原標題：從“中華(hua)第一刀”述說銅(tong)的前世今(jin)生

　　●馮俊禮

　　2023年5月(yue)8日，“文明(ming)匯聚·光耀河州——史前文化臨夏(xia)論壇”在臨夏(xia)市開幕，臨夏(xia)出土的(de)不少史前文物引起(qi)專家學者的(de)濃厚興趣和熱(re)情關注。

　　臨夏不僅出(chu)土(tu)了享(xiang)譽全國的“彩(cai)陶王”、史前三大(da)名盆(pen)之一(yi)的馬(ma)家窯類型(xing)弧線水(shui)波(bo)紋彩(cai)陶盆(pen)，也出(chu)土(tu)了被(bei)譽為“中(zhong)華第一(yi)刀(dao)(dao)”的馬(ma)家窯文化青銅(tong)(tong)刀(dao)(dao)、被(bei)譽為“天(tian)下(xia)第一(yi)鏡(jing)”的齊家文化青銅(tong)(tong)鏡(jing)。其(qi)中(zhong)，最引人矚目的是東鄉縣(xian)東塬鄉林家村(cun)林家遺址出(chu)土(tu)的一(yi)把青銅(tong)(tong)刀(dao)(dao)。

　　為什(shen)么這把青銅(tong)(tong)刀被譽(yu)為“中(zhong)華第(di)一(yi)刀”呢(ni)？原(yuan)來(lai)，這把長12.7厘米(mi)、寬(kuan)2.5厘米(mi)的銅(tong)(tong)刀，由錫青銅(tong)(tong)模(mo)鑄而成，刀身薄厚均(jun)勻，短柄長刃，是中(zhong)國(guo)目(mu)前(qian)發現最早的青銅(tong)(tong)器，把我國(guo)制作青銅(tong)(tong)器的歷史提早了1000年。

　　銅是(shi)人類(lei)最早使用(yong)的金屬，是(shi)與人類(lei)關(guan)系十分親密的有色金屬，被(bei)普遍地應用(yong)于電(dian)氣、輕工、機(ji)械制(zhi)造(zao)、建(jian)筑(zhu)等工業領(ling)域，在我(wo)國有色金屬材料的消費中僅次于鋁(lv)。銅在元素周期表中位于第4周期IB族。純銅呈紫(zi)紅(hong)色，故又稱(cheng)紫(zi)銅。密度(du)為(wei)8.96g/cm^3，比(bi)鐵略大，熔點為(wei)1083℃，具(ju)有優良(liang)的導電(dian)性、導熱性、延展(zhan)性和耐(nai)腐(fu)蝕性。

　　制造銅(tong)(tong)器(qi)所用的銅(tong)(tong)一般不(bu)是純銅(tong)(tong)，而是銅(tong)(tong)合(he)金。因為純銅(tong)(tong)質地(di)比較柔軟(ruan)，非常(chang)容易(yi)彎曲，所以(yi)鑄造刀劍、工具(ju)及器(qi)物時不(bu)用純銅(tong)(tong)。那么(me)什(shen)么(me)是合(he)金呢？合(he)金有(you)什(shen)么(me)優點？

　　把兩種或兩種以上的(de)(de)金(jin)(jin)(jin)屬(shu)(shu)(shu)（或金(jin)(jin)(jin)屬(shu)(shu)(shu)與非金(jin)(jin)(jin)屬(shu)(shu)(shu)）熔合(he)而成(cheng)(cheng)的(de)(de)具有(you)金(jin)(jin)(jin)屬(shu)(shu)(shu)特(te)性(xing)(xing)的(de)(de)物質叫(jiao)作合(he)金(jin)(jin)(jin)。合(he)金(jin)(jin)(jin)具有(you)如(ru)(ru)下特(te)性(xing)(xing)，一(yi)是(shi)具有(you)比各成(cheng)(cheng)分中(zhong)(zhong)金(jin)(jin)(jin)屬(shu)(shu)(shu)更大(da)的(de)(de)硬(ying)度(du)，如(ru)(ru)鎂鋁合(he)金(jin)(jin)(jin)比鎂和(he)鋁都(dou)硬(ying)。二是(shi)熔點(dian)一(yi)般(ban)比其中(zhong)(zhong)任一(yi)成(cheng)(cheng)分金(jin)(jin)(jin)屬(shu)(shu)(shu)低，如(ru)(ru)一(yi)般(ban)家用(yong)保險(xian)絲大(da)都(dou)是(shi)用(yong)鉛（不少于98%）和(he)銻(ti)（0.3%-1.5%）的(de)(de)合(he)金(jin)(jin)(jin)制成(cheng)(cheng)。鉛的(de)(de)熔點(dian)為327℃，銻(ti)的(de)(de)熔點(dian)為630.5℃，而合(he)金(jin)(jin)(jin)的(de)(de)熔點(dian)僅僅為246℃。三是(shi)導電(dian)性(xing)(xing)低于任一(yi)成(cheng)(cheng)分金(jin)(jin)(jin)屬(shu)(shu)(shu)。四是(shi)有(you)的(de)(de)抗(kang)腐(fu)蝕能力強(qiang)(qiang)，如(ru)(ru)不銹鋼(gang)比鐵(tie)抗(kang)腐(fu)蝕能力強(qiang)(qiang)。

