鉛是(shi)一種金(jin)屬(shu)化學元(yuan)素(su),元(yuan)素(su)符號Pb,原(yuan)(yuan)子序數為82,原(yuan)(yuan)子量為207.2,是(shi)原(yuan)(yuan)子量最(zui)大(da)的非放射性(xing)元(yuan)素(su)。金(jin)屬(shu)鉛為面心(xin)立方晶體。
金(jin)屬鉛是一種耐(nai)蝕(shi)的(de)重有(you)(you)色金(jin)屬材料,鉛具有(you)(you)熔點低、耐(nai)蝕(shi)性(xing)高、X射線和(he)γ射線等不易穿透、塑性(xing)好等優點,常(chang)被加工成板材和(he)管材,廣(guang)泛(fan)用(yong)于化工、電纜、蓄(xu)電池和(he)放(fang)射性(xing)防護等工業部門。
2017年10月27日,世界衛生組織國際癌癥研究機構(gou)公(gong)布的致癌物清單初步整理參考,鉛在2B類致癌物清單中。
2019年7月23日,鉛被(bei)列入(ru)有毒有害(hai)水(shui)污染物名錄(第一批(pi))。
鉛(qian)(qian)(Pb)是一(yi)種(zhong)高密度、柔軟的(de)藍(lan)灰色金(jin)屬,熔點327℃,沸點1740℃,溫(wen)度超過400℃時即有大量鉛(qian)(qian)蒸氣逸出,在(zai)空(kong)氣中迅速(su)氧化(hua)成氧化(hua)鉛(qian)(qian)煙。常見含鉛(qian)(qian)的(de)物(wu)(wu)質(zhi)包(bao)括有密陀僧(PbO)、黃丹(Pb2O3)、鉛(qian)(qian)丹(Pb3O4)、鉛(qian)(qian)白(Pb(OH)2·2PbCO3)、硫酸鉛(qian)(qian)(PbSO4)等。自然(ran)(ran)界主要以方(fang)鉛(qian)(qian)礦(kuang)(kuang)(PbS)及白鉛(qian)(qian)礦(kuang)(kuang)(PbCO3)的(de)形(xing)式存在(zai),也存在(zai)于鉛(qian)(qian)礬(PbSO4)中,偶然(ran)(ran)也有本色鉛(qian)(qian)。鉛(qian)(qian)礦(kuang)(kuang)中常雜(za)有鋅、銀、銅等元素。鉛(qian)(qian)及其化(hua)合(he)物(wu)(wu)的(de)用途很廣,冶(ye)金(jin)、蓄電池、印刷、顏料、油漆、釉料、焊錫等作(zuo)業(ye)均可接(jie)觸(chu)鉛(qian)(qian)及其化(hua)合(he)物(wu)(wu)。
鉛的晶體結構(gou)為立方晶格。鉛的密度大、硬(ying)度小、熔(rong)點低、沸點高,對電(dian)和熱的傳(chuan)導性能差,可吸(xi)收(shou)放射線(xian),故用(yong)(yong)于制造放射性物質的容器和用(yong)(yong)作防護材料。
此金屬抗腐(fu)蝕(shi)力很強,有一些古羅馬人安裝(zhuang)的鉛(qian)(qian)管至今完(wan)好(hao)無損(sun)。鉛(qian)(qian)多用于管道(雖然現在(zai)已由塑料取代)。鉛(qian)(qian)也用來遮隔(ge)X射線(xian),用于制造軍火、充當電纜的外(wai)套(tao),用于結晶玻璃(li)(作(zuo)鉛(qian)(qian)氧化物(wu)),以及用作(zuo)抗爆劑(如四乙鉛(qian)(qian),(C2H5)4Pb)。大(da)(da)多數(shu)鉛(qian)(qian)鹽(yan)(yan)不溶于水,只有硝酸鹽(yan)(yan)(Pb(NO3)2)和醋酸鹽(yan)(yan)(Pb(CH3COO)2)例外(wai)。嚴重鉛(qian)(qian)中毒會引起(qi)腹瀉與嘔吐,但(dan)鉛(qian)(qian)中毒通(tong)常是慢性的,癥狀(zhuang)是腹痛(tong)、肌肉痛(tong)、貧血(xue)及神經與大(da)(da)腦損(sun)傷。兒(er)童尤其(qi)易從(cong)汽車排放的廢氣中吸(xi)入過量的鉛(qian)(qian)。居(ju)民(min)區大(da)(da)氣中鉛(qian)(qian)的日平均最(zui)高(gao)容許濃度為0.00007mg/mL,地面水中最(zui)高(gao)容許濃度為0.1mg/L。
鉛位于第六周期(qi)ⅣA族,原子(zi)半(ban)徑146pm,Pb半(ban)徑84pm,第一電離能718.96kJ/mol,電負性1.8,主要氧化數+2、+4。銀灰(hui)色有(you)光澤的重(zhong)金屬(shu),在空氣中易(yi)氧化而失去光澤,變灰(hui)暗,質柔軟,延(yan)性弱,展性強(qiang)。密(mi)度11.34g/cm3,熔點327.5℃,沸點1740℃。有(you)較(jiao)強(qiang)的抗放(fang)射穿透的性能。
鉛的再(zai)結(jie)晶溫(wen)度(du)在室(shi)溫(wen)以下,壓力加工(gong)性能(neng)極好,不產(chan)生加工(gong)硬化。鉛和(he)鉛合金的強(qiang)(qiang)度(du)、硬度(du),特別是(shi)疲勞(lao)強(qiang)(qiang)度(du)和(he)蠕變(bian)強(qiang)(qiang)度(du)較低(di),易遭疲勞(lao)和(he)蠕變(bian)破壞(huai),在設計和(he)用作構(gou)件(jian)時應予(yu)以注(zhu)意(yi)。
鉛的主要(yao)物理和力學性能
性能 數據
密度(20℃)/g·cm-3 11.68
熔點(dian)/℃ 327.4
沸點/℃ 1740
平均比熱容(0~100℃)/J·(kg·K)-1 129.8
熔化(hua)熱/kJ·mol-1 4.98
氣化熱/kJ·mol-1 178.8
熱導率(0~100℃)/W·(m·K)-1 34.9
電阻率(20℃)/μΩ·cm 20.6
抗(kang)拉強度/MPa 14.7
伸(shen)長(chang)率/% 60~70
布(bu)氏硬度/MPa 30~48
鉛有四種穩定的(de)(de)同位素(su):Pb-204(豐(feng)度(du)為1.4%)、Pb-206(豐(feng)度(du)24.1%)、Pb-207(豐(feng)度(du)22.1%)和(he)Pb-208(豐(feng)度(du)52.4%)。后三種是鈾-238、鈾-235和(he)釷-232經過一系列裂變(bian)后的(de)(de)最(zui)終產物,只有Pb是自(zi)然存在(zai)的(de)(de)、非衰變(bian)產物。Pb-208在(zai)穩定的(de)(de)同位素(su)中(zhong)質量最(zui)大(da)。
在(zai)常溫下在(zai)空(kong)氣(qi)中(zhong),鉛(qian)(qian)(qian)(qian)表(biao)(biao)面易生(sheng)(sheng)(sheng)成(cheng)一(yi)層氧(yang)化(hua)(hua)鉛(qian)(qian)(qian)(qian)或堿式碳(tan)酸(suan)(suan)鉛(qian)(qian)(qian)(qian),使鉛(qian)(qian)(qian)(qian)失去光澤且防止進一(yi)步氧(yang)化(hua)(hua)。易和(he)鹵素(su)、硫化(hua)(hua)合,生(sheng)(sheng)(sheng)成(cheng)PbCl4、PbI2、PbS等(deng)。熔(rong)融(rong)的(de)鉛(qian)(qian)(qian)(qian)空(kong)氣(qi)反(fan)(fan)(fan)應(ying)(ying)(ying)生(sheng)(sheng)(sheng)成(cheng)一(yi)氧(yang)化(hua)(hua)鉛(qian)(qian)(qian)(qian),將(jiang)鉛(qian)(qian)(qian)(qian)在(zai)純氧(yang)中(zhong)加熱(re)可得二氧(yang)化(hua)(hua)鉛(qian)(qian)(qian)(qian)。與(yu)(yu)鹽酸(suan)(suan)反(fan)(fan)(fan)應(ying)(ying)(ying)放(fang)出(chu)氫(qing)氣(qi)并生(sheng)(sheng)(sheng)成(cheng)微溶(rong)(rong)性(xing)的(de)PbCl2,覆蓋(gai)在(zai)鉛(qian)(qian)(qian)(qian)表(biao)(biao)面,使反(fan)(fan)(fan)應(ying)(ying)(ying)中(zhong)止。與(yu)(yu)熱(re)濃(nong)鹽酸(suan)(suan)反(fan)(fan)(fan)應(ying)(ying)(ying)生(sheng)(sheng)(sheng)成(cheng)HPbCl3和(he)H2。與(yu)(yu)稀(xi)硫酸(suan)(suan)反(fan)(fan)(fan)應(ying)(ying)(ying)放(fang)出(chu)氫(qing)并生(sheng)(sheng)(sheng)成(cheng)難溶(rong)(rong)的(de)PbSO4覆蓋(gai)層,使反(fan)(fan)(fan)應(ying)(ying)(ying)中(zhong)止。但易溶(rong)(rong)于熱(re)的(de)濃(nong)硫酸(suan)(suan)生(sheng)(sheng)(sheng)成(cheng)Pb(HSO4)2并放(fang)出(chu)SO2。跟稀(xi)硝(xiao)(xiao)酸(suan)(suan)或濃(nong)硝(xiao)(xiao)酸(suan)(suan)反(fan)(fan)(fan)應(ying)(ying)(ying)都可生(sheng)(sheng)(sheng)成(cheng)硝(xiao)(xiao)酸(suan)(suan)鉛(qian)(qian)(qian)(qian)Pb(NO3)2。在(zai)有(you)氧(yang)存(cun)生(sheng)(sheng)(sheng)條件(jian)下可溶(rong)(rong)于醋酸(suan)(suan)等(deng)有(you)機酸(suan)(suan),生(sheng)(sheng)(sheng)成(cheng)可溶(rong)(rong)性(xing)的(de)鉛(qian)(qian)(qian)(qian)鹽。跟強堿溶(rong)(rong)液緩慢的(de)反(fan)(fan)(fan)應(ying)(ying)(ying)放(fang)出(chu)氫(qing)氣(qi)生(sheng)(sheng)(sheng)成(cheng)亞鉛(qian)(qian)(qian)(qian)酸(suan)(suan)鹽。在(zai)有(you)氧(yang)氣(qi)條件(jian)下跟水反(fan)(fan)(fan)應(ying)(ying)(ying)生(sheng)(sheng)(sheng)成(cheng)難溶(rong)(rong)的(de)Pb(OH)2。
鉛在(zai)加熱熔化時最(zui)初氧化為PbO2,繼(ji)續升(sheng)溫(wen)分解(jie)為PbO,升(sheng)溫(wen)到603~723K時生成(cheng)Pb3O4(即鉛丹)。Pb2O3或(huo)Pb3O4在(zai)高溫(wen)下易(yi)離解(jie)生成(cheng)穩定的(de)PbO。
