黑龍江合成鎂鈣砂的煅燒工藝和煅燒設備
發布日(ri)期:2022-01-21 瀏覽(lan)次數:34573目前我國生產黑龍江合成鎂鈣砂所使用的(de)原料(liao)有菱(ling)鎂(mei)石(shi)(shi)、白(bai)云(yun)石(shi)(shi)和(he)石(shi)(shi)灰石(shi)(shi)。所采用的(de)工(gong)(gong)藝(yi)(yi)為二步(bu)煅燒(shao)、入工(gong)(gong)合成(cheng)(cheng)工(gong)(gong)藝(yi)(yi)。即先(xian)將菱(ling)鎂(mei)石(shi)(shi)、白(bai)云(yun)石(shi)(shi)和(he)石(shi)(shi)灰石(shi)(shi)在較低的(de)溫度下輕燒(shao),生產出輕燒(shao)氧化鎂(mei)、輕燒(shao)白(bai)云(yun)石(shi)(shi)和(he)生石(shi)(shi)灰。然后進(jin)行配(pei)料(liao)、磨細(xi)、混料(liao)、成(cheng)(cheng)型,最后經過(guo)高溫煅燒(shao),煅燒(shao)出不同牌號(hao)的(de)合成(cheng)(cheng)鎂(mei)鈣砂。具體(ti)的(de)煅燒(shao)工(gong)(gong)藝(yi)(yi)有半干法(fa)(fa)壓坯、隧道窯(yao)(yao)煅燒(shao)工(gong)(gong)藝(yi)(yi);半干法(fa)(fa)壓球、焦炭豎窯(yao)(yao)煅燒(shao)工(gong)(gong)藝(yi)(yi);干法(fa)(fa)壓球、高溫燃(ran)油豎窯(yao)(yao)和(he)回(hui)轉(zhuan)窯(yao)(yao)煅燒(shao)工(gong)(gong)藝(yi)(yi)。
1、半(ban)干法壓坯、隧道窯煅燒(shao)工(gong)藝該煅燒(shao)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、半干法壓球(qiu)、焦炭(tan)豎窯(yao)煅(duan)燒工藝(yi)
該(gai)煅燒(shao)(shao)工藝(yi)生(sheng)產(chan)(chan)合成(cheng)鎂(mei)(mei)鈣砂是(shi)以(yi)輕(qing)燒(shao)(shao)白(bai)云石(shi)和輕(qing)燒(shao)(shao)氧化(hua)鎂(mei)(mei)為(wei)原料。將(jiang)輕(qing)燒(shao)(shao)白(bai)云石(shi)和輕(qing)燒(shao)(shao)氧化(hua)鎂(mei)(mei)分別磨成(cheng)細(xi)粉(fen),計(ji)量(liang)后按比例(li)加入輪碾機中(zhong)再加水混合,混好的(de)(de)(de)合成(cheng)料在(zai)雙(shuang)輥壓(ya)(ya)球(qiu)(qiu)(qiu)機上壓(ya)(ya)成(cheng)料球(qiu)(qiu)(qiu),干燥后裝(zhuang)入以(yi)焦(jiao)炭或(huo)無煙煤(mei)(mei)為(wei)燃(ran)料的(de)(de)(de)豎窯內煅燒(shao)(shao)。裝(zhuang)料方式(shi)是(shi)焦(jiao)炭或(huo)無煙煤(mei)(mei)和料球(qiu)(qiu)(qiu)分層裝(zhuang)入。我國遼寧省生(sheng)產(chan)(chan)合成(cheng)鎂(mei)(mei)鈣砂的(de)(de)(de)企業(ye)中(zhong),大部(bu)分采用該(gai)煅燒(shao)(shao)工藝(yi)。所用豎窯的(de)(de)(de)規(gui)格一般為(wei)3m×16m。該(gai)煅燒(shao)(shao)工藝(yi)簡單,產(chan)(chan)品(pin)成(cheng)本低,但在(zai)煅燒(shao)(shao)過程中(zhong)料球(qiu)(qiu)(qiu)和焦(jiao)炭混在(zai)一起,焦(jiao)炭燃(ran)燒(shao)(shao)產(chan)(chan)生(sheng)的(de)(de)(de)灰分有(you)一部(bu)分混入到(dao)料球(qiu)(qiu)(qiu)中(zhong),增加了(le)產(chan)(chan)品(pin)的(de)(de)(de)雜質含量(liang)。
