Experimental Study On Enhanced Germanium Extraction From Germanium - Containing Slag By Ultrasonic Wave

Germanium is a kind of high-tech materials with many particular features. And hard zinc is a major source of germanium recovery. The main technological process of recovering germanium from the hard zinc usually is as follows,1) the vacuum distillation, 2) the neutral leaching,3) the oxidizing roasting,4) the chlorination distillation and 5) the hydrolysis. But, there are many problems during the process of chlorination distillation, such as the high acidity, low leaching rate of germanium, equipment corrosion and some security issues. A new technological of using ultrasonic energy in HCl-CaCl2 mixed solution reaction system to leach germanium is adopted in the study. While, roasting residue from industry used as raw material, Ca(C10)2 is employed as oxidizing agent. The leaching time, material particle size, leaching temperature, the amount of oxidant, the initial acidity, the concentration of CaCl2 and microwave power on the germanium leaching are mainly researched. Besides, the differences on the ultrasonic and conventional leaching are studied in detail. The adoption of new technology can bring results of greatly improvement the leaching efficiency, reduction the initial hydrochloric acidity, and convenient oxidant to adding, etc.At last, the main conclusions to recovery germanium by regular and ultrasonic leaching are as follows:(1) The research indicates that the optimum leaching rate of germanium 92.7% about ultrasonic leaching is obtained at temperature 80℃ for a leaching duration of 40 min using 700 W ultrasonic power. And the ultrasonic power too high is adverse for leaching. The concentration of initial hydrochloric acid and CaCl2 are 3.5 mol/L and 150 g/L respectively, while the oxidizing agent is adopt 58.33 g/L. In addition, except the leaching time, the best suitable values for the other factors researched in the article are same by the two methods. While the optimum leaching time by conventional method is 100 min and time-consuming more than ultrasonic about 60%; And the leaching rate of germanium under optimal conventional conditions is 88.35%, which lower 4.35% than ultrasonic method under best condition.In short, the research proved ultrasonic method can greatly shorten the reaction time, and raise the leaching rate of Ge 3-5%.(2) By means of X-ray diffraction, SEM and laser particle size, the phase, morphology and particle size of leaching residue are analyzed, etc. In addition to the leaching experiment result is proved again, these analyses also more clearly present the effect of broken, crush materials and open the package by ultrasound, and so on. The ultrasonic-assist can promote liquid-solid reaction, and play an important role in strengthening the leaching process.