鉛(qian)(qian)在(zai)SO2中非(fei)常(chang)穩定,鉛(qian)(qian)幾(ji)乎不(bu)與純的(de)(de)CO2作(zuo)用,普通水對(dui)鉛(qian)(qian)的(de)(de)腐蝕(shi)很輕微。鉛(qian)(qian)易(yi)溶(rong)(rong)(rong)(rong)于(yu)硝(xiao)酸(suan)、硼氟酸(suan)、硅氟酸(suan)和醋酸(suan),常(chang)溫下難溶(rong)(rong)(rong)(rong)于(yu)硫(liu)酸(suan)、鹽(yan)酸(suan)、氫氟酸(suan)。NH4OH溶(rong)(rong)(rong)(rong)液或(huo)通空氣的(de)(de)稀NaOH溶(rong)(rong)(rong)(rong)液能(neng)徐徐溶(rong)(rong)(rong)(rong)解鉛(qian)(qian)。鉛(qian)(qian)能(neng)溶(rong)(rong)(rong)(rong)于(yu)硝(xiao)酸(suan)銀溶(rong)(rong)(rong)(rong)液,其他的(de)(de)硝(xiao)酸(suan)鹽(yan)和氯化物(wu)會腐蝕(shi)鉛(qian)(qian)。鉀、鈉(na)、鐵、氨的(de)(de)硫(liu)酸(suan)鹽(yan)和鉀的(de)(de)碳酸(suan)鹽(yan)、氰化物(wu)溶(rong)(rong)(rong)(rong)液對(dui)鉛(qian)(qian)不(bu)起作(zuo)用。
鉛在空(kong)氣(qi)(qi)中(zhong)(zhong)(zhong)(zhong)表面生成(cheng)致(zhi)密(mi)的(de)(de)(de)(de)(de)氧(yang)化鉛膜,在潮濕并(bing)含(han)有二(er)氧(yang)化碳(tan)的(de)(de)(de)(de)(de)空(kong)氣(qi)(qi)中(zhong)(zhong)(zhong)(zhong)生成(cheng)碳(tan)酸鉛膜,在硫酸中(zhong)(zhong)(zhong)(zhong)生成(cheng)硫酸鉛膜,這些生成(cheng)膜起到(dao)良(liang)好的(de)(de)(de)(de)(de)保護(hu)作用。因此鉛在許多(duo)介(jie)質中(zhong)(zhong)(zhong)(zhong),特別是在硫酸中(zhong)(zhong)(zhong)(zhong),有極好的(de)(de)(de)(de)(de)耐蝕性(xing)。鉛工業區(qu)大氣(qi)(qi)中(zhong)(zhong)(zhong)(zhong)的(de)(de)(de)(de)(de)腐蝕速度為(wei)0.00043~0.00068mm/a;在天然海水(shui)中(zhong)(zhong)(zhong)(zhong)的(de)(de)(de)(de)(de)腐蝕速度為(wei)0.01~0.015mm/a;當硫酸的(de)(de)(de)(de)(de)濃度高達70%~80%、溫度為(wei)50℃時,鉛仍有很(hen)好的(de)(de)(de)(de)(de)耐蝕性(xing)。
鉛(qian)(qian)的(de)(de)地(di)殼豐(feng)度(du)較(jiao)銅、鋅、錫(xi)小(xiao)。自(zi)然界中最主要(yao)(yao)的(de)(de)鉛(qian)(qian)礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)是硫化(hua)(hua)礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang),其次是氧(yang)化(hua)(hua)鉛(qian)(qian)礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)。硫化(hua)(hua)鉛(qian)(qian)礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)主要(yao)(yao)組成(cheng)為原生(sheng)(sheng)的(de)(de)方鉛(qian)(qian)礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(PbS)。但單一的(de)(de)硫化(hua)(hua)鉛(qian)(qian)礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)很少,常(chang)與閃鋅礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)伴生(sheng)(sheng),合稱鉛(qian)(qian)鋅礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)。另外的(de)(de)伴生(sheng)(sheng)礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)物常(chang)有輝(hui)銀礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(Ag2S)、黃鐵礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(FeS2)、黃銅礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(CuFeS2)、硫砷鐵礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(FeAsS)、輝(hui)鉍礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(Bi2S3)及銦、鍺(zang)、鎵(jia)、鉈(she)、碲(di)等稀(xi)散元素的(de)(de)礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)物。鉛(qian)(qian)鋅礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)成(cheng)分(fen)復(fu)雜,要(yao)(yao)預先經過選礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)富集方宜(yi)進行冶煉。氧(yang)化(hua)(hua)鉛(qian)(qian)礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)主要(yao)(yao)由白鉛(qian)(qian)礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(PbCO3)和鉛(qian)(qian)礬(fan)(PbSO4)組成(cheng),屬次生(sheng)(sheng)礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang),多出現在硫化(hua)(hua)礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)的(de)(de)上層(ceng),或與硫化(hua)(hua)礦(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)(kuang)共生(sheng)(sheng)。含鉛(qian)(qian)廢雜料也是生(sheng)(sheng)產鉛(qian)(qian)的(de)(de)重(zhong)要(yao)(yao)資(zi)源。
鉛(qian)(qian)(qian)(qian)的(de)(de)提(ti)取冶金分火(huo)(huo)法(fa)(fa)(fa)(fa)(fa)(fa)煉(lian)鉛(qian)(qian)(qian)(qian)和濕法(fa)(fa)(fa)(fa)(fa)(fa)煉(lian)鉛(qian)(qian)(qian)(qian)兩(liang)類方法(fa)(fa)(fa)(fa)(fa)(fa),在(zai)工業生(sheng)(sheng)產(chan)中前者應用(yong)較(jiao)多(duo)(duo)。傳統的(de)(de)火(huo)(huo)法(fa)(fa)(fa)(fa)(fa)(fa)煉(lian)鉛(qian)(qian)(qian)(qian)方法(fa)(fa)(fa)(fa)(fa)(fa)一般包括(kuo)鉛(qian)(qian)(qian)(qian)精(jing)礦燒(shao)結焙燒(shao)、鉛(qian)(qian)(qian)(qian)熔煉(lian)、粗(cu)(cu)(cu)鉛(qian)(qian)(qian)(qian)火(huo)(huo)法(fa)(fa)(fa)(fa)(fa)(fa)精(jing)煉(lian)或(鉛(qian)(qian)(qian)(qian)電解精(jing)煉(lian))三(san)大環節。傳統的(de)(de)鉛(qian)(qian)(qian)(qian)熔煉(lian)方法(fa)(fa)(fa)(fa)(fa)(fa)以鼓(gu)風爐(lu)還(huan)(huan)原(yuan)(yuan)熔煉(lian)法(fa)(fa)(fa)(fa)(fa)(fa)煉(lian)鉛(qian)(qian)(qian)(qian)的(de)(de)應用(yong)最為(wei)廣泛。用(yong)這種(zhong)方法(fa)(fa)(fa)(fa)(fa)(fa)生(sheng)(sheng)產(chan)的(de)(de)鉛(qian)(qian)(qian)(qian)占總產(chan)鉛(qian)(qian)(qian)(qian)量的(de)(de)85%。鼓(gu)風爐(lu)還(huan)(huan)原(yuan)(yuan)熔煉(lian)法(fa)(fa)(fa)(fa)(fa)(fa)煉(lian)鉛(qian)(qian)(qian)(qian)是一種(zhong)用(yong)焦炭(tan)作還(huan)(huan)原(yuan)(yuan)劑(ji)把鉛(qian)(qian)(qian)(qian)的(de)(de)氧化物(wu)還(huan)(huan)原(yuan)(yuan)為(wei)粗(cu)(cu)(cu)鉛(qian)(qian)(qian)(qian)的(de)(de)方法(fa)(fa)(fa)(fa)(fa)(fa),此法(fa)(fa)(fa)(fa)(fa)(fa)須先經燒(shao)結焙燒(shao)把硫化鉛(qian)(qian)(qian)(qian)精(jing)礦中的(de)(de)大部(bu)分PbS轉(zhuan)變(bian)成PbO,并使燒(shao)結焙燒(shao)料燒(shao)結成塊。鉛(qian)(qian)(qian)(qian)熔煉(lian)產(chan)出的(de)(de)粗(cu)(cu)(cu)鉛(qian)(qian)(qian)(qian)還(huan)(huan)含有很多(duo)(duo)雜質,需經火(huo)(huo)法(fa)(fa)(fa)(fa)(fa)(fa)精(jing)煉(lian)或電解精(jing)煉(lian)才能獲得達到產(chan)品(pin)質量標準、滿(man)足用(yong)戶要求的(de)(de)精(jing)鉛(qian)(qian)(qian)(qian),并回(hui)收粗(cu)(cu)(cu)鉛(qian)(qian)(qian)(qian)中的(de)(de)有價金屬(shu)。粗(cu)(cu)(cu)鉛(qian)(qian)(qian)(qian)火(huo)(huo)法(fa)(fa)(fa)(fa)(fa)(fa)精(jing)煉(lian)在(zai)當今的(de)(de)鉛(qian)(qian)(qian)(qian)精(jing)煉(lian)中占主導(dao)地位(wei)。
