Investigations Of Preparating Lead-sulfate And Mangano-manganic-oxide From Galena Concentrate And Pyrolusit

In this paper, the preparation of electrode active material lead-sulfate and mangano-manganic-oxide from galena concentrate and pyrolusit using two-ores method is investigated.There are four main components in this research: the recover of lead and manganese, the purification of leaching solution, the preparation of the lead sulfate and the mangano-manganic oxide, and some discussions on reaction mechanism using XRD, SEM, XPS, the electrochemistry test and complexing coordinate computation,More details are described as follows:Some factors which have an effect on the lead recovery and the leaching reaction rate was explored and optimized. Reaction mechanism was studied using electrochemistry test, the complexing computation and the microscopic examination. The results revealed that the formation of production S° membrane and the insolvent production lead-chloride membrane prevent the reaction between galena and the pyrolusite. Adding sodium-chloride at the start of reaction and adding hydrochloric acid twice during reaction will remarkably increase the lead and manganese recovery.The iron in the leaching solution can be removed by the goethite method. The most appropriate pulp pH value was found out by the experiment; The concentration of the iron-ion, the lead-ion, the manganese-ion, the zinc-ion at the different pulp pH value are calculated by thermodynamics method, the computed results are consistent with the experimental conclusion.The influence of diluting the leaching solution with distilled water on the lead separating from the solution is researched. The complexing computation revealed that the lead ion dissolves in the solution with the different complex compound shape at the different temperature and concentration of chloride-ion. [Cl~-] =1mol/L is the appropriate value of separating the lead chloride from the sodium-chloride solution. The atmospherics pressure vulcanization is used to remove heavy metal ion from solution. The influence of the factors of vulcanization on the removing rate of the heavy metal ion is studied by the experiment, and the most appropriate factors ofvulcanization are found out. The analysis on the thermodynamics indicated that the concentration of sulfur-ion is the key affecting the removing rate of the heavy metal ion at the certain pulp pH value.The conditions of synthesis the lead sulfate are studied. The experimental results showed that the reaction time and the pulp pH value are the key factors affecting the purity and the average grain diameter of product. The XRD and SEM analyses on composition and the appearance of product showed that the purity of product is 99.83%, the average grain diameter of product is 250nm.The mangano-manganic oxide is prepared from the purified manganese chloride solution. The preparing conditions are researched by the single factor method and the orthogonal factor method, the most appropriate factors of preparing the mangano-manganic oxide are found out. The E-pH chart of Mn-O-tkO at 60 °C is drawn up by the thermo-dynamicsis calculation. In addition, the condition of the mangano-manganic-oxide stable existence has been discussed based on the E-pH chart. The theoretical calculation and the experimental result both showed that the pulp pH value is the determining factor preparing the mangano-manganic-oxide pure phase; Also it is the key factor increasing the produce rate. The XRD and XPS analyses on the product have further showed that the production is the pure phase mangano-manganic-oxide.