　　銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)合(he)金(jin)(jin)是(shi)以(yi)純銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)為(wei)基體加(jia)入一種(zhong)(zhong)或幾種(zhong)(zhong)其他元(yuan)素(su)(su)所(suo)(suo)構成(cheng)(cheng)的(de)(de)(de)(de)合(he)金(jin)(jin)。銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)能與(yu)鋅(xin)、錫(xi)、鉛、錳(meng)、鈷、鎳(nie)(nie)(nie)、鋁、鐵(tie)、硅(gui)等(deng)(deng)金(jin)(jin)屬(shu)和(he)非(fei)金(jin)(jin)屬(shu)形(xing)成(cheng)(cheng)合(he)金(jin)(jin)。形(xing)成(cheng)(cheng)的(de)(de)(de)(de)合(he)金(jin)(jin)主要(yao)(yao)(yao)分為(wei)3類：黃(huang)(huang)(huang)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)、青銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)、白(bai)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)。黃(huang)(huang)(huang)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)是(shi)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)鋅(xin)合(he)金(jin)(jin)，以(yi)鋅(xin)為(wei)主要(yao)(yao)(yao)添(tian)加(jia)元(yuan)素(su)(su)。添(tian)加(jia)3種(zhong)(zhong)以(yi)上元(yuan)素(su)(su)的(de)(de)(de)(de)黃(huang)(huang)(huang)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)稱(cheng)為(wei)特(te)(te)殊黃(huang)(huang)(huang)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)或復(fu)雜(za)黃(huang)(huang)(huang)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)。黃(huang)(huang)(huang)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)機(ji)械(xie)性(xing)(xing)(xing)能和(he)耐磨性(xing)(xing)(xing)能都很(hen)好(hao)，可用(yong)(yong)于制(zhi)(zhi)造(zao)精密(mi)儀(yi)器(qi)(qi)、船舶零件、槍炮(pao)的(de)(de)(de)(de)彈殼(ke)等(deng)(deng)。黃(huang)(huang)(huang)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)聽起來(lai)聲音好(hao)聽，所(suo)(suo)以(yi)鑼、鈸(ba)、鈴、號等(deng)(deng)樂器(qi)(qi)都是(shi)用(yong)(yong)黃(huang)(huang)(huang)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)制(zhi)(zhi)作的(de)(de)(de)(de)。青銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)原指銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)錫(xi)合(he)金(jin)(jin)，后來(lai)除黃(huang)(huang)(huang)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)、白(bai)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)以(yi)外的(de)(de)(de)(de)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)合(he)金(jin)(jin)均稱(cheng)青銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)，并常在(zai)青銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)名(ming)(ming)字(zi)前冠(guan)以(yi)第一主要(yao)(yao)(yao)添(tian)加(jia)元(yuan)素(su)(su)的(de)(de)(de)(de)名(ming)(ming)。錫(xi)青銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)鑄造(zao)性(xing)(xing)(xing)能、耐磨性(xing)(xing)(xing)能和(he)機(ji)械(xie)性(xing)(xing)(xing)能好(hao)，適合(he)于制(zhi)(zhi)造(zao)軸(zhou)承、渦(wo)輪、齒(chi)輪等(deng)(deng)。鉛青銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)是(shi)現(xian)代發(fa)動機(ji)和(he)磨床廣泛使用(yong)(yong)的(de)(de)(de)(de)軸(zhou)承材料。鋁青銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)強(qiang)度高，耐磨性(xing)(xing)(xing)和(he)耐腐蝕(shi)(shi)性(xing)(xing)(xing)好(hao)，用(yong)(yong)于鑄造(zao)高載荷的(de)(de)(de)(de)齒(chi)輪、軸(zhou)套、船用(yong)(yong)螺旋(xuan)槳等(deng)(deng)。白(bai)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)是(shi)以(yi)鎳(nie)(nie)(nie)為(wei)主要(yao)(yao)(yao)添(tian)加(jia)元(yuan)素(su)(su)的(de)(de)(de)(de)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)合(he)金(jin)(jin)。銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)鎳(nie)(nie)(nie)二(er)元(yuan)合(he)金(jin)(jin)稱(cheng)為(wei)普通(tong)白(bai)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)；加(jia)有錳(meng)、鐵(tie)、鋅(xin)、鋁等(deng)(deng)元(yuan)素(su)(su)的(de)(de)(de)(de)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)合(he)金(jin)(jin)稱(cheng)為(wei)復(fu)雜(za)白(bai)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)。工(gong)業(ye)用(yong)(yong)白(bai)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)分為(wei)結構白(bai)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)和(he)電工(gong)白(bai)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)兩大類。前者(zhe)的(de)(de)(de)(de)特(te)(te)點(dian)是(shi)機(ji)械(xie)性(xing)(xing)(xing)能和(he)耐腐蝕(shi)(shi)性(xing)(xing)(xing)好(hao)，色澤美觀。這種(zhong)(zhong)白(bai)銅(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)(tong)廣泛用(yong)(yong)于制(zhi)(zhi)造(zao)精密(mi)機(ji)械(xie)、化工(gong)機(ji)械(xie)和(he)船舶構件，后者(zhe)一般有良好(hao)的(de)(de)(de)(de)熱(re)電性(xing)(xing)(xing)能。

