撫順合成鎂鈣砂的煅燒工藝和煅燒設備
發布日期:2022-01-21 瀏覽(lan)次數:34922目前我國生產撫順合成鎂鈣砂所使(shi)用的原(yuan)料有(you)菱(ling)(ling)鎂石(shi)(shi)(shi)、白云石(shi)(shi)(shi)和(he)(he)石(shi)(shi)(shi)灰石(shi)(shi)(shi)。所采(cai)用的工(gong)(gong)(gong)藝為二步煅(duan)燒、入工(gong)(gong)(gong)合成(cheng)工(gong)(gong)(gong)藝。即先將(jiang)菱(ling)(ling)鎂石(shi)(shi)(shi)、白云石(shi)(shi)(shi)和(he)(he)石(shi)(shi)(shi)灰石(shi)(shi)(shi)在較低的溫(wen)度下輕燒,生產出輕燒氧(yang)化鎂、輕燒白云石(shi)(shi)(shi)和(he)(he)生石(shi)(shi)(shi)灰。然后進行配料、磨細(xi)、混料、成(cheng)型,最后經過高(gao)溫(wen)煅(duan)燒,煅(duan)燒出不同牌號的合成(cheng)鎂鈣砂(sha)。具體(ti)的煅(duan)燒工(gong)(gong)(gong)藝有(you)半(ban)干(gan)法壓(ya)坯(pi)、隧道窯煅(duan)燒工(gong)(gong)(gong)藝;半(ban)干(gan)法壓(ya)球(qiu)(qiu)、焦炭豎(shu)窯煅(duan)燒工(gong)(gong)(gong)藝;干(gan)法壓(ya)球(qiu)(qiu)、高(gao)溫(wen)燃油(you)豎(shu)窯和(he)(he)回轉窯煅(duan)燒工(gong)(gong)(gong)藝。
1、半干法(fa)壓坯、隧道窯(yao)煅(duan)燒工(gong)藝該煅(duan)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、半干法壓(ya)球、焦炭豎窯煅燒工(gong)藝
該煅(duan)燒(shao)(shao)工藝(yi)生(sheng)產(chan)合成(cheng)(cheng)鎂(mei)鈣砂(sha)是(shi)以輕(qing)燒(shao)(shao)白云(yun)石和(he)輕(qing)燒(shao)(shao)氧化(hua)鎂(mei)為原料(liao)。將輕(qing)燒(shao)(shao)白云(yun)石和(he)輕(qing)燒(shao)(shao)氧化(hua)鎂(mei)分(fen)別磨成(cheng)(cheng)細粉,計(ji)量后(hou)按比例加入(ru)(ru)輪碾機中再加水混(hun)(hun)合,混(hun)(hun)好的(de)(de)合成(cheng)(cheng)料(liao)在雙輥壓球機上壓成(cheng)(cheng)料(liao)球,干燥后(hou)裝(zhuang)入(ru)(ru)以焦(jiao)(jiao)炭或無煙(yan)煤為燃(ran)料(liao)的(de)(de)豎(shu)窯(yao)內煅(duan)燒(shao)(shao)。裝(zhuang)料(liao)方(fang)式是(shi)焦(jiao)(jiao)炭或無煙(yan)煤和(he)料(liao)球分(fen)層裝(zhuang)入(ru)(ru)。我國遼(liao)寧(ning)省生(sheng)產(chan)合成(cheng)(cheng)鎂(mei)鈣砂(sha)的(de)(de)企業中,大部分(fen)采(cai)用該煅(duan)燒(shao)(shao)工藝(yi)。所用豎(shu)窯(yao)的(de)(de)規格一(yi)般(ban)為3m×16m。該煅(duan)燒(shao)(shao)工藝(yi)簡單(dan),產(chan)品成(cheng)(cheng)本低,但在煅(duan)燒(shao)(shao)過程中料(liao)球和(he)焦(jiao)(jiao)炭混(hun)(hun)在一(yi)起(qi),焦(jiao)(jiao)炭燃(ran)燒(shao)(shao)產(chan)生(sheng)的(de)(de)灰分(fen)有一(yi)部分(fen)混(hun)(hun)入(ru)(ru)到(dao)料(liao)球中,增加了產(chan)品的(de)(de)雜質含(han)量。
3、干法壓球、燃油(you)豎窯(yao)煅(duan)燒工藝
該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工(gong)藝用(yong)(yong)(yong)于生產高(gao)純度合成(cheng)鎂鈣(gai)砂。將(jiang)高(gao)純度輕(qing)燒(shao)(shao)(shao)(shao)(shao)(shao)氧化(hua)鎂和輕(qing)燒(shao)(shao)(shao)(shao)(shao)(shao)白(bai)云石(shi)配(pei)料(liao)(liao)、混合磨(mo)細后,直接(jie)將(jiang)干粉料(liao)(liao)送(song)入(ru)高(gao)壓壓球機中(zhong)干壓成(cheng)球,然后再送(song)入(ru)高(gao)溫燃油豎窯內(nei)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)。這(zhe)種煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工(gong)藝的(de)優勢是燃料(liao)(liao)油噴入(ru)到料(liao)(liao)層內(nei),在料(liao)(liao)層內(nei)部燃燒(shao)(shao)(shao)(shao)(shao)(shao),煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)溫度高(gao),可(ke)達到1800℃以(yi)上;燃料(liao)(liao)燃燒(shao)(shao)(shao)(shao)(shao)(shao)后不產生灰分,對物料(liao)(liao)的(de)純度沒有影響。目前,國內(nei)采用(yong)(yong)(yong)該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工(gong)藝生產合成(cheng)鎂鈣(gai)砂的(de)企業,只有南方一家公司。該(gai)公司燃油豎窯的(de)規格為φ1.75m×11.5m,窯的(de)工(gong)作襯(chen)(chen)用(yong)(yong)(yong)高(gao)純度堿性(xing)耐火制(zhi)品砌(qi)筑,厚度為350mm。工(gong)作襯(chen)(chen)于窯體鋼殼之(zhi)間用(yong)(yong)(yong)輕(qing)質保(bao)溫磚(zhuan)砌(qi)筑。以(yi)重柴油為燃料(liao)(liao),煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)溫度>1800℃。設(she)計4排燒(shao)(shao)(shao)(shao)(shao)(shao)嘴,上下布置,間距(ju)900mm。每(mei)排設(she)計16支燒(shao)(shao)(shao)(shao)(shao)(shao)嘴,沿圓周均布。采用(yong)(yong)(yong)無冷卻燒(shao)(shao)(shao)(shao)(shao)(shao)嘴,每(mei)支燒(shao)(shao)(shao)(shao)(shao)(shao)嘴配(pei)一臺計量泵供油,一次空氣由羅茨風機供應。實(shi)際生產中(zhong)使用(yong)(yong)(yong)一排燒(shao)(shao)(shao)(shao)(shao)(shao)嘴。連續(xu)裝(zhuang)窯和出窯,全部自(zi)動化(hua)控(kong)制(zhi),生產能力。
4、干法壓球、回轉(zhuan)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。