連云港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:34913目前我國生產連云港合成鎂鈣砂所(suo)使用的(de)原料有菱鎂(mei)石(shi)(shi)(shi)(shi)(shi)、白(bai)云石(shi)(shi)(shi)(shi)(shi)和(he)(he)石(shi)(shi)(shi)(shi)(shi)灰石(shi)(shi)(shi)(shi)(shi)。所(suo)采用的(de)工(gong)(gong)藝(yi)為二步煅(duan)(duan)燒(shao)(shao)(shao)、入工(gong)(gong)合成工(gong)(gong)藝(yi)。即先(xian)將菱鎂(mei)石(shi)(shi)(shi)(shi)(shi)、白(bai)云石(shi)(shi)(shi)(shi)(shi)和(he)(he)石(shi)(shi)(shi)(shi)(shi)灰石(shi)(shi)(shi)(shi)(shi)在(zai)較低(di)的(de)溫(wen)度下(xia)輕燒(shao)(shao)(shao),生產出(chu)輕燒(shao)(shao)(shao)氧化鎂(mei)、輕燒(shao)(shao)(shao)白(bai)云石(shi)(shi)(shi)(shi)(shi)和(he)(he)生石(shi)(shi)(shi)(shi)(shi)灰。然后(hou)進行配料、磨細、混(hun)料、成型,最后(hou)經過(guo)高(gao)(gao)溫(wen)煅(duan)(duan)燒(shao)(shao)(shao),煅(duan)(duan)燒(shao)(shao)(shao)出(chu)不(bu)同牌(pai)號的(de)合成鎂(mei)鈣砂(sha)。具體的(de)煅(duan)(duan)燒(shao)(shao)(shao)工(gong)(gong)藝(yi)有半干(gan)(gan)法(fa)壓(ya)(ya)坯、隧(sui)道窯(yao)煅(duan)(duan)燒(shao)(shao)(shao)工(gong)(gong)藝(yi);半干(gan)(gan)法(fa)壓(ya)(ya)球、焦炭豎窯(yao)煅(duan)(duan)燒(shao)(shao)(shao)工(gong)(gong)藝(yi);干(gan)(gan)法(fa)壓(ya)(ya)球、高(gao)(gao)溫(wen)燃油豎窯(yao)和(he)(he)回(hui)轉窯(yao)煅(duan)(duan)燒(shao)(shao)(shao)工(gong)(gong)藝(yi)。
1、半干法壓坯、隧(sui)道窯(yao)煅(duan)燒(shao)工(gong)藝該煅(duan)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)、焦炭豎窯煅燒工(gong)藝
該(gai)煅(duan)(duan)燒(shao)(shao)(shao)工藝生(sheng)產(chan)(chan)合(he)(he)成(cheng)鎂鈣砂是(shi)以(yi)輕燒(shao)(shao)(shao)白(bai)(bai)云石(shi)和(he)輕燒(shao)(shao)(shao)氧化(hua)(hua)鎂為(wei)原料。將輕燒(shao)(shao)(shao)白(bai)(bai)云石(shi)和(he)輕燒(shao)(shao)(shao)氧化(hua)(hua)鎂分(fen)別磨(mo)成(cheng)細(xi)粉,計量后(hou)(hou)按比例(li)加(jia)(jia)入(ru)輪(lun)碾機(ji)中再加(jia)(jia)水混合(he)(he),混好的(de)合(he)(he)成(cheng)料在雙輥(gun)壓(ya)球機(ji)上(shang)壓(ya)成(cheng)料球,干燥(zao)后(hou)(hou)裝入(ru)以(yi)焦(jiao)炭或無(wu)煙煤為(wei)燃(ran)(ran)料的(de)豎窯(yao)內煅(duan)(duan)燒(shao)(shao)(shao)。裝料方式是(shi)焦(jiao)炭或無(wu)煙煤和(he)料球分(fen)層裝入(ru)。我國遼寧省生(sheng)產(chan)(chan)合(he)(he)成(cheng)鎂鈣砂的(de)企(qi)業中,大部分(fen)采(cai)用該(gai)煅(duan)(duan)燒(shao)(shao)(shao)工藝。所用豎窯(yao)的(de)規格一般為(wei)3m×16m。該(gai)煅(duan)(duan)燒(shao)(shao)(shao)工藝簡單,產(chan)(chan)品(pin)成(cheng)本低,但在煅(duan)(duan)燒(shao)(shao)(shao)過程中料球和(he)焦(jiao)炭混在一起,焦(jiao)炭燃(ran)(ran)燒(shao)(shao)(shao)產(chan)(chan)生(sheng)的(de)灰(hui)分(fen)有(you)一部分(fen)混入(ru)到料球中,增加(jia)(jia)了產(chan)(chan)品(pin)的(de)雜質(zhi)含量。
