銅礦石如何提煉銅

從銅礦中開采出來的銅礦石，經(jing)過(guo)選礦(kuang)成為含銅(tong)(tong)品(pin)位較高(gao)的銅(tong)(tong)精礦(kuang)或者說是銅(tong)(tong)礦(kuang)砂，銅(tong)(tong)精礦(kuang)需要經(jing)過(guo)冶煉提(ti)成，才能成為精銅(tong)(tong)及銅(tong)(tong)制品(pin)。最早(zao)的銅(tong)(tong)礦(kuang)石來源是孔雀(que)石。

1、礦石的加工

銅礦石的分類(lei)及屬性：

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

（1）硫化(hua)礦(kuang)，如黃(huang)銅礦(kuang)（CuFeS2）、斑銅礦(kuang)（Cu5FeS4）和(he)輝銅礦(kuang)（Cu2S）等(deng)。

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

（3）自然(ran)銅(tong)(tong)。銅(tong)(tong)礦(kuang)石中(zhong)銅(tong)(tong)的(de)含(han)(han)量在1%左右（0.5%～3%）的(de)便有開采價值(zhi)，因為(wei)采用浮(fu)選法可以(yi)把礦(kuang)石中(zhong)一部分脈石等雜(za)質除去，而(er)得(de)到(dao)含(han)(han)銅(tong)(tong)量較高（8%～35%）的(de)精(jing)礦(kuang)砂。

2、冶煉過程

（1）火法煉銅

通(tong)過熔融冶煉和電(dian)(dian)解精(jing)火(huo)煉生(sheng)產(chan)(chan)出(chu)陰(yin)極(ji)銅(tong)(tong)(tong)(tong)，也即電(dian)(dian)解銅(tong)(tong)(tong)(tong)，一(yi)般(ban)(ban)適于高品(pin)位(wei)的(de)硫化銅(tong)(tong)(tong)(tong)礦。火(huo)法冶煉一(yi)般(ban)(ban)是先將含(han)銅(tong)(tong)(tong)(tong)百分之幾或千分之幾的(de)原礦石，通(tong)過選礦提高到(dao)20%～30%，作為(wei)銅(tong)(tong)(tong)(tong)精(jing)礦，在(zai)密閉鼓(gu)風爐(lu)、反射(she)爐(lu)、電(dian)(dian)爐(lu)或閃速(su)爐(lu)進行(xing)(xing)造(zao)(zao)锍(liu)熔煉，產(chan)(chan)出(chu)的(de)熔锍(liu)（冰(bing)銅(tong)(tong)(tong)(tong)）接(jie)著送入轉爐(lu)進行(xing)(xing)吹煉成(cheng)粗銅(tong)(tong)(tong)(tong)，再在(zai)另(ling)一(yi)種反射(she)爐(lu)內經過氧化精(jing)煉脫(tuo)雜，或鑄成(cheng)陽極(ji)板(ban)進行(xing)(xing)電(dian)(dian)解，獲(huo)得品(pin)位(wei)高達(da)99.9%的(de)電(dian)(dian)解銅(tong)(tong)(tong)(tong)。該流程簡短、適應性(xing)強，銅(tong)(tong)(tong)(tong)的(de)回(hui)收(shou)率可達(da)95%，但因(yin)礦石中(zhong)的(de)硫在(zai)造(zao)(zao)锍(liu)和吹煉兩階段(duan)作為(wei)二氧化硫廢氣排出(chu)，不易回(hui)收(shou)，易造(zao)(zao)成(cheng)污染。

