中文摘要：

采用氯化铵氯化—二酰异羟肟酸萃取法从粉煤灰中提取锗.即用氯化铵氯化粉煤灰中的锗,使锗以氯化物的形式挥发富集,用浓度小于6 mol/L的盐酸溶液吸收富集水解GeCl4得到氧化锗.煤灰中锗的氯化适宜条件为向粉煤灰中加入其重量20%的NaHCO3焙烧1 h,往焙砂中加入粉煤灰重量15%的氯化铵,在400℃下焙烧90min,锗的氯化回收率≥81.5%.用1.5%H2SO4（固液质量比为1∶2）进行逆流浸取氯化焙渣中的锗,调节浸出液pH=1.0,以二酰异羟肟酸（DHYA）为萃取剂,异辛醇为溶剂,磺化煤油为稀释剂,在VO/VA=1∶4、CDHYA=0.5mol/Lt、=8 min的条件下进行三级逆流萃取酸浸出液中的锗,锗总萃取率≥99.5%;用2.5 mol/L的NH4F进行二级反萃取锗,反萃率≥99.5%.氯化铵氯化焙烧—DHYA萃取法提取粉煤灰中锗的综合回收率≥95%.

英文摘要：

A process for extracting germanium from coal ash by chlorination with ammonium chloride and extraction with dihydroxamic acid（DHYA） as extractant was investigated.Ammonium chloride was used to chorinate the germanium from coal ash and the chloride was vapored and enriched,the hydrolyzate of which was germanium dioxide through hydrochloric acid with a molarity lower than 6 mol/L.The optimum conditions were established based on the experimental results/ The coal ash was roasted for an hour by adding 20 % weight NaHCO3 The roasted residues were calcined for 90 minutes at 400 C by adding 15 % weight ratio of ammonium chloride dosage to coal ash and the recovery of germanium was not lower than 81.5 %. 1.5 % sulfuric acid （solid-liquid massratio was 1 ： 2） was used to counter flow leaching germanium from the chlorination roasted residues. When the pH value of the leaching liquor was 1.0 , under the experimental conditions of DHYA as extractant, iso-octylalcohol as solvent, sulfonated kerosene as diluent, Vo/VA = 1 ： 4, CDHYA = 0. 5 mol/L, t = 8 min, the three step counter-flow was carried out to extract germanium and the orerall extraction rate was not lower than 99.5 %. 2.5 mol/L NH, F solution was used for two-step reverse extracting germanium, counter-extraction rate was not lower than 99.5 %. In the process, the overall recovery rate of germanium from coal ash was greater than 95 %.