靜海合成鎂鈣砂的煅燒工藝和煅燒設備
發布日期:2022-01-21 瀏(liu)覽次數:34927目前我國生產靜海合成鎂鈣砂所使用(yong)(yong)的原料(liao)有(you)菱(ling)鎂(mei)石(shi)(shi)(shi)、白云石(shi)(shi)(shi)和石(shi)(shi)(shi)灰(hui)(hui)石(shi)(shi)(shi)。所采用(yong)(yong)的工(gong)(gong)藝為二步(bu)煅(duan)(duan)燒(shao)、入工(gong)(gong)合(he)成工(gong)(gong)藝。即先將菱(ling)鎂(mei)石(shi)(shi)(shi)、白云石(shi)(shi)(shi)和石(shi)(shi)(shi)灰(hui)(hui)石(shi)(shi)(shi)在較低的溫(wen)度下輕(qing)燒(shao),生(sheng)(sheng)產出(chu)輕(qing)燒(shao)氧化(hua)鎂(mei)、輕(qing)燒(shao)白云石(shi)(shi)(shi)和生(sheng)(sheng)石(shi)(shi)(shi)灰(hui)(hui)。然后進(jin)行(xing)配料(liao)、磨細、混料(liao)、成型,最(zui)后經過高溫(wen)煅(duan)(duan)燒(shao),煅(duan)(duan)燒(shao)出(chu)不同牌號的合(he)成鎂(mei)鈣砂。具體的煅(duan)(duan)燒(shao)工(gong)(gong)藝有(you)半(ban)(ban)干法壓坯、隧道窯煅(duan)(duan)燒(shao)工(gong)(gong)藝;半(ban)(ban)干法壓球、焦炭豎窯煅(duan)(duan)燒(shao)工(gong)(gong)藝;干法壓球、高溫(wen)燃油豎窯和回轉窯煅(duan)(duan)燒(shao)工(gong)(gong)藝。
1、半(ban)干法(fa)壓坯(pi)、隧道窯煅(duan)(duan)燒工(gong)藝(yi)該(gai)煅(duan)(duan)燒工(gong)藝(yi)
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、半干法壓球、焦炭豎(shu)窯煅燒(shao)工藝(yi)
該(gai)煅燒(shao)工藝生(sheng)產合(he)成(cheng)(cheng)鎂(mei)(mei)鈣(gai)砂(sha)是以(yi)輕燒(shao)白云石(shi)和輕燒(shao)氧化鎂(mei)(mei)為原料(liao)(liao)。將輕燒(shao)白云石(shi)和輕燒(shao)氧化鎂(mei)(mei)分(fen)別(bie)磨(mo)成(cheng)(cheng)細粉,計(ji)量后(hou)按比例加入(ru)輪碾機中(zhong)再加水(shui)混(hun)合(he),混(hun)好的(de)合(he)成(cheng)(cheng)料(liao)(liao)在雙(shuang)輥(gun)壓球機上壓成(cheng)(cheng)料(liao)(liao)球,干(gan)燥后(hou)裝(zhuang)入(ru)以(yi)焦(jiao)(jiao)炭(tan)或無(wu)煙(yan)煤為燃(ran)料(liao)(liao)的(de)豎窯(yao)內煅燒(shao)。裝(zhuang)料(liao)(liao)方式是焦(jiao)(jiao)炭(tan)或無(wu)煙(yan)煤和料(liao)(liao)球分(fen)層裝(zhuang)入(ru)。我國遼寧(ning)省生(sheng)產合(he)成(cheng)(cheng)鎂(mei)(mei)鈣(gai)砂(sha)的(de)企業中(zhong),大部分(fen)采用(yong)該(gai)煅燒(shao)工藝。所(suo)用(yong)豎窯(yao)的(de)規格一般(ban)為3m×16m。該(gai)煅燒(shao)工藝簡單,產品成(cheng)(cheng)本低,但在煅燒(shao)過(guo)程中(zhong)料(liao)(liao)球和焦(jiao)(jiao)炭(tan)混(hun)在一起,焦(jiao)(jiao)炭(tan)燃(ran)燒(shao)產生(sheng)的(de)灰分(fen)有一部分(fen)混(hun)入(ru)到料(liao)(liao)球中(zhong),增加了產品的(de)雜(za)質含量。