　　世界(jie)上各古老(lao)的(de)(de)文化發源地(di)在(zai)使用和冶煉(lian)金屬(shu)的(de)(de)歷(li)史上，都(dou)是(shi)銅先于鐵，這是(shi)一個普遍規律。那這又是(shi)為什么呢？其原因是(shi)，在(zai)金屬(shu)活(huo)動性“排行榜”中，銅排在(zai)鐵之后，它的(de)(de)還(huan)原性比(bi)鐵弱，要從化合態(tai)中把它還(huan)原成(cheng)游(you)離(li)態(tai)相對容易(yi)一些。說到這兒，你們會問我國古代銅是(shi)怎樣(yang)煉(lian)成(cheng)的(de)(de)呢？

　　銅在(zai)地殼中的含量約為0.01%，在(zai)自然界中銅多以化合(he)態(tai)存在(zai)。常見的銅礦(kuang)石(shi)有黃銅礦(kuang)、輝銅礦(kuang)、孔雀石(shi)、赤銅礦(kuang)、膽礬等。

　　我國古代(dai)煉(lian)銅(tong)(tong)(tong)(tong)(tong)(tong)主要有(you)2種方法。一(yi)種是(shi)濕(shi)(shi)法煉(lian)銅(tong)(tong)(tong)(tong)(tong)(tong)。西(xi)漢時期(qi)劉安所著(zhu)的《淮南(nan)萬畢術(shu)(shu)》中有(you)“曾青(qing)得(de)鐵(tie)則(ze)化為銅(tong)(tong)(tong)(tong)(tong)(tong)”的記載，其(qi)含義是(shi)把(ba)(ba)鐵(tie)放入(ru)硫酸銅(tong)(tong)(tong)(tong)(tong)(tong)溶(rong)液(ye)中，可以(yi)(yi)置(zhi)換(huan)出(chu)單質銅(tong)(tong)(tong)(tong)(tong)(tong)，這種方法是(shi)現代(dai)濕(shi)(shi)法冶(ye)金的先驅。沈(shen)括所著(zhu)的《夢溪筆談》有(you)“信州鉛(qian)山縣有(you)苦(ku)泉(quan)，流以(yi)(yi)為澗。挹其(qi)水熬之，則(ze)成(cheng)膽(dan)(dan)礬(fan)。烹(peng)膽(dan)(dan)礬(fan)則(ze)成(cheng)銅(tong)(tong)(tong)(tong)(tong)(tong)。熬膽(dan)(dan)礬(fan)鐵(tie)釜亦化為銅(tong)(tong)(tong)(tong)(tong)(tong)。”“烹(peng)膽(dan)(dan)礬(fan)則(ze)成(cheng)銅(tong)(tong)(tong)(tong)(tong)(tong)”說(shuo)的是(shi)五水合硫酸銅(tong)(tong)(tong)(tong)(tong)(tong)受熱最終分解得(de)到單質銅(tong)(tong)(tong)(tong)(tong)(tong)。“熬膽(dan)(dan)礬(fan)鐵(tie)釜亦化為銅(tong)(tong)(tong)(tong)(tong)(tong)”說(shuo)的仍然是(shi)單質鐵(tie)與(yu)硫酸銅(tong)(tong)(tong)(tong)(tong)(tong)溶(rong)液(ye)發生置(zhi)換(huan)反應(ying)，得(de)到單質銅(tong)(tong)(tong)(tong)(tong)(tong)。