含(han)冰(bing)晶石的(de)(de)鋁(lv)在鋁(lv)和鋁(lv)合(he)金的(de)(de)熔(rong)(rong)(rong)(rong)化(hua)過程中(zhong)熔(rong)(rong)(rong)(rong)化(hua)，為了防止(zhi)熔(rong)(rong)(rong)(rong)體(ti)的(de)(de)氧(yang)化(hua)和去除(chu)熔(rong)(rong)(rong)(rong)體(ti)中(zhong)的(de)(de)夾雜(za)物，通常通過添加熔(rong)(rong)(rong)(rong)劑(ji)來達到(dao)目的(de)(de)。前者是在熔(rong)(rong)(rong)(rong)體(ti)表面去除(chu)一(yi)層叫做(zuo)覆(fu)蓋(gai)劑(ji)的(de)(de)熔(rong)(rong)(rong)(rong)劑(ji)，熔(rong)(rong)(rong)(rong)化(hua)后形(xing)成一(yi)定(ding)厚(hou)度的(de)(de)致密(mi)液體(ti)層，可以(yi)(yi)阻止(zhi)氧(yang)氣的(de)(de)滲入(ru)，從而防止(zhi)鋁(lv)的(de)(de)氧(yang)化(hua)，顯著降低鋁(lv)的(de)(de)燒損，后者是在熔(rong)(rong)(rong)(rong)體(ti)中(zhong)加入(ru)一(yi)定(ding)量(liang)的(de)(de)精(jing)(jing)煉劑(ji)，可以(yi)(yi)將Al2O3等(deng)夾雜(za)物從鋁(lv)熔(rong)(rong)(rong)(rong)體(ti)中(zhong)分離出(chu)來，一(yi)起浮(fu)在熔(rong)(rong)(rong)(rong)體(ti)上(shang)形(xing)成待去除(chu)的(de)(de)熔(rong)(rong)(rong)(rong)渣(zha)，并(bing)可以(yi)(yi)吸收熔(rong)(rong)(rong)(rong)體(ti)中(zhong)一(yi)定(ding)量(liang)的(de)(de)氫氣，因此精(jing)(jing)煉劑(ji)具(ju)有(you)除(chu)雜(za)和除(chu)氫的(de)(de)雙重功能。
鋁及鋁合(he)金熔(rong)(rong)(rong)體(ti)的覆蓋(gai)(gai)劑和(he)(he)精煉劑多(duo)由(you)(you)氯鹽和(he)(he)氟鹽組成，部分還含(han)有冰(bing)晶(jing)石創(Na3AlF6)，但因價格(ge)較高(gao)，不含(han)鉀冰(bing)晶(jing)石曲(KAlF4)，常(chang)用(yong)的1號覆蓋(gai)(gai)劑由(you)(you)40-50kcl、25-35NaCl和(he)(he)18-26Na3AlF6組成。它是一種(zhong)含(han)冰(bing)晶(jing)石的粉狀(zhuang)熔(rong)(rong)(rong)劑，密(mi)度約為2.3千克/米，熔(rong)(rong)(rong)點(dian)約為670℃。由(you)(you)于冰(bing)晶(jing)石，鋁熔(rong)(rong)(rong)體(ti)與熔(rong)(rong)(rong)劑之間(jian)的界面張力增加(jia)，熔(rong)(rong)(rong)劑的揮發性(xing)和(he)(he)吸濕性(xing)降低，覆蓋(gai)(gai)層變多(duo)。
原則上(shang)可(ke)以(yi)用(yong)(yong)鉀冰(bing)(bing)晶石(KAlF4)代替熔劑中的所(suo)有冰(bing)(bing)晶石，獲(huo)得更好的覆蓋和精煉(lian)效果，但是鉀冰(bing)(bing)晶石價格昂貴，所(suo)以(yi)從性(xing)價比來看還是不要用(yong)(yong)鉀冰(bing)(bing)晶石比較好，一般情況下，氯化(hua)(hua)物鹽(yan)對(dui)氧化(hua)(hua)鋁的熔融能(neng)力很(hen)小(xiao)，為1%-2%。如果加入(ru)冰(bing)(bing)晶石，熔劑對(dui)氧化(hua)(hua)鋁的熔化(hua)(hua)能(neng)力將大大增強(qiang)。
