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)成為(wei)含(han)銅(tong)品位較(jiao)高的銅(tong)精礦(kuang)或者說是(shi)銅(tong)礦(kuang)砂，銅(tong)精礦(kuang)需要經過冶煉提(ti)成，才能成為(wei)精銅(tong)及銅(tong)制(zhi)品。最早的銅(tong)礦(kuang)石(shi)來(lai)源是(shi)孔雀石(shi)。

1、礦石的加工

銅礦(kuang)石的分類及屬(shu)性(xing)：

煉銅的原料(liao)是銅礦(kuang)(kuang)石。銅礦(kuang)(kuang)石可(ke)分為三類：

（1）硫(liu)化礦(kuang)(kuang)(kuang)，如黃銅礦(kuang)(kuang)(kuang)（CuFeS2）、斑銅礦(kuang)(kuang)(kuang)（Cu5FeS4）和輝銅礦(kuang)(kuang)(kuang)（Cu2S）等。

（2）氧(yang)化(hua)礦(kuang)(kuang)，如赤銅(tong)礦(kuang)(kuang)（Cu2O）、孔(kong)雀石(shi)[Cu?(OH)?CO?]、藍銅(tong)礦(kuang)(kuang)[2CuCO3·Cu(OH)2]、硅孔(kong)雀石(shi)（CuSiO3·2H2O）等。

（3）自然銅(tong)。銅(tong)礦(kuang)石(shi)中銅(tong)的(de)含量(liang)在1%左右（0.5%～3%）的(de)便有開采價值(zhi)，因為采用(yong)浮選法可以把礦(kuang)石(shi)中一(yi)部分脈(mo)石(shi)等雜(za)質除去，而得(de)到含銅(tong)量(liang)較高（8%～35%）的(de)精(jing)礦(kuang)砂。

2、冶煉過程

（1）火法煉銅

通過熔融冶煉(lian)(lian)和電解(jie)精(jing)火煉(lian)(lian)生產(chan)出(chu)陰極銅，也即電解(jie)銅，一般(ban)適于高(gao)品位的硫化銅礦。火法冶煉(lian)(lian)一般(ban)是先將(jiang)含銅百(bai)分之(zhi)幾或千分之(zhi)幾的原(yuan)礦石，通過選(xuan)礦提高(gao)到(dao)20%～30%，作(zuo)為銅精(jing)礦，在密(mi)閉鼓風爐(lu)(lu)、反射(she)爐(lu)(lu)、電爐(lu)(lu)或閃速爐(lu)(lu)進行造锍(liu)熔煉(lian)(lian)，產(chan)出(chu)的熔锍(liu)（冰銅）接著送入轉爐(lu)(lu)進行吹煉(lian)(lian)成(cheng)粗銅，再在另一種反射(she)爐(lu)(lu)內(nei)經過氧(yang)化精(jing)煉(lian)(lian)脫雜，或鑄成(cheng)陽極板(ban)進行電解(jie)，獲得品位高(gao)達99.9%的電解(jie)銅。該流程(cheng)簡短、適應(ying)性強(qiang)，銅的回收(shou)率(lv)可(ke)達95%，但因(yin)礦石中(zhong)的硫在造锍(liu)和吹煉(lian)(lian)兩階段作(zuo)為二氧(yang)化硫廢氣排(pai)出(chu)，不易回收(shou)，易造成(cheng)污染。