傳(chuan)統的(de)火法(fa)煉(lian)鉛(qian)(qian)法(fa)存在對環(huan)境污(wu)(wu)染嚴重、原料中的(de)硫難以(yi)回收、能耗大和生產(chan)(chan)效率低(di)等問題,自(zi)20世(shi)紀(ji)50年代(dai)(dai)以(yi)來世(shi)界一些(xie)國家(jia)競相研(yan)究直(zhi)接煉(lian)鉛(qian)(qian)法(fa),以(yi)取代(dai)(dai)傳(chuan)統的(de)火法(fa)煉(lian)鉛(qian)(qian)法(fa)。到90年代(dai)(dai)已進行工業生產(chan)(chan)或半工業試(shi)驗的(de)有(you)基(ji)夫(fu)賽特(te)煉(lian)鉛(qian)(qian)法(fa)(KIVCET-CS)、氧氣(qi)(qi)底吹煉(lian)鉛(qian)(qian)法(fa)(QSL)、艾薩(sa)熔煉(lian)法(fa)煉(lian)鉛(qian)(qian)(ISA)、閃速熔煉(lian)法(fa)煉(lian)鉛(qian)(qian)等。這(zhe)些(xie)直(zhi)接煉(lian)鉛(qian)(qian)法(fa)的(de)共同特(te)點是不要(yao)經過單獨(du)的(de)燒(shao)結焙燒(shao)處理,基(ji)本實(shi)現(xian)自(zi)熱熔煉(lian),煙氣(qi)(qi)便(bian)于(yu)制(zhi)酸,對環(huan)境污(wu)(wu)染程度(du)輕,從發展看(kan),有(you)可能取代(dai)(dai)傳(chuan)統的(de)火法(fa)煉(lian)鉛(qian)(qian)法(fa)。
(1)鉛冶煉技術(shu)的(de)改造
隨著(zhu)我(wo)(wo)(wo)(wo)(wo)國工業(ye)的(de)(de)(de)(de)不(bu)斷(duan)(duan)發展,對鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)產(chan)(chan)品(pin)(pin)(pin)的(de)(de)(de)(de)需求量(liang)(liang)越來越大。但是由于我(wo)(wo)(wo)(wo)(wo)國鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)冶(ye)煉(lian)技(ji)(ji)術(shu)的(de)(de)(de)(de)限制,鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)產(chan)(chan)品(pin)(pin)(pin)的(de)(de)(de)(de)供(gong)給遠遠達不(bu)到鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)產(chan)(chan)品(pin)(pin)(pin)的(de)(de)(de)(de)實(shi)際需求。這就要(yao)求我(wo)(wo)(wo)(wo)(wo)國鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)冶(ye)煉(lian)技(ji)(ji)術(shu)進(jin)一步提(ti)升(sheng)(sheng),隨著(zhu)冶(ye)煉(lian)技(ji)(ji)術(shu)的(de)(de)(de)(de)不(bu)斷(duan)(duan)進(jin)步和實(shi)踐經(jing)驗的(de)(de)(de)(de)不(bu)斷(duan)(duan)積累,我(wo)(wo)(wo)(wo)(wo)國鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)冶(ye)煉(lian)技(ji)(ji)術(shu)有(you)了(le)(le)一定的(de)(de)(de)(de)提(ti)升(sheng)(sheng),鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)生(sheng)(sheng)產(chan)(chan)企業(ye)正在(zai)對鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)冶(ye)煉(lian)技(ji)(ji)術(shu)進(jin)行(xing)改(gai)造,進(jin)一步提(ti)升(sheng)(sheng)鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)產(chan)(chan)品(pin)(pin)(pin)的(de)(de)(de)(de)產(chan)(chan)量(liang)(liang)和質量(liang)(liang)。在(zai)我(wo)(wo)(wo)(wo)(wo)國鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)產(chan)(chan)品(pin)(pin)(pin)生(sheng)(sheng)產(chan)(chan)過(guo)程中(zhong)(zhong),鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)產(chan)(chan)品(pin)(pin)(pin)的(de)(de)(de)(de)生(sheng)(sheng)產(chan)(chan)正朝著(zhu)底吹爐(lu)(lu)+側吹還原爐(lu)(lu)+煙化(hua)爐(lu)(lu)的(de)(de)(de)(de)方式進(jin)行(xing)改(gai)造。鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)產(chan)(chan)品(pin)(pin)(pin)冶(ye)煉(lian)技(ji)(ji)術(shu)的(de)(de)(de)(de)改(gai)造,不(bu)僅大大提(ti)升(sheng)(sheng)了(le)(le)鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)產(chan)(chan)品(pin)(pin)(pin)的(de)(de)(de)(de)產(chan)(chan)量(liang)(liang)和質量(liang)(liang),還使得鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)冶(ye)煉(lian)過(guo)程中(zhong)(zhong)的(de)(de)(de)(de)能源消耗降低,進(jin)一步提(ti)高(gao)了(le)(le)能源利用(yong)率。相信隨著(zhu)鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)冶(ye)煉(lian)技(ji)(ji)術(shu)的(de)(de)(de)(de)不(bu)斷(duan)(duan)進(jin)步,我(wo)(wo)(wo)(wo)(wo)國的(de)(de)(de)(de)鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)產(chan)(chan)品(pin)(pin)(pin)供(gong)應會逐漸滿足我(wo)(wo)(wo)(wo)(wo)國工業(ye)對鉛(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)(qian)產(chan)(chan)品(pin)(pin)(pin)的(de)(de)(de)(de)需要(yao)。
(2)存在問題
我(wo)(wo)國(guo)(guo)鉛(qian)(qian)(qian)(qian)冶(ye)煉(lian)(lian)(lian)過程(cheng)中(zhong)存在的問(wen)題,制約了(le)我(wo)(wo)國(guo)(guo)鉛(qian)(qian)(qian)(qian)冶(ye)煉(lian)(lian)(lian)技(ji)術(shu)的進(jin)步,從而影響我(wo)(wo)國(guo)(guo)鉛(qian)(qian)(qian)(qian)產(chan)(chan)品的供(gong)應(ying)。我(wo)(wo)國(guo)(guo)鉛(qian)(qian)(qian)(qian)冶(ye)煉(lian)(lian)(lian)過程(cheng)中(zhong)存在的問(wen)題主要(yao)分(fen)為三方面。首先,我(wo)(wo)國(guo)(guo)鉛(qian)(qian)(qian)(qian)資(zi)源(yuan)較(jiao)為短缺,制約著(zhu)我(wo)(wo)國(guo)(guo)鉛(qian)(qian)(qian)(qian)產(chan)(chan)品的供(gong)應(ying)。就我(wo)(wo)國(guo)(guo)鉛(qian)(qian)(qian)(qian)資(zi)源(yuan)分(fen)布來看,雖然鉛(qian)(qian)(qian)(qian)資(zi)源(yuan)分(fen)布比較(jiao)廣(guang),但是(shi)鉛(qian)(qian)(qian)(qian)資(zi)源(yuan)儲量(liang)比較(jiao)低,無(wu)法(fa)(fa)為鉛(qian)(qian)(qian)(qian)冶(ye)煉(lian)(lian)(lian)提(ti)供(gong)足(zu)夠的原料。另外,鉛(qian)(qian)(qian)(qian)產(chan)(chan)品冶(ye)煉(lian)(lian)(lian)過程(cheng)中(zhong)浪(lang)費比較(jiao)嚴重,能(neng)源(yuan)消耗(hao)量(liang)大,這也(ye)使(shi)(shi)得鉛(qian)(qian)(qian)(qian)資(zi)源(yuan)沒有得到充分(fen)利用,從而使(shi)(shi)鉛(qian)(qian)(qian)(qian)的供(gong)應(ying)無(wu)法(fa)(fa)滿(man)足(zu)需(xu)求。其次,我(wo)(wo)國(guo)(guo)鉛(qian)(qian)(qian)(qian)冶(ye)煉(lian)(lian)(lian)監管不嚴,導致鉛(qian)(qian)(qian)(qian)資(zi)源(yuan)浪(lang)費嚴重。
