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(cheng)為(wei)含銅(tong)品位較高的銅(tong)精(jing)礦或者說是銅(tong)礦砂，銅(tong)精(jing)礦需要經過冶煉提(ti)成(cheng)，才(cai)能成(cheng)為(wei)精(jing)銅(tong)及銅(tong)制品。最早的銅(tong)礦石(shi)來(lai)源是孔雀石(shi)。

1、礦石的加工

銅(tong)礦石的分類及屬(shu)性：

煉銅(tong)的原料是銅(tong)礦石。銅(tong)礦石可分(fen)為三類：

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

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

（3）自(zi)然銅(tong)。銅(tong)礦石(shi)中(zhong)銅(tong)的含量在(zai)1%左右(you)（0.5%～3%）的便有開采價值，因為(wei)采用浮選(xuan)法可以把礦石(shi)中(zhong)一部分脈石(shi)等雜質(zhi)除(chu)去(qu)，而得到含銅(tong)量較高（8%～35%）的精(jing)礦砂。

2、冶煉過程

（1）火法煉銅

通過熔融(rong)冶煉(lian)(lian)和(he)電解(jie)精火煉(lian)(lian)生產(chan)出陰極(ji)銅(tong)(tong)，也即電解(jie)銅(tong)(tong)，一(yi)般(ban)適于高品(pin)位(wei)的(de)硫化(hua)(hua)銅(tong)(tong)礦(kuang)(kuang)。火法冶煉(lian)(lian)一(yi)般(ban)是先將含(han)銅(tong)(tong)百分之幾(ji)(ji)或千分之幾(ji)(ji)的(de)原(yuan)礦(kuang)(kuang)石，通過選礦(kuang)(kuang)提高到(dao)20%～30%，作為銅(tong)(tong)精礦(kuang)(kuang)，在密閉鼓風爐(lu)、反(fan)射(she)爐(lu)、電爐(lu)或閃速爐(lu)進(jin)行(xing)造(zao)锍(liu)熔煉(lian)(lian)，產(chan)出的(de)熔锍(liu)（冰銅(tong)(tong)）接著送入(ru)轉爐(lu)進(jin)行(xing)吹煉(lian)(lian)成粗(cu)銅(tong)(tong)，再(zai)在另(ling)一(yi)種反(fan)射(she)爐(lu)內(nei)經(jing)過氧(yang)化(hua)(hua)精煉(lian)(lian)脫雜，或鑄成陽極(ji)板進(jin)行(xing)電解(jie)，獲得品(pin)位(wei)高達(da)99.9%的(de)電解(jie)銅(tong)(tong)。該流程簡短(duan)、適應(ying)性強，銅(tong)(tong)的(de)回收率(lv)可達(da)95%，但因礦(kuang)(kuang)石中的(de)硫在造(zao)锍(liu)和(he)吹煉(lian)(lian)兩階(jie)段作為二(er)氧(yang)化(hua)(hua)硫廢(fei)氣(qi)排出，不易回收，易造(zao)成污染。

