北海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(ci)數:36068目前我國生產北海合成鎂鈣砂所使用的(de)(de)原料(liao)(liao)有菱鎂(mei)石(shi)(shi)(shi)(shi)、白(bai)云石(shi)(shi)(shi)(shi)和石(shi)(shi)(shi)(shi)灰石(shi)(shi)(shi)(shi)。所采用的(de)(de)工(gong)(gong)(gong)(gong)藝(yi)為二步煅(duan)燒(shao)(shao)(shao)(shao)、入工(gong)(gong)(gong)(gong)合成(cheng)(cheng)工(gong)(gong)(gong)(gong)藝(yi)。即先(xian)將菱鎂(mei)石(shi)(shi)(shi)(shi)、白(bai)云石(shi)(shi)(shi)(shi)和石(shi)(shi)(shi)(shi)灰石(shi)(shi)(shi)(shi)在較低的(de)(de)溫(wen)度下輕燒(shao)(shao)(shao)(shao),生產出(chu)輕燒(shao)(shao)(shao)(shao)氧化鎂(mei)、輕燒(shao)(shao)(shao)(shao)白(bai)云石(shi)(shi)(shi)(shi)和生石(shi)(shi)(shi)(shi)灰。然后進(jin)行配料(liao)(liao)、磨(mo)細、混料(liao)(liao)、成(cheng)(cheng)型,最后經過(guo)高溫(wen)煅(duan)燒(shao)(shao)(shao)(shao),煅(duan)燒(shao)(shao)(shao)(shao)出(chu)不同牌號的(de)(de)合成(cheng)(cheng)鎂(mei)鈣砂(sha)。具體的(de)(de)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)(gong)(gong)藝(yi)有半干(gan)法壓坯、隧道窯(yao)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)(gong)(gong)藝(yi);半干(gan)法壓球、焦炭豎窯(yao)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)(gong)(gong)藝(yi);干(gan)法壓球、高溫(wen)燃油豎窯(yao)和回轉窯(yao)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)(gong)(gong)藝(yi)。
1、半(ban)干法(fa)壓坯、隧道窯煅燒工藝該煅燒工藝
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、半干法壓球、焦炭豎窯煅燒(shao)工藝
該煅(duan)燒(shao)工藝(yi)生(sheng)產(chan)合(he)成(cheng)鎂鈣(gai)(gai)砂(sha)是(shi)以輕(qing)(qing)燒(shao)白(bai)云石和(he)輕(qing)(qing)燒(shao)氧化鎂為原料(liao)。將輕(qing)(qing)燒(shao)白(bai)云石和(he)輕(qing)(qing)燒(shao)氧化鎂分別磨成(cheng)細粉,計(ji)量(liang)后按比例加入(ru)輪(lun)碾機中再加水混(hun)(hun)合(he),混(hun)(hun)好的(de)(de)合(he)成(cheng)料(liao)在(zai)(zai)雙輥壓球(qiu)機上壓成(cheng)料(liao)球(qiu),干燥后裝入(ru)以焦炭(tan)(tan)(tan)或無煙煤為燃料(liao)的(de)(de)豎(shu)窯內(nei)煅(duan)燒(shao)。裝料(liao)方式是(shi)焦炭(tan)(tan)(tan)或無煙煤和(he)料(liao)球(qiu)分層裝入(ru)。我國遼寧省生(sheng)產(chan)合(he)成(cheng)鎂鈣(gai)(gai)砂(sha)的(de)(de)企業中,大部(bu)分采用(yong)該煅(duan)燒(shao)工藝(yi)。所(suo)用(yong)豎(shu)窯的(de)(de)規(gui)格(ge)一(yi)般為3m×16m。該煅(duan)燒(shao)工藝(yi)簡(jian)單(dan),產(chan)品成(cheng)本低(di),但在(zai)(zai)煅(duan)燒(shao)過程中料(liao)球(qiu)和(he)焦炭(tan)(tan)(tan)混(hun)(hun)在(zai)(zai)一(yi)起,焦炭(tan)(tan)(tan)燃燒(shao)產(chan)生(sheng)的(de)(de)灰(hui)分有一(yi)部(bu)分混(hun)(hun)入(ru)到料(liao)球(qiu)中,增(zeng)加了產(chan)品的(de)(de)雜質含量(liang)。
3、干法壓球、燃(ran)油豎窯煅燒(shao)工藝
該煅(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工藝用(yong)于生(sheng)產高(gao)(gao)純度(du)合成鎂(mei)鈣砂。將高(gao)(gao)純度(du)輕燒(shao)(shao)(shao)(shao)(shao)(shao)氧化鎂(mei)和(he)(he)輕燒(shao)(shao)(shao)(shao)(shao)(shao)白云(yun)石(shi)配(pei)料、混合磨細(xi)后,直接(jie)將干粉料送入(ru)高(gao)(gao)壓壓球機中干壓成球,然后再(zai)送入(ru)高(gao)(gao)溫(wen)燃(ran)油豎(shu)窯(yao)(yao)內煅(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)。這種煅(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工藝的(de)優勢是燃(ran)料油噴入(ru)到(dao)料層內,在料層內部燃(ran)燒(shao)(shao)(shao)(shao)(shao)(shao),煅(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)溫(wen)度(du)高(gao)(gao),可(ke)達到(dao)1800℃以上;燃(ran)料燃(ran)燒(shao)(shao)(shao)(shao)(shao)(shao)后不產生(sheng)灰(hui)分,對物料的(de)純度(du)沒有(you)影響。目(mu)前,國內采(cai)用(yong)該煅(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工藝生(sheng)產合成鎂(mei)鈣砂的(de)企業,只有(you)南(nan)方一(yi)家公司。該公司燃(ran)油豎(shu)窯(yao)(yao)的(de)規格為(wei)φ1.75m×11.5m,窯(yao)(yao)的(de)工作襯(chen)(chen)用(yong)高(gao)(gao)純度(du)堿性耐火(huo)制(zhi)品砌筑,厚度(du)為(wei)350mm。工作襯(chen)(chen)于窯(yao)(yao)體鋼殼之間用(yong)輕質保溫(wen)磚砌筑。以重(zhong)柴油為(wei)燃(ran)料,煅(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)溫(wen)度(du)>1800℃。設(she)計(ji)4排燒(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui),上下布置,間距900mm。每排設(she)計(ji)16支燒(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui),沿圓周(zhou)均布。采(cai)用(yong)無(wu)冷卻燒(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui),每支燒(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui)配(pei)一(yi)臺計(ji)量泵(beng)供油,一(yi)次(ci)空氣(qi)由羅茨(ci)風機供應。實際生(sheng)產中使用(yong)一(yi)排燒(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui)。連續裝(zhuang)窯(yao)(yao)和(he)(he)出窯(yao)(yao),全部自動化控制(zhi),生(sheng)產能力。
4、干法壓球、回轉窯煅燒工藝
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。