在我國(guo)鉛(qian)(qian)(qian)(qian)產(chan)(chan)(chan)(chan)(chan)(chan)(chan)品的(de)(de)(de)生產(chan)(chan)(chan)(chan)(chan)(chan)(chan)過(guo)(guo)程(cheng)中,相(xiang)關部門不(bu)注重鉛(qian)(qian)(qian)(qian)冶(ye)煉的(de)(de)(de)監(jian)管(guan)(guan),一方(fang)面,導致部分(fen)企(qi)業(ye)未(wei)按(an)照生產(chan)(chan)(chan)(chan)(chan)(chan)(chan)標準進(jin)行鉛(qian)(qian)(qian)(qian)產(chan)(chan)(chan)(chan)(chan)(chan)(chan)品的(de)(de)(de)生產(chan)(chan)(chan)(chan)(chan)(chan)(chan),造(zao)(zao)成了(le)鉛(qian)(qian)(qian)(qian)資源(yuan)的(de)(de)(de)浪費。另一方(fang)面,由于(yu)監(jian)管(guan)(guan)力度不(bu)夠,鉛(qian)(qian)(qian)(qian)生產(chan)(chan)(chan)(chan)(chan)(chan)(chan)企(qi)業(ye)往往對能源(yuan)的(de)(de)(de)消(xiao)耗和環(huan)境的(de)(de)(de)污(wu)染(ran)不(bu)重視,造(zao)(zao)成了(le)能源(yuan)浪費。與此同時,鉛(qian)(qian)(qian)(qian)產(chan)(chan)(chan)(chan)(chan)(chan)(chan)品生產(chan)(chan)(chan)(chan)(chan)(chan)(chan)過(guo)(guo)程(cheng)中的(de)(de)(de)污(wu)染(ran),造(zao)(zao)成了(le)對環(huan)境的(de)(de)(de)破壞。另外(wai),由于(yu)監(jian)管(guan)(guan)力度不(bu)足,部分(fen)企(qi)業(ye)為(wei)了(le)滿(man)足外(wai)國(guo)對鉛(qian)(qian)(qian)(qian)產(chan)(chan)(chan)(chan)(chan)(chan)(chan)品的(de)(de)(de)需求,使用落后(hou)的(de)(de)(de)冶(ye)煉技(ji)術,進(jin)一步(bu)加(jia)劇(ju)了(le)我國(guo)的(de)(de)(de)資源(yuan)短(duan)缺(que)以及環(huan)境污(wu)染(ran)。最后(hou),鉛(qian)(qian)(qian)(qian)冶(ye)煉過(guo)(guo)程(cheng)中對環(huan)境造(zao)(zao)成的(de)(de)(de)污(wu)染(ran),加(jia)大了(le)我國(guo)的(de)(de)(de)環(huan)境壓力。由于(yu)我國(guo)鉛(qian)(qian)(qian)(qian)冶(ye)煉技(ji)術水平的(de)(de)(de)制約,在鉛(qian)(qian)(qian)(qian)產(chan)(chan)(chan)(chan)(chan)(chan)(chan)品生產(chan)(chan)(chan)(chan)(chan)(chan)(chan)過(guo)(guo)程(cheng)中會產(chan)(chan)(chan)(chan)(chan)(chan)(chan)生粉(fen)塵以及廢氣(qi),這(zhe)些粉(fen)塵以及廢氣(qi)沒有得到妥當的(de)(de)(de)處置,導致鉛(qian)(qian)(qian)(qian)產(chan)(chan)(chan)(chan)(chan)(chan)(chan)品生產(chan)(chan)(chan)(chan)(chan)(chan)(chan)過(guo)(guo)程(cheng)會造(zao)(zao)成嚴重的(de)(de)(de)環(huan)境污(wu)染(ran)。
在鉛產(chan)品(pin)生產(chan)過程(cheng)中(zhong)會(hui)產(chan)生二(er)氧(yang)化硫(liu),二(er)氧(yang)化硫(liu)會(hui)導致酸雨(yu)的(de)產(chan)生,對(dui)農(nong)作物以及建(jian)筑物造(zao)(zao)成很大(da)的(de)損害,會(hui)造(zao)(zao)成經濟損失(shi)。鉛冶(ye)煉(lian)過程(cheng)中(zhong)造(zao)(zao)成的(de)污染(ran),也制(zhi)約著鉛產(chan)品(pin)的(de)供應。
(1)氧氣頂(ding)吹熔煉技術
艾(ai)薩(sa)(sa)法(fa)(fa)(ISA法(fa)(fa))、Ausmelt法(fa)(fa)都屬氧氣頂(ding)吹法(fa)(fa),其(qi)中(zhong)以艾(ai)薩(sa)(sa)法(fa)(fa)(ISA法(fa)(fa))為(wei)例來進一(yi)步說(shuo)明氧氣頂(ding)吹熔煉(lian)技術的(de)(de)(de)技術特(te)(te)點。艾(ai)薩(sa)(sa)法(fa)(fa)不(bu)同(tong)于基夫賽特(te)(te)法(fa)(fa),它對(dui)爐料(liao)的(de)(de)(de)要求比較低(di),但是此法(fa)(fa)的(de)(de)(de)煙塵率較高。艾(ai)薩(sa)(sa)法(fa)(fa)還(huan)有一(yi)點優(you)勢(shi)就是爐體設(she)備占地面積比較少,能(neng)夠(gou)為(wei)鉛冶(ye)煉(lian)節省空間,在一(yi)定程度上降(jiang)低(di)了(le)鉛冶(ye)煉(lian)的(de)(de)(de)成本,增加了(le)企業的(de)(de)(de)經濟(ji)效益(yi)。
(2)氧氣底吹熔煉技術
QSL法(fa)和SKS法(fa)均為底(di)吹(chui)熔(rong)池熔(rong)煉(lian)(lian)技(ji)(ji)術,其中以(yi)QSL法(fa)為例進一步說明氧氣(qi)底(di)吹(chui)熔(rong)煉(lian)(lian)技(ji)(ji)術的技(ji)(ji)術特點(dian)。QSL法(fa)同艾薩(sa)法(fa)(ISA法(fa))一樣,煙塵率較高,QSL法(fa)爐體設備占地面(mian)積(ji)也比較少,能(neng)夠為鉛冶煉(lian)(lian)節(jie)省空間(jian),在(zai)一定(ding)程度上降(jiang)低了(le)鉛冶煉(lian)(lian)的成(cheng)本(ben),增(zeng)加(jia)了(le)企(qi)業(ye)的經濟效益。
(3)氧氣側吹(chui)熔煉技術
氧氣側(ce)吹熔煉技(ji)(ji)(ji)術(shu)(shu)是我(wo)國(guo)開發的(de)(de)一種熔池熔煉直接煉鉛技(ji)(ji)(ji)術(shu)(shu)。該(gai)(gai)技(ji)(ji)(ji)術(shu)(shu)所需(xu)要(yao)的(de)(de)設備(bei)比(bi)較(jiao)簡單,投資的(de)(de)數額也比(bi)較(jiao)小。金屬回收率也很(hen)高,創造的(de)(de)經濟效益(yi)比(bi)較(jiao)好(hao)(hao)。但是該(gai)(gai)技(ji)(ji)(ji)術(shu)(shu)不(bu)能(neng)很(hen)好(hao)(hao)地對散熱進行控制,導致進行鉛冶煉時能(neng)耗很(hen)大。該(gai)(gai)技(ji)(ji)(ji)術(shu)(shu)因為所需(xu)要(yao)的(de)(de)成(cheng)本比(bi)較(jiao)低,所以在我(wo)國(guo)得(de)到了(le)廣(guang)泛(fan)應(ying)用。不(bu)過廣(guang)泛(fan)使用該(gai)(gai)技(ji)(ji)(ji)術(shu)(shu)也對我(wo)國(guo)的(de)(de)能(neng)源造成(cheng)了(le)很(hen)大的(de)(de)壓力,不(bu)利于可持(chi)續發展。這(zhe)是我(wo)國(guo)對于該(gai)(gai)技(ji)(ji)(ji)術(shu)(shu)下一步必須要(yao)解決(jue)的(de)(de)問題。
鉛(qian)的化(hua)合(he)物(wu)種類很多,具(ju)有工業價值的主要化(hua)合(he)物(wu)有PbS、PbO、PbSO4及氯化(hua)鉛(qian)。
中文(wen)名 一氧化(hua)鉛
別(bie)名 又(you)稱黃(huang)色氧化鉛;俗名黃(huang)丹或(huo)密陀僧
化學式 PbO
式量 223.19
熔點 888℃
密(mi)度 9.53g/cm3無定形者為黃色(se)到紅(hong)黃色(se),密(mi)度9.2~9.5g/cm3
外觀 有多種變體,四方晶體呈(cheng)黃紅(hong)色;斜方正交晶體呈(cheng)黃色
溶(rong)(rong)(rong)解性 一氧化鉛(qian)難溶(rong)(rong)(rong)于水和乙醇(chun),溶(rong)(rong)(rong)于硝酸、醋酸生(sheng)成相(xiang)應的鉛(qian)鹽,溶(rong)(rong)(rong)于熱的強堿溶(rong)(rong)(rong)液生(sheng)成亞鉛(qian)酸鹽
化學(xue)活性 一(yi)氧(yang)(yang)(yang)化鉛能(neng)吸(xi)收空氣中(zhong)二氧(yang)(yang)(yang)化碳(tan)生成碳(tan)酸(suan)鉛,在空氣中(zhong)加熱(re)至500℃可生成四氧(yang)(yang)(yang)化三鉛。加熱(re)時可被碳(tan)、氫氣、一(yi)氧(yang)(yang)(yang)化碳(tan)還原成鉛,與甘(gan)油混和生成堅硬的物質(zhi)、可作粘合劑。
制(zhi)取方法及用途 一氧化鉛(qian)通常(chang)是由空氣(qi)氧化熔融鉛(qian)或加熱碳酸鉛(qian)、硝酸鉛(qian)分解制(zhi)得,常(chang)用作顏料、涂料油(you)漆的催干劑、冶(ye)金助熔劑,還用于制(zhi)特種鉛(qian)玻璃、搪(tang)瓷、蓄電池電極、橡膠。
化學式 PbS
式量 239.25
外觀 藍(lan)色有(you)金屬光澤(ze)立(li)方晶體或棕(zong)黑(hei)色粉末
密度 7.5g/cm3
熔點 1114℃,在860℃時開始部分揮發
溶(rong)解性 難溶(rong)于水和堿溶(rong)液。可溶(rong)于硝(xiao)酸
化(hua)學活性(xing) 在空氣中灼燒,可生成一氧化(hua)鉛和二氧化(hua)硫
制(zhi)取方(fang)法(fa)及(ji)用途(tu) 人工制(zhi)取硫化(hua)鉛(qian)通常(chang)是將硫化(hua)氫通入酸性硝酸鉛(qian)溶液。自(zi)然界中硫化(hua)鉛(qian)的主要礦石為方(fang)鉛(qian)礦,是煉(lian)鉛(qian)的原料。制(zhi)取硫化(hua)鉛(qian)提純后,可用作(zuo)半導體。
