江蘇合成鎂鈣砂的煅燒工藝和煅燒設備
發布日期:2022-01-21 瀏覽次(ci)數:34605目前我國生產江蘇合成鎂鈣砂所(suo)使(shi)用的(de)原料(liao)有菱鎂石(shi)(shi)(shi)、白(bai)云石(shi)(shi)(shi)和(he)石(shi)(shi)(shi)灰(hui)石(shi)(shi)(shi)。所(suo)采用的(de)工(gong)(gong)藝(yi)(yi)為二步煅燒(shao)(shao)、入(ru)工(gong)(gong)合(he)(he)成(cheng)工(gong)(gong)藝(yi)(yi)。即(ji)先將(jiang)菱鎂石(shi)(shi)(shi)、白(bai)云石(shi)(shi)(shi)和(he)石(shi)(shi)(shi)灰(hui)石(shi)(shi)(shi)在較低的(de)溫(wen)度(du)下輕(qing)(qing)(qing)燒(shao)(shao),生產出(chu)輕(qing)(qing)(qing)燒(shao)(shao)氧化鎂、輕(qing)(qing)(qing)燒(shao)(shao)白(bai)云石(shi)(shi)(shi)和(he)生石(shi)(shi)(shi)灰(hui)。然后(hou)進(jin)行配料(liao)、磨細、混(hun)料(liao)、成(cheng)型(xing),最后(hou)經過高溫(wen)煅燒(shao)(shao),煅燒(shao)(shao)出(chu)不同牌號的(de)合(he)(he)成(cheng)鎂鈣(gai)砂(sha)。具體的(de)煅燒(shao)(shao)工(gong)(gong)藝(yi)(yi)有半干法(fa)壓坯、隧道窯(yao)(yao)煅燒(shao)(shao)工(gong)(gong)藝(yi)(yi);半干法(fa)壓球、焦炭豎窯(yao)(yao)煅燒(shao)(shao)工(gong)(gong)藝(yi)(yi);干法(fa)壓球、高溫(wen)燃油豎窯(yao)(yao)和(he)回轉窯(yao)(yao)煅燒(shao)(shao)工(gong)(gong)藝(yi)(yi)。
1、半干(gan)法(fa)壓坯(pi)、隧道窯(yao)煅燒(shao)(shao)工藝該(gai)煅燒(shao)(shao)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(ban)干法壓球、焦炭(tan)豎窯煅燒工藝(yi)
該煅(duan)燒(shao)工(gong)藝生產(chan)(chan)合(he)成(cheng)(cheng)(cheng)鎂鈣砂是(shi)(shi)以輕(qing)燒(shao)白(bai)(bai)云石和(he)輕(qing)燒(shao)氧(yang)(yang)化鎂為原料(liao)。將輕(qing)燒(shao)白(bai)(bai)云石和(he)輕(qing)燒(shao)氧(yang)(yang)化鎂分(fen)別磨成(cheng)(cheng)(cheng)細粉,計量(liang)后按比例(li)加(jia)入(ru)輪(lun)碾機中(zhong)再加(jia)水混合(he),混好(hao)的(de)(de)合(he)成(cheng)(cheng)(cheng)料(liao)在(zai)雙輥(gun)壓(ya)球(qiu)機上壓(ya)成(cheng)(cheng)(cheng)料(liao)球(qiu),干(gan)燥后裝(zhuang)入(ru)以焦(jiao)炭(tan)或(huo)無煙(yan)煤為燃料(liao)的(de)(de)豎窯內煅(duan)燒(shao)。裝(zhuang)料(liao)方(fang)式(shi)是(shi)(shi)焦(jiao)炭(tan)或(huo)無煙(yan)煤和(he)料(liao)球(qiu)分(fen)層(ceng)裝(zhuang)入(ru)。我國遼(liao)寧省生產(chan)(chan)合(he)成(cheng)(cheng)(cheng)鎂鈣砂的(de)(de)企業中(zhong),大部分(fen)采(cai)用(yong)該煅(duan)燒(shao)工(gong)藝。所(suo)用(yong)豎窯的(de)(de)規格一(yi)般為3m×16m。該煅(duan)燒(shao)工(gong)藝簡單,產(chan)(chan)品成(cheng)(cheng)(cheng)本低,但在(zai)煅(duan)燒(shao)過程中(zhong)料(liao)球(qiu)和(he)焦(jiao)炭(tan)混在(zai)一(yi)起(qi),焦(jiao)炭(tan)燃燒(shao)產(chan)(chan)生的(de)(de)灰分(fen)有一(yi)部分(fen)混入(ru)到料(liao)球(qiu)中(zhong),增加(jia)了產(chan)(chan)品的(de)(de)雜質含量(liang)。
