大連合成鎂鈣砂的煅燒工藝和煅燒設備
發(fa)布日期(qi):2022-01-21 瀏覽(lan)次數(shu):34684目前我國生產大連合成鎂鈣砂所(suo)使用(yong)的(de)(de)原料(liao)有菱鎂(mei)石(shi)、白(bai)(bai)云(yun)石(shi)和(he)石(shi)灰石(shi)。所(suo)采用(yong)的(de)(de)工(gong)(gong)(gong)(gong)藝(yi)(yi)為二步煅(duan)燒(shao)(shao)、入(ru)工(gong)(gong)(gong)(gong)合成工(gong)(gong)(gong)(gong)藝(yi)(yi)。即先將(jiang)菱鎂(mei)石(shi)、白(bai)(bai)云(yun)石(shi)和(he)石(shi)灰石(shi)在較低的(de)(de)溫(wen)度下輕燒(shao)(shao),生產(chan)出(chu)輕燒(shao)(shao)氧化鎂(mei)、輕燒(shao)(shao)白(bai)(bai)云(yun)石(shi)和(he)生石(shi)灰。然(ran)后進行配(pei)料(liao)、磨細、混(hun)料(liao)、成型,最(zui)后經過高(gao)溫(wen)煅(duan)燒(shao)(shao),煅(duan)燒(shao)(shao)出(chu)不同牌號的(de)(de)合成鎂(mei)鈣(gai)砂。具體的(de)(de)煅(duan)燒(shao)(shao)工(gong)(gong)(gong)(gong)藝(yi)(yi)有半干(gan)(gan)法壓坯、隧道窯(yao)煅(duan)燒(shao)(shao)工(gong)(gong)(gong)(gong)藝(yi)(yi);半干(gan)(gan)法壓球、焦炭豎(shu)窯(yao)煅(duan)燒(shao)(shao)工(gong)(gong)(gong)(gong)藝(yi)(yi);干(gan)(gan)法壓球、高(gao)溫(wen)燃油豎(shu)窯(yao)和(he)回(hui)轉(zhuan)窯(yao)煅(duan)燒(shao)(shao)工(gong)(gong)(gong)(gong)藝(yi)(yi)。
1、半(ban)干法(fa)壓坯(pi)、隧道窯煅燒工(gong)藝該煅燒工(gong)藝
生產合成鎂鈣砂是以生石灰和輕燒氧化鎂為原料。首先將生石灰加水消化成消石灰,然后將消石灰與輕燒氧化鎂配料,經過攪拌混合,入筒磨機內共同磨細、均化,再將磨細的合成料在輪碾機內加水混合成半干料,在摩擦壓力機上壓成具有一定外形尺寸的磚坯,經過干燥,裝于隧道窯車上,推入隧道窯內高溫煅燒成合成鎂鈣砂熟料。我國某公司煅燒合成鎂鈣砂使用的隧道窯規格為104.5m×2.0m×1.2m,共52個車位,以熱發生爐煤氣為燃料,設12對套管式煤氣燒嘴,煅燒溫度1620~1650℃,年產量1.5萬t。以隧道窯作為煅燒設備煅燒溫度均勻,保溫時間長,物料達到充分燒結。因此,可獲得高致密度的合成耐火原料。
2、半干法(fa)壓球、焦炭豎窯煅(duan)燒工藝
該煅(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)藝(yi)生產(chan)合(he)(he)(he)(he)成鎂鈣砂(sha)是以輕(qing)燒(shao)(shao)白云石和(he)輕(qing)燒(shao)(shao)氧(yang)化(hua)鎂為(wei)原料(liao)(liao)。將(jiang)輕(qing)燒(shao)(shao)白云石和(he)輕(qing)燒(shao)(shao)氧(yang)化(hua)鎂分別磨成細粉,計量(liang)后按(an)比例加(jia)入(ru)輪碾機中(zhong)再加(jia)水混合(he)(he)(he)(he),混好的(de)合(he)(he)(he)(he)成料(liao)(liao)在雙輥(gun)壓(ya)球(qiu)機上壓(ya)成料(liao)(liao)球(qiu),干燥后裝(zhuang)(zhuang)入(ru)以焦(jiao)(jiao)炭(tan)或(huo)無(wu)煙煤為(wei)燃料(liao)(liao)的(de)豎窯內煅(duan)(duan)燒(shao)(shao)。裝(zhuang)(zhuang)料(liao)(liao)方式是焦(jiao)(jiao)炭(tan)或(huo)無(wu)煙煤和(he)料(liao)(liao)球(qiu)分層裝(zhuang)(zhuang)入(ru)。我國遼寧省生產(chan)合(he)(he)(he)(he)成鎂鈣砂(sha)的(de)企業中(zhong),大部分采用該煅(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)藝(yi)。