3、干法壓(ya)球(qiu)、燃油豎窯煅燒工藝
該煅燒(shao)(shao)(shao)工(gong)(gong)藝用(yong)于生(sheng)(sheng)產(chan)(chan)高(gao)純(chun)(chun)度(du)合成鎂(mei)鈣砂。將高(gao)純(chun)(chun)度(du)輕(qing)燒(shao)(shao)(shao)氧化(hua)鎂(mei)和輕(qing)燒(shao)(shao)(shao)白云石配料(liao)(liao)、混合磨(mo)細后(hou)(hou),直(zhi)接(jie)將干(gan)粉料(liao)(liao)送(song)入高(gao)壓(ya)(ya)壓(ya)(ya)球(qiu)機中干(gan)壓(ya)(ya)成球(qiu),然后(hou)(hou)再送(song)入高(gao)溫燃(ran)油豎窯(yao)(yao)內煅燒(shao)(shao)(shao)。這種煅燒(shao)(shao)(shao)工(gong)(gong)藝的(de)(de)優(you)勢(shi)是燃(ran)料(liao)(liao)油噴(pen)入到料(liao)(liao)層(ceng)內,在料(liao)(liao)層(ceng)內部燃(ran)燒(shao)(shao)(shao),煅燒(shao)(shao)(shao)溫度(du)高(gao),可達到1800℃以上;燃(ran)料(liao)(liao)燃(ran)燒(shao)(shao)(shao)后(hou)(hou)不產(chan)(chan)生(sheng)(sheng)灰分,對物料(liao)(liao)的(de)(de)純(chun)(chun)度(du)沒有影(ying)響。目前,國內采用(yong)該煅燒(shao)(shao)(shao)工(gong)(gong)藝生(sheng)(sheng)產(chan)(chan)合成鎂(mei)鈣砂的(de)(de)企(qi)業,只有南方一(yi)(yi)家公司(si)。該公司(si)燃(ran)油豎窯(yao)(yao)的(de)(de)規格為φ1.75m×11.5m,窯(yao)(yao)的(de)(de)工(gong)(gong)作襯(chen)用(yong)高(gao)純(chun)(chun)度(du)堿(jian)性耐火(huo)制品(pin)砌筑,厚度(du)為350mm。工(gong)(gong)作襯(chen)于窯(yao)(yao)體鋼殼之間用(yong)輕(qing)質保溫磚砌筑。以重柴(chai)油為燃(ran)料(liao)(liao),煅燒(shao)(shao)(shao)溫度(du)>1800℃。設計4排(pai)燒(shao)(shao)(shao)嘴(zui),上下布置,間距(ju)900mm。每排(pai)設計16支燒(shao)(shao)(shao)嘴(zui),沿(yan)圓周均布。采用(yong)無冷卻燒(shao)(shao)(shao)嘴(zui),每支燒(shao)(shao)(shao)嘴(zui)配一(yi)(yi)臺計量泵供(gong)油,一(yi)(yi)次空氣(qi)由(you)羅茨(ci)風(feng)機供(gong)應(ying)。實際生(sheng)(sheng)產(chan)(chan)中使用(yong)一(yi)(yi)排(pai)燒(shao)(shao)(shao)嘴(zui)。連(lian)續裝窯(yao)(yao)和出窯(yao)(yao),全部自動化(hua)控制,生(sheng)(sheng)產(chan)(chan)能力(li)。
4、干法壓球、回轉窯煅燒工藝(yi)
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。