銅礦石如何提煉銅

從銅礦中開采出來的銅礦石，經過選礦成為含銅(tong)(tong)品(pin)位較高的銅(tong)(tong)精礦或者說(shuo)是(shi)銅(tong)(tong)礦砂，銅(tong)(tong)精礦需要(yao)經過冶煉提成，才能成為精銅(tong)(tong)及(ji)銅(tong)(tong)制(zhi)品(pin)。最(zui)早的銅(tong)(tong)礦石來源是(shi)孔雀石。

1、礦石的加工

銅礦石的分類及屬性：

煉(lian)銅(tong)(tong)的原料是銅(tong)(tong)礦(kuang)石。銅(tong)(tong)礦(kuang)石可分為三類：

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

（2）氧化礦(kuang)，如赤(chi)銅(tong)礦(kuang)（Cu2O）、孔(kong)(kong)雀石[Cu?(OH)?CO?]、藍銅(tong)礦(kuang)[2CuCO3·Cu(OH)2]、硅孔(kong)(kong)雀石（CuSiO3·2H2O）等(deng)。

（3）自然銅。銅礦石中銅的含量在1%左右(you)（0.5%～3%）的便有(you)開采(cai)價值，因為采(cai)用浮選法可以把礦石中一(yi)部分脈(mo)石等雜(za)質(zhi)除去，而(er)得到(dao)含銅量較高（8%～35%）的精礦砂。

2、冶煉過程

（1）火法煉銅

通(tong)過(guo)(guo)熔(rong)融冶(ye)煉(lian)和電(dian)解(jie)(jie)(jie)精火煉(lian)生(sheng)產出(chu)(chu)陰(yin)極銅(tong)，也即電(dian)解(jie)(jie)(jie)銅(tong)，一般適于高(gao)(gao)品(pin)位的硫(liu)化(hua)銅(tong)礦(kuang)。火法冶(ye)煉(lian)一般是先將含銅(tong)百分之幾或(huo)(huo)千分之幾的原(yuan)礦(kuang)石，通(tong)過(guo)(guo)選礦(kuang)提高(gao)(gao)到20%～30%，作(zuo)為銅(tong)精礦(kuang)，在密閉鼓(gu)風爐、反射爐、電(dian)爐或(huo)(huo)閃(shan)速爐進(jin)行造锍(liu)(liu)熔(rong)煉(lian)，產出(chu)(chu)的熔(rong)锍(liu)(liu)（冰銅(tong)）接著送入轉爐進(jin)行吹(chui)煉(lian)成(cheng)(cheng)粗(cu)銅(tong)，再在另一種反射爐內經(jing)過(guo)(guo)氧(yang)化(hua)精煉(lian)脫雜，或(huo)(huo)鑄成(cheng)(cheng)陽(yang)極板進(jin)行電(dian)解(jie)(jie)(jie)，獲(huo)得品(pin)位高(gao)(gao)達(da)99.9%的電(dian)解(jie)(jie)(jie)銅(tong)。該(gai)流程簡短、適應性強，銅(tong)的回(hui)收(shou)(shou)率可達(da)95%，但因礦(kuang)石中的硫(liu)在造锍(liu)(liu)和吹(chui)煉(lian)兩階段作(zuo)為二氧(yang)化(hua)硫(liu)廢氣排出(chu)(chu)，不易回(hui)收(shou)(shou)，易造成(cheng)(cheng)污(wu)染(ran)。

