銅礦石如何提煉銅

從銅礦中開采出來的銅礦石，經(jing)過選礦(kuang)(kuang)成(cheng)(cheng)為含銅(tong)(tong)品位(wei)較高的(de)銅(tong)(tong)精(jing)礦(kuang)(kuang)或者說是銅(tong)(tong)礦(kuang)(kuang)砂，銅(tong)(tong)精(jing)礦(kuang)(kuang)需要經(jing)過冶(ye)煉提成(cheng)(cheng)，才能成(cheng)(cheng)為精(jing)銅(tong)(tong)及(ji)銅(tong)(tong)制品。最早(zao)的(de)銅(tong)(tong)礦(kuang)(kuang)石(shi)來源(yuan)是孔(kong)雀石(shi)。

1、礦石的加工

銅礦石的分類及屬性：

煉(lian)銅的原料(liao)是銅礦石(shi)。銅礦石(shi)可分(fen)為三(san)類：

（1）硫(liu)化礦，如黃銅(tong)礦（CuFeS2）、斑銅(tong)礦（Cu5FeS4）和輝銅(tong)礦（Cu2S）等(deng)。

（2）氧化礦，如赤銅礦（Cu2O）、孔(kong)(kong)雀(que)石[Cu?(OH)?CO?]、藍銅礦[2CuCO3·Cu(OH)2]、硅孔(kong)(kong)雀(que)石（CuSiO3·2H2O）等。

（3）自然銅(tong)(tong)。銅(tong)(tong)礦石中銅(tong)(tong)的含量(liang)在(zai)1%左右（0.5%～3%）的便有開(kai)采價值，因為(wei)采用浮(fu)選(xuan)法可以(yi)把礦石中一(yi)部(bu)分脈石等(deng)雜(za)質(zhi)除(chu)去，而得(de)到(dao)含銅(tong)(tong)量(liang)較高（8%～35%）的精礦砂。

2、冶煉過程

（1）火法煉銅

通過(guo)熔(rong)融冶煉(lian)(lian)和電解(jie)(jie)精(jing)火(huo)煉(lian)(lian)生(sheng)產出(chu)陰極銅(tong)(tong)，也即電解(jie)(jie)銅(tong)(tong)，一(yi)般(ban)適(shi)于高(gao)品(pin)位的(de)硫(liu)(liu)化銅(tong)(tong)礦(kuang)。火(huo)法冶煉(lian)(lian)一(yi)般(ban)是先將含銅(tong)(tong)百分(fen)之幾(ji)或千分(fen)之幾(ji)的(de)原礦(kuang)石，通過(guo)選礦(kuang)提(ti)高(gao)到20%～30%，作(zuo)為銅(tong)(tong)精(jing)礦(kuang)，在密閉(bi)鼓風(feng)爐(lu)、反射爐(lu)、電爐(lu)或閃速爐(lu)進(jin)行造锍(liu)熔(rong)煉(lian)(lian)，產出(chu)的(de)熔(rong)锍(liu)（冰銅(tong)(tong)）接著送入轉爐(lu)進(jin)行吹(chui)煉(lian)(lian)成粗銅(tong)(tong)，再在另一(yi)種反射爐(lu)內經過(guo)氧化精(jing)煉(lian)(lian)脫雜，或鑄成陽極板進(jin)行電解(jie)(jie)，獲得品(pin)位高(gao)達(da)99.9%的(de)電解(jie)(jie)銅(tong)(tong)。該流(liu)程簡(jian)短、適(shi)應性強，銅(tong)(tong)的(de)回收率可(ke)達(da)95%，但因(yin)礦(kuang)石中的(de)硫(liu)(liu)在造锍(liu)和吹(chui)煉(lian)(lian)兩(liang)階段作(zuo)為二(er)氧化硫(liu)(liu)廢(fei)氣排出(chu)，不易回收，易造成污染(ran)。

