銅礦石如何提煉銅

從銅礦中開采出來的銅礦石，經過選礦(kuang)成(cheng)為含銅(tong)品(pin)位較高的銅(tong)精礦(kuang)或(huo)者說是銅(tong)礦(kuang)砂，銅(tong)精礦(kuang)需要經過冶煉(lian)提成(cheng)，才能成(cheng)為精銅(tong)及銅(tong)制品(pin)。最早(zao)的銅(tong)礦(kuang)石來源是孔(kong)雀石。

1、礦石的加工

銅礦石的分類(lei)及屬性：

煉銅的原(yuan)料是(shi)銅礦(kuang)石。銅礦(kuang)石可分為三類：

（1）硫化礦(kuang)，如(ru)黃銅礦(kuang)（CuFeS2）、斑銅礦(kuang)（Cu5FeS4）和輝銅礦(kuang)（Cu2S）等。

（2）氧化(hua)礦，如赤銅礦（Cu2O）、孔(kong)雀石[Cu?(OH)?CO?]、藍銅礦[2CuCO3·Cu(OH)2]、硅孔(kong)雀石（CuSiO3·2H2O）等。

（3）自(zi)然銅(tong)(tong)。銅(tong)(tong)礦石(shi)(shi)中銅(tong)(tong)的(de)含量(liang)在1%左右（0.5%～3%）的(de)便有(you)開采價值，因為采用浮選(xuan)法(fa)可以把礦石(shi)(shi)中一部分脈(mo)石(shi)(shi)等(deng)雜質除去，而得到含銅(tong)(tong)量(liang)較高（8%～35%）的(de)精礦砂。

2、冶煉過程

（1）火法煉銅

通過(guo)熔(rong)融冶煉和電解精火煉生產出陰極銅(tong)(tong)，也即(ji)電解銅(tong)(tong)，一(yi)般適于高(gao)品位的(de)硫化銅(tong)(tong)礦(kuang)。火法冶煉一(yi)般是(shi)先(xian)將含(han)銅(tong)(tong)百分(fen)之幾或(huo)(huo)千分(fen)之幾的(de)原礦(kuang)石，通過(guo)選(xuan)礦(kuang)提高(gao)到(dao)20%～30%，作(zuo)為銅(tong)(tong)精礦(kuang)，在密(mi)閉鼓風爐(lu)(lu)、反射爐(lu)(lu)、電爐(lu)(lu)或(huo)(huo)閃速爐(lu)(lu)進(jin)行造锍熔(rong)煉，產出的(de)熔(rong)锍（冰(bing)銅(tong)(tong)）接(jie)著送入轉爐(lu)(lu)進(jin)行吹煉成粗銅(tong)(tong)，再在另(ling)一(yi)種反射爐(lu)(lu)內經(jing)過(guo)氧化精煉脫雜，或(huo)(huo)鑄(zhu)成陽極板進(jin)行電解，獲得品位高(gao)達99.9%的(de)電解銅(tong)(tong)。該流程簡短、適應性(xing)強，銅(tong)(tong)的(de)回(hui)收率可達95%，但因礦(kuang)石中的(de)硫在造锍和吹煉兩(liang)階(jie)段作(zuo)為二氧化硫廢(fei)氣排出，不易回(hui)收，易造成污染。