從銅礦石冶煉銅(tong)(tong)：以黃銅(tong)(tong)礦為(wei)(wei)例，首先把精礦砂、熔(rong)(rong)(rong)劑（石(shi)灰石(shi)、砂等(deng)）和燃(ran)料（焦炭、木(mu)炭或無煙(yan)煤(mei)）混合(he)，投(tou)入(ru)(ru)“密(mi)閉(bi)”鼓(gu)風(feng)爐中(zhong)，在(zai)1000℃左右進行(xing)(xing)熔(rong)(rong)(rong)煉。于是(shi)礦石(shi)中(zhong)一(yi)(yi)部(bu)(bu)(bu)分硫(liu)成(cheng)為(wei)(wei)SO?（用于制(zhi)硫(liu)酸(suan)），大部(bu)(bu)(bu)分的(de)砷、銻(ti)等(deng)雜(za)(za)(za)(za)質(zhi)成(cheng)為(wei)(wei)As?O?、Sb?O?等(deng)揮發(fa)性物(wu)(wu)質(zhi)而(er)被除(chu)去(qu)：2CuFeS?+O?=Cu?S+2FeS+SO?↑。一(yi)(yi)部(bu)(bu)(bu)分鐵的(de)硫(liu)化物(wu)(wu)轉(zhuan)(zhuan)(zhuan)變(bian)為(wei)(wei)氧(yang)(yang)(yang)(yang)化物(wu)(wu)：2FeS+3O?=2FeO+2SO?↑。Cu?S跟(gen)剩(sheng)余(yu)的(de)FeS等(deng)便熔(rong)(rong)(rong)融在(zai)一(yi)(yi)起而(er)形成(cheng)“冰(bing)銅(tong)(tong)”（主(zhu)要由Cu?S和FeS互(hu)相溶(rong)解形成(cheng)的(de)，它的(de)含銅(tong)(tong)率(lv)在(zai)20%～50%之(zhi)(zhi)間，含硫(liu)率(lv)在(zai)23%～27%之(zhi)(zhi)間），FeO跟(gen)SiO?形成(cheng)熔(rong)(rong)(rong)渣(zha)(zha)：FeO+SiO?=FeSiO?。熔(rong)(rong)(rong)渣(zha)(zha)浮(fu)在(zai)熔(rong)(rong)(rong)融冰(bing)銅(tong)(tong)的(de)上面，容易分離，借以除(chu)去(qu)一(yi)(yi)部(bu)(bu)(bu)分雜(za)(za)(za)(za)質(zhi)。然后把冰(bing)銅(tong)(tong)移入(ru)(ru)轉(zhuan)(zhuan)(zhuan)爐中(zhong)，加入(ru)(ru)熔(rong)(rong)(rong)劑（石(shi)英砂）后鼓(gu)入(ru)(ru)空(kong)氣(qi)(qi)進行(xing)(xing)吹煉（1100～1300℃）。由于鐵比銅(tong)(tong)對氧(yang)(yang)(yang)(yang)有較大的(de)親和力(li)，而(er)銅(tong)(tong)比鐵對硫(liu)有較大的(de)親和力(li)，因此冰(bing)銅(tong)(tong)中(zhong)的(de)FeS先轉(zhuan)(zhuan)(zhuan)變(bian)為(wei)(wei)FeO，跟(gen)熔(rong)(rong)(rong)劑結合(he)成(cheng)渣(zha)(zha)，而(er)后Cu?S才(cai)轉(zhuan)(zhuan)(zhuan)變(bian)為(wei)(wei)Cu?O，Cu?O跟(gen)Cu?S反應生(sheng)成(cheng)粗(cu)銅(tong)(tong)（含銅(tong)(tong)量(liang)約為(wei)(wei)98.5%）。2Cu?S+3O?=2Cu?O+2SO?↑，2Cu?O+Cu?S=6Cu+SO?↑，再(zai)把粗(cu)銅(tong)(tong)移入(ru)(ru)反射爐，加入(ru)(ru)熔(rong)(rong)(rong)劑（石(shi)英砂），通入(ru)(ru)空(kong)氣(qi)(qi)，使粗(cu)銅(tong)(tong)中(zhong)的(de)雜(za)(za)(za)(za)質(zhi)氧(yang)(yang)(yang)(yang)化，跟(gen)熔(rong)(rong)(rong)劑形成(cheng)爐渣(zha)(zha)而(er)除(chu)去(qu)。在(zai)雜(za)(za)(za)(za)質(zhi)除(chu)到一(yi)(yi)定程度后，再(zai)噴(pen)入(ru)(ru)重油(you)，由重油(you)燃(ran)燒產生(sheng)的(de)一(yi)(yi)氧(yang)(yang)(yang)(yang)化碳(tan)等(deng)還(huan)原(yuan)性氣(qi)(qi)體使氧(yang)(yang)(yang)(yang)化亞(ya)銅(tong)(tong)在(zai)高溫下還(huan)原(yuan)為(wei)(wei)銅(tong)(tong)。得到的(de)精銅(tong)(tong)約含銅(tong)(tong)99.7%。

除了銅(tong)(tong)(tong)(tong)(tong)精礦之外(wai)，廢(fei)銅(tong)(tong)(tong)(tong)(tong)作為(wei)(wei)精煉銅(tong)(tong)(tong)(tong)(tong)的(de)(de)主(zhu)要原料之一，包括舊(jiu)廢(fei)銅(tong)(tong)(tong)(tong)(tong)和(he)新廢(fei)銅(tong)(tong)(tong)(tong)(tong)，舊(jiu)廢(fei)銅(tong)(tong)(tong)(tong)(tong)來自舊(jiu)設備和(he)舊(jiu)機器，廢(fei)棄的(de)(de)樓房和(he)地下管道(dao)；新廢(fei)銅(tong)(tong)(tong)(tong)(tong)來自加工廠棄掉的(de)(de)銅(tong)(tong)(tong)(tong)(tong)屑（銅(tong)(tong)(tong)(tong)(tong)材(cai)的(de)(de)產(chan)出比(bi)為(wei)(wei)50%左右），一般廢(fei)銅(tong)(tong)(tong)(tong)(tong)供應較(jiao)穩定，廢(fei)銅(tong)(tong)(tong)(tong)(tong)可以(yi)分(fen)為(wei)(wei)：裸雜銅(tong)(tong)(tong)(tong)(tong)：品(pin)位在90%以(yi)上；黃雜銅(tong)(tong)(tong)(tong)(tong)（電線）：含(han)銅(tong)(tong)(tong)(tong)(tong)物料（舊(jiu)馬達、電路板）；由廢(fei)銅(tong)(tong)(tong)(tong)(tong)和(he)其他類似材(cai)料生產(chan)出的(de)(de)銅(tong)(tong)(tong)(tong)(tong)，也稱(cheng)為(wei)(wei)再生銅(tong)(tong)(tong)(tong)(tong)。

（2）濕法煉銅

一船適于低品(pin)位的氧化銅，生(sheng)產(chan)出的精(jing)銅稱(cheng)為電積(ji)銅。現(xian)代濕法冶(ye)煉(lian)有硫酸化焙燒—浸出—電積(ji)，浸出—萃取(qu)—電積(ji)，細菌(jun)浸出等(deng)法，適于低品(pin)位復雜(za)礦、氧化銅礦、含銅廢(fei)礦石(shi)的堆浸、槽浸選(xuan)用或就(jiu)地(di)浸出。濕法冶(ye)煉(lian)技術正(zheng)在逐步推廣，預計本世紀末可(ke)達總產(chan)量的20%，濕法冶(ye)煉(lian)的推出使銅的冶(ye)煉(lian)成本大(da)大(da)降(jiang)低。