從銅礦石冶煉銅(tong)(tong)(tong)：以(yi)黃銅(tong)(tong)(tong)礦(kuang)為(wei)(wei)例，首先把精礦(kuang)砂(sha)(sha)、熔(rong)(rong)(rong)劑(ji)（石(shi)灰石(shi)、砂(sha)(sha)等(deng)）和(he)燃(ran)料（焦炭、木炭或無煙(yan)煤(mei)）混合，投入(ru)(ru)“密閉”鼓風爐中，在(zai)(zai)1000℃左(zuo)右進(jin)行(xing)熔(rong)(rong)(rong)煉。于(yu)是(shi)礦(kuang)石(shi)中一(yi)部分(fen)硫成(cheng)(cheng)(cheng)為(wei)(wei)SO?（用于(yu)制硫酸），大(da)部分(fen)的(de)(de)(de)砷、銻等(deng)雜(za)(za)質(zhi)成(cheng)(cheng)(cheng)為(wei)(wei)As?O?、Sb?O?等(deng)揮(hui)發性物(wu)(wu)質(zhi)而(er)被除去(qu)：2CuFeS?+O?=Cu?S+2FeS+SO?↑。一(yi)部分(fen)鐵(tie)的(de)(de)(de)硫化物(wu)(wu)轉變為(wei)(wei)氧(yang)化物(wu)(wu)：2FeS+3O?=2FeO+2SO?↑。Cu?S跟剩(sheng)余的(de)(de)(de)FeS等(deng)便熔(rong)(rong)(rong)融在(zai)(zai)一(yi)起而(er)形(xing)(xing)成(cheng)(cheng)(cheng)“冰銅(tong)(tong)(tong)”（主要由Cu?S和(he)FeS互相溶(rong)解形(xing)(xing)成(cheng)(cheng)(cheng)的(de)(de)(de)，它的(de)(de)(de)含(han)銅(tong)(tong)(tong)率在(zai)(zai)20%～50%之間，含(han)硫率在(zai)(zai)23%～27%之間），FeO跟SiO?形(xing)(xing)成(cheng)(cheng)(cheng)熔(rong)(rong)(rong)渣(zha)(zha)：FeO+SiO?=FeSiO?。熔(rong)(rong)(rong)渣(zha)(zha)浮(fu)在(zai)(zai)熔(rong)(rong)(rong)融冰銅(tong)(tong)(tong)的(de)(de)(de)上面(mian)，容易(yi)分(fen)離，借以(yi)除去(qu)一(yi)部分(fen)雜(za)(za)質(zhi)。然后把冰銅(tong)(tong)(tong)移(yi)入(ru)(ru)轉爐中，加入(ru)(ru)熔(rong)(rong)(rong)劑(ji)（石(shi)英砂(sha)(sha)）后鼓入(ru)(ru)空氣(qi)進(jin)行(xing)吹煉（1100～1300℃）。由于(yu)鐵(tie)比銅(tong)(tong)(tong)對氧(yang)有較大(da)的(de)(de)(de)親和(he)力，而(er)銅(tong)(tong)(tong)比鐵(tie)對硫有較大(da)的(de)(de)(de)親和(he)力，因此(ci)冰銅(tong)(tong)(tong)中的(de)(de)(de)FeS先轉變為(wei)(wei)FeO，跟熔(rong)(rong)(rong)劑(ji)結合成(cheng)(cheng)(cheng)渣(zha)(zha)，而(er)后Cu?S才轉變為(wei)(wei)Cu?O，Cu?O跟Cu?S反(fan)應(ying)生成(cheng)(cheng)(cheng)粗(cu)(cu)銅(tong)(tong)(tong)（含(han)銅(tong)(tong)(tong)量(liang)約(yue)為(wei)(wei)98.5%）。2Cu?S+3O?=2Cu?O+2SO?↑，2Cu?O+Cu?S=6Cu+SO?↑，再把粗(cu)(cu)銅(tong)(tong)(tong)移(yi)入(ru)(ru)反(fan)射爐，加入(ru)(ru)熔(rong)(rong)(rong)劑(ji)（石(shi)英砂(sha)(sha)），通入(ru)(ru)空氣(qi)，使粗(cu)(cu)銅(tong)(tong)(tong)中的(de)(de)(de)雜(za)(za)質(zhi)氧(yang)化，跟熔(rong)(rong)(rong)劑(ji)形(xing)(xing)成(cheng)(cheng)(cheng)爐渣(zha)(zha)而(er)除去(qu)。在(zai)(zai)雜(za)(za)質(zhi)除到一(yi)定程度后，再噴入(ru)(ru)重(zhong)油(you)，由重(zhong)油(you)燃(ran)燒產生的(de)(de)(de)一(yi)氧(yang)化碳等(deng)還原性氣(qi)體使氧(yang)化亞銅(tong)(tong)(tong)在(zai)(zai)高溫(wen)下還原為(wei)(wei)銅(tong)(tong)(tong)。得到的(de)(de)(de)精銅(tong)(tong)(tong)約(yue)含(han)銅(tong)(tong)(tong)99.7%。

