烏蘭察布合成鎂鈣砂的煅燒工藝和煅燒設備
發布日期:2022-01-21 瀏覽次數:34695目前我國生產烏蘭察布合成鎂鈣砂所(suo)使用(yong)的(de)(de)原料(liao)有菱鎂石(shi)(shi)(shi)(shi)、白云石(shi)(shi)(shi)(shi)和石(shi)(shi)(shi)(shi)灰石(shi)(shi)(shi)(shi)。所(suo)采(cai)用(yong)的(de)(de)工(gong)藝(yi)(yi)為二步煅(duan)燒(shao)(shao)(shao)、入(ru)工(gong)合成(cheng)工(gong)藝(yi)(yi)。即先將菱鎂石(shi)(shi)(shi)(shi)、白云石(shi)(shi)(shi)(shi)和石(shi)(shi)(shi)(shi)灰石(shi)(shi)(shi)(shi)在(zai)較低的(de)(de)溫(wen)度(du)下輕燒(shao)(shao)(shao),生產出(chu)輕燒(shao)(shao)(shao)氧化鎂、輕燒(shao)(shao)(shao)白云石(shi)(shi)(shi)(shi)和生石(shi)(shi)(shi)(shi)灰。然后(hou)進(jin)行配(pei)料(liao)、磨細、混料(liao)、成(cheng)型(xing),最后(hou)經過高溫(wen)煅(duan)燒(shao)(shao)(shao),煅(duan)燒(shao)(shao)(shao)出(chu)不(bu)同牌號的(de)(de)合成(cheng)鎂鈣砂。具體的(de)(de)煅(duan)燒(shao)(shao)(shao)工(gong)藝(yi)(yi)有半干法(fa)壓坯、隧道窯(yao)煅(duan)燒(shao)(shao)(shao)工(gong)藝(yi)(yi);半干法(fa)壓球(qiu)、焦(jiao)炭豎窯(yao)煅(duan)燒(shao)(shao)(shao)工(gong)藝(yi)(yi);干法(fa)壓球(qiu)、高溫(wen)燃油豎窯(yao)和回(hui)轉窯(yao)煅(duan)燒(shao)(shao)(shao)工(gong)藝(yi)(yi)。
1、半干法壓坯、隧(sui)道(dao)窯煅(duan)燒工藝(yi)該煅(duan)燒工藝(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(qiu)、焦炭豎(shu)窯煅(duan)燒工藝
該煅(duan)燒(shao)(shao)工(gong)(gong)藝生產(chan)合(he)(he)成(cheng)(cheng)(cheng)鎂鈣(gai)砂(sha)是以(yi)輕(qing)燒(shao)(shao)白云(yun)石和輕(qing)燒(shao)(shao)氧(yang)化鎂為(wei)原(yuan)料(liao)。將輕(qing)燒(shao)(shao)白云(yun)石和輕(qing)燒(shao)(shao)氧(yang)化鎂分(fen)別磨成(cheng)(cheng)(cheng)細粉,計量后按比例加入(ru)輪碾(nian)機中(zhong)再加水混合(he)(he),混好的(de)合(he)(he)成(cheng)(cheng)(cheng)料(liao)在(zai)雙輥壓球(qiu)(qiu)機上(shang)壓成(cheng)(cheng)(cheng)料(liao)球(qiu)(qiu),干燥后裝入(ru)以(yi)焦(jiao)炭(tan)(tan)或無煙(yan)煤(mei)為(wei)燃料(liao)的(de)豎(shu)窯內煅(duan)燒(shao)(shao)。裝料(liao)方式是焦(jiao)炭(tan)(tan)或無煙(yan)煤(mei)和料(liao)球(qiu)(qiu)分(fen)層裝入(ru)。我(wo)國遼寧省(sheng)生產(chan)合(he)(he)成(cheng)(cheng)(cheng)鎂鈣(gai)砂(sha)的(de)企(qi)業(ye)中(zhong),大(da)部分(fen)采用該煅(duan)燒(shao)(shao)工(gong)(gong)藝。所用豎(shu)窯的(de)規格一般為(wei)3m×16m。該煅(duan)燒(shao)(shao)工(gong)(gong)藝簡單,產(chan)品成(cheng)(cheng)(cheng)本低(di),但在(zai)煅(duan)燒(shao)(shao)過程(cheng)中(zhong)料(liao)球(qiu)(qiu)和焦(jiao)炭(tan)(tan)混在(zai)一起,焦(jiao)炭(tan)(tan)燃燒(shao)(shao)產(chan)生的(de)灰分(fen)有一部分(fen)混入(ru)到料(liao)球(qiu)(qiu)中(zhong),增(zeng)加了產(chan)品的(de)雜質含量。
3、干法壓球、燃油豎窯煅燒工藝
該煅燒(shao)(shao)工藝用(yong)(yong)(yong)于生產(chan)(chan)高(gao)純(chun)度(du)(du)(du)合成鎂(mei)(mei)鈣(gai)砂。將高(gao)純(chun)度(du)(du)(du)輕(qing)燒(shao)(shao)氧化鎂(mei)(mei)和輕(qing)燒(shao)(shao)白云石配料(liao)、混合磨(mo)細后,直接將干粉料(liao)送入高(gao)壓壓球(qiu)機中干壓成球(qiu),然后再送入高(gao)溫燃(ran)油(you)豎窯(yao)內煅燒(shao)(shao)。這種煅燒(shao)(shao)工藝的優(you)勢(shi)是燃(ran)料(liao)油(you)噴入到(dao)料(liao)層內,在料(liao)層內部(bu)燃(ran)燒(shao)(shao),煅燒(shao)(shao)溫度(du)(du)(du)高(gao),可達(da)到(dao)1800℃以(yi)上;燃(ran)料(liao)燃(ran)燒(shao)(shao)后不產(chan)(chan)生灰分,對(dui)物(wu)料(liao)的純(chun)度(du)(du)(du)沒有影響。目(mu)前,國內采(cai)用(yong)(yong)(yong)該煅燒(shao)(shao)工藝生產(chan)(chan)合成鎂(mei)(mei)鈣(gai)砂的企業,只有南方一家公(gong)司。該公(gong)司燃(ran)油(you)豎窯(yao)的規格為(wei)φ1.75m×11.5m,窯(yao)的工作襯用(yong)(yong)(yong)高(gao)純(chun)度(du)(du)(du)堿(jian)性耐火(huo)制品砌筑,厚度(du)(du)(du)為(wei)350mm。工作襯于窯(yao)體鋼(gang)殼之間(jian)用(yong)(yong)(yong)輕(qing)質保溫磚砌筑。以(yi)重柴油(you)為(wei)燃(ran)料(liao),煅燒(shao)(shao)溫度(du)(du)(du)>1800℃。設計(ji)4排(pai)燒(shao)(shao)嘴(zui)(zui),上下布置,間(jian)距900mm。每排(pai)設計(ji)16支(zhi)燒(shao)(shao)嘴(zui)(zui),沿圓(yuan)周均布。采(cai)用(yong)(yong)(yong)無(wu)冷卻燒(shao)(shao)嘴(zui)(zui),每支(zhi)燒(shao)(shao)嘴(zui)(zui)配一臺(tai)計(ji)量(liang)泵供(gong)油(you),一次空氣由羅茨風機供(gong)應。實際生產(chan)(chan)中使用(yong)(yong)(yong)一排(pai)燒(shao)(shao)嘴(zui)(zui)。連續裝(zhuang)窯(yao)和出窯(yao),全部(bu)自動化控制,生產(chan)(chan)能力。
4、干法壓球、回轉窯(yao)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。