3、干法壓球、燃油(you)豎(shu)窯煅(duan)燒工藝(yi)
該(gai)(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工(gong)藝(yi)用(yong)于(yu)(yu)生產(chan)高(gao)純(chun)度(du)(du)合成鎂(mei)鈣砂。將(jiang)高(gao)純(chun)度(du)(du)輕燒(shao)(shao)(shao)(shao)(shao)(shao)氧化(hua)(hua)鎂(mei)和輕燒(shao)(shao)(shao)(shao)(shao)(shao)白云石配料(liao)(liao)、混合磨細后,直接將(jiang)干粉料(liao)(liao)送入高(gao)壓(ya)壓(ya)球機(ji)(ji)中干壓(ya)成球,然(ran)后再送入高(gao)溫(wen)燃(ran)(ran)(ran)油豎窯(yao)(yao)內煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)。這種(zhong)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工(gong)藝(yi)的優勢是燃(ran)(ran)(ran)料(liao)(liao)油噴(pen)入到料(liao)(liao)層內,在料(liao)(liao)層內部燃(ran)(ran)(ran)燒(shao)(shao)(shao)(shao)(shao)(shao),煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)溫(wen)度(du)(du)高(gao),可(ke)達到1800℃以上;燃(ran)(ran)(ran)料(liao)(liao)燃(ran)(ran)(ran)燒(shao)(shao)(shao)(shao)(shao)(shao)后不產(chan)生灰分,對物料(liao)(liao)的純(chun)度(du)(du)沒有(you)影響。目(mu)前,國(guo)內采(cai)用(yong)該(gai)(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工(gong)藝(yi)生產(chan)合成鎂(mei)鈣砂的企(qi)業,只有(you)南方一家(jia)公司。該(gai)(gai)公司燃(ran)(ran)(ran)油豎窯(yao)(yao)的規格(ge)為φ1.75m×11.5m,窯(yao)(yao)的工(gong)作襯用(yong)高(gao)純(chun)度(du)(du)堿性耐火(huo)制品砌筑(zhu),厚度(du)(du)為350mm。工(gong)作襯于(yu)(yu)窯(yao)(yao)體鋼殼(ke)之間用(yong)輕質保(bao)溫(wen)磚砌筑(zhu)。以重柴油為燃(ran)(ran)(ran)料(liao)(liao),煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)溫(wen)度(du)(du)>1800℃。設(she)計(ji)4排燒(shao)(shao)(shao)(shao)(shao)(shao)嘴,上下布(bu)置,間距(ju)900mm。每排設(she)計(ji)16支燒(shao)(shao)(shao)(shao)(shao)(shao)嘴,沿(yan)圓(yuan)周(zhou)均布(bu)。采(cai)用(yong)無(wu)冷(leng)卻燒(shao)(shao)(shao)(shao)(shao)(shao)嘴,每支燒(shao)(shao)(shao)(shao)(shao)(shao)嘴配一臺計(ji)量泵(beng)供(gong)油,一次空氣由羅茨(ci)風機(ji)(ji)供(gong)應(ying)。實際生產(chan)中使(shi)用(yong)一排燒(shao)(shao)(shao)(shao)(shao)(shao)嘴。連續裝窯(yao)(yao)和出窯(yao)(yao),全部自動化(hua)(hua)控制,生產(chan)能力。
4、干法壓球(qiu)、回轉窯(yao)煅燒工(gong)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。