從銅礦石冶(ye)煉(lian)銅(tong)(tong)(tong)：以(yi)黃(huang)銅(tong)(tong)(tong)礦(kuang)為例，首(shou)先(xian)把精礦(kuang)砂(sha)、熔劑（石灰(hui)石、砂(sha)等(deng)）和(he)(he)(he)燃(ran)料（焦炭、木炭或無(wu)煙煤）混合(he)，投入“密閉”鼓(gu)風(feng)爐(lu)中(zhong)，在(zai)1000℃左右進(jin)(jin)行熔煉(lian)。于(yu)是礦(kuang)石中(zhong)一(yi)部(bu)分硫(liu)(liu)(liu)成(cheng)為SO?（用于(yu)制硫(liu)(liu)(liu)酸），大(da)部(bu)分的(de)(de)砷(shen)、銻等(deng)雜質(zhi)成(cheng)為As?O?、Sb?O?等(deng)揮發(fa)性(xing)物質(zhi)而被除(chu)去(qu)(qu)：2CuFeS?+O?=Cu?S+2FeS+SO?↑。一(yi)部(bu)分鐵的(de)(de)硫(liu)(liu)(liu)化物轉(zhuan)變(bian)為氧化物：2FeS+3O?=2FeO+2SO?↑。Cu?S跟(gen)剩余的(de)(de)FeS等(deng)便(bian)熔融(rong)在(zai)一(yi)起(qi)而形(xing)(xing)(xing)成(cheng)“冰銅(tong)(tong)(tong)”（主要由Cu?S和(he)(he)(he)FeS互相溶解形(xing)(xing)(xing)成(cheng)的(de)(de)，它(ta)的(de)(de)含銅(tong)(tong)(tong)率(lv)在(zai)20%～50%之間，含硫(liu)(liu)(liu)率(lv)在(zai)23%～27%之間），FeO跟(gen)SiO?形(xing)(xing)(xing)成(cheng)熔渣：FeO+SiO?=FeSiO?。熔渣浮在(zai)熔融(rong)冰銅(tong)(tong)(tong)的(de)(de)上(shang)面(mian)，容易分離，借(jie)以(yi)除(chu)去(qu)(qu)一(yi)部(bu)分雜質(zhi)。然(ran)后(hou)把冰銅(tong)(tong)(tong)移入轉(zhuan)爐(lu)中(zhong)，加(jia)入熔劑（石英(ying)砂(sha)）后(hou)鼓(gu)入空氣進(jin)(jin)行吹(chui)煉(lian)（1100～1300℃）。由于(yu)鐵比(bi)銅(tong)(tong)(tong)對氧有較(jiao)大(da)的(de)(de)親和(he)(he)(he)力，而銅(tong)(tong)(tong)比(bi)鐵對硫(liu)(liu)(liu)有較(jiao)大(da)的(de)(de)親和(he)(he)(he)力，因此(ci)冰銅(tong)(tong)(tong)中(zhong)的(de)(de)FeS先(xian)轉(zhuan)變(bian)為FeO，跟(gen)熔劑結合(he)成(cheng)渣，而后(hou)Cu?S才(cai)轉(zhuan)變(bian)為Cu?O，Cu?O跟(gen)Cu?S反應生成(cheng)粗銅(tong)(tong)(tong)（含銅(tong)(tong)(tong)量(liang)約(yue)為98.5%）。2Cu?S+3O?=2Cu?O+2SO?↑，2Cu?O+Cu?S=6Cu+SO?↑，再把粗銅(tong)(tong)(tong)移入反射爐(lu)，加(jia)入熔劑（石英(ying)砂(sha)），通入空氣，使粗銅(tong)(tong)(tong)中(zhong)的(de)(de)雜質(zhi)氧化，跟(gen)熔劑形(xing)(xing)(xing)成(cheng)爐(lu)渣而除(chu)去(qu)(qu)。在(zai)雜質(zhi)除(chu)到一(yi)定程(cheng)度后(hou)，再噴入重(zhong)油(you)，由重(zhong)油(you)燃(ran)燒產生的(de)(de)一(yi)氧化碳等(deng)還原性(xing)氣體使氧化亞銅(tong)(tong)(tong)在(zai)高(gao)溫下還原為銅(tong)(tong)(tong)。得到的(de)(de)精銅(tong)(tong)(tong)約(yue)含銅(tong)(tong)(tong)99.7%。

除(chu)了銅(tong)(tong)精礦之外(wai)，廢(fei)銅(tong)(tong)作(zuo)為(wei)(wei)精煉銅(tong)(tong)的主要原料之一(yi)，包(bao)括(kuo)舊廢(fei)銅(tong)(tong)和(he)新廢(fei)銅(tong)(tong)，舊廢(fei)銅(tong)(tong)來自舊設備和(he)舊機(ji)器，廢(fei)棄(qi)的樓房(fang)和(he)地下管(guan)道；新廢(fei)銅(tong)(tong)來自加工廠棄(qi)掉的銅(tong)(tong)屑（銅(tong)(tong)材的產出比為(wei)(wei)50%左(zuo)右(you)），一(yi)般廢(fei)銅(tong)(tong)供應較穩定，廢(fei)銅(tong)(tong)可(ke)以(yi)分(fen)為(wei)(wei)：裸雜銅(tong)(tong)：品位(wei)在90%以(yi)上；黃雜銅(tong)(tong)（電線）：含銅(tong)(tong)物料（舊馬(ma)達、電路(lu)板）；由廢(fei)銅(tong)(tong)和(he)其他類似材料生產出的銅(tong)(tong)，也稱為(wei)(wei)再(zai)生銅(tong)(tong)。

（2）濕法煉銅

一(yi)船適(shi)于低(di)品(pin)位的氧化銅(tong)(tong)，生產出的精銅(tong)(tong)稱為電積(ji)銅(tong)(tong)。現代(dai)濕(shi)法冶(ye)(ye)煉有硫酸化焙燒—浸(jin)出—電積(ji)，浸(jin)出—萃取—電積(ji)，細菌浸(jin)出等法，適(shi)于低(di)品(pin)位復(fu)雜礦(kuang)、氧化銅(tong)(tong)礦(kuang)、含(han)銅(tong)(tong)廢(fei)礦(kuang)石的堆浸(jin)、槽浸(jin)選用或(huo)就地(di)浸(jin)出。濕(shi)法冶(ye)(ye)煉技術正在逐步推廣，預計本世紀末可達總產量的20%，濕(shi)法冶(ye)(ye)煉的推出使銅(tong)(tong)的冶(ye)(ye)煉成本大(da)大(da)降低(di)。