從銅礦石冶煉銅(tong)(tong)(tong)(tong)：以黃銅(tong)(tong)(tong)(tong)礦為(wei)例，首先(xian)把(ba)精(jing)礦砂(sha)、熔(rong)劑（石(shi)灰石(shi)、砂(sha)等）和(he)燃料（焦炭、木炭或無煙煤(mei)）混(hun)合(he)，投入(ru)(ru)(ru)“密(mi)閉”鼓風爐(lu)(lu)(lu)中(zhong)，在(zai)1000℃左右進行(xing)熔(rong)煉。于是礦石(shi)中(zhong)一(yi)部(bu)分硫(liu)成(cheng)(cheng)為(wei)SO?（用于制硫(liu)酸），大部(bu)分的(de)(de)砷、銻等雜(za)(za)質(zhi)成(cheng)(cheng)為(wei)As?O?、Sb?O?等揮發性物(wu)質(zhi)而(er)(er)被除(chu)(chu)去(qu)(qu)：2CuFeS?+O?=Cu?S+2FeS+SO?↑。一(yi)部(bu)分鐵的(de)(de)硫(liu)化物(wu)轉(zhuan)(zhuan)變為(wei)氧(yang)(yang)化物(wu)：2FeS+3O?=2FeO+2SO?↑。Cu?S跟(gen)剩余的(de)(de)FeS等便熔(rong)融在(zai)一(yi)起而(er)(er)形(xing)成(cheng)(cheng)“冰(bing)(bing)銅(tong)(tong)(tong)(tong)”（主要由(you)Cu?S和(he)FeS互(hu)相溶解形(xing)成(cheng)(cheng)的(de)(de)，它的(de)(de)含(han)銅(tong)(tong)(tong)(tong)率(lv)在(zai)20%～50%之間，含(han)硫(liu)率(lv)在(zai)23%～27%之間），FeO跟(gen)SiO?形(xing)成(cheng)(cheng)熔(rong)渣(zha)：FeO+SiO?=FeSiO?。熔(rong)渣(zha)浮在(zai)熔(rong)融冰(bing)(bing)銅(tong)(tong)(tong)(tong)的(de)(de)上(shang)面，容(rong)易分離，借以除(chu)(chu)去(qu)(qu)一(yi)部(bu)分雜(za)(za)質(zhi)。然后(hou)(hou)把(ba)冰(bing)(bing)銅(tong)(tong)(tong)(tong)移入(ru)(ru)(ru)轉(zhuan)(zhuan)爐(lu)(lu)(lu)中(zhong)，加(jia)入(ru)(ru)(ru)熔(rong)劑（石(shi)英(ying)砂(sha)）后(hou)(hou)鼓入(ru)(ru)(ru)空氣(qi)(qi)進行(xing)吹煉（1100～1300℃）。由(you)于鐵比銅(tong)(tong)(tong)(tong)對氧(yang)(yang)有較大的(de)(de)親和(he)力(li)，而(er)(er)銅(tong)(tong)(tong)(tong)比鐵對硫(liu)有較大的(de)(de)親和(he)力(li)，因此冰(bing)(bing)銅(tong)(tong)(tong)(tong)中(zhong)的(de)(de)FeS先(xian)轉(zhuan)(zhuan)變為(wei)FeO，跟(gen)熔(rong)劑結合(he)成(cheng)(cheng)渣(zha)，而(er)(er)后(hou)(hou)Cu?S才轉(zhuan)(zhuan)變為(wei)Cu?O，Cu?O跟(gen)Cu?S反(fan)(fan)應生成(cheng)(cheng)粗銅(tong)(tong)(tong)(tong)（含(han)銅(tong)(tong)(tong)(tong)量約(yue)為(wei)98.5%）。2Cu?S+3O?=2Cu?O+2SO?↑，2Cu?O+Cu?S=6Cu+SO?↑，再(zai)(zai)把(ba)粗銅(tong)(tong)(tong)(tong)移入(ru)(ru)(ru)反(fan)(fan)射爐(lu)(lu)(lu)，加(jia)入(ru)(ru)(ru)熔(rong)劑（石(shi)英(ying)砂(sha)），通(tong)入(ru)(ru)(ru)空氣(qi)(qi)，使粗銅(tong)(tong)(tong)(tong)中(zhong)的(de)(de)雜(za)(za)質(zhi)氧(yang)(yang)化，跟(gen)熔(rong)劑形(xing)成(cheng)(cheng)爐(lu)(lu)(lu)渣(zha)而(er)(er)除(chu)(chu)去(qu)(qu)。在(zai)雜(za)(za)質(zhi)除(chu)(chu)到一(yi)定程度后(hou)(hou)，再(zai)(zai)噴(pen)入(ru)(ru)(ru)重油(you)，由(you)重油(you)燃燒產生的(de)(de)一(yi)氧(yang)(yang)化碳等還(huan)(huan)原性氣(qi)(qi)體(ti)使氧(yang)(yang)化亞銅(tong)(tong)(tong)(tong)在(zai)高(gao)溫下(xia)還(huan)(huan)原為(wei)銅(tong)(tong)(tong)(tong)。得到的(de)(de)精(jing)銅(tong)(tong)(tong)(tong)約(yue)含(han)銅(tong)(tong)(tong)(tong)99.7%。

