.Mg²⁺and Pb²⁺can strengthen the depressing effect of XBL on chalcopyrite and reduce the floatability of galena.The results of artificial mixed mineral flotating tests show that compared with other depressants,XBL has higher separating efficiency in both"high copper and low lead"and"high lead and low copper"artificial mixed mineral,the index of seperating efficiency respectively reached to 54.08%and 69.90%.Therefore,XBL can be used for the flotating separation of different types of copper-lead sulfide mineral.At the same time,the flotating separation tests are carried out for a real copper-lead mixed concentrate from Gansu province.The results show that when the grinding fineness is the content of-0.074mm is86.37%,the pH value of the pulp is 9,the amount of the collector is 400g/t and the amount of XBL is 600g/t,the recovery of lead in the lead concentrate is 83.22%,and the copper content is 6.78%.The recovery of copper in copper concentrate is 79.21%,the lead content is 5.01%,and the seperating efficiency is 62.43%.The index is higher than that when sodium thioglycollate,sodium cyanide and potassium dichromate were used as depressants.The selective depression mechanism of XBL has been studied by FTIR and other methods.Results show that XBL can not only reduce the hydrophobicity of the chalcopyrite and produce the adsorption on the surface of chalcopyrite,but also hinder the effect of isobutyl xanthate and chalcopyrite.The effect of XBL on the wettability of galena is relatively small and it?s adsorption capacity on galena is weaker,but the adsorption of isobutyl xanthate on chalcopyrite is stronger.A depressant of chalcopyrite named XBL was found,which could be used for the flotating separation of copper-lead sulfide mineral beacause of its high efficiency,low toxicity and low cost.The feasibility of its application in the separation flotating of copper-lead sulfide mineral was verified and it?s depressing mechanism on chalcopyrite was studied,which laid a theoretical foundation for the industrial application of this depressant in the field of copper-lead flotating separation.