氯(lv)化鉛(qian)主要(yao)有PbCl2和(he)PbCl4,氯(lv)化鉛(qian)中以(yi)PbCl2最(zui)重要(yao)。
二(er)氯(lv)化鉛 四(si)氯(lv)化鉛
外觀 白色晶體(ti)(ti),有毒 黃(huang)色易(yi)揮發油狀液體(ti)(ti),有毒
別名 - 氯化高鉛(qian)
分(fen)子(zi)量 278.11 349.01
相對密度(du) 5.85 3.18(0℃)
熔點 501℃ -15℃
沸點 950℃ -
溶(rong)(rong)(rong)(rong)解性 稍(shao)溶(rong)(rong)(rong)(rong)于冷(leng)水,可溶(rong)(rong)(rong)(rong)于熱水,難溶(rong)(rong)(rong)(rong)于稀鹽(yan)酸(suan)(suan),卻(que)能溶(rong)(rong)(rong)(rong)于濃(nong)鹽(yan)酸(suan)(suan)及堿金屬(shu)氯(lv)化物濃(nong)溶(rong)(rong)(rong)(rong)液,形(xing)成四氯(lv)合鉛(Ⅱ)陰絡離子。難溶(rong)(rong)(rong)(rong)于醇,能形(xing)成堿式鹽(yan)與復鹽(yan)。能溶(rong)(rong)(rong)(rong)于濃(nong)鹽(yan)酸(suan)(suan)形(xing)成六氯(lv)合鉛(Ⅳ)酸(suan)(suan)。不溶(rong)(rong)(rong)(rong)于濃(nong)硫酸(suan)(suan)。
制取 多用一(yi)氧化鉛(qian)或堿式(shi)碳酸鉛(qian)與鹽酸的(de)反(fan)應制取,也(ye)可用鹽酸沉淀硝酸鉛(qian)而(er)(er)得(de)。通常將(jiang)二氧化鉛(qian)溶于冷的(de)濃鹽酸,或用濃硫酸與六(liu)氯合鉛(qian)(Ⅳ)酸銨反(fan)應而(er)(er)得(de)。
用(yong)途(tu) 用(yong)于制取顏料,也可用(yong)作焊料或助熔劑。也用(yong)于生產各種(zhong)鉛鹽和含鉛顏料。
毒性 對鼠(shu)最(zui)小致(zhi)死量為2000mg/kg,進入(ru)人體中的鉛可(ke)結合在(zai)骨骼和頭發里,但集中在(zai)肝里時才(cai)危害(hai)。
其(qi)他-只(zhi)在低溫下(xia)穩定,在常溫下(xia)即有分(fen)解(jie)(生成二氯(lv)化鉛與氯(lv)氣(qi)),105℃時(shi)猛烈分(fen)解(jie)以至爆炸。遇濕氣(qi)及水很易水解(jie)為二氧(yang)化鉛及氯(lv)化氫、而強(qiang)烈發煙。
又名 鉛礬
外觀 通(tong)常為白色晶體(ti)或粉(fen)末(mo)
分子量 303.26
相對密度 6.2
分解溫(wen)度(du) 1000℃時出現分解
熔(rong)點 約為(wei)1170℃
溶解性 微溶于(yu)水,難溶于(yu)乙醇及稀(xi)硫(liu)酸(suan),溶于(yu)熱濃(nong)硫(liu)酸(suan)、濃(nong)鹽酸(suan)、濃(nong)硝酸(suan)、濃(nong)堿(jian)液、醋酸(suan)銨(an)、酒石酸(suan)銨(an)等溶液。
制取方法及用途 硫(liu)酸(suan)鉛通(tong)常由(you)一氧化鉛與硫(liu)酸(suan)作(zuo)用,或用可溶性鉛鹽溶液與稀硫(liu)酸(suan)反應(ying)生成(cheng)沉淀物。常用作(zuo)白色(se)顏料,制電池及快干漆的原料等(deng)。
鉛(qian)(qian)(qian)是(shi)制(zhi)造蓄電池、電纜、子彈和(he)彈藥的(de)原材料,也是(shi)汽油的(de)添加劑。鉛(qian)(qian)(qian)化合物(wu)用(yong)(yong)作顏料、玻璃、塑料和(he)橡膠的(de)原料。由于(yu)金屬鉛(qian)(qian)(qian)具(ju)有優良的(de)耐酸、堿腐蝕(shi)性能,廣泛用(yong)(yong)于(yu)制(zhi)造化工和(he)冶金設(she)備。鉛(qian)(qian)(qian)合金用(yong)(yong)作軸承、活字(zi)金和(he)焊料等(deng)。此外,鉛(qian)(qian)(qian)也開拓了一(yi)些(xie)新的(de)用(yong)(yong)途。如用(yong)(yong)作瀝青(qing)的(de)穩定劑,以(yi)延長路面(mian)使用(yong)(yong)壽命;用(yong)(yong)于(yu)制(zhi)造核(he)(he)電站屏蔽和(he)核(he)(he)廢料貯罐,電業部(bu)門調整負荷的(de)大功率蓄電池組,及磁流體動力學(xue)裝置(zhi)等(deng)。
鉛(qian)是人類較(jiao)早(zao)(zao)提煉出來的(de)(de)金屬之一,早(zao)(zao)在(zai)(zai)公元(yuan)前(qian)(qian)(qian)三千年左右就被(bei)人類發(fa)(fa)現并應用(yong)。埃(ai)及前(qian)(qian)(qian)王朝時期(早(zao)(zao)于公元(yuan)前(qian)(qian)(qian)3000年)即有用(yong)鉛(qian)制作的(de)(de)小的(de)(de)人像,美索不(bu)達(da)米(mi)亞于烏拉克三期(UruⅢ,公元(yuan)前(qian)(qian)(qian)3000年)已用(yong)鉛(qian)制成小容器或(huo)錘成薄片(pian),中國(guo)(guo)發(fa)(fa)現最早(zao)(zao)的(de)(de)是河(he)南偃(yan)師二里頭遺(yi)址(zhi)出土(tu)(tu)的(de)(de)鉛(qian)塊(kuai),它存在(zai)(zai)于距(ju)今約3500至4000年。在(zai)(zai)商代和西(xi)周的(de)(de)墓(mu)葬中出土(tu)(tu)了鉛(qian)制的(de)(de)爵(jue)、觚、尊(zun)、鼎和戈,西(xi)周(公元(yuan)前(qian)(qian)(qian)11世(shi)紀(ji)(ji)~前(qian)(qian)(qian)771年)的(de)(de)鉛(qian)戈含(han)鉛(qian)達(da)99.75%。直到(dao)公元(yuan)前(qian)(qian)(qian)15世(shi)紀(ji)(ji)之后,鉛(qian)才(cai)較(jiao)常見(jian)于巴勒(le)斯坦一帶(dai)。但(dan)直到(dao)17~18世(shi)紀(ji)(ji)鉛(qian)才(cai)開始較(jiao)大規模生產,主要產鉛(qian)國(guo)(guo)家有美國(guo)(guo)、前(qian)(qian)(qian)蘇聯(lian)、日本、德(de)國(guo)(guo)、英國(guo)(guo)、中國(guo)(guo)等。
鉛(qian)酸蓄(xu)電(dian)(dian)池(簡稱鉛(qian)酸電(dian)(dian)池)從問世(shi)至今(jin)已有150多(duo)年的歷史(shi),因其價格低廉、技術(shu)成(cheng)熟、性能可靠等優勢,已成(cheng)為目前化學電(dian)(dian)源中產(chan)量(liang)最大(da)、應用最廣的二次(ci)電(dian)(dian)池,長期以來被廣泛應用于社會(hui)生(sheng)產(chan)和(he)生(sheng)活的多(duo)種場合。
鉛(qian)(qian)酸(suan)(suan)電(dian)(dian)(dian)(dian)池是利用(yong)鉛(qian)(qian)的不同價態(tai)固(gu)相反應(ying)(ying)實(shi)現充(chong)放(fang)電(dian)(dian)(dian)(dian)的,電(dian)(dian)(dian)(dian)池放(fang)電(dian)(dian)(dian)(dian)時(shi),兩個電(dian)(dian)(dian)(dian)極(ji)的活性物(wu)質分(fen)別變成PbSO4,充(chong)電(dian)(dian)(dian)(dian)時(shi),反應(ying)(ying)向逆(ni)反應(ying)(ying)方向進(jin)行(xing),電(dian)(dian)(dian)(dian)解(jie)質硫酸(suan)(suan)是一(yi)種(zhong)活性物(wu)質。正負極(ji)電(dian)(dian)(dian)(dian)極(ji)反應(ying)(ying)適用(yong)溶解(jie)-沉淀機理而不是固(gu)態(tai)離子傳遞或者膜形成機理。鉛(qian)(qian)酸(suan)(suan)電(dian)(dian)(dian)(dian)池在室溫室壓下的標準(zhun)槽(cao)電(dian)(dian)(dian)(dian)壓為2.1V。
護(hu)套材(cai)料主要(yao)是化(hua)學鉛(qian)(qian)、含1%銻或砷的(de)(de)(de)鉛(qian)(qian)合(he)金,以(yi)及含0.03%鈣或蹄(ti)的(de)(de)(de)鉛(qian)(qian)合(he)金,用(yong)鉛(qian)(qian)作電(dian)(dian)(dian)纜護(hu)套主要(yao)起(qi)防(fang)潮、防(fang)腐蝕以(yi)及屏蔽(bi)支(zhi)撐(cheng)作用(yong)。電(dian)(dian)(dian)纜行業用(yong)鉛(qian)(qian)主要(yao)是電(dian)(dian)(dian)力(li)電(dian)(dian)(dian)纜與通(tong)訊電(dian)(dian)(dian)纜,雖然國(guo)(guo)內電(dian)(dian)(dian)力(li)通(tong)訊電(dian)(dian)(dian)纜的(de)(de)(de)鉛(qian)(qian)包皮(pi)大部(bu)分已被(bei)塑料等其它材(cai)料代替(ti),但(dan)仍(reng)有少量(liang)的(de)(de)(de)電(dian)(dian)(dian)纜使(shi)用(yong)鉛(qian)(qian)護(hu)套。國(guo)(guo)外囿于環保(bao)的(de)(de)(de)考(kao)慮(lv),對使(shi)用(yong)鉛(qian)(qian)于越洋海底電(dian)(dian)(dian)纜護(hu)套引(yin)發很多爭議,但(dan)該領(ling)域(yu)的(de)(de)(de)鉛(qian)(qian)耗量(liang)仍(reng)占其使(shi)用(yong)的(de)(de)(de)很大一部(bu)分。
目(mu)前(qian),有相當(dang)多的(de)鉛(qian)化(hua)合物應用(yong)(yong)于(yu)化(hua)工方面。在(zai)此(ci)僅(jin)介紹幾種應用(yong)(yong)廣泛的(de)產品。氧化(hua)鉛(qian)廣泛用(yong)(yong)于(yu)鉛(qian)酸(suan)蓄電(dian)池(chi)板(ban)柵的(de)糊狀混合物以及水泥、玻璃、陶瓷中,且可用(yong)(yong)于(yu)制(zhi)備其它的(de)鉛(qian)化(hua)合物;紅(hong)丹是重要的(de)防銹涂料,用(yong)(yong)作(zuo)底(di)漆與內漆層,防止鋼銹蝕。