除了銅(tong)(tong)精(jing)礦之(zhi)外(wai)，廢(fei)(fei)銅(tong)(tong)作為(wei)精(jing)煉(lian)銅(tong)(tong)的(de)(de)主(zhu)要(yao)原(yuan)料(liao)之(zhi)一，包括(kuo)舊(jiu)(jiu)廢(fei)(fei)銅(tong)(tong)和(he)新(xin)廢(fei)(fei)銅(tong)(tong)，舊(jiu)(jiu)廢(fei)(fei)銅(tong)(tong)來自舊(jiu)(jiu)設備和(he)舊(jiu)(jiu)機器，廢(fei)(fei)棄(qi)的(de)(de)樓(lou)房和(he)地下(xia)管(guan)道(dao)；新(xin)廢(fei)(fei)銅(tong)(tong)來自加(jia)工廠(chang)棄(qi)掉(diao)的(de)(de)銅(tong)(tong)屑（銅(tong)(tong)材(cai)的(de)(de)產(chan)(chan)出比為(wei)50%左(zuo)右(you)），一般廢(fei)(fei)銅(tong)(tong)供應較穩定，廢(fei)(fei)銅(tong)(tong)可以分(fen)為(wei)：裸(luo)雜(za)銅(tong)(tong)：品(pin)位在90%以上；黃雜(za)銅(tong)(tong)（電(dian)線(xian)）：含銅(tong)(tong)物料(liao)（舊(jiu)(jiu)馬達、電(dian)路板）；由廢(fei)(fei)銅(tong)(tong)和(he)其他類(lei)似材(cai)料(liao)生產(chan)(chan)出的(de)(de)銅(tong)(tong)，也(ye)稱為(wei)再生銅(tong)(tong)。

（2）濕法煉銅

一船適于低品(pin)位的(de)(de)氧(yang)化(hua)銅(tong)，生產(chan)出(chu)(chu)的(de)(de)精銅(tong)稱為電積(ji)銅(tong)。現代濕法(fa)冶煉有硫(liu)酸化(hua)焙燒(shao)—浸出(chu)(chu)—電積(ji)，浸出(chu)(chu)—萃(cui)取—電積(ji)，細菌浸出(chu)(chu)等(deng)法(fa)，適于低品(pin)位復雜礦(kuang)(kuang)、氧(yang)化(hua)銅(tong)礦(kuang)(kuang)、含銅(tong)廢礦(kuang)(kuang)石的(de)(de)堆浸、槽(cao)浸選用或就地浸出(chu)(chu)。濕法(fa)冶煉技術正在逐步推廣，預計本世(shi)紀末可(ke)達總(zong)產(chan)量的(de)(de)20%，濕法(fa)冶煉的(de)(de)推出(chu)(chu)使銅(tong)的(de)(de)冶煉成本大大降低。