遼寧合成鎂鈣砂的煅燒工藝和煅燒設備
發布日期:2022-01-21 瀏覽次數:34606目前我國生產遼寧合成鎂鈣砂所使用的(de)原(yuan)料有菱鎂石(shi)(shi)(shi)、白(bai)(bai)云(yun)(yun)(yun)石(shi)(shi)(shi)和(he)石(shi)(shi)(shi)灰石(shi)(shi)(shi)。所采用的(de)工(gong)(gong)藝(yi)(yi)為二步煅燒、入工(gong)(gong)合成工(gong)(gong)藝(yi)(yi)。即(ji)先將菱鎂石(shi)(shi)(shi)、白(bai)(bai)云(yun)(yun)(yun)石(shi)(shi)(shi)和(he)石(shi)(shi)(shi)灰石(shi)(shi)(shi)在較低的(de)溫度下輕燒,生產出(chu)(chu)輕燒氧(yang)化鎂、輕燒白(bai)(bai)云(yun)(yun)(yun)石(shi)(shi)(shi)和(he)生石(shi)(shi)(shi)灰。然(ran)后(hou)進(jin)行配料、磨(mo)細、混料、成型,最(zui)后(hou)經過高溫煅燒,煅燒出(chu)(chu)不同牌號的(de)合成鎂鈣砂。具體的(de)煅燒工(gong)(gong)藝(yi)(yi)有半(ban)干(gan)法壓(ya)坯、隧道窯煅燒工(gong)(gong)藝(yi)(yi);半(ban)干(gan)法壓(ya)球、焦炭豎窯煅燒工(gong)(gong)藝(yi)(yi);干(gan)法壓(ya)球、高溫燃油(you)豎窯和(he)回(hui)轉窯煅燒工(gong)(gong)藝(yi)(yi)。
1、半(ban)干(gan)法壓坯、隧道窯煅(duan)燒工(gong)藝該煅(duan)燒工(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(fa)壓球、焦炭(tan)豎窯煅燒工藝(yi)
該煅(duan)燒(shao)(shao)(shao)工藝生(sheng)產(chan)(chan)合(he)(he)成鎂(mei)鈣(gai)砂(sha)是以輕(qing)燒(shao)(shao)(shao)白(bai)云(yun)石和(he)輕(qing)燒(shao)(shao)(shao)氧化鎂(mei)為(wei)原料(liao)(liao)(liao)。將輕(qing)燒(shao)(shao)(shao)白(bai)云(yun)石和(he)輕(qing)燒(shao)(shao)(shao)氧化鎂(mei)分(fen)(fen)(fen)別磨(mo)成細粉,計量后按(an)比例加(jia)入(ru)輪碾機中(zhong)再加(jia)水混(hun)合(he)(he),混(hun)好的(de)合(he)(he)成料(liao)(liao)(liao)在(zai)(zai)雙輥壓(ya)球機上(shang)壓(ya)成料(liao)(liao)(liao)球,干燥后裝(zhuang)入(ru)以焦炭或無煙煤為(wei)燃料(liao)(liao)(liao)的(de)豎窯(yao)內(nei)煅(duan)燒(shao)(shao)(shao)。裝(zhuang)料(liao)(liao)(liao)方式(shi)是焦炭或無煙煤和(he)料(liao)(liao)(liao)球分(fen)(fen)(fen)層裝(zhuang)入(ru)。我國遼寧省(sheng)生(sheng)產(chan)(chan)合(he)(he)成鎂(mei)鈣(gai)砂(sha)的(de)企業中(zhong),大部分(fen)(fen)(fen)采用(yong)該煅(duan)燒(shao)(shao)(shao)工藝。所用(yong)豎窯(yao)的(de)規格一般為(wei)3m×16m。該煅(duan)燒(shao)(shao)(shao)工藝簡(jian)單,產(chan)(chan)品成本低,但在(zai)(zai)煅(duan)燒(shao)(shao)(shao)過程(cheng)中(zhong)料(liao)(liao)(liao)球和(he)焦炭混(hun)在(zai)(zai)一起,焦炭燃燒(shao)(shao)(shao)產(chan)(chan)生(sheng)的(de)灰分(fen)(fen)(fen)有一部分(fen)(fen)(fen)混(hun)入(ru)到料(liao)(liao)(liao)球中(zhong),增加(jia)了產(chan)(chan)品的(de)雜(za)質含量。