工業上重要(yao)的白色防(fang)腐蝕顏料(liao)是一元碳酸(suan)(suan)鉛(qian),二元亞磷酸(suan)(suan)鉛(qian)、二元磷硅(gui)酸(suan)(suan)鉛(qian)和一元硅(gui)酸(suan)(suan)鉛(qian)。硼酸(suan)(suan)鉛(qian)鹽可用(yong)于玻(bo)璃制(zhi)(zhi)造、防(fang)火(huo)涂料(liao)、漆催干劑;硝酸(suan)(suan)鉛(qian)鹽用(yong)于制(zhi)(zhi)藥、礦石浮(fu)選。此外,鉛(qian)化工產品還在(zai)電子(zi)粉(fen)體材料(liao)、彩(cai)色電子(zi)超(chao)黑顯像管中作發(fa)光(guang)材料(liao)。
鉛合(he)金焊料(liao)(liao)即通常所說的(de)(de)(de)軟釬焊料(liao)(liao),其中(zhong)鉛錫合(he)金焊料(liao)(liao)在(zai)所有(you)焊接材料(liao)(liao)中(zhong)應用(yong)最廣泛(fan)、使用(yong)歷史(shi)較(jiao)長。它(ta)具有(you)低的(de)(de)(de)熔點,可(ke)以在(zai)不損傷熱敏感元件的(de)(de)(de)前提下,用(yong)簡單的(de)(de)(de)加熱方法(fa),比(bi)較(jiao)理想地連接大多數(shu)金屬。
傳統(tong)合金(jin)焊(han)料的(de)應用,應特(te)別引起使(shi)用廠家(jia)注意(yi)的(de)是:應該針對具體的(de)焊(han)接對象(xiang)、要(yao)(yao)求(qiu),使(shi)用不同(tong)錫(xi)含量的(de)合金(jin)。以達到(dao)在滿足使(shi)用要(yao)(yao)求(qiu)的(de)前提下,節(jie)約昂貴的(de)錫(xi)、降(jiang)低成本的(de)目的(de)。如(ru):錫(xi)含量不少于(yu)5%的(de)焊(han)料,主要(yao)(yao)用于(yu)密(mi)封,常用來密(mi)封預堆焊(han)后的(de)容(rong)器,涂覆、焊(han)接金(jin)屬,還(huan)可用于(yu)服役溫度超過120℃。
(1)鉛板
一般鉛材被軋制成3.6m以下(xia)(xia)寬度,任意厚(hou)度的(de)(de)薄鉛板(ban),0.4mm厚(hou)的(de)(de)鉛板(ban)重。鉛板(ban)作為結構(gou)(gou)材料,是(shi)化學及其相關工(gong)業的(de)(de)一種很重要(yao)的(de)(de)耐蝕(shi)(shi)材料,這(zhe)主要(yao)得利于(yu)鉛具有對(dui)多種腐(fu)蝕(shi)(shi)環境(jing)的(de)(de)抗蝕(shi)(shi)能力。當然(ran)也可用作建筑結構(gou)(gou)材料,例(li)如屋頂防(fang)蝕(shi)(shi)板(ban)、浴(yu)室中的(de)(de)地板(ban)。鉛板(ban)與水泥等接觸(chu),一般都在表面(mian)涂一層(ceng)瀝青(qing)。作為X射線(xian)與γ射線(xian)的(de)(de)屏(ping)蔽層(ceng)則是(shi)大家熟(shu)悉的(de)(de)一種應用。利用鉛優(you)良的(de)(de)減(jian)(jian)震(zhen)(zhen)、隔音的(de)(de)性能,也有大量(liang)的(de)(de)鉛板(ban)應用于(yu)減(jian)(jian)震(zhen)(zhen)隔音上。例(li)如,安裝(zhuang)于(yu)建筑物地基下(xia)(xia)阻礙震(zhen)(zhen)動傳播的(de)(de)鋼和鉛片(pian)減(jian)(jian)震(zhen)(zhen)墊;純鉛可吸收(shou)地震(zhen)(zhen)時釋(shi)放的(de)(de)大部分震(zhen)(zhen)動能量(liang),在近年(nian)日本的(de)(de)一次(ci)地震(zhen)(zhen)中,這(zhe)種減(jian)(jian)震(zhen)(zhen)器經受了檢驗。
(2)鉛管
鉛材(cai)中(zhong)鉛管(guan)也是一個主要方(fang)面(mian),大量(liang)應用于化學工業以及(ji)排水管(guan)道中(zhong)。用化學鉛或含6%銻(ti)的(de)鉛擠壓成無縫管(guan)。直徑(jing)從細管(guan)到300mm或更大,幾乎各種(zhong)厚度的(de)管(guan)子(zi)都有生(sheng)產應用。
(3)絲網鉛材
在建筑用鉛(qian)材料(liao)中,除(chu)使用鉛(qian)板、管、焊(han)料(liao)外(wai)還有用于(yu)堵漏的(de)(de)(de)鉛(qian)網布;上述鉛(qian)錫焊(han)料(liao)中的(de)(de)(de)相當一部分,作為低熔點的(de)(de)(de)易熔合(he)金(鉛(qian)與錫、鉍、鎘、銦等(deng)的(de)(de)(de)合(he)金)幾乎(hu)全(quan)部都(dou)是絲線材。后者中最低熔點在100℃以下,用于(yu)自動滅弧(hu)、電保(bao)險絲、鍋爐栓塞等(deng)。
在發(fa)達國家(jia),鉛材(cai)已構成(cheng)一個獨立的(de)消費去(qu)向,尤以英(ying)國為突出,將鉛皮作屋(wu)頂(ding)材(cai)料以防止來自大(da)氣中氛原子(zi)造成(cheng)的(de)輻射。然(ran)而,在中國鉛材(cai)的(de)產量很小(xiao),年(nian)產量在1萬(wan)t左右。隨著人民生活的(de)提高,鉛材(cai)有可能成(cheng)為鉛的(de)主要消費用途之一閉。
鉛的鑄(zhu)造材(cai)料中(zhong)最主要的是軸承合金(jin)和鉛字(zi)(zi)合金(jin);鑄(zhu)造產品(pin)中(zhong)則(ze)包括(kuo)軸承、鉛字(zi)(zi)板(ban)、配(pei)重、密封墊圈、彈頭、壓艙配(pei)重,甚至大(da)型核電站防(fang)輻射層的整體鑄(zhu)件。
在(zai)兩(liang)塊錫片之(zhi)間夾上鉛(qian)(qian)片,軋制(zhi)成(cheng)一(yi)種厚0.01mm或更薄的(de)緊密結(jie)合(he)的(de)Sn-Pb-Sn復(fu)(fu)合(he)箔(bo)(bo)(bo),即一(yi)般所稱的(de)“鉛(qian)(qian)箔(bo)(bo)(bo)”。在(zai)建筑工業(ye)上用(yong)(yong)(yong)于(yu)防潮,或作為(wei)葡萄(tao)、香檳酒瓶的(de)防氧化箔(bo)(bo)(bo)。也(ye)有的(de)用(yong)(yong)(yong)于(yu)電子工業(ye)。這處“鉛(qian)(qian)箔(bo)(bo)(bo)”在(zai)國外大量生產,廣(guang)泛(fan)應(ying)用(yong)(yong)(yong)。而國內在(zai)生產、應(ying)用(yong)(yong)(yong)兩(liang)方面都有差距。當(dang)然更普遍、用(yong)(yong)(yong)得更多(duo)的(de)鉛(qian)(qian)復(fu)(fu)合(he)材(cai)料是鉛(qian)(qian)與較(jiao)強(qiang)硬的(de)材(cai)料結(jie)合(he)制(zhi)成(cheng),其(qi)性(xing)能(neng)較(jiao)單(dan)一(yi)兩(liang)種材(cai)料都好。鉛(qian)(qian)可(ke)與鋼、混凝土、木材(cai)、磚或其(qi)它適當(dang)材(cai)料復(fu)(fu)合(he),該(gai)(gai)結(jie)構復(fu)(fu)合(he)材(cai)料具有優(you)良的(de)耐蝕(shi)性(xing)和高的(de)強(qiang)度。鉛(qian)(qian)與塑(su)料復(fu)(fu)合(he)雖然強(qiang)度稍低,但該(gai)(gai)復(fu)(fu)合(he)材(cai)料具備了優(you)異的(de)隔音性(xing)能(neng)。
鉛與較(jiao)強硬(ying)材(cai)料結合(he)制成的復合(he)材(cai)料結構包括:
①基本鉛復(fu)合結構:鑄造或(huo)擠壓鉛或(huo)鉛合金,在有限的復(fu)合基上(shang)。如鑄造所得的含銻鉛閥、泵、陽極和容器(qi)。
②鉛(qian)復合于高強基:片(pian)狀、管狀或(huo)其它擠(ji)壓(ya)成型(xing)的鉛(qian)及其合金,與鋼(gang)、木(mu)、混凝土(tu)、銅或(huo)其它金屬牢固復合,用作暖氣(qi)管、輸(shu)送器、地(di)板、電纜護(hu)套、屋頂與陽極板。
③粘貼復合鉛材(cai):片、管(guan)或(huo)其它(ta)形式的鉛及其合金,用粘附劑與鋼、混凝土、木材(cai)或(huo)其它(ta)材(cai)料連接,用作(zuo)鉛皮蓄酸容器。
④冶(ye)金(jin)鍵合(he)的鉛(qian)(qian)復(fu)(fu)合(he)材(cai)料(liao):與鋼(gang)、銅或(huo)其它金(jin)屬(shu)冶(ye)金(jin)結合(he)的重(zhong)鉛(qian)(qian)或(huo)鉛(qian)(qian)合(he)金(jin)復(fu)(fu)合(he)材(cai)料(liao),用作包鉛(qian)(qian)的鋼(gang)反應池,包鉛(qian)(qian)的銅冷卻、加熱蛇形管。
⑤無(wu)機材料(liao)復合(he)鉛(qian):在(zai)混凝(ning)土或(huo)鋼與瓷磚材料(liao)之(zhi)間(jian)嵌人鉛(qian)片,鉛(qian)片與內(nei)外(wai)層(ceng)機械或(huo)化學(xue)連接。例如(ru),在(zai)鋼片與內(nei)層(ceng)之(zhi)間(jian)嵌入墊(dian)層(ceng)材料(liao),用于(yu)硫酸霧洗滌、沉淀、收(shou)集、貯存器等(deng)。
⑥鉛涂層(ceng)復(fu)合(he)材(cai):涂層(ceng)與(yu)設備表(biao)面,機械或(huo)冶金連結,具有(you)耐蝕性。在(zai)鋼(gang)上涂Pb-Sn,用于(yu)屋(wu)頂、水槽(cao)與(yu)溜槽(cao)。以(yi)上6種(zhong)鉛復(fu)合(he)材(cai)料,均具有(you)低(di)的材(cai)料成(cheng)本、低(di)安裝與(yu)維(wei)修成(cheng)本,優良(liang)的耐蝕性、較長(chang)的服(fu)役壽(shou)命(ming),適于(yu)各(ge)種(zhong)操作條件等優點。
