盤錦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:34688目前我國生產盤錦合成鎂鈣砂所使用的(de)原料(liao)有(you)(you)菱鎂石(shi)(shi)、白云(yun)(yun)石(shi)(shi)和石(shi)(shi)灰(hui)石(shi)(shi)。所采用的(de)工(gong)(gong)藝(yi)(yi)(yi)為二步煅(duan)(duan)燒(shao)、入工(gong)(gong)合(he)成工(gong)(gong)藝(yi)(yi)(yi)。即先將菱鎂石(shi)(shi)、白云(yun)(yun)石(shi)(shi)和石(shi)(shi)灰(hui)石(shi)(shi)在較低(di)的(de)溫(wen)度下輕燒(shao),生產出(chu)(chu)輕燒(shao)氧化(hua)鎂、輕燒(shao)白云(yun)(yun)石(shi)(shi)和生石(shi)(shi)灰(hui)。然(ran)后進(jin)行配料(liao)、磨細(xi)、混料(liao)、成型(xing),最后經過高溫(wen)煅(duan)(duan)燒(shao),煅(duan)(duan)燒(shao)出(chu)(chu)不同牌號的(de)合(he)成鎂鈣砂(sha)。具(ju)體的(de)煅(duan)(duan)燒(shao)工(gong)(gong)藝(yi)(yi)(yi)有(you)(you)半干(gan)法(fa)壓坯、隧道窯煅(duan)(duan)燒(shao)工(gong)(gong)藝(yi)(yi)(yi);半干(gan)法(fa)壓球、焦(jiao)炭豎(shu)窯煅(duan)(duan)燒(shao)工(gong)(gong)藝(yi)(yi)(yi);干(gan)法(fa)壓球、高溫(wen)燃(ran)油豎(shu)窯和回轉窯煅(duan)(duan)燒(shao)工(gong)(gong)藝(yi)(yi)(yi)。
1、半干法壓坯、隧道窯煅燒(shao)工藝該(gai)煅燒(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、半干法壓(ya)球(qiu)、焦炭(tan)豎窯煅(duan)燒工藝
該煅(duan)燒(shao)(shao)工藝生產(chan)(chan)合(he)成(cheng)鎂(mei)鈣砂是(shi)以(yi)輕(qing)(qing)(qing)燒(shao)(shao)白云(yun)石(shi)和(he)輕(qing)(qing)(qing)燒(shao)(shao)氧化鎂(mei)為(wei)(wei)原料(liao)(liao)。將輕(qing)(qing)(qing)燒(shao)(shao)白云(yun)石(shi)和(he)輕(qing)(qing)(qing)燒(shao)(shao)氧化鎂(mei)分(fen)別磨成(cheng)細粉,計量后(hou)按(an)比例(li)加(jia)(jia)入(ru)(ru)輪碾機(ji)中(zhong)再(zai)加(jia)(jia)水混(hun)合(he),混(hun)好的合(he)成(cheng)料(liao)(liao)在雙(shuang)輥壓(ya)球機(ji)上壓(ya)成(cheng)料(liao)(liao)球,干燥(zao)后(hou)裝入(ru)(ru)以(yi)焦炭(tan)或無(wu)煙(yan)煤(mei)為(wei)(wei)燃料(liao)(liao)的豎窯(yao)內煅(duan)燒(shao)(shao)。裝料(liao)(liao)方(fang)式(shi)是(shi)焦炭(tan)或無(wu)煙(yan)煤(mei)和(he)料(liao)(liao)球分(fen)層裝入(ru)(ru)。我國(guo)遼(liao)寧省生產(chan)(chan)合(he)成(cheng)鎂(mei)鈣砂的企業中(zhong),大部分(fen)采用(yong)該煅(duan)燒(shao)(shao)工藝。所(suo)用(yong)豎窯(yao)的規格一般為(wei)(wei)3m×16m。該煅(duan)燒(shao)(shao)工藝簡單,產(chan)(chan)品成(cheng)本低,但(dan)在煅(duan)燒(shao)(shao)過程(cheng)中(zhong)料(liao)(liao)球和(he)焦炭(tan)混(hun)在一起,焦炭(tan)燃燒(shao)(shao)產(chan)(chan)生的灰分(fen)有一部分(fen)混(hun)入(ru)(ru)到(dao)料(liao)(liao)球中(zhong),增(zeng)加(jia)(jia)了產(chan)(chan)品的雜(za)質含量。