從銅礦石冶煉銅(tong)(tong)(tong)(tong)(tong)：以(yi)黃銅(tong)(tong)(tong)(tong)(tong)礦為(wei)例(li)，首先把(ba)精(jing)礦砂(sha)、熔(rong)(rong)(rong)(rong)劑(ji)（石(shi)灰石(shi)、砂(sha)等）和(he)燃(ran)料(liao)（焦炭(tan)、木(mu)炭(tan)或(huo)無煙煤）混(hun)合，投入(ru)(ru)“密閉”鼓(gu)風(feng)爐(lu)中，在1000℃左右進行(xing)熔(rong)(rong)(rong)(rong)煉。于是礦石(shi)中一(yi)(yi)部分(fen)硫(liu)成為(wei)SO?（用于制硫(liu)酸），大部分(fen)的(de)(de)(de)(de)(de)(de)砷、銻等雜(za)質(zhi)(zhi)成為(wei)As?O?、Sb?O?等揮發性物質(zhi)(zhi)而(er)被除去：2CuFeS?+O?=Cu?S+2FeS+SO?↑。一(yi)(yi)部分(fen)鐵(tie)的(de)(de)(de)(de)(de)(de)硫(liu)化(hua)物轉(zhuan)(zhuan)變(bian)為(wei)氧化(hua)物：2FeS+3O?=2FeO+2SO?↑。Cu?S跟(gen)剩余(yu)的(de)(de)(de)(de)(de)(de)FeS等便熔(rong)(rong)(rong)(rong)融在一(yi)(yi)起而(er)形成“冰(bing)(bing)銅(tong)(tong)(tong)(tong)(tong)”（主要(yao)由Cu?S和(he)FeS互相溶解形成的(de)(de)(de)(de)(de)(de)，它(ta)的(de)(de)(de)(de)(de)(de)含(han)銅(tong)(tong)(tong)(tong)(tong)率在20%～50%之(zhi)(zhi)間，含(han)硫(liu)率在23%～27%之(zhi)(zhi)間），FeO跟(gen)SiO?形成熔(rong)(rong)(rong)(rong)渣：FeO+SiO?=FeSiO?。熔(rong)(rong)(rong)(rong)渣浮在熔(rong)(rong)(rong)(rong)融冰(bing)(bing)銅(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)(de)(de)上面，容易分(fen)離，借(jie)以(yi)除去一(yi)(yi)部分(fen)雜(za)質(zhi)(zhi)。然(ran)后(hou)把(ba)冰(bing)(bing)銅(tong)(tong)(tong)(tong)(tong)移入(ru)(ru)轉(zhuan)(zhuan)爐(lu)中，加入(ru)(ru)熔(rong)(rong)(rong)(rong)劑(ji)（石(shi)英砂(sha)）后(hou)鼓(gu)入(ru)(ru)空(kong)氣(qi)進行(xing)吹煉（1100～1300℃）。由于鐵(tie)比銅(tong)(tong)(tong)(tong)(tong)對(dui)氧有較大的(de)(de)(de)(de)(de)(de)親和(he)力，而(er)銅(tong)(tong)(tong)(tong)(tong)比鐵(tie)對(dui)硫(liu)有較大的(de)(de)(de)(de)(de)(de)親和(he)力，因此(ci)冰(bing)(bing)銅(tong)(tong)(tong)(tong)(tong)中的(de)(de)(de)(de)(de)(de)FeS先轉(zhuan)(zhuan)變(bian)為(wei)FeO，跟(gen)熔(rong)(rong)(rong)(rong)劑(ji)結(jie)合成渣，而(er)后(hou)Cu?S才轉(zhuan)(zhuan)變(bian)為(wei)Cu?O，Cu?O跟(gen)Cu?S反應(ying)生成粗銅(tong)(tong)(tong)(tong)(tong)（含(han)銅(tong)(tong)(tong)(tong)(tong)量約為(wei)98.5%）。2Cu?S+3O?=2Cu?O+2SO?↑，2Cu?O+Cu?S=6Cu+SO?↑，再(zai)把(ba)粗銅(tong)(tong)(tong)(tong)(tong)移入(ru)(ru)反射(she)爐(lu)，加入(ru)(ru)熔(rong)(rong)(rong)(rong)劑(ji)（石(shi)英砂(sha)），通入(ru)(ru)空(kong)氣(qi)，使(shi)粗銅(tong)(tong)(tong)(tong)(tong)中的(de)(de)(de)(de)(de)(de)雜(za)質(zhi)(zhi)氧化(hua)，跟(gen)熔(rong)(rong)(rong)(rong)劑(ji)形成爐(lu)渣而(er)除去。在雜(za)質(zhi)(zhi)除到一(yi)(yi)定程(cheng)度后(hou)，再(zai)噴入(ru)(ru)重油，由重油燃(ran)燒產生的(de)(de)(de)(de)(de)(de)一(yi)(yi)氧化(hua)碳等還原性氣(qi)體使(shi)氧化(hua)亞銅(tong)(tong)(tong)(tong)(tong)在高溫下(xia)還原為(wei)銅(tong)(tong)(tong)(tong)(tong)。得到的(de)(de)(de)(de)(de)(de)精(jing)銅(tong)(tong)(tong)(tong)(tong)約含(han)銅(tong)(tong)(tong)(tong)(tong)99.7%。

除了銅(tong)(tong)(tong)精礦之外(wai)，廢(fei)銅(tong)(tong)(tong)作為精煉(lian)銅(tong)(tong)(tong)的(de)主要原料(liao)之一，包括(kuo)舊(jiu)廢(fei)銅(tong)(tong)(tong)和新廢(fei)銅(tong)(tong)(tong)，舊(jiu)廢(fei)銅(tong)(tong)(tong)來(lai)自舊(jiu)設備和舊(jiu)機(ji)器，廢(fei)棄的(de)樓房和地下管(guan)道；新廢(fei)銅(tong)(tong)(tong)來(lai)自加(jia)工(gong)廠棄掉(diao)的(de)銅(tong)(tong)(tong)屑(xie)（銅(tong)(tong)(tong)材的(de)產出比為50%左右），一般(ban)廢(fei)銅(tong)(tong)(tong)供應(ying)較穩定(ding)，廢(fei)銅(tong)(tong)(tong)可以分為：裸雜銅(tong)(tong)(tong)：品位在90%以上；黃(huang)雜銅(tong)(tong)(tong)（電(dian)線）：含(han)銅(tong)(tong)(tong)物料(liao)（舊(jiu)馬達(da)、電(dian)路板）；由(you)廢(fei)銅(tong)(tong)(tong)和其(qi)他類似(si)材料(liao)生產出的(de)銅(tong)(tong)(tong)，也稱(cheng)為再生銅(tong)(tong)(tong)。

（2）濕法煉銅

一船適(shi)于低(di)品(pin)位的(de)氧(yang)化銅(tong)(tong)(tong)，生產出(chu)的(de)精(jing)銅(tong)(tong)(tong)稱為電(dian)積銅(tong)(tong)(tong)。現代濕(shi)法(fa)冶煉有(you)硫酸化焙燒—浸(jin)(jin)(jin)出(chu)—電(dian)積，浸(jin)(jin)(jin)出(chu)—萃(cui)取—電(dian)積，細菌浸(jin)(jin)(jin)出(chu)等法(fa)，適(shi)于低(di)品(pin)位復雜(za)礦(kuang)、氧(yang)化銅(tong)(tong)(tong)礦(kuang)、含銅(tong)(tong)(tong)廢礦(kuang)石的(de)堆(dui)浸(jin)(jin)(jin)、槽(cao)浸(jin)(jin)(jin)選用或就地浸(jin)(jin)(jin)出(chu)。濕(shi)法(fa)冶煉技術正在(zai)逐步推廣，預計(ji)本世紀末(mo)可達總產量的(de)20%，濕(shi)法(fa)冶煉的(de)推出(chu)使銅(tong)(tong)(tong)的(de)冶煉成本大(da)大(da)降低(di)。