我國(guo)(guo)(guo)鉛(qian)(qian)(qian)礦資源豐(feng)富(fu),隨著國(guo)(guo)(guo)內鉛(qian)(qian)(qian)需(xu)求的增加,我國(guo)(guo)(guo)鉛(qian)(qian)(qian)礦開采量(liang)達到世界第一。但是,我國(guo)(guo)(guo)鉛(qian)(qian)(qian)冶煉行業(ye)集(ji)中(zhong)度卻相(xiang)對(dui)較(jiao)低(di),全國(guo)(guo)(guo)鉛(qian)(qian)(qian)產量(liang)前十位的鉛(qian)(qian)(qian)企產量(liang)總和不到全國(guo)(guo)(guo)的50%,而65%的鉛(qian)(qian)(qian)蓄(xu)電池產能在浙江幾(ji)大生(sheng)產商手(shou)里(li),消費的相(xiang)對(dui)集(ji)中(zhong)使得話語(yu)權牢牢落(luo)在了買方(fang)手(shou)里(li),因此(ci)買方(fang)市(shi)場是國(guo)(guo)(guo)內鉛(qian)(qian)(qian)市(shi)的重要特征(zheng)。
中(zhong)國國家(jia)統計局公布數據顯示,2014年中(zhong)國精(jing)煉鉛產(chan)量(liang)總計422萬噸,同比(bi)下(xia)降(jiang)5.5%。2001-2014年中(zhong)國精(jing)煉鉛產(chan)量(liang)如右圖所示:
數據還顯示(shi),2014年中(zhong)國鉛(qian)精(jing)礦總產(chan)量達(da)到299.7萬噸,同比下降(jiang)4.84%。2010-2014年期間中(zhong)國鉛(qian)精(jing)礦產(chan)量增速逐(zhu)年下降(jiang)。2008-2014年鉛(qian)精(jing)礦產(chan)量如右圖(tu)所(suo)示(shi):
鉛(qian)(qian)(qian)是(shi)國民(min)(min)經濟中最重要的基本金屬之(zhi)一,廣(guang)泛應用于電池(chi)、電纜(lan)護套、汽車制造、軍工等行(xing)業(ye)。其中鉛(qian)(qian)(qian)酸蓄電池(chi)為鉛(qian)(qian)(qian)的主(zhu)要消費領域,耗鉛(qian)(qian)(qian)量占整個鉛(qian)(qian)(qian)需求(qiu)的80%以上。隨著國民(min)(min)經濟的快速發展,工業(ye)原料的社(she)會需求(qiu)日(ri)益增加,在鉛(qian)(qian)(qian)酸蓄電池(chi)行(xing)業(ye)強勁(jing)需求(qiu)拉動(dong)下,我國鉛(qian)(qian)(qian)的消耗量已(yi)經趕(gan)超(chao)美國,躍居為全球首位。
中國(guo)(guo)鉛(qian)(qian)(qian)鋅業生產(chan)(chan)布局,依(yi)據鉛(qian)(qian)(qian)鋅礦(kuang)產(chan)(chan)地(di)的分(fen)布和(he)建設條(tiao)件,經(jing)40多年(nian)來的發展(zhan)、建設,現已形成東北、湖(hu)南(nan)、兩廣、滇川、西(xi)北等五大(da)鉛(qian)(qian)(qian)鋅采(cai)選冶和(he)加(jia)工配(pei)套的生產(chan)(chan)基地(di),其鉛(qian)(qian)(qian)產(chan)(chan)量占全(quan)(quan)國(guo)(guo)總產(chan)(chan)量的85%以上,鋅產(chan)(chan)量占全(quan)(quan)國(guo)(guo)總產(chan)(chan)量的95%。
(1)東北(bei)生產(chan)基(ji)地
東北地(di)(di)區是(shi)中國(guo)(guo)(guo)開發較早的(de)鉛(qian)(qian)(qian)鋅(xin)(xin)生產(chan)基地(di)(di)之一(yi)。早在50年代初(chu)期(qi),其鉛(qian)(qian)(qian)產(chan)量占全(quan)國(guo)(guo)(guo)鉛(qian)(qian)(qian)產(chan)量的(de)80%以(yi)上,在中國(guo)(guo)(guo)鉛(qian)(qian)(qian)鋅(xin)(xin)生產(chan)居于重要地(di)(di)位(wei)。東北基地(di)(di)以(yi)七(qi)礦兩(liang)(liang)廠為主,即(ji)青城子鉛(qian)(qian)(qian)鋅(xin)(xin)礦、八(ba)家(jia)子鉛(qian)(qian)(qian)鋅(xin)(xin)礦、柴河鉛(qian)(qian)(qian)鋅(xin)(xin)礦(現(xian)已(yi)閉坑)、桓仁銅鋅(xin)(xin)礦、紅(hong)透山銅鋅(xin)(xin)礦、西(xi)林鉛(qian)(qian)(qian)鋅(xin)(xin)礦(現(xian)已(yi)破產(chan)閉坑)、天寶山鉛(qian)(qian)(qian)鋅(xin)(xin)礦和(he)沈陽(yang)冶煉(lian)廠、葫蘆島鋅(xin)(xin)廠。七(qi)礦兩(liang)(liang)廠不僅是(shi)東北鉛(qian)(qian)(qian)鋅(xin)(xin)生產(chan)基地(di)(di)的(de)支(zhi)柱廠礦,也是(shi)培(pei)養造(zao)就科(ke)技(ji)人才的(de)基地(di)(di)。六七(qi)十年代曾(ceng)向全(quan)國(guo)(guo)(guo)新(xin)建的(de)鉛(qian)(qian)(qian)鋅(xin)(xin)企(qi)業(ye)(ye)輸(shu)送大(da)批具有(you)實踐(jian)經驗的(de)科(ke)技(ji)和(he)管(guan)理(li)人才以(yi)及生產(chan)技(ji)術工人,為中國(guo)(guo)(guo)鉛(qian)(qian)(qian)鋅(xin)(xin)業(ye)(ye)的(de)發展做出了積(ji)極貢獻。
(2)湖南生產基地
湖(hu)南鉛(qian)鋅(xin)礦(kuang)產資源豐富,而且富礦(kuang)多(duo),大部(bu)分礦(kuang)產地(di)(di)(di)可開發利用。該基地(di)(di)(di)鉛(qian)鋅(xin)廠礦(kuang)是(shi)五(wu)六十年代建成的(de)(de),由(you)水口山礦(kuang)務(wu)局(ju)、桃林鉛(qian)鋅(xin)礦(kuang)、黃沙(sha)坪鉛(qian)鋅(xin)礦(kuang)、東(dong)坡鉛(qian)鋅(xin)礦(kuang)和(he)株(zhu)洲冶煉廠等組成的(de)(de)湖(hu)南鉛(qian)鋅(xin)生產基地(di)(di)(di),是(shi)當(dang)時全國自產原料的(de)(de)全國最(zui)大的(de)(de)鉛(qian)鋅(xin)生產基地(di)(di)(di),在(zai)全國產量占有重要地(di)(di)(di)位。
(3)兩廣(guang)生產基地
廣(guang)東(dong)、廣(guang)西(xi)兩省(sheng)區的鉛(qian)鋅(xin)資源豐富,兩省(sheng)區是70年代(dai)形成的我國大型鉛(qian)鋅(xin)生產基地之(zhi)一(yi)。廣(guang)東(dong)以(yi)凡口鉛(qian)鋅(xin)礦(kuang)(kuang)和(he)韶關(guan)冶(ye)煉廠為主,其次是丙(bing)村鉛(qian)鋅(xin)礦(kuang)(kuang)、昌化鉛(qian)鋅(xin)礦(kuang)(kuang)、大尖山鉛(qian)鋅(xin)礦(kuang)(kuang)。廣(guang)西(xi)有泗頂鉛(qian)鋅(xin)礦(kuang)(kuang)、大新鉛(qian)鋅(xin)礦(kuang)(kuang)、河(he)三鉛(qian)鋅(xin)礦(kuang)(kuang)、柳(liu)州(zhou)鋅(xin)品廠和(he)大廠礦(kuang)(kuang)務局等。
(4)滇川生產基地
云南鉛(qian)(qian)(qian)鋅(xin)(xin)礦產資源(yuan)十分(fen)豐富(fu),現鉛(qian)(qian)(qian)鋅(xin)(xin)保有儲(chu)量均居(ju)全國之首。該基地鉛(qian)(qian)(qian)鋅(xin)(xin)企(qi)業也是(shi)五(wu)六十年(nian)代建成的,主(zhu)要是(shi)會(hui)澤(ze)鉛(qian)(qian)(qian)鋅(xin)(xin)礦、瀾滄老廠鉛(qian)(qian)(qian)鋅(xin)(xin)礦和昆明冶(ye)煉(lian)(lian)廠、個(ge)舊雞街冶(ye)煉(lian)(lian)廠。云南鉛(qian)(qian)(qian)鋅(xin)(xin)礦產資源(yuan)具有廣闊的開(kai)發前景,90年(nian)代開(kai)始(shi)興建超大型鉛(qian)(qian)(qian)鋅(xin)(xin)礦床金頂礦山(shan)(shan)。四川有會(hui)東(dong)鉛(qian)(qian)(qian)鋅(xin)(xin)礦、會(hui)理鉛(qian)(qian)(qian)鋅(xin)(xin)礦兩個(ge)主(zhu)要礦山(shan)(shan)以(yi)及一批中小型礦山(shan)(shan),鉛(qian)(qian)(qian)鋅(xin)(xin)精礦產量猛增。
(5)西(xi)北(bei)生(sheng)產基地
西(xi)(xi)北地區(qu)鉛(qian)(qian)(qian)鋅(xin)(xin)礦(kuang)(kuang)產資(zi)源也很豐富,主要分布在甘陜(shan)青三(san)省,而且西(xi)(xi)成(cheng)(cheng)(cheng)礦(kuang)(kuang)帶(dai)(dai)經(jing)勘查儲量(liang)(liang)又有(you)大(da)(da)(da)幅度的(de)增長,資(zi)源前(qian)景(jing)十分可觀。該基(ji)(ji)地鉛(qian)(qian)(qian)鋅(xin)(xin)生產以白銀(yin)有(you)色金屬公司(si)為(wei)主,有(you)白銀(yin)廠(chang)小(xiao)鐵(tie)山鉛(qian)(qian)(qian)鋅(xin)(xin)礦(kuang)(kuang)、第三(san)冶(ye)煉(lian)廠(chang)和西(xi)(xi)北鉛(qian)(qian)(qian)鋅(xin)(xin)冶(ye)煉(lian)廠(chang),陜(shan)西(xi)(xi)有(you)鉛(qian)(qian)(qian)硐山鉛(qian)(qian)(qian)鋅(xin)(xin)礦(kuang)(kuang)、二里河鉛(qian)(qian)(qian)鋅(xin)(xin)礦(kuang)(kuang)、銀(yin)洞梁(liang)鉛(qian)(qian)(qian)鋅(xin)(xin)礦(kuang)(kuang)等和青海錫鐵(tie)山礦(kuang)(kuang)務局。西(xi)(xi)北鉛(qian)(qian)(qian)鋅(xin)(xin)產量(liang)(liang)較(jiao)少(shao),但開發前(qian)景(jing)可觀。一是(shi)有(you)豐富的(de)鉛(qian)(qian)(qian)鋅(xin)(xin)礦(kuang)(kuang)產資(zi)源,位(wei)于甘陜(shan)交界(jie)的(de)西(xi)(xi)成(cheng)(cheng)(cheng)-鳳太礦(kuang)(kuang)帶(dai)(dai),勘查出10多個大(da)(da)(da)中型(xing)鉛(qian)(qian)(qian)鋅(xin)(xin)銀(yin)金礦(kuang)(kuang)床(chuang),其中廠(chang)壩(ba)-李家溝鉛(qian)(qian)(qian)鋅(xin)(xin)達到(dao)(dao)超大(da)(da)(da)型(xing)規模,銀(yin)達到(dao)(dao)大(da)(da)(da)型(xing)。二是(shi)廠(chang)壩(ba)正在抓緊建設一座大(da)(da)(da)型(xing)礦(kuang)(kuang)山,將(jiang)成(cheng)(cheng)(cheng)為(wei)西(xi)(xi)北冶(ye)煉(lian)廠(chang)主要礦(kuang)(kuang)物原料供(gong)給基(ji)(ji)地,是(shi)全國大(da)(da)(da)型(xing)鉛(qian)(qian)(qian)鋅(xin)(xin)礦(kuang)(kuang)山之一。
