提高含锗煤烟尘氯化蒸馏回收率的工艺研究

Improving Germanium Distillation Recovery Rate from Coal Dust

针对常规盐酸蒸馏分离提锗法处理,火法冶炼褐煤得到含锗煤烟尘回收率较低的问题,研究了一种经碱加热预处理后再进行蒸馏回收锗的方法,即通过加入锗煤烟尘重量20%～30%的氢氧化钠、2～3倍的水与锗煤烟尘混合搅拌均匀后,再加热至90～95℃并搅拌充分反应3～4 h,使锗煤烟尘中酸难溶的四面体型GeO2,GeO及GeS等形态的锗与氢氧化钠充分反应转变为盐酸可溶的锗酸钠。同时氢氧化钠与包裹锗的煤焦油发生皂化、或与二氧化硅发生反应后形成偏硅酸钠进入溶液,使被煤焦油、二氧化硅包裹的锗释放出来后会进一步与氢氧化钠反应形成锗酸钠。然后升温至碱处理后液沸腾,蒸发浓缩至处理后液的体积与锗烟尘的重量相当,以蒸发掉处理后溶液中过多水分。再加入烟尘重量8～9倍的10 mol·L-1工业盐酸中和过量的氢氧化钠,升温至90～110℃蒸馏分离得到四氯化锗,锗回收率可以提高5.39%～33.18%。该工艺适合烧失量较大的煤锗烟尘,具有锗回收率高,工艺流程简短,设备简单,可操作性强,辅料消耗较少,运行成本较低,对环境无污染等特点。

According to the conventional hydrochloric acid distillation separation of germanium extracting method,while low recovery rate of pyrometallurgical lignite containing germanium from coal dust,a way was studied by alkali heat pretreatment followed by distillation method for recovering germanium,adding germanium coal dust weight of 20% ～30% NaOH,2～3 times water and germanium coal soot mixed evenly,and heated to 90～95 ℃ to react 3～4 h,made the germanium coal dust in the acid insoluble tetrahedral GeO2,GeO and GeS forms of germanium with sodium hydroxide reacting fully into hydrochloric acid soluble sodium germanate.At the same time,sodium hydroxide with the package of germanium silicon dioxide,the coal tar saponification reacted and formed sodium silicate solution into solution,package germanium released again and further reacted with sodium hydroxide to form sodium germanate.Then heated to boiling the alkali treatment solution,evaporated and concentrated solution volume closed to germanium dust weight,so as to reduce too much water.Adding germanium coal dust weight of 8～9 times 10 mol · L-1 industrial hydrochloric acid for neutralizing excess sodium hydroxide,then heated up to 90～110 ℃ to distil to separate germanium tetrachloride,germanium recovery rate could be improved 5.39% ～33.18%.The process particularly suited for the ignition loss of large coal germanium dust,had high rate of recovery of germanium,technological process short,simple equipment,strong operability,less material consumption,low operation cost,waste water had no pollution to environment by neutralization etc.