武清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:34953目前我國生產武清合成鎂鈣砂所(suo)使用的(de)(de)原料有(you)(you)菱鎂(mei)石(shi)(shi)(shi)(shi)、白云(yun)(yun)石(shi)(shi)(shi)(shi)和石(shi)(shi)(shi)(shi)灰石(shi)(shi)(shi)(shi)。所(suo)采用的(de)(de)工(gong)藝(yi)為二步煅(duan)燒(shao)(shao)(shao)(shao)、入工(gong)合成(cheng)(cheng)工(gong)藝(yi)。即先將菱鎂(mei)石(shi)(shi)(shi)(shi)、白云(yun)(yun)石(shi)(shi)(shi)(shi)和石(shi)(shi)(shi)(shi)灰石(shi)(shi)(shi)(shi)在(zai)較低的(de)(de)溫(wen)度下輕(qing)燒(shao)(shao)(shao)(shao),生(sheng)產出輕(qing)燒(shao)(shao)(shao)(shao)氧化鎂(mei)、輕(qing)燒(shao)(shao)(shao)(shao)白云(yun)(yun)石(shi)(shi)(shi)(shi)和生(sheng)石(shi)(shi)(shi)(shi)灰。然后進行(xing)配料、磨細、混料、成(cheng)(cheng)型,最后經(jing)過高(gao)溫(wen)煅(duan)燒(shao)(shao)(shao)(shao),煅(duan)燒(shao)(shao)(shao)(shao)出不同(tong)牌號的(de)(de)合成(cheng)(cheng)鎂(mei)鈣砂。具(ju)體的(de)(de)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)藝(yi)有(you)(you)半干(gan)法壓坯(pi)、隧道窯(yao)(yao)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)藝(yi);半干(gan)法壓球、焦炭豎窯(yao)(yao)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)藝(yi);干(gan)法壓球、高(gao)溫(wen)燃油(you)豎窯(yao)(yao)和回轉窯(yao)(yao)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)藝(yi)。
1、半(ban)干法壓坯、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、半干法壓(ya)球、焦(jiao)炭豎窯煅燒工藝
該煅燒(shao)工藝生產(chan)(chan)(chan)合成(cheng)鎂鈣砂(sha)是以輕(qing)燒(shao)白云石和(he)輕(qing)燒(shao)氧化鎂為原(yuan)料(liao)。將輕(qing)燒(shao)白云石和(he)輕(qing)燒(shao)氧化鎂分(fen)(fen)別磨成(cheng)細粉,計(ji)量(liang)后按(an)比例加入輪碾機(ji)中再加水混合,混好(hao)的(de)合成(cheng)料(liao)在雙輥壓球(qiu)(qiu)機(ji)上壓成(cheng)料(liao)球(qiu)(qiu),干燥后裝入以焦(jiao)(jiao)炭(tan)或無煙(yan)煤為燃料(liao)的(de)豎窯(yao)(yao)內煅燒(shao)。裝料(liao)方(fang)式是焦(jiao)(jiao)炭(tan)或無煙(yan)煤和(he)料(liao)球(qiu)(qiu)分(fen)(fen)層裝入。我國遼寧省生產(chan)(chan)(chan)合成(cheng)鎂鈣砂(sha)的(de)企業中,大部分(fen)(fen)采用(yong)(yong)該煅燒(shao)工藝。所用(yong)(yong)豎窯(yao)(yao)的(de)規格一(yi)般為3m×16m。該煅燒(shao)工藝簡單,產(chan)(chan)(chan)品成(cheng)本低(di),但(dan)在煅燒(shao)過程(cheng)中料(liao)球(qiu)(qiu)和(he)焦(jiao)(jiao)炭(tan)混在一(yi)起,焦(jiao)(jiao)炭(tan)燃燒(shao)產(chan)(chan)(chan)生的(de)灰分(fen)(fen)有一(yi)部分(fen)(fen)混入到料(liao)球(qiu)(qiu)中,增加了產(chan)(chan)(chan)品的(de)雜(za)質含量(liang)。