濕(shi)(shi)法冶(ye)銅(tong)(tong)(tong)(tong)(tong)(tong)也稱(cheng)膽(dan)(dan)銅(tong)(tong)(tong)(tong)(tong)(tong)法，其(qi)生產過程主要包括2個步(bu)驟(zou)，一(yi)是(shi)浸銅(tong)(tong)(tong)(tong)(tong)(tong)，把(ba)(ba)鐵(tie)放在(zai)膽(dan)(dan)礬(fan)溶(rong)液(ye)中，使膽(dan)(dan)礬(fan)溶(rong)液(ye)中的銅(tong)(tong)(tong)(tong)(tong)(tong)離子被鐵(tie)置(zhi)換(huan)成(cheng)單質銅(tong)(tong)(tong)(tong)(tong)(tong)沉積下來；二是(shi)將沉積的銅(tong)(tong)(tong)(tong)(tong)(tong)粉收(shou)(shou)集(ji)起來，再(zai)加以(yi)(yi)熔煉(lian)。到南(nan)宋時，膽(dan)(dan)銅(tong)(tong)(tong)(tong)(tong)(tong)占總產量的85%。世界濕(shi)(shi)法冶(ye)銅(tong)(tong)(tong)(tong)(tong)(tong)第一(yi)人，北宋學者張潛，根據前人記述和自(zi)己(ji)長期(qi)實踐(jian)經(jing)驗，總結出(chu)一(yi)套(tao)比較完整的膽(dan)(dan)水浸銅(tong)(tong)(tong)(tong)(tong)(tong)技(ji)術(shu)(shu)，寫成(cheng)濕(shi)(shi)法冶(ye)銅(tong)(tong)(tong)(tong)(tong)(tong)專(zhuan)著(zhu)《浸銅(tong)(tong)(tong)(tong)(tong)(tong)要略》，命其(qi)子張甲獻(xian)給朝(chao)廷，這種技(ji)術(shu)(shu)因“用費少而收(shou)(shou)功博”，“歲收(shou)(shou)銅(tong)(tong)(tong)(tong)(tong)(tong)百萬”，受到朝(chao)廷嘉(jia)獎。

　　另(ling)一(yi)種是(shi)火(huo)法(fa)煉銅(tong)(tong)(tong)。據考證，商代的火(huo)法(fa)煉銅(tong)(tong)(tong)，主要(yao)是(shi)以(yi)孔雀石(shi)和木炭(tan)為(wei)原(yuan)料，在高(gao)溫下灼燒(shao)。其原(yuan)理(li)是(shi)，讓孔雀石(shi)首先分解得(de)到氧化銅(tong)(tong)(tong)。再用(yong)還(huan)(huan)(huan)原(yuan)劑木炭(tan)和一(yi)氧化碳在較高(gao)溫度下與氧化銅(tong)(tong)(tong)發生氧化還(huan)(huan)(huan)原(yuan)反應，還(huan)(huan)(huan)原(yuan)制得(de)單質(zhi)銅(tong)(tong)(tong)。

　　“中(zhong)華第一刀”經過碳-14年(nian)(nian)代(dai)測(ce)定，約在公元(yuan)前3280年(nian)(nian)至公元(yuan)前2740年(nian)(nian)之(zhi)間，它(ta)是迄今為(wei)止中(zhong)國發現最早的(de)青銅(tong)器，距今已有(you)5000年(nian)(nian)的(de)歷史(shi)，將我國青銅(tong)器的(de)制(zhi)造歷史(shi)整整向前挪了1000年(nian)(nian)。小小銅(tong)刀，輕輕劃開了我國青銅(tong)器時代(dai)的(de)序幕，我為(wei)自己的(de)家鄉(xiang)在史(shi)前文化發展中(zhong)的(de)重要地位感(gan)到自豪。