從銅礦石冶煉(lian)(lian)銅：以(yi)黃銅礦為(wei)例，首先把(ba)精(jing)礦砂(sha)、熔(rong)(rong)劑(ji)（石(shi)灰(hui)石(shi)、砂(sha)等(deng)）和燃(ran)料（焦炭(tan)、木炭(tan)或(huo)無煙(yan)煤）混(hun)合(he)，投入(ru)(ru)“密閉”鼓(gu)風爐(lu)(lu)中(zhong)(zhong)，在(zai)(zai)(zai)1000℃左右進行(xing)熔(rong)(rong)煉(lian)(lian)。于(yu)是礦石(shi)中(zhong)(zhong)一(yi)部(bu)(bu)分(fen)(fen)硫(liu)成(cheng)(cheng)(cheng)為(wei)SO?（用于(yu)制硫(liu)酸），大部(bu)(bu)分(fen)(fen)的(de)(de)(de)(de)砷、銻等(deng)雜質(zhi)成(cheng)(cheng)(cheng)為(wei)As?O?、Sb?O?等(deng)揮發性物質(zhi)而(er)(er)被除(chu)去：2CuFeS?+O?=Cu?S+2FeS+SO?↑。一(yi)部(bu)(bu)分(fen)(fen)鐵(tie)(tie)的(de)(de)(de)(de)硫(liu)化(hua)物轉(zhuan)變(bian)(bian)為(wei)氧化(hua)物：2FeS+3O?=2FeO+2SO?↑。Cu?S跟(gen)剩余的(de)(de)(de)(de)FeS等(deng)便熔(rong)(rong)融在(zai)(zai)(zai)一(yi)起而(er)(er)形成(cheng)(cheng)(cheng)“冰銅”（主要由Cu?S和FeS互相溶解形成(cheng)(cheng)(cheng)的(de)(de)(de)(de)，它的(de)(de)(de)(de)含(han)(han)銅率(lv)在(zai)(zai)(zai)20%～50%之(zhi)間，含(han)(han)硫(liu)率(lv)在(zai)(zai)(zai)23%～27%之(zhi)間），FeO跟(gen)SiO?形成(cheng)(cheng)(cheng)熔(rong)(rong)渣：FeO+SiO?=FeSiO?。熔(rong)(rong)渣浮(fu)在(zai)(zai)(zai)熔(rong)(rong)融冰銅的(de)(de)(de)(de)上面，容(rong)易(yi)分(fen)(fen)離，借以(yi)除(chu)去一(yi)部(bu)(bu)分(fen)(fen)雜質(zhi)。然后(hou)把(ba)冰銅移(yi)入(ru)(ru)轉(zhuan)爐(lu)(lu)中(zhong)(zhong)，加入(ru)(ru)熔(rong)(rong)劑(ji)（石(shi)英砂(sha)）后(hou)鼓(gu)入(ru)(ru)空氣進行(xing)吹煉(lian)(lian)（1100～1300℃）。由于(yu)鐵(tie)(tie)比(bi)銅對氧有較大的(de)(de)(de)(de)親(qin)和力，而(er)(er)銅比(bi)鐵(tie)(tie)對硫(liu)有較大的(de)(de)(de)(de)親(qin)和力，因此冰銅中(zhong)(zhong)的(de)(de)(de)(de)FeS先轉(zhuan)變(bian)(bian)為(wei)FeO，跟(gen)熔(rong)(rong)劑(ji)結合(he)成(cheng)(cheng)(cheng)渣，而(er)(er)后(hou)Cu?S才(cai)轉(zhuan)變(bian)(bian)為(wei)Cu?O，Cu?O跟(gen)Cu?S反應(ying)生(sheng)成(cheng)(cheng)(cheng)粗銅（含(han)(han)銅量約(yue)為(wei)98.5%）。2Cu?S+3O?=2Cu?O+2SO?↑，2Cu?O+Cu?S=6Cu+SO?↑，再把(ba)粗銅移(yi)入(ru)(ru)反射爐(lu)(lu)，加入(ru)(ru)熔(rong)(rong)劑(ji)（石(shi)英砂(sha)），通入(ru)(ru)空氣，使粗銅中(zhong)(zhong)的(de)(de)(de)(de)雜質(zhi)氧化(hua)，跟(gen)熔(rong)(rong)劑(ji)形成(cheng)(cheng)(cheng)爐(lu)(lu)渣而(er)(er)除(chu)去。在(zai)(zai)(zai)雜質(zhi)除(chu)到(dao)一(yi)定程度后(hou)，再噴入(ru)(ru)重油，由重油燃(ran)燒產生(sheng)的(de)(de)(de)(de)一(yi)氧化(hua)碳等(deng)還原(yuan)性氣體使氧化(hua)亞(ya)銅在(zai)(zai)(zai)高溫下還原(yuan)為(wei)銅。得到(dao)的(de)(de)(de)(de)精(jing)銅約(yue)含(han)(han)銅99.7%。

除了銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)精礦之外，廢(fei)(fei)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)作為(wei)精煉銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)的(de)主要原(yuan)料(liao)之一，包括舊廢(fei)(fei)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)和(he)(he)新廢(fei)(fei)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)，舊廢(fei)(fei)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)來自舊設備和(he)(he)舊機器，廢(fei)(fei)棄(qi)的(de)樓房和(he)(he)地(di)下管道；新廢(fei)(fei)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)來自加工廠(chang)棄(qi)掉的(de)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)屑(xie)（銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)材的(de)產出(chu)比為(wei)50%左右），一般(ban)廢(fei)(fei)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)供應(ying)較穩定，廢(fei)(fei)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)可以分(fen)為(wei)：裸(luo)雜銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)：品位在90%以上(shang)；黃(huang)雜銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)（電線）：含銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)物料(liao)（舊馬達(da)、電路板）；由廢(fei)(fei)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)和(he)(he)其(qi)他類似材料(liao)生產出(chu)的(de)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)，也稱為(wei)再(zai)生銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)。

（2）濕法煉銅

一船適(shi)于低品位的(de)(de)氧化銅(tong)，生產出(chu)(chu)(chu)的(de)(de)精銅(tong)稱為電積銅(tong)。現代濕法冶煉(lian)(lian)有硫酸(suan)化焙(bei)燒—浸出(chu)(chu)(chu)—電積，浸出(chu)(chu)(chu)—萃取—電積，細菌浸出(chu)(chu)(chu)等法，適(shi)于低品位復雜礦(kuang)、氧化銅(tong)礦(kuang)、含銅(tong)廢礦(kuang)石的(de)(de)堆浸、槽浸選用或就地浸出(chu)(chu)(chu)。濕法冶煉(lian)(lian)技術(shu)正在逐步推廣，預計本(ben)世紀末可達總產量的(de)(de)20%，濕法冶煉(lian)(lian)的(de)(de)推出(chu)(chu)(chu)使銅(tong)的(de)(de)冶煉(lian)(lian)成本(ben)大(da)(da)大(da)(da)降低。