所用豎窯的(de)規(gui)格一(yi)般為(wei)3m×16m。該煅(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)藝(yi)簡單,產(chan)品(pin)成本低,但在煅(duan)(duan)燒(shao)(shao)過程中(zhong)料(liao)(liao)球(qiu)和(he)焦(jiao)(jiao)炭(tan)混在一(yi)起,焦(jiao)(jiao)炭(tan)燃燒(shao)(shao)產(chan)生的(de)灰分有一(yi)部分混入(ru)到料(liao)(liao)球(qiu)中(zhong),增(zeng)加(jia)了產(chan)品(pin)的(de)雜質含量(liang)。
3、干法壓球(qiu)、燃油豎窯煅燒工藝
該煅(duan)(duan)燒(shao)(shao)工(gong)(gong)藝用(yong)于生(sheng)(sheng)產(chan)(chan)高(gao)(gao)純(chun)(chun)度合(he)成(cheng)鎂鈣砂。將高(gao)(gao)純(chun)(chun)度輕燒(shao)(shao)氧(yang)化鎂和輕燒(shao)(shao)白云石配料(liao)、混合(he)磨細(xi)后,直接(jie)將干粉料(liao)送(song)入高(gao)(gao)壓(ya)壓(ya)球機(ji)中(zhong)干壓(ya)成(cheng)球,然后再送(song)入高(gao)(gao)溫(wen)燃油(you)(you)(you)豎窯(yao)內(nei)煅(duan)(duan)燒(shao)(shao)。這種煅(duan)(duan)燒(shao)(shao)工(gong)(gong)藝的(de)優勢是燃料(liao)油(you)(you)(you)噴入到(dao)料(liao)層內(nei),在料(liao)層內(nei)部燃燒(shao)(shao),煅(duan)(duan)燒(shao)(shao)溫(wen)度高(gao)(gao),可達到(dao)1800℃以上;燃料(liao)燃燒(shao)(shao)后不(bu)產(chan)(chan)生(sheng)(sheng)灰分,對物料(liao)的(de)純(chun)(chun)度沒有影(ying)響。目前(qian),國內(nei)采用(yong)該煅(duan)(duan)燒(shao)(shao)工(gong)(gong)藝生(sheng)(sheng)產(chan)(chan)合(he)成(cheng)鎂鈣砂的(de)企業(ye),只有南方(fang)一(yi)家公司。該公司燃油(you)(you)(you)豎窯(yao)的(de)規(gui)格為(wei)(wei)φ1.75m×11.5m,窯(yao)的(de)工(gong)(gong)作襯用(yong)高(gao)(gao)純(chun)(chun)度堿性耐火(huo)制品砌筑,厚(hou)度為(wei)(wei)350mm。工(gong)(gong)作襯于窯(yao)體鋼殼之間(jian)用(yong)輕質保溫(wen)磚砌筑。以重柴油(you)(you)(you)為(wei)(wei)燃料(liao),煅(duan)(duan)燒(shao)(shao)溫(wen)度>1800℃。設計4排燒(shao)(shao)嘴(zui),上下布置,間(jian)距900mm。每排設計16支燒(shao)(shao)嘴(zui),沿(yan)圓周均布。采用(yong)無(wu)冷卻燒(shao)(shao)嘴(zui),每支燒(shao)(shao)嘴(zui)配一(yi)臺計量泵(beng)供(gong)油(you)(you)(you),一(yi)次空(kong)氣由羅(luo)茨風機(ji)供(gong)應。實際生(sheng)(sheng)產(chan)(chan)中(zhong)使用(yong)一(yi)排燒(shao)(shao)嘴(zui)。連(lian)續裝(zhuang)窯(yao)和出窯(yao),全部自動化控(kong)制,生(sheng)(sheng)產(chan)(chan)能力(li)。
4、干法壓球(qiu)、回轉窯煅(duan)燒工藝
目前,國內有部分企業采用高溫回轉窯煅燒合成鎂鈣砂。其煅燒工藝為:將高純度輕燒氧化鎂和高純度輕燒白云石按比例配料后,經過攪拌昆合,磨成細粉,送入高壓壓球機中干壓成球,然后送入高溫回轉窯內煅燒。如某公司采用φ2.5m×60m超高溫回轉窯煅燒合成鎂鈣砂,以重油作燃料,采用機械霧化燒嘴,窯尾設煙氣換熱器,將一次空氣預熱到450~500℃,煅燒溫度>1850℃。煅燒CaO含量20%~30%合成鎂鈣砂,產量2~2.5t/h,油耗300kg/t。