通州合成鎂鈣砂的煅燒工藝和煅燒設備
發(fa)布日期:2022-01-21 瀏覽次數:34751目前我國生產通州合成鎂鈣砂所(suo)使用的(de)(de)原料(liao)有菱(ling)鎂石(shi)(shi)(shi)、白云石(shi)(shi)(shi)和石(shi)(shi)(shi)灰(hui)石(shi)(shi)(shi)。所(suo)采用的(de)(de)工(gong)(gong)(gong)藝為(wei)二(er)步煅(duan)(duan)燒(shao)(shao)(shao)、入工(gong)(gong)(gong)合(he)成工(gong)(gong)(gong)藝。即先將菱(ling)鎂石(shi)(shi)(shi)、白云石(shi)(shi)(shi)和石(shi)(shi)(shi)灰(hui)石(shi)(shi)(shi)在較低的(de)(de)溫度下輕燒(shao)(shao)(shao),生產(chan)出輕燒(shao)(shao)(shao)氧化鎂、輕燒(shao)(shao)(shao)白云石(shi)(shi)(shi)和生石(shi)(shi)(shi)灰(hui)。然(ran)后(hou)進行配料(liao)、磨(mo)細(xi)、混料(liao)、成型,最后(hou)經過高溫煅(duan)(duan)燒(shao)(shao)(shao),煅(duan)(duan)燒(shao)(shao)(shao)出不同牌(pai)號的(de)(de)合(he)成鎂鈣砂(sha)。具體的(de)(de)煅(duan)(duan)燒(shao)(shao)(shao)工(gong)(gong)(gong)藝有半干法(fa)壓坯、隧(sui)道窯煅(duan)(duan)燒(shao)(shao)(shao)工(gong)(gong)(gong)藝;半干法(fa)壓球(qiu)、焦(jiao)炭豎(shu)窯煅(duan)(duan)燒(shao)(shao)(shao)工(gong)(gong)(gong)藝;干法(fa)壓球(qiu)、高溫燃油豎(shu)窯和回轉(zhuan)窯煅(duan)(duan)燒(shao)(shao)(shao)工(gong)(gong)(gong)藝。
1、半干法壓(ya)坯、隧(sui)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、焦炭豎窯煅燒工藝
該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)工藝(yi)生產(chan)合(he)(he)成(cheng)鎂(mei)鈣砂(sha)是以輕(qing)(qing)燒(shao)(shao)(shao)(shao)(shao)白云(yun)石和輕(qing)(qing)燒(shao)(shao)(shao)(shao)(shao)氧化(hua)鎂(mei)為原料。將(jiang)輕(qing)(qing)燒(shao)(shao)(shao)(shao)(shao)白云(yun)石和輕(qing)(qing)燒(shao)(shao)(shao)(shao)(shao)氧化(hua)鎂(mei)分別(bie)磨成(cheng)細粉(fen),計量(liang)后按比例加(jia)入(ru)輪碾(nian)機中(zhong)再(zai)加(jia)水混合(he)(he),混好的(de)(de)(de)合(he)(he)成(cheng)料在雙輥壓(ya)球(qiu)機上壓(ya)成(cheng)料球(qiu),干燥后裝(zhuang)入(ru)以焦(jiao)(jiao)(jiao)炭或(huo)無(wu)煙煤(mei)為燃料的(de)(de)(de)豎窯內煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)。裝(zhuang)料方式是焦(jiao)(jiao)(jiao)炭或(huo)無(wu)煙煤(mei)和料球(qiu)分層裝(zhuang)入(ru)。我國遼寧(ning)省生產(chan)合(he)(he)成(cheng)鎂(mei)鈣砂(sha)的(de)(de)(de)企業中(zhong),大部(bu)分采用(yong)該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)工藝(yi)。所(suo)用(yong)豎窯的(de)(de)(de)規格(ge)一般(ban)為3m×16m。該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)工藝(yi)簡(jian)單(dan),產(chan)品(pin)成(cheng)本(ben)低,但(dan)在煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)過(guo)程(cheng)中(zhong)料球(qiu)和焦(jiao)(jiao)(jiao)炭混在一起,焦(jiao)(jiao)(jiao)炭燃燒(shao)(shao)(shao)(shao)(shao)產(chan)生的(de)(de)(de)灰(hui)分有一部(bu)分混入(ru)到(dao)料球(qiu)中(zhong),增(zeng)加(jia)了產(chan)品(pin)的(de)(de)(de)雜質含量(liang)。
