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Beneficiation of carbonaceous lead and zinc ores by a combined flotation and leaching method

Sarılar, Sena
Within the scope of this thesis study carbonaceous lead and zinc ore obtained from Yozgat – Akdağmadeni region of Turkey was used. Main objective of the study is to obtain lead concentrate at possible maximum grade and recovery rates by using conventional flotation beneficiation method. In addition to that second main motivation of the study is the extraction of zinc from flotation tailing by using hydrometallurgical method named as leaching under a range of experimental conditions by using different types of leaching reagents. According to chemical analysis of run of mine material, the ore contains 3.17% Pb, 6.19% Zn and 6.72% Fe, 4.35% Al, 23.16 % Si. As was expected, iron, aluminum and silica were observed as the main impurities, thereby efforts were focused on the rejection of these elements. Moreover, mineralogical analysis indicated that the major zinc bearing minerals are smithsonite (zinc carbonate) and willemite (zinc silicate) in addition to that major lead mineral is cerussite (lead carbonate). Within the scope of present study, cerussite concentrate having 60.20% Pb grade at 64.29% recovery rate by using 250 g/t Na2SiO3 as dispersant (conditioned for 10 minutes), H2SO4 as pH regulator, 4000 g/t Na2S as sulfidizer agent (conditioned for 15 minutes), 500 g/t PAX as collector (conditioned for 10 minutes) and 75 g/t F-533 as frother was applied. In order to obtain maximum possible grade at a maximum reasonable recovery value 3 cleaning stages without vi additional reagent were applied. Following, by using flotation tailing as feed material for leaching tests 60 leaching test by using sulphuric acid, ammonia, ammonium carbonate, ammonium chloride, citric acid and boric acid were conducted under range of variable operational parameters. With the consideration of performed leaching tests statistical models were constructed in order to determine optimum leaching parameters and leaching reagent which provide maximum zinc extraction ratio with rejection of impurities. From the this point of view ammonium chloride leaching provided maximum reasonable technical zinc extraction rate as 86.17% rate by using 5 M ammonium chloride at 90°C with leach duration as 60 minutes. From the industrial applicability point of view sulphuric acid leaching would be considered as best solution since 96.63% Zn was extracted rates by using 1M sulphuric acid at 30°C with leaching duration as 60 minutes.