我厂在熔炼铝合金时,由于炉料、熔化工具带进水份及合金液态时易吸气等因素,使铝液中含有大量氢离子。高温时,氢有较大的溶解度,随温度降低,溶解度迅速减少,在凝固过程中氢大量析出,而形成针孔。为此,熔炼铝合金时,必须进行精炼除气处理。我厂曾采用氯化锌(ZnCl_2)进行精炼,由于它吸潮严重,精炼前如烘干不良,非但不起除气作用,反而带人大量气体。后改用六氯乙烷(C_2Cl_6),精炼效果好,但除气时产生大量刺激性恶味烟雾,有氯气(Cl_2)、氯化氢(HCl)、四氯化碳(CCl_4)、四氯乙烯(C_2Cl_4)、光气 I plant aluminum smelting, due to the charge, melting tool into the water and liquid alloy easy to breathe and other factors, so that a large number of liquid aluminum hydrogen ions. High temperature, hydrogen has a greater solubility, with the temperature decreases, the rapid decrease in solubility, hydrogen precipitation in the solidification process, and the formation of pinholes. To this end, melting aluminum alloy, the gas must be refined degassing. I used zinc chloride plant (ZnCl2) for refining, because of its serious moisture absorption, such as poor drying before refining, not only can not afford to remove gas, but with a large amount of gas. After the conversion to hexachloroethane (C_2Cl_6), the refining effect is good, but when deaeration produces a large number of irritating smell smoke, chlorine (Cl_2), hydrogen chloride (HCl), carbon tetrachloride (CCl_4), tetrachlorethylene C_2Cl_4), phosgene