屯昌合成鎂鈣砂的煅燒工藝和煅燒設備
發(fa)布日(ri)期:2022-01-21 瀏(liu)覽次數:35996目前我國生產屯昌合成鎂鈣砂所使用(yong)(yong)的(de)原料有(you)菱鎂(mei)石(shi)(shi)(shi)、白云(yun)石(shi)(shi)(shi)和(he)石(shi)(shi)(shi)灰石(shi)(shi)(shi)。所采用(yong)(yong)的(de)工(gong)(gong)藝為二步(bu)煅(duan)燒(shao)(shao)(shao)(shao)、入工(gong)(gong)合成(cheng)工(gong)(gong)藝。即先將(jiang)菱鎂(mei)石(shi)(shi)(shi)、白云(yun)石(shi)(shi)(shi)和(he)石(shi)(shi)(shi)灰石(shi)(shi)(shi)在較低的(de)溫度下輕(qing)燒(shao)(shao)(shao)(shao),生(sheng)產出輕(qing)燒(shao)(shao)(shao)(shao)氧化鎂(mei)、輕(qing)燒(shao)(shao)(shao)(shao)白云(yun)石(shi)(shi)(shi)和(he)生(sheng)石(shi)(shi)(shi)灰。然后(hou)進(jin)行配料、磨細(xi)、混料、成(cheng)型,最后(hou)經(jing)過高溫煅(duan)燒(shao)(shao)(shao)(shao),煅(duan)燒(shao)(shao)(shao)(shao)出不同(tong)牌號的(de)合成(cheng)鎂(mei)鈣砂。具體的(de)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝有(you)半干(gan)法(fa)(fa)壓(ya)坯、隧道窯(yao)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝;半干(gan)法(fa)(fa)壓(ya)球(qiu)、焦炭豎窯(yao)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝;干(gan)法(fa)(fa)壓(ya)球(qiu)、高溫燃油豎窯(yao)和(he)回轉窯(yao)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝。
1、半干法壓坯、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(gan)法壓球、焦炭豎窯(yao)煅燒工(gong)藝
該煅燒(shao)(shao)(shao)工藝(yi)生產(chan)合(he)成鎂(mei)鈣(gai)砂(sha)是以輕燒(shao)(shao)(shao)白(bai)云石(shi)和(he)輕燒(shao)(shao)(shao)氧化鎂(mei)為(wei)(wei)原料(liao)(liao)。將輕燒(shao)(shao)(shao)白(bai)云石(shi)和(he)輕燒(shao)(shao)(shao)氧化鎂(mei)分(fen)(fen)別磨(mo)成細(xi)粉,計量后按比(bi)例(li)加入輪(lun)碾機(ji)中再加水(shui)混(hun)(hun)合(he),混(hun)(hun)好的(de)(de)(de)合(he)成料(liao)(liao)在(zai)雙輥壓球(qiu)機(ji)上(shang)壓成料(liao)(liao)球(qiu),干燥(zao)后裝入以焦(jiao)(jiao)炭或無(wu)煙煤為(wei)(wei)燃(ran)料(liao)(liao)的(de)(de)(de)豎窯(yao)內煅燒(shao)(shao)(shao)。裝料(liao)(liao)方式是焦(jiao)(jiao)炭或無(wu)煙煤和(he)料(liao)(liao)球(qiu)分(fen)(fen)層裝入。我(wo)國(guo)遼寧省生產(chan)合(he)成鎂(mei)鈣(gai)砂(sha)的(de)(de)(de)企業(ye)中,大(da)部分(fen)(fen)采(cai)用該煅燒(shao)(shao)(shao)工藝(yi)。所(suo)用豎窯(yao)的(de)(de)(de)規格(ge)一般為(wei)(wei)3m×16m。該煅燒(shao)(shao)(shao)工藝(yi)簡單,產(chan)品成本低,但在(zai)煅燒(shao)(shao)(shao)過(guo)程中料(liao)(liao)球(qiu)和(he)焦(jiao)(jiao)炭混(hun)(hun)在(zai)一起,焦(jiao)(jiao)炭燃(ran)燒(shao)(shao)(shao)產(chan)生的(de)(de)(de)灰分(fen)(fen)有一部分(fen)(fen)混(hun)(hun)入到料(liao)(liao)球(qiu)中,增加了產(chan)品的(de)(de)(de)雜質(zhi)含量。
