Study On The New Process Of Leaching Zinc From Low-grade Zinc Oxide Ore In The Field

Zinc plays an important role as a national defense strategy of nonferrous resources.With the increase of the demand of the zinc and the shortage of the main zinc smelting resources,the development of the much zinc oxide mineral resource which is hard to process becomes more and more valuable.However,high silica content and a large number of alkali gangue often exist in the zinc oxide mineral.In the conventional acid leaching technology,the silica gel which made the solid-liquid separation characteristic of the residues poor will formed and large amounts of inorganic acid will be consumed.Therefore,it is urgently to develop an appropriate new treatment for the low grade zinc oxide ores.In this paper,the complex low-grade zinc oxide ores was the raw materials,the ammonia-ammonium chloride was employed as the leaching agent,the roasting pretreatment,the ultrasonic enhancement technology and the ammonium citrate ligand strengthen the leaching rate was employed.To reveal the microwave irradiation pretreatment-ultrasonic strengthening leaching mechanism of the cooperative coordination,the mineral phase,the morphology was characterized with the XRD,SEM-EDS,FI-IR and the ESI-MS analytical means.The main research conclusions were as follows:(1)Comparing with the phase change before and after the raw ores leached at the room temperature,it was found that the ZnCO3 phase was the main reason for the low leaching rate of the raw ores.The mineral phase transformation took place at the conventional muffile furnace roasting and the microwave temperature of 400 ?,the refractory ZnCO3 phase was transformed into the ZnO phase being easy processing,which could increase the leaching rate of the zinc ores.(2)In the conventional leaching experiment which was conducted in the ammonia-ammonium chloride solution,the optimum leaching rate of the roast ores pretreated in the muffile furnace was 84.7%,which increased 25.8%compared with the raw ores leaching in the conventional leaching experiment(58.9%).The optimization leaching rate of the roast ores pretreated in the muffile furnace was 88.3%,which increased 29.4%compared with the raw ores leaching in the conventional leaching experiment(58.9%).(3)In order to increase the leaching rate of the microwave irradiation ores,the ultrasonic enhancement technology and the ammonium citrate ligand strengthen the leaching rate was employed to deal with the ores.The stable[Zn(C6H8O7)Cl]+ and the[Zn(C6H8O7)2Cl]+ were formed in the ammonium citrate ligand leaching process,the leaching rate of the microwave irradiation ores was further increased.(4)Under the enhancement of ultrasonic technology and the strengthen coordination leaching of the ammonium citrate ligand,the optimum leaching rate of the ores irradiated in the microwave was 95.6%,which increased 36.7%compared with the raw ores leaching in the conventional leaching experiment(58.9%).In this paper,the leaching of the low grade ores which was increased by the outfield enhancement was feasible through the above research,it was provided for the exploitation of the low-grade complex zinc oxide ores.