上海合成鎂鈣砂的煅燒工藝和煅燒設備
發布日期:2022-01-21 瀏(liu)覽次數:34747目前我國生產上海合成鎂鈣砂所(suo)使用的原(yuan)料有菱鎂石(shi)(shi)(shi)(shi)、白(bai)云(yun)石(shi)(shi)(shi)(shi)和(he)(he)石(shi)(shi)(shi)(shi)灰(hui)石(shi)(shi)(shi)(shi)。所(suo)采(cai)用的工(gong)(gong)藝(yi)為二(er)步煅燒(shao)、入工(gong)(gong)合成(cheng)工(gong)(gong)藝(yi)。即先將菱鎂石(shi)(shi)(shi)(shi)、白(bai)云(yun)石(shi)(shi)(shi)(shi)和(he)(he)石(shi)(shi)(shi)(shi)灰(hui)石(shi)(shi)(shi)(shi)在較低的溫(wen)度下輕(qing)燒(shao),生(sheng)(sheng)產出輕(qing)燒(shao)氧化(hua)鎂、輕(qing)燒(shao)白(bai)云(yun)石(shi)(shi)(shi)(shi)和(he)(he)生(sheng)(sheng)石(shi)(shi)(shi)(shi)灰(hui)。然后進行配(pei)料、磨細、混料、成(cheng)型,最后經過(guo)高溫(wen)煅燒(shao),煅燒(shao)出不同牌(pai)號的合成(cheng)鎂鈣砂。具體的煅燒(shao)工(gong)(gong)藝(yi)有半(ban)干(gan)(gan)法壓(ya)坯、隧道窯煅燒(shao)工(gong)(gong)藝(yi);半(ban)干(gan)(gan)法壓(ya)球(qiu)、焦炭(tan)豎窯煅燒(shao)工(gong)(gong)藝(yi);干(gan)(gan)法壓(ya)球(qiu)、高溫(wen)燃油豎窯和(he)(he)回(hui)轉窯煅燒(shao)工(gong)(gong)藝(yi)。
1、半干(gan)法壓(ya)坯、隧道窯煅燒工(gong)藝該煅燒工(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、焦炭豎窯煅燒工藝
該煅燒(shao)(shao)(shao)工藝(yi)生(sheng)產(chan)合成鎂鈣砂是以(yi)輕燒(shao)(shao)(shao)白云(yun)石和(he)(he)輕燒(shao)(shao)(shao)氧化鎂為(wei)原料(liao)。將輕燒(shao)(shao)(shao)白云(yun)石和(he)(he)輕燒(shao)(shao)(shao)氧化鎂分(fen)別磨成細粉,計量(liang)(liang)后(hou)按比例(li)加入(ru)(ru)輪碾機(ji)中再加水混合,混好的(de)合成料(liao)在(zai)雙(shuang)輥壓球(qiu)(qiu)機(ji)上(shang)壓成料(liao)球(qiu)(qiu),干燥后(hou)裝(zhuang)入(ru)(ru)以(yi)焦(jiao)炭或無煙(yan)煤為(wei)燃料(liao)的(de)豎(shu)窯(yao)內煅燒(shao)(shao)(shao)。裝(zhuang)料(liao)方式是焦(jiao)炭或無煙(yan)煤和(he)(he)料(liao)球(qiu)(qiu)分(fen)層裝(zhuang)入(ru)(ru)。我國(guo)遼(liao)寧省生(sheng)產(chan)合成鎂鈣砂的(de)企業中,大部分(fen)采(cai)用該煅燒(shao)(shao)(shao)工藝(yi)。所用豎(shu)窯(yao)的(de)規格一般為(wei)3m×16m。該煅燒(shao)(shao)(shao)工藝(yi)簡單,產(chan)品成本(ben)低,但在(zai)煅燒(shao)(shao)(shao)過程中料(liao)球(qiu)(qiu)和(he)(he)焦(jiao)炭混在(zai)一起,焦(jiao)炭燃燒(shao)(shao)(shao)產(chan)生(sheng)的(de)灰分(fen)有(you)一部分(fen)混入(ru)(ru)到料(liao)球(qiu)(qiu)中,增(zeng)加了產(chan)品的(de)雜質(zhi)含量(liang)(liang)。
3、干法壓球、燃油豎(shu)窯煅燒(shao)工藝
該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝用(yong)(yong)于(yu)生(sheng)產高(gao)(gao)(gao)純(chun)度(du)(du)(du)合成(cheng)鎂鈣(gai)砂(sha)。將高(gao)(gao)(gao)純(chun)度(du)(du)(du)輕燒(shao)(shao)(shao)(shao)氧化鎂和輕燒(shao)(shao)(shao)(shao)白云石(shi)配料(liao)、混合磨細后,直接(jie)將干(gan)粉料(liao)送入高(gao)(gao)(gao)壓(ya)(ya)壓(ya)(ya)球機中(zhong)干(gan)壓(ya)(ya)成(cheng)球,然后再送入高(gao)(gao)(gao)溫(wen)燃油(you)(you)(you)(you)豎窯(yao)內(nei)煅(duan)(duan)燒(shao)(shao)(shao)(shao)。這種煅(duan)(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝的優勢是(shi)燃料(liao)油(you)(you)(you)(you)噴入到(dao)料(liao)層內(nei),在(zai)料(liao)層內(nei)部燃燒(shao)(shao)(shao)(shao),煅(duan)(duan)燒(shao)(shao)(shao)(shao)溫(wen)度(du)(du)(du)高(gao)(gao)(gao),可達(da)到(dao)1800℃以(yi)上;燃料(liao)燃燒(shao)(shao)(shao)(shao)后不產生(sheng)灰分,對物料(liao)的純(chun)度(du)(du)(du)沒(mei)有影響。目前,國(guo)內(nei)采用(yong)(yong)該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝生(sheng)產合成(cheng)鎂鈣(gai)砂(sha)的企業,只(zhi)有南方一(yi)家公司(si)。該(gai)公司(si)燃油(you)(you)(you)(you)豎窯(yao)的規格為(wei)φ1.75m×11.5m,窯(yao)的工(gong)(gong)作襯用(yong)(yong)高(gao)(gao)(gao)純(chun)度(du)(du)(du)堿性耐火制品(pin)砌筑,厚度(du)(du)(du)為(wei)350mm。工(gong)(gong)作襯于(yu)窯(yao)體鋼殼之間(jian)用(yong)(yong)輕質(zhi)保溫(wen)磚(zhuan)砌筑。以(yi)重(zhong)柴(chai)油(you)(you)(you)(you)為(wei)燃料(liao),煅(duan)(duan)燒(shao)(shao)(shao)(shao)溫(wen)度(du)(du)(du)>1800℃。設計(ji)4排燒(shao)(shao)(shao)(shao)嘴(zui)(zui),上下布置(zhi),間(jian)距900mm。每(mei)排設計(ji)16支燒(shao)(shao)(shao)(shao)嘴(zui)(zui),沿圓周均布。采用(yong)(yong)無冷卻燒(shao)(shao)(shao)(shao)嘴(zui)(zui),每(mei)支燒(shao)(shao)(shao)(shao)嘴(zui)(zui)配一(yi)臺計(ji)量泵供油(you)(you)(you)(you),一(yi)次空氣由(you)羅茨風機供應。實際生(sheng)產中(zhong)使(shi)用(yong)(yong)一(yi)排燒(shao)(shao)(shao)(shao)嘴(zui)(zui)。連續裝窯(yao)和出(chu)窯(yao),全部自動化控(kong)制,生(sheng)產能力。
4、干法(fa)壓球、回轉窯煅燒工藝
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。