平谷合成鎂鈣砂的煅燒工藝和煅燒設備
發(fa)布日期:2022-01-21 瀏覽次數:34935目前我國生產平谷合成鎂鈣砂所使用的(de)(de)原料(liao)有菱鎂(mei)(mei)(mei)石(shi)(shi)、白(bai)云石(shi)(shi)和(he)石(shi)(shi)灰石(shi)(shi)。所采(cai)用的(de)(de)工(gong)藝(yi)(yi)為二步煅(duan)(duan)燒(shao)(shao)、入工(gong)合(he)成(cheng)工(gong)藝(yi)(yi)。即(ji)先將菱鎂(mei)(mei)(mei)石(shi)(shi)、白(bai)云石(shi)(shi)和(he)石(shi)(shi)灰石(shi)(shi)在較低的(de)(de)溫(wen)度下輕(qing)(qing)燒(shao)(shao),生產出(chu)輕(qing)(qing)燒(shao)(shao)氧化鎂(mei)(mei)(mei)、輕(qing)(qing)燒(shao)(shao)白(bai)云石(shi)(shi)和(he)生石(shi)(shi)灰。然后進行配料(liao)、磨細(xi)、混料(liao)、成(cheng)型,最后經過高溫(wen)煅(duan)(duan)燒(shao)(shao),煅(duan)(duan)燒(shao)(shao)出(chu)不(bu)同牌(pai)號(hao)的(de)(de)合(he)成(cheng)鎂(mei)(mei)(mei)鈣砂(sha)。具體的(de)(de)煅(duan)(duan)燒(shao)(shao)工(gong)藝(yi)(yi)有半(ban)干(gan)(gan)法(fa)(fa)(fa)壓坯、隧道窯(yao)煅(duan)(duan)燒(shao)(shao)工(gong)藝(yi)(yi);半(ban)干(gan)(gan)法(fa)(fa)(fa)壓球、焦炭豎窯(yao)煅(duan)(duan)燒(shao)(shao)工(gong)藝(yi)(yi);干(gan)(gan)法(fa)(fa)(fa)壓球、高溫(wen)燃油(you)豎窯(yao)和(he)回(hui)轉窯(yao)煅(duan)(duan)燒(shao)(shao)工(gong)藝(yi)(yi)。
1、半干法壓坯、隧(sui)道(dao)窯煅(duan)燒工藝該煅(duan)燒工藝
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(fa)壓(ya)球、焦炭豎(shu)窯(yao)煅燒工藝
該煅燒(shao)工(gong)藝生產(chan)合(he)(he)成鎂(mei)鈣砂是(shi)以輕燒(shao)白云石(shi)和輕燒(shao)氧化鎂(mei)為原料(liao)(liao)。將輕燒(shao)白云石(shi)和輕燒(shao)氧化鎂(mei)分別(bie)磨成細(xi)粉,計(ji)量后按比(bi)例加(jia)入(ru)(ru)輪碾機中(zhong)(zhong)再加(jia)水混合(he)(he),混好的(de)合(he)(he)成料(liao)(liao)在(zai)雙輥(gun)壓球(qiu)(qiu)(qiu)機上壓成料(liao)(liao)球(qiu)(qiu)(qiu),干燥后裝入(ru)(ru)以焦(jiao)炭(tan)或(huo)(huo)無(wu)煙煤為燃料(liao)(liao)的(de)豎(shu)窯內煅燒(shao)。裝料(liao)(liao)方式是(shi)焦(jiao)炭(tan)或(huo)(huo)無(wu)煙煤和料(liao)(liao)球(qiu)(qiu)(qiu)分層裝入(ru)(ru)。我國(guo)遼寧省生產(chan)合(he)(he)成鎂(mei)鈣砂的(de)企業中(zhong)(zhong),大部分采用(yong)(yong)該煅燒(shao)工(gong)藝。所用(yong)(yong)豎(shu)窯的(de)規格一般為3m×16m。該煅燒(shao)工(gong)藝簡單,產(chan)品(pin)成本(ben)低(di),但在(zai)煅燒(shao)過程(cheng)中(zhong)(zhong)料(liao)(liao)球(qiu)(qiu)(qiu)和焦(jiao)炭(tan)混在(zai)一起,焦(jiao)炭(tan)燃燒(shao)產(chan)生的(de)灰分有一部分混入(ru)(ru)到料(liao)(liao)球(qiu)(qiu)(qiu)中(zhong)(zhong),增加(jia)了(le)產(chan)品(pin)的(de)雜質含量。
3、干法壓球、燃(ran)油(you)豎窯煅燒工藝
該煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)工(gong)(gong)藝用(yong)(yong)于生(sheng)(sheng)產(chan)(chan)(chan)高(gao)純度(du)(du)合成(cheng)(cheng)鎂(mei)(mei)(mei)鈣(gai)砂(sha)。將高(gao)純度(du)(du)輕(qing)燒(shao)(shao)(shao)(shao)(shao)氧化(hua)(hua)鎂(mei)(mei)(mei)和(he)輕(qing)燒(shao)(shao)(shao)(shao)(shao)白云(yun)石配料(liao)、混合磨細(xi)后(hou),直接將干粉料(liao)送(song)(song)入高(gao)壓(ya)壓(ya)球機(ji)中干壓(ya)成(cheng)(cheng)球,然后(hou)再送(song)(song)入高(gao)溫(wen)(wen)燃(ran)油(you)豎窯(yao)內(nei)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)。這種(zhong)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)工(gong)(gong)藝的(de)優(you)勢是燃(ran)料(liao)油(you)噴入到料(liao)層(ceng)內(nei),在料(liao)層(ceng)內(nei)部燃(ran)燒(shao)(shao)(shao)(shao)(shao),煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)溫(wen)(wen)度(du)(du)高(gao),可達到1800℃以上(shang)(shang);燃(ran)料(liao)燃(ran)燒(shao)(shao)(shao)(shao)(shao)后(hou)不產(chan)(chan)(chan)生(sheng)(sheng)灰分,對物料(liao)的(de)純度(du)(du)沒有影響。目前,國內(nei)采(cai)用(yong)(yong)該煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)工(gong)(gong)藝生(sheng)(sheng)產(chan)(chan)(chan)合成(cheng)(cheng)鎂(mei)(mei)(mei)鈣(gai)砂(sha)的(de)企(qi)業(ye),只有南方一(yi)(yi)家公司(si)。該公司(si)燃(ran)油(you)豎窯(yao)的(de)規格(ge)為φ1.75m×11.5m,窯(yao)的(de)工(gong)(gong)作(zuo)襯用(yong)(yong)高(gao)純度(du)(du)堿性(xing)耐火制(zhi)品砌筑(zhu),厚度(du)(du)為350mm。工(gong)(gong)作(zuo)襯于窯(yao)體鋼殼之間(jian)用(yong)(yong)輕(qing)質保溫(wen)(wen)磚(zhuan)砌筑(zhu)。以重柴油(you)為燃(ran)料(liao),煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)溫(wen)(wen)度(du)(du)>1800℃。設計(ji)(ji)4排燒(shao)(shao)(shao)(shao)(shao)嘴(zui),上(shang)(shang)下布置,間(jian)距900mm。每排設計(ji)(ji)16支燒(shao)(shao)(shao)(shao)(shao)嘴(zui),沿圓周均布。采(cai)用(yong)(yong)無(wu)冷卻燒(shao)(shao)(shao)(shao)(shao)嘴(zui),每支燒(shao)(shao)(shao)(shao)(shao)嘴(zui)配一(yi)(yi)臺計(ji)(ji)量泵供油(you),一(yi)(yi)次空氣由羅茨風機(ji)供應。實際生(sheng)(sheng)產(chan)(chan)(chan)中使用(yong)(yong)一(yi)(yi)排燒(shao)(shao)(shao)(shao)(shao)嘴(zui)。連續裝窯(yao)和(he)出(chu)窯(yao),全部自動化(hua)(hua)控制(zhi),生(sheng)(sheng)產(chan)(chan)(chan)能力。
4、干(gan)法壓(ya)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。