除上(shang)述(shu)五大(da)(da)鉛鋅(xin)生(sheng)產(chan)基地外(wai),內蒙(meng)古、江(jiang)西(xi)、貴州(zhou)等(deng)省區(qu)也建設(she)了一批(pi)中小型礦(kuang)山(shan)(shan)(shan)。其(qi)中內蒙(meng)古梧桐(tong)花鉛鋅(xin)礦(kuang)、白音諾鉛鋅(xin)礦(kuang)、翁牛特旗(qi)硐子鉛鋅(xin)礦(kuang)等(deng)礦(kuang)山(shan)(shan)(shan)。內蒙(meng)古是全(quan)國(guo)生(sheng)產(chan)鉛鋅(xin)精礦(kuang)主要(yao)省區(qu)之一,開(kai)發(fa)前景巨大(da)(da)。江(jiang)西(xi)有銀山(shan)(shan)(shan)鉛鋅(xin)礦(kuang)等(deng)。貴州(zhou)有赫章鉛鋅(xin)礦(kuang)、杉(shan)樹林鉛鋅(xin)礦(kuang)等(deng)。
鉛(qian)(qian)屬于三大重金(jin)屬污染物之(zhi)一(yi),是(shi)一(yi)種嚴重危害人(ren)(ren)體(ti)(ti)健康(kang)的重金(jin)屬元素,人(ren)(ren)體(ti)(ti)中理想的含(han)鉛(qian)(qian)量為零。人(ren)(ren)體(ti)(ti)多(duo)通過攝取食物、飲用(yong)自來水等方式(shi)把鉛(qian)(qian)帶入人(ren)(ren)體(ti)(ti),進入人(ren)(ren)體(ti)(ti)的鉛(qian)(qian)90%儲存在骨骼,10%隨血液循環(huan)流動而(er)分布到(dao)全身各組織(zhi)和(he)器官,影響血紅細胞和(he)腦、腎、神經(jing)系統功能,特別(bie)是(shi)嬰幼兒吸收鉛(qian)(qian)后,將有(you)超過30%保留在體(ti)(ti)內(nei),影響嬰幼兒的生(sheng)長(chang)和(he)智力發育。
由(you)于鉛(qian)是蓄(xu)積性(xing)的(de)中毒,只有當人體(ti)中鉛(qian)含量達到一定程度時,才會引發身體(ti)的(de)不適,在長期攝入(ru)鉛(qian)后,會對(dui)機體(ti)的(de)血(xue)液系統、神經系統產生(sheng)(sheng)嚴重的(de)損害(hai),尤其對(dui)兒童健康和(he)智(zhi)能(neng)的(de)危害(hai)產生(sheng)(sheng)難(nan)以逆轉的(de)影響。
工業生產(chan)中(zhong)(zhong)鉛以(yi)鉛塵(煙)方式(shi)被(bei)吸入人體,職業性鉛中(zhong)(zhong)毒多(duo)為(wei)(wei)慢(man)性中(zhong)(zhong)毒,臨床上有神(shen)經、消(xiao)化、血液等系(xi)統(tong)的綜(zong)合(he)癥狀(zhuang)。神(shen)經系(xi)統(tong)主要表(biao)現為(wei)(wei)神(shen)經衰弱、多(duo)發(fa)性神(shen)經病(bing)和腦(nao)病(bing)。神(shen)經衰弱是鉛中(zhong)(zhong)毒早期和較常見癥狀(zhuang)之一,表(biao)現為(wei)(wei)頭昏、頭痛、全身無力、記憶力減退(tui)、睡眠(mian)障礙、多(duo)夢等。多(duo)發(fa)性神(shen)經病(bing),可分(fen)為(wei)(wei)感覺型(xing)、運動型(xing)和混合(he)型(xing):
感(gan)(gan)覺型表現(xian)(xian)為(wei)肢端麻木(mu)和四肢末(mo)端呈手套襪子(zi)型感(gan)(gan)覺障礙;運(yun)動型表現(xian)(xian)有肌(ji)無力和肌(ji)肉麻痹。鉛(qian)中(zhong)毒腦(nao)病極少見到,為(wei)最(zui)嚴重鉛(qian)中(zhong)毒,表現(xian)(xian)為(wei)頭(tou)痛(tong)、惡(e)心、嘔吐、高熱(re)、煩躁、抽搐(chu)、嗜睡、精神障礙、昏(hun)迷等癥(zheng)狀。消化系(xi)統(tong)癥(zheng)狀輕(qing)者可(ke)表現(xian)(xian)為(wei)口(kou)內金屬味,食欲不振,上腹(fu)部脹悶、不適,腹(fu)隱痛(tong)和便秘;重者出現(xian)(xian)腹(fu)絞痛(tong)。血液系(xi)統(tong)主(zhu)要是鉛(qian)干(gan)擾血紅蛋白合(he)成過程,而(er)導致貧血。一般情(qing)況下,鉛(qian)中(zhong)毒經驅鉛(qian)治(zhi)療(liao)后,可(ke)很快(kuai)恢(hui)復(fu),除鉛(qian)中(zhong)毒性腦(nao)病外,很少有后遺(yi)癥(zheng)。
(1)直接污染
涉及到食品(pin)(pin)制作工藝(yi)及盛裝食品(pin)(pin)的器皿,食品(pin)(pin)在生產過程中直接(jie)接(jie)觸鉛(qian)(qian)或者由于生產工藝(yi)的原(yuan)因直接(jie)加入含鉛(qian)(qian)的原(yuan)料均會導致鉛(qian)(qian)污(wu)染,現在較為普遍的便是含鉛(qian)(qian)罐頭食品(pin)(pin)、皮蛋及爆米花等食品(pin)(pin)的生產均存在這種現象。
2001-2008年(nian)監測的(de)16大類2766份食(shi)品(pin)鉛(qian)超(chao)(chao)標率為5.42%,雖然(ran)總(zong)體污(wu)(wu)染不(bu)算嚴(yan)重,但皮(pi)(pi)蛋(dan)等食(shi)品(pin)中(zhong)鉛(qian)含(han)量較高(gao);2009-2010年(nian)對(dui)廣東省食(shi)品(pin)中(zhong)鉛(qian)、鎘(ge)污(wu)(wu)染情況進行檢測,結果顯示食(shi)品(pin)中(zhong)受(shou)鉛(qian)污(wu)(wu)染的(de)食(shi)品(pin)主要是海帶、紫菜(cai)、皮(pi)(pi)蛋(dan),其超(chao)(chao)標率分(fen)別是20%、30%、28%;另外調查表明(ming)不(bu)經常吃罐(guan)頭(tou)食(shi)品(pin)、皮(pi)(pi)蛋(dan)、爆米花等的(de)小孩智商要高(gao),這些調查結果顯示直接(jie)受(shou)鉛(qian)污(wu)(wu)染的(de)食(shi)品(pin)其危(wei)害性不(bu)可小視。
(2)間接污染
食品原材(cai)料在生(sheng)長、生(sheng)產過(guo)程(cheng)中通(tong)(tong)(tong)過(guo)土壤、空氣、水等(deng)途徑導致鉛(qian)污(wu)(wu)染。隨著(zhu)現代工(gong)(gong)業的發展,工(gong)(gong)業“三廢”的排(pai)放,使得(de)有(you)(you)毒重(zhong)(zhong)金屬鉛(qian)能通(tong)(tong)(tong)過(guo)各種途徑進入生(sheng)態系統(tong)中。有(you)(you)資(zi)料表明,早在1997年(nian)我國鉛(qian)污(wu)(wu)染面(mian)積已(yi)達(da)2000萬m2,占全國耕地總面(mian)積的20%,隨著(zhu)近(jin)年(nian)來污(wu)(wu)染情(qing)況(kuang)的加重(zhong)(zhong),污(wu)(wu)染面(mian)積已(yi)經超過(guo)1997年(nian)的污(wu)(wu)染面(mian)積;同時關(guan)于重(zhong)(zhong)金屬鉛(qian)通(tong)(tong)(tong)過(guo)土壤、空氣、水等(deng)污(wu)(wu)染時有(you)(you)報道,2011年(nian)5月(yue)在廣州(zhou)中山市(shi)發生(sheng)的血鉛(qian)事件(jian)就是通(tong)(tong)(tong)過(guo)水源污(wu)(wu)染的結果。
(1)遏制污染源頭
我(wo)國(guo)是(shi)鉛(qian)生(sheng)產(chan)的大(da)國(guo),現(xian)在(zai)我(wo)國(guo)鉛(qian)產(chan)量已(yi)經(jing)位居(ju)世界第一,因此,鉛(qian)礦(kuang)在(zai)生(sheng)產(chan)過程中如果(guo)控制(zhi)不當極易發(fa)生(sheng)大(da)范圍的鉛(qian)污(wu)染(ran)(ran)事件,2012年初在(zai)陜西省鳳(feng)翔發(fa)生(sheng)的鉛(qian)中毒事件,就是(shi)由(you)于在(zai)開(kai)采前沒(mei)有及時搬遷附近居(ju)民,導致鉛(qian)礦(kuang)開(kai)采污(wu)染(ran)(ran)事件發(fa)生(sheng)。
(2)控(kong)制流通途徑
傳播(bo)途徑包括通(tong)過(guo)水源(yuan)、餐(can)具、罐(guan)頭(tou)等方式污染食(shi)品,定(ding)期(qi)檢測受威脅(xie)區水體(ti)中鉛含量的(de)水平,嚴防重金屬鉛通(tong)過(guo)正常的(de)流(liu)通(tong)途徑進入食(shi)品,此外,定(ding)期(qi)對市場上的(de)食(shi)品隨機(ji)進行鉛含量監(jian)測,發(fa)現(xian)超標食(shi)品及(ji)時處理(li)。
(3)治療受害人群
鉛(qian)對(dui)人(ren)體危(wei)害巨大,兒(er)童(tong)(tong)身體中鉛(qian)含量達到10μg/dL左右時,將會比(bi)同齡兒(er)童(tong)(tong)智力(li)低9%,定期對(dui)受(shou)威(wei)脅(xie)地(di)區(qu)人(ren)群進(jin)行(xing)血鉛(qian)監測,及(ji)時治療(liao)中毒(du)病人(ren),是當前必(bi)須(xu)考慮的問題之(zhi)一(yi)。