3、干法壓球(qiu)、燃油豎窯煅燒工藝(yi)
該煅(duan)燒(shao)(shao)(shao)(shao)(shao)工(gong)藝(yi)用(yong)于生(sheng)產高(gao)純(chun)度(du)合成(cheng)(cheng)鎂鈣(gai)砂(sha)。將(jiang)高(gao)純(chun)度(du)輕燒(shao)(shao)(shao)(shao)(shao)氧化(hua)(hua)鎂和輕燒(shao)(shao)(shao)(shao)(shao)白云石配料、混合磨細后(hou),直接將(jiang)干(gan)粉料送入高(gao)壓壓球(qiu)(qiu)機(ji)中(zhong)干(gan)壓成(cheng)(cheng)球(qiu)(qiu),然后(hou)再(zai)送入高(gao)溫(wen)燃(ran)油豎窯內(nei)煅(duan)燒(shao)(shao)(shao)(shao)(shao)。這(zhe)種煅(duan)燒(shao)(shao)(shao)(shao)(shao)工(gong)藝(yi)的優勢是燃(ran)料油噴入到(dao)料層(ceng)內(nei),在料層(ceng)內(nei)部燃(ran)燒(shao)(shao)(shao)(shao)(shao),煅(duan)燒(shao)(shao)(shao)(shao)(shao)溫(wen)度(du)高(gao),可達到(dao)1800℃以上;燃(ran)料燃(ran)燒(shao)(shao)(shao)(shao)(shao)后(hou)不產生(sheng)灰(hui)分,對物料的純(chun)度(du)沒有影(ying)響。目(mu)前,國內(nei)采用(yong)該煅(duan)燒(shao)(shao)(shao)(shao)(shao)工(gong)藝(yi)生(sheng)產合成(cheng)(cheng)鎂鈣(gai)砂(sha)的企業(ye),只(zhi)有南方(fang)一家公(gong)司。該公(gong)司燃(ran)油豎窯的規(gui)格為φ1.75m×11.5m,窯的工(gong)作襯(chen)用(yong)高(gao)純(chun)度(du)堿性耐(nai)火制品(pin)砌(qi)筑,厚度(du)為350mm。工(gong)作襯(chen)于窯體鋼殼(ke)之間用(yong)輕質保溫(wen)磚(zhuan)砌(qi)筑。以重柴油為燃(ran)料,煅(duan)燒(shao)(shao)(shao)(shao)(shao)溫(wen)度(du)>1800℃。設計4排燒(shao)(shao)(shao)(shao)(shao)嘴(zui),上下布置(zhi),間距900mm。每排設計16支(zhi)燒(shao)(shao)(shao)(shao)(shao)嘴(zui),沿圓周均布。采用(yong)無冷卻燒(shao)(shao)(shao)(shao)(shao)嘴(zui),每支(zhi)燒(shao)(shao)(shao)(shao)(shao)嘴(zui)配一臺計量泵供油,一次空氣由羅(luo)茨風機(ji)供應。實際生(sheng)產中(zhong)使用(yong)一排燒(shao)(shao)(shao)(shao)(shao)嘴(zui)。連(lian)續裝窯和出(chu)窯,全(quan)部自動(dong)化(hua)(hua)控制,生(sheng)產能力。
4、干法壓球(qiu)、回(hui)轉窯煅(duan)燒(shao)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。