除(chu)了銅(tong)(tong)(tong)(tong)精礦之(zhi)外，廢(fei)(fei)銅(tong)(tong)(tong)(tong)作為(wei)精煉(lian)銅(tong)(tong)(tong)(tong)的(de)(de)主要原料(liao)之(zhi)一(yi)，包(bao)括舊廢(fei)(fei)銅(tong)(tong)(tong)(tong)和新(xin)廢(fei)(fei)銅(tong)(tong)(tong)(tong)，舊廢(fei)(fei)銅(tong)(tong)(tong)(tong)來自(zi)舊設備和舊機器(qi)，廢(fei)(fei)棄的(de)(de)樓房和地下(xia)管道；新(xin)廢(fei)(fei)銅(tong)(tong)(tong)(tong)來自(zi)加工廠棄掉的(de)(de)銅(tong)(tong)(tong)(tong)屑（銅(tong)(tong)(tong)(tong)材(cai)的(de)(de)產出比為(wei)50%左右），一(yi)般(ban)廢(fei)(fei)銅(tong)(tong)(tong)(tong)供(gong)應較穩定，廢(fei)(fei)銅(tong)(tong)(tong)(tong)可(ke)以分(fen)為(wei)：裸雜銅(tong)(tong)(tong)(tong)：品位在90%以上(shang)；黃雜銅(tong)(tong)(tong)(tong)（電(dian)線）：含銅(tong)(tong)(tong)(tong)物料(liao)（舊馬達、電(dian)路板）；由廢(fei)(fei)銅(tong)(tong)(tong)(tong)和其他(ta)類似材(cai)料(liao)生產出的(de)(de)銅(tong)(tong)(tong)(tong)，也稱(cheng)為(wei)再(zai)生銅(tong)(tong)(tong)(tong)。

（2）濕法煉銅

一(yi)船適于(yu)低(di)品位(wei)(wei)的(de)(de)氧化(hua)銅(tong)，生產(chan)出(chu)的(de)(de)精(jing)銅(tong)稱為電積(ji)(ji)銅(tong)。現(xian)代濕(shi)法冶(ye)煉(lian)有(you)硫酸化(hua)焙燒—浸出(chu)—電積(ji)(ji)，浸出(chu)—萃取—電積(ji)(ji)，細菌浸出(chu)等(deng)法，適于(yu)低(di)品位(wei)(wei)復雜礦、氧化(hua)銅(tong)礦、含銅(tong)廢礦石的(de)(de)堆浸、槽浸選用(yong)或就地浸出(chu)。濕(shi)法冶(ye)煉(lian)技術正在逐(zhu)步推(tui)廣，預計本世紀末可達總產(chan)量的(de)(de)20%，濕(shi)法冶(ye)煉(lian)的(de)(de)推(tui)出(chu)使銅(tong)的(de)(de)冶(ye)煉(lian)成本大大降低(di)。