3、干法(fa)壓球、燃油豎(shu)窯煅(duan)燒(shao)工藝
該(gai)煅(duan)(duan)(duan)燒(shao)(shao)(shao)工藝(yi)用(yong)于生(sheng)產(chan)高(gao)純(chun)度(du)(du)合(he)成鎂鈣(gai)砂。將(jiang)高(gao)純(chun)度(du)(du)輕(qing)(qing)(qing)燒(shao)(shao)(shao)氧化鎂和輕(qing)(qing)(qing)燒(shao)(shao)(shao)白(bai)云石配料(liao)(liao)(liao)、混合(he)磨細后,直接將(jiang)干粉料(liao)(liao)(liao)送入高(gao)壓壓球(qiu)機中干壓成球(qiu),然后再送入高(gao)溫(wen)燃(ran)(ran)(ran)油(you)(you)豎窯內(nei)煅(duan)(duan)(duan)燒(shao)(shao)(shao)。這種煅(duan)(duan)(duan)燒(shao)(shao)(shao)工藝(yi)的(de)優勢是燃(ran)(ran)(ran)料(liao)(liao)(liao)油(you)(you)噴入到料(liao)(liao)(liao)層內(nei),在料(liao)(liao)(liao)層內(nei)部(bu)燃(ran)(ran)(ran)燒(shao)(shao)(shao),煅(duan)(duan)(duan)燒(shao)(shao)(shao)溫(wen)度(du)(du)高(gao),可達到1800℃以(yi)上(shang);燃(ran)(ran)(ran)料(liao)(liao)(liao)燃(ran)(ran)(ran)燒(shao)(shao)(shao)后不產(chan)生(sheng)灰分,對(dui)物(wu)料(liao)(liao)(liao)的(de)純(chun)度(du)(du)沒有影(ying)響。目前,國(guo)內(nei)采用(yong)該(gai)煅(duan)(duan)(duan)燒(shao)(shao)(shao)工藝(yi)生(sheng)產(chan)合(he)成鎂鈣(gai)砂的(de)企(qi)業,只(zhi)有南(nan)方一(yi)家公司。該(gai)公司燃(ran)(ran)(ran)油(you)(you)豎窯的(de)規(gui)格為(wei)φ1.75m×11.5m,窯的(de)工作襯(chen)用(yong)高(gao)純(chun)度(du)(du)堿(jian)性耐火制品砌筑,厚度(du)(du)為(wei)350mm。工作襯(chen)于窯體(ti)鋼殼(ke)之間用(yong)輕(qing)(qing)(qing)質保溫(wen)磚砌筑。以(yi)重柴油(you)(you)為(wei)燃(ran)(ran)(ran)料(liao)(liao)(liao),煅(duan)(duan)(duan)燒(shao)(shao)(shao)溫(wen)度(du)(du)>1800℃。設(she)計(ji)4排燒(shao)(shao)(shao)嘴,上(shang)下布置,間距900mm。每排設(she)計(ji)16支燒(shao)(shao)(shao)嘴,沿圓周均布。采用(yong)無冷卻燒(shao)(shao)(shao)嘴,每支燒(shao)(shao)(shao)嘴配一(yi)臺計(ji)量(liang)泵供油(you)(you),一(yi)次空(kong)氣由(you)羅茨風機供應。實(shi)際生(sheng)產(chan)中使用(yong)一(yi)排燒(shao)(shao)(shao)嘴。連續(xu)裝窯和出窯,全部(bu)自(zi)動化控制,生(sheng)產(chan)能力。
4、干法壓(ya)球、回轉窯煅(duan)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。