韶關合成鎂鈣砂的煅燒工藝和煅燒設備
發布(bu)日期(qi):2022-01-21 瀏覽次數(shu):35957目前我國生產韶關合成鎂鈣砂所(suo)使(shi)用的原料有(you)菱(ling)鎂(mei)石(shi)(shi)(shi)、白(bai)(bai)云(yun)石(shi)(shi)(shi)和(he)石(shi)(shi)(shi)灰石(shi)(shi)(shi)。所(suo)采用的工(gong)(gong)(gong)藝(yi)為(wei)二步煅燒(shao)(shao)、入(ru)工(gong)(gong)(gong)合成工(gong)(gong)(gong)藝(yi)。即先(xian)將菱(ling)鎂(mei)石(shi)(shi)(shi)、白(bai)(bai)云(yun)石(shi)(shi)(shi)和(he)石(shi)(shi)(shi)灰石(shi)(shi)(shi)在較低的溫度(du)下輕燒(shao)(shao),生產出輕燒(shao)(shao)氧化(hua)鎂(mei)、輕燒(shao)(shao)白(bai)(bai)云(yun)石(shi)(shi)(shi)和(he)生石(shi)(shi)(shi)灰。然后進行(xing)配(pei)料、磨細、混料、成型,最后經(jing)過高溫煅燒(shao)(shao),煅燒(shao)(shao)出不(bu)同(tong)牌號的合成鎂(mei)鈣砂(sha)。具體的煅燒(shao)(shao)工(gong)(gong)(gong)藝(yi)有(you)半干(gan)(gan)法(fa)壓(ya)坯、隧道窯(yao)煅燒(shao)(shao)工(gong)(gong)(gong)藝(yi);半干(gan)(gan)法(fa)壓(ya)球、焦炭豎(shu)窯(yao)煅燒(shao)(shao)工(gong)(gong)(gong)藝(yi);干(gan)(gan)法(fa)壓(ya)球、高溫燃油豎(shu)窯(yao)和(he)回轉窯(yao)煅燒(shao)(shao)工(gong)(gong)(gong)藝(yi)。
1、半干法(fa)壓坯、隧道窯煅(duan)燒(shao)工藝該煅(duan)燒(shao)工藝
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(ban)干法壓球、焦(jiao)炭豎窯(yao)煅燒工藝(yi)
該煅(duan)燒(shao)(shao)工藝生(sheng)產(chan)合(he)成鎂(mei)鈣砂(sha)是以輕(qing)燒(shao)(shao)白(bai)云石和(he)輕(qing)燒(shao)(shao)氧化(hua)鎂(mei)為原料(liao)(liao)。將輕(qing)燒(shao)(shao)白(bai)云石和(he)輕(qing)燒(shao)(shao)氧化(hua)鎂(mei)分(fen)(fen)別磨成細粉,計量后(hou)按比(bi)例加入輪碾機中再加水混合(he),混好的(de)合(he)成料(liao)(liao)在雙輥壓球(qiu)(qiu)機上壓成料(liao)(liao)球(qiu)(qiu),干燥(zao)后(hou)裝入以焦(jiao)(jiao)(jiao)炭(tan)(tan)或無煙(yan)煤為燃料(liao)(liao)的(de)豎窯(yao)內(nei)煅(duan)燒(shao)(shao)。裝料(liao)(liao)方式是焦(jiao)(jiao)(jiao)炭(tan)(tan)或無煙(yan)煤和(he)料(liao)(liao)球(qiu)(qiu)分(fen)(fen)層裝入。我國(guo)遼寧省生(sheng)產(chan)合(he)成鎂(mei)鈣砂(sha)的(de)企業(ye)中,大部(bu)分(fen)(fen)采(cai)用(yong)該煅(duan)燒(shao)(shao)工藝。所用(yong)豎窯(yao)的(de)規格一般為3m×16m。該煅(duan)燒(shao)(shao)工藝簡單,產(chan)品(pin)成本低(di),但在煅(duan)燒(shao)(shao)過程中料(liao)(liao)球(qiu)(qiu)和(he)焦(jiao)(jiao)(jiao)炭(tan)(tan)混在一起,焦(jiao)(jiao)(jiao)炭(tan)(tan)燃燒(shao)(shao)產(chan)生(sheng)的(de)灰分(fen)(fen)有一部(bu)分(fen)(fen)混入到料(liao)(liao)球(qiu)(qiu)中,增加了產(chan)品(pin)的(de)雜質(zhi)含(han)量。