3、干(gan)法壓球(qiu)、燃油(you)豎窯煅燒工(gong)藝
該(gai)(gai)煅(duan)燒(shao)(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)用(yong)(yong)于生(sheng)(sheng)產高(gao)(gao)純度(du)合成鎂鈣砂(sha)。將高(gao)(gao)純度(du)輕燒(shao)(shao)(shao)(shao)(shao)氧化(hua)鎂和輕燒(shao)(shao)(shao)(shao)(shao)白云(yun)石配料(liao)(liao)、混合磨(mo)細后,直接將干(gan)粉料(liao)(liao)送(song)入高(gao)(gao)壓(ya)壓(ya)球機中干(gan)壓(ya)成球,然后再送(song)入高(gao)(gao)溫燃油(you)豎窯(yao)內(nei)煅(duan)燒(shao)(shao)(shao)(shao)(shao)。這種煅(duan)燒(shao)(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)的(de)(de)優(you)勢(shi)是(shi)燃料(liao)(liao)油(you)噴入到料(liao)(liao)層內(nei),在料(liao)(liao)層內(nei)部燃燒(shao)(shao)(shao)(shao)(shao),煅(duan)燒(shao)(shao)(shao)(shao)(shao)溫度(du)高(gao)(gao),可達到1800℃以(yi)上;燃料(liao)(liao)燃燒(shao)(shao)(shao)(shao)(shao)后不產生(sheng)(sheng)灰分,對物料(liao)(liao)的(de)(de)純度(du)沒有影響。目前,國內(nei)采(cai)用(yong)(yong)該(gai)(gai)煅(duan)燒(shao)(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)生(sheng)(sheng)產合成鎂鈣砂(sha)的(de)(de)企(qi)業(ye),只有南方一(yi)(yi)(yi)家公司。該(gai)(gai)公司燃油(you)豎窯(yao)的(de)(de)規格為φ1.75m×11.5m,窯(yao)的(de)(de)工(gong)(gong)作(zuo)襯(chen)用(yong)(yong)高(gao)(gao)純度(du)堿性耐火制品砌筑(zhu),厚(hou)度(du)為350mm。工(gong)(gong)作(zuo)襯(chen)于窯(yao)體鋼殼之間用(yong)(yong)輕質保溫磚砌筑(zhu)。以(yi)重柴油(you)為燃料(liao)(liao),煅(duan)燒(shao)(shao)(shao)(shao)(shao)溫度(du)>1800℃。設計4排(pai)燒(shao)(shao)(shao)(shao)(shao)嘴,上下布置(zhi),間距900mm。每排(pai)設計16支(zhi)燒(shao)(shao)(shao)(shao)(shao)嘴,沿圓周均布。采(cai)用(yong)(yong)無冷卻燒(shao)(shao)(shao)(shao)(shao)嘴,每支(zhi)燒(shao)(shao)(shao)(shao)(shao)嘴配一(yi)(yi)(yi)臺計量(liang)泵供油(you),一(yi)(yi)(yi)次空氣(qi)由羅茨風機供應。實際(ji)生(sheng)(sheng)產中使(shi)用(yong)(yong)一(yi)(yi)(yi)排(pai)燒(shao)(shao)(shao)(shao)(shao)嘴。連續(xu)裝窯(yao)和出窯(yao),全部自動化(hua)控制,生(sheng)(sheng)產能(neng)力。
4、干法壓(ya)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。