深圳合成鎂鈣砂的煅燒工藝和煅燒設備
發布日(ri)期:2022-01-21 瀏覽次數:35958目前我國生產深圳合成鎂鈣砂所(suo)使用(yong)的原料(liao)有菱(ling)鎂石(shi)(shi)、白(bai)(bai)云(yun)石(shi)(shi)和石(shi)(shi)灰石(shi)(shi)。所(suo)采(cai)用(yong)的工(gong)(gong)(gong)藝(yi)(yi)為二步煅(duan)(duan)燒(shao)(shao)、入工(gong)(gong)(gong)合成(cheng)工(gong)(gong)(gong)藝(yi)(yi)。即先(xian)將菱(ling)鎂石(shi)(shi)、白(bai)(bai)云(yun)石(shi)(shi)和石(shi)(shi)灰石(shi)(shi)在較低的溫度下輕燒(shao)(shao),生產出輕燒(shao)(shao)氧化鎂、輕燒(shao)(shao)白(bai)(bai)云(yun)石(shi)(shi)和生石(shi)(shi)灰。然(ran)后進行(xing)配(pei)料(liao)、磨(mo)細、混料(liao)、成(cheng)型,最后經過高溫煅(duan)(duan)燒(shao)(shao),煅(duan)(duan)燒(shao)(shao)出不同牌號(hao)的合成(cheng)鎂鈣砂。具(ju)體的煅(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)藝(yi)(yi)有半干(gan)法(fa)壓坯、隧道窯(yao)煅(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)藝(yi)(yi);半干(gan)法(fa)壓球(qiu)、焦炭豎(shu)窯(yao)煅(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)藝(yi)(yi);干(gan)法(fa)壓球(qiu)、高溫燃油豎(shu)窯(yao)和回(hui)轉窯(yao)煅(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)藝(yi)(yi)。
1、半(ban)干法壓坯、隧道窯(yao)煅(duan)燒(shao)工藝該煅(duan)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、半干法壓球(qiu)、焦炭豎窯煅(duan)燒(shao)工(gong)藝
該(gai)煅燒(shao)工藝(yi)生(sheng)(sheng)產合(he)成(cheng)鎂鈣(gai)(gai)砂(sha)是(shi)以輕(qing)(qing)(qing)燒(shao)白云石和輕(qing)(qing)(qing)燒(shao)氧化鎂為(wei)(wei)原料(liao)(liao)(liao)(liao)(liao)。將輕(qing)(qing)(qing)燒(shao)白云石和輕(qing)(qing)(qing)燒(shao)氧化鎂分別磨成(cheng)細粉,計量后(hou)按比例加(jia)入輪碾機中再(zai)加(jia)水混(hun)合(he),混(hun)好的(de)(de)合(he)成(cheng)料(liao)(liao)(liao)(liao)(liao)在(zai)雙(shuang)輥壓球(qiu)(qiu)機上壓成(cheng)料(liao)(liao)(liao)(liao)(liao)球(qiu)(qiu),干燥后(hou)裝(zhuang)入以焦(jiao)(jiao)炭(tan)(tan)或無煙煤為(wei)(wei)燃料(liao)(liao)(liao)(liao)(liao)的(de)(de)豎窯內煅燒(shao)。裝(zhuang)料(liao)(liao)(liao)(liao)(liao)方式是(shi)焦(jiao)(jiao)炭(tan)(tan)或無煙煤和料(liao)(liao)(liao)(liao)(liao)球(qiu)(qiu)分層裝(zhuang)入。我國遼寧省生(sheng)(sheng)產合(he)成(cheng)鎂鈣(gai)(gai)砂(sha)的(de)(de)企業中,大部分采用該(gai)煅燒(shao)工藝(yi)。所用豎窯的(de)(de)規格一(yi)(yi)般為(wei)(wei)3m×16m。該(gai)煅燒(shao)工藝(yi)簡單,產品成(cheng)本低(di),但在(zai)煅燒(shao)過程(cheng)中料(liao)(liao)(liao)(liao)(liao)球(qiu)(qiu)和焦(jiao)(jiao)炭(tan)(tan)混(hun)在(zai)一(yi)(yi)起,焦(jiao)(jiao)炭(tan)(tan)燃燒(shao)產生(sheng)(sheng)的(de)(de)灰分有一(yi)(yi)部分混(hun)入到料(liao)(liao)(liao)(liao)(liao)球(qiu)(qiu)中,增加(jia)了(le)產品的(de)(de)雜質含量。
3、干法(fa)壓球、燃(ran)油豎窯煅(duan)燒(shao)工藝
該煅燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)工藝用(yong)于生產(chan)高(gao)純(chun)度合成鎂(mei)鈣砂(sha)。將高(gao)純(chun)度輕燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)氧化鎂(mei)和輕燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)白云(yun)石配料(liao)、混(hun)合磨細后,直接(jie)將干粉料(liao)送(song)入(ru)高(gao)壓壓球機中干壓成球,然后再送(song)入(ru)高(gao)溫(wen)(wen)(wen)燃油豎窯(yao)內(nei)煅燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)。這種(zhong)煅燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)工藝的(de)優勢是(shi)燃料(liao)油噴(pen)入(ru)到(dao)(dao)料(liao)層內(nei),在料(liao)層內(nei)部燃燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao),煅燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)溫(wen)(wen)(wen)度高(gao),可(ke)達到(dao)(dao)1800℃以上;燃料(liao)燃燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)后不(bu)產(chan)生灰(hui)分,對物料(liao)的(de)純(chun)度沒有(you)(you)影響。目前,國內(nei)采用(yong)該煅燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)工藝生產(chan)合成鎂(mei)鈣砂(sha)的(de)企業,只有(you)(you)南(nan)方一(yi)家(jia)公(gong)司。該公(gong)司燃油豎窯(yao)的(de)規格(ge)為(wei)φ1.75m×11.5m,窯(yao)的(de)工作襯用(yong)高(gao)純(chun)度堿性耐火制(zhi)品(pin)砌筑(zhu),厚度為(wei)350mm。工作襯于窯(yao)體鋼殼之(zhi)間(jian)用(yong)輕質保溫(wen)(wen)(wen)磚砌筑(zhu)。以重(zhong)柴油為(wei)燃料(liao),煅燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)溫(wen)(wen)(wen)度>1800℃。設(she)計4排(pai)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴,上下布置(zhi),間(jian)距900mm。每排(pai)設(she)計16支(zhi)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴,沿圓周均布。采用(yong)無(wu)冷卻燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴,每支(zhi)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴配一(yi)臺計量泵(beng)供(gong)油,一(yi)次空氣由羅茨風(feng)機供(gong)應。實際生產(chan)中使用(yong)一(yi)排(pai)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴。連續裝窯(yao)和出(chu)窯(yao),全部自動化控制(zhi),生產(chan)能(neng)力。
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。