3、干法壓球、燃(ran)油豎(shu)窯煅燒工藝(yi)
該(gai)煅(duan)(duan)燒(shao)(shao)工(gong)藝用(yong)于生(sheng)產高純(chun)度(du)(du)合(he)成鎂(mei)鈣砂。將(jiang)高純(chun)度(du)(du)輕燒(shao)(shao)氧化(hua)鎂(mei)和輕燒(shao)(shao)白云石(shi)配料(liao)(liao)(liao)、混合(he)磨細后,直接將(jiang)干粉(fen)料(liao)(liao)(liao)送(song)(song)入(ru)高壓(ya)壓(ya)球(qiu)機(ji)中干壓(ya)成球(qiu),然后再送(song)(song)入(ru)高溫(wen)燃油豎窯(yao)(yao)內煅(duan)(duan)燒(shao)(shao)。這種煅(duan)(duan)燒(shao)(shao)工(gong)藝的(de)優勢是燃料(liao)(liao)(liao)油噴入(ru)到料(liao)(liao)(liao)層內,在(zai)料(liao)(liao)(liao)層內部(bu)燃燒(shao)(shao),煅(duan)(duan)燒(shao)(shao)溫(wen)度(du)(du)高,可(ke)達到1800℃以(yi)上;燃料(liao)(liao)(liao)燃燒(shao)(shao)后不產生(sheng)灰分,對(dui)物料(liao)(liao)(liao)的(de)純(chun)度(du)(du)沒(mei)有影(ying)響(xiang)。目前,國(guo)內采用(yong)該(gai)煅(duan)(duan)燒(shao)(shao)工(gong)藝生(sheng)產合(he)成鎂(mei)鈣砂的(de)企業,只有南方一(yi)家公(gong)(gong)司(si)。該(gai)公(gong)(gong)司(si)燃油豎窯(yao)(yao)的(de)規格(ge)為φ1.75m×11.5m,窯(yao)(yao)的(de)工(gong)作襯用(yong)高純(chun)度(du)(du)堿性耐(nai)火制品砌(qi)筑(zhu),厚度(du)(du)為350mm。工(gong)作襯于窯(yao)(yao)體鋼殼之(zhi)間(jian)用(yong)輕質保溫(wen)磚砌(qi)筑(zhu)。以(yi)重柴油為燃料(liao)(liao)(liao),煅(duan)(duan)燒(shao)(shao)溫(wen)度(du)(du)>1800℃。設計(ji)4排燒(shao)(shao)嘴(zui),上下布(bu)置(zhi),間(jian)距900mm。每(mei)(mei)排設計(ji)16支燒(shao)(shao)嘴(zui),沿圓周(zhou)均布(bu)。采用(yong)無冷卻燒(shao)(shao)嘴(zui),每(mei)(mei)支燒(shao)(shao)嘴(zui)配一(yi)臺計(ji)量(liang)泵供(gong)油,一(yi)次空氣由羅茨風機(ji)供(gong)應。實際生(sheng)產中使用(yong)一(yi)排燒(shao)(shao)嘴(zui)。連續裝窯(yao)(yao)和出窯(yao)(yao),全部(bu)自動化(hua)控制,生(sheng)產能力(li)。
4、干(gan)法(fa)壓球、回轉(zhuan)窯煅燒工藝
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。