3、干法壓球、燃(ran)油豎窯煅(duan)燒工(gong)藝
該煅燒(shao)(shao)(shao)(shao)(shao)工藝用(yong)(yong)于生(sheng)產(chan)(chan)高(gao)(gao)純(chun)度合成(cheng)鎂鈣砂。將(jiang)高(gao)(gao)純(chun)度輕燒(shao)(shao)(shao)(shao)(shao)氧化鎂和輕燒(shao)(shao)(shao)(shao)(shao)白云石配料(liao)(liao)、混合磨細后(hou),直接將(jiang)干粉料(liao)(liao)送(song)入高(gao)(gao)壓壓球機(ji)(ji)中干壓成(cheng)球,然(ran)后(hou)再送(song)入高(gao)(gao)溫(wen)燃(ran)油(you)(you)豎窯內煅燒(shao)(shao)(shao)(shao)(shao)。這種煅燒(shao)(shao)(shao)(shao)(shao)工藝的(de)(de)優勢(shi)是燃(ran)料(liao)(liao)油(you)(you)噴(pen)入到料(liao)(liao)層(ceng)內,在料(liao)(liao)層(ceng)內部燃(ran)燒(shao)(shao)(shao)(shao)(shao),煅燒(shao)(shao)(shao)(shao)(shao)溫(wen)度高(gao)(gao),可達到1800℃以上;燃(ran)料(liao)(liao)燃(ran)燒(shao)(shao)(shao)(shao)(shao)后(hou)不產(chan)(chan)生(sheng)灰(hui)分,對物(wu)料(liao)(liao)的(de)(de)純(chun)度沒有影響。目前(qian),國內采用(yong)(yong)該煅燒(shao)(shao)(shao)(shao)(shao)工藝生(sheng)產(chan)(chan)合成(cheng)鎂鈣砂的(de)(de)企(qi)業(ye),只有南(nan)方(fang)一(yi)家公司。該公司燃(ran)油(you)(you)豎窯的(de)(de)規格為φ1.75m×11.5m,窯的(de)(de)工作襯用(yong)(yong)高(gao)(gao)純(chun)度堿性耐火(huo)制(zhi)品砌(qi)筑,厚度為350mm。工作襯于窯體鋼殼之(zhi)間用(yong)(yong)輕質保溫(wen)磚砌(qi)筑。以重柴(chai)油(you)(you)為燃(ran)料(liao)(liao),煅燒(shao)(shao)(shao)(shao)(shao)溫(wen)度>1800℃。設計4排(pai)燒(shao)(shao)(shao)(shao)(shao)嘴(zui),上下布置,間距(ju)900mm。每排(pai)設計16支燒(shao)(shao)(shao)(shao)(shao)嘴(zui),沿圓周均(jun)布。采用(yong)(yong)無冷卻(que)燒(shao)(shao)(shao)(shao)(shao)嘴(zui),每支燒(shao)(shao)(shao)(shao)(shao)嘴(zui)配一(yi)臺計量泵(beng)供(gong)油(you)(you),一(yi)次空氣由羅(luo)茨風機(ji)(ji)供(gong)應(ying)。實際生(sheng)產(chan)(chan)中使用(yong)(yong)一(yi)排(pai)燒(shao)(shao)(shao)(shao)(shao)嘴(zui)。連續裝(zhuang)窯和出窯,全部自動化控(kong)制(zhi),生(sheng)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。