3、干法(fa)壓球、燃油豎窯煅(duan)燒(shao)工藝(yi)
該煅燒(shao)(shao)(shao)(shao)工(gong)(gong)(gong)(gong)藝(yi)用于(yu)生(sheng)產(chan)高純(chun)度(du)(du)(du)合(he)成鎂(mei)鈣(gai)砂。將(jiang)高純(chun)度(du)(du)(du)輕(qing)燒(shao)(shao)(shao)(shao)氧化鎂(mei)和輕(qing)燒(shao)(shao)(shao)(shao)白云石配料(liao)(liao)(liao)、混合(he)磨細后,直接將(jiang)干(gan)粉(fen)料(liao)(liao)(liao)送入高壓(ya)壓(ya)球機中(zhong)干(gan)壓(ya)成球,然(ran)后再送入高溫(wen)(wen)(wen)(wen)燃(ran)油(you)(you)豎窯(yao)內(nei)煅燒(shao)(shao)(shao)(shao)。這(zhe)種煅燒(shao)(shao)(shao)(shao)工(gong)(gong)(gong)(gong)藝(yi)的優勢是燃(ran)料(liao)(liao)(liao)油(you)(you)噴入到料(liao)(liao)(liao)層內(nei),在(zai)料(liao)(liao)(liao)層內(nei)部(bu)燃(ran)燒(shao)(shao)(shao)(shao),煅燒(shao)(shao)(shao)(shao)溫(wen)(wen)(wen)(wen)度(du)(du)(du)高,可達(da)到1800℃以(yi)(yi)上(shang);燃(ran)料(liao)(liao)(liao)燃(ran)燒(shao)(shao)(shao)(shao)后不產(chan)生(sheng)灰分,對物料(liao)(liao)(liao)的純(chun)度(du)(du)(du)沒有(you)影響。目前,國內(nei)采(cai)用該煅燒(shao)(shao)(shao)(shao)工(gong)(gong)(gong)(gong)藝(yi)生(sheng)產(chan)合(he)成鎂(mei)鈣(gai)砂的企業,只有(you)南(nan)方(fang)一(yi)(yi)家(jia)公司。該公司燃(ran)油(you)(you)豎窯(yao)的規格為φ1.75m×11.5m,窯(yao)的工(gong)(gong)(gong)(gong)作襯用高純(chun)度(du)(du)(du)堿(jian)性耐火制品(pin)砌筑(zhu)(zhu),厚度(du)(du)(du)為350mm。工(gong)(gong)(gong)(gong)作襯于(yu)窯(yao)體(ti)鋼殼之間(jian)用輕(qing)質保溫(wen)(wen)(wen)(wen)磚砌筑(zhu)(zhu)。以(yi)(yi)重柴油(you)(you)為燃(ran)料(liao)(liao)(liao),煅燒(shao)(shao)(shao)(shao)溫(wen)(wen)(wen)(wen)度(du)(du)(du)>1800℃。設(she)計4排燒(shao)(shao)(shao)(shao)嘴(zui),上(shang)下布(bu)置(zhi),間(jian)距900mm。每排設(she)計16支燒(shao)(shao)(shao)(shao)嘴(zui),沿圓周均(jun)布(bu)。采(cai)用無冷卻燒(shao)(shao)(shao)(shao)嘴(zui),每支燒(shao)(shao)(shao)(shao)嘴(zui)配一(yi)(yi)臺計量泵供油(you)(you),一(yi)(yi)次空氣(qi)由羅茨風機供應。實際生(sheng)產(chan)中(zhong)使用一(yi)(yi)排燒(shao)(shao)(shao)(shao)嘴(zui)。連續裝窯(yao)和出窯(yao),全部(bu)自動化控制,生(sheng)產(chan)能力。
4、干法(fa)壓球、回(hui)轉窯煅燒工藝(yi)
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。