3、干法壓球(qiu)、燃油豎窯煅(duan)燒工藝
該(gai)煅(duan)燒(shao)(shao)(shao)工(gong)(gong)(gong)藝用(yong)于生(sheng)產(chan)(chan)(chan)(chan)高(gao)純度(du)合成鎂鈣(gai)砂。將(jiang)高(gao)純度(du)輕(qing)(qing)燒(shao)(shao)(shao)氧化(hua)(hua)鎂和輕(qing)(qing)燒(shao)(shao)(shao)白云石配料(liao)、混(hun)合磨細后,直接將(jiang)干粉(fen)料(liao)送入高(gao)壓壓球(qiu)機(ji)中(zhong)干壓成球(qiu),然后再(zai)送入高(gao)溫(wen)燃(ran)(ran)油(you)豎窯(yao)(yao)(yao)內煅(duan)燒(shao)(shao)(shao)。這種(zhong)煅(duan)燒(shao)(shao)(shao)工(gong)(gong)(gong)藝的(de)優勢是燃(ran)(ran)料(liao)油(you)噴入到料(liao)層內,在料(liao)層內部(bu)燃(ran)(ran)燒(shao)(shao)(shao),煅(duan)燒(shao)(shao)(shao)溫(wen)度(du)高(gao),可達(da)到1800℃以上(shang);燃(ran)(ran)料(liao)燃(ran)(ran)燒(shao)(shao)(shao)后不產(chan)(chan)(chan)(chan)生(sheng)灰分,對物料(liao)的(de)純度(du)沒有(you)影響。目前,國內采用(yong)該(gai)煅(duan)燒(shao)(shao)(shao)工(gong)(gong)(gong)藝生(sheng)產(chan)(chan)(chan)(chan)合成鎂鈣(gai)砂的(de)企業,只有(you)南方一(yi)(yi)(yi)家公(gong)司(si)。該(gai)公(gong)司(si)燃(ran)(ran)油(you)豎窯(yao)(yao)(yao)的(de)規格為(wei)φ1.75m×11.5m,窯(yao)(yao)(yao)的(de)工(gong)(gong)(gong)作襯用(yong)高(gao)純度(du)堿性(xing)耐(nai)火制品(pin)砌筑,厚度(du)為(wei)350mm。工(gong)(gong)(gong)作襯于窯(yao)(yao)(yao)體鋼殼之間用(yong)輕(qing)(qing)質保(bao)溫(wen)磚砌筑。以重柴油(you)為(wei)燃(ran)(ran)料(liao),煅(duan)燒(shao)(shao)(shao)溫(wen)度(du)>1800℃。設(she)計(ji)4排燒(shao)(shao)(shao)嘴(zui)(zui),上(shang)下布(bu)置(zhi),間距900mm。每(mei)(mei)排設(she)計(ji)16支(zhi)燒(shao)(shao)(shao)嘴(zui)(zui),沿圓周均(jun)布(bu)。采用(yong)無冷卻(que)燒(shao)(shao)(shao)嘴(zui)(zui),每(mei)(mei)支(zhi)燒(shao)(shao)(shao)嘴(zui)(zui)配一(yi)(yi)(yi)臺計(ji)量泵(beng)供油(you),一(yi)(yi)(yi)次(ci)空(kong)氣由羅(luo)茨風機(ji)供應(ying)。實際(ji)生(sheng)產(chan)(chan)(chan)(chan)中(zhong)使用(yong)一(yi)(yi)(yi)排燒(shao)(shao)(shao)嘴(zui)(zui)。連續(xu)裝窯(yao)(yao)(yao)和出窯(yao)(yao)(yao),全部(bu)自動化(hua)(hua)控制,生(sheng)產(chan)(chan)(chan)(chan)能力。
4、干法壓球、回(hui)轉窯煅燒(shao)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。