3、干(gan)法壓球、燃油豎窯煅燒工藝
該煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)(yi)用(yong)(yong)(yong)于生產(chan)(chan)高(gao)(gao)純度(du)(du)(du)合(he)(he)成(cheng)(cheng)鎂(mei)鈣(gai)砂。將高(gao)(gao)純度(du)(du)(du)輕(qing)燒(shao)(shao)(shao)(shao)(shao)(shao)氧化鎂(mei)和輕(qing)燒(shao)(shao)(shao)(shao)(shao)(shao)白云石(shi)配(pei)料(liao)、混合(he)(he)磨細(xi)后(hou),直(zhi)接(jie)將干粉(fen)料(liao)送入高(gao)(gao)壓壓球(qiu)機中(zhong)干壓成(cheng)(cheng)球(qiu),然后(hou)再送入高(gao)(gao)溫燃(ran)油(you)(you)豎窯(yao)內(nei)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)。這(zhe)種煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)(yi)的(de)優勢是燃(ran)料(liao)油(you)(you)噴(pen)入到(dao)料(liao)層(ceng)內(nei),在料(liao)層(ceng)內(nei)部燃(ran)燒(shao)(shao)(shao)(shao)(shao)(shao),煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)溫度(du)(du)(du)高(gao)(gao),可(ke)達到(dao)1800℃以(yi)上;燃(ran)料(liao)燃(ran)燒(shao)(shao)(shao)(shao)(shao)(shao)后(hou)不產(chan)(chan)生灰分,對物料(liao)的(de)純度(du)(du)(du)沒有影響。目前,國內(nei)采用(yong)(yong)(yong)該煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)(yi)生產(chan)(chan)合(he)(he)成(cheng)(cheng)鎂(mei)鈣(gai)砂的(de)企業,只有南方一家(jia)公司。該公司燃(ran)油(you)(you)豎窯(yao)的(de)規(gui)格為φ1.75m×11.5m,窯(yao)的(de)工(gong)(gong)作(zuo)襯用(yong)(yong)(yong)高(gao)(gao)純度(du)(du)(du)堿性(xing)耐火制品(pin)砌筑(zhu),厚度(du)(du)(du)為350mm。工(gong)(gong)作(zuo)襯于窯(yao)體鋼殼之(zhi)間(jian)用(yong)(yong)(yong)輕(qing)質保溫磚砌筑(zhu)。以(yi)重柴(chai)油(you)(you)為燃(ran)料(liao),煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)溫度(du)(du)(du)>1800℃。設計4排(pai)燒(shao)(shao)(shao)(shao)(shao)(shao)嘴,上下布置,間(jian)距900mm。每排(pai)設計16支燒(shao)(shao)(shao)(shao)(shao)(shao)嘴,沿圓周均布。采用(yong)(yong)(yong)無冷卻燒(shao)(shao)(shao)(shao)(shao)(shao)嘴,每支燒(shao)(shao)(shao)(shao)(shao)(shao)嘴配(pei)一臺計量(liang)泵供油(you)(you),一次空氣由羅茨風(feng)機供應。實際生產(chan)(chan)中(zhong)使用(yong)(yong)(yong)一排(pai)燒(shao)(shao)(shao)(shao)(shao)(shao)嘴。連續裝窯(yao)和出窯(yao),全部自動(dong)化控制,生產(chan)(chan)能力(li)。
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。