臨滄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(ci)數:35970目前我國生產臨滄合成鎂鈣砂所(suo)使用(yong)的(de)(de)原料(liao)有菱(ling)鎂(mei)石(shi)(shi)(shi)(shi)、白云(yun)石(shi)(shi)(shi)(shi)和(he)石(shi)(shi)(shi)(shi)灰(hui)(hui)石(shi)(shi)(shi)(shi)。所(suo)采用(yong)的(de)(de)工藝為(wei)二(er)步煅(duan)(duan)燒(shao)(shao)(shao)、入工合成(cheng)工藝。即先(xian)將(jiang)菱(ling)鎂(mei)石(shi)(shi)(shi)(shi)、白云(yun)石(shi)(shi)(shi)(shi)和(he)石(shi)(shi)(shi)(shi)灰(hui)(hui)石(shi)(shi)(shi)(shi)在較低(di)的(de)(de)溫度下輕燒(shao)(shao)(shao),生(sheng)產出(chu)輕燒(shao)(shao)(shao)氧化鎂(mei)、輕燒(shao)(shao)(shao)白云(yun)石(shi)(shi)(shi)(shi)和(he)生(sheng)石(shi)(shi)(shi)(shi)灰(hui)(hui)。然后進行配(pei)料(liao)、磨(mo)細、混料(liao)、成(cheng)型(xing),最(zui)后經過高溫煅(duan)(duan)燒(shao)(shao)(shao),煅(duan)(duan)燒(shao)(shao)(shao)出(chu)不同牌號(hao)的(de)(de)合成(cheng)鎂(mei)鈣(gai)砂。具體的(de)(de)煅(duan)(duan)燒(shao)(shao)(shao)工藝有半干(gan)(gan)法(fa)壓(ya)坯(pi)、隧道窯(yao)煅(duan)(duan)燒(shao)(shao)(shao)工藝;半干(gan)(gan)法(fa)壓(ya)球(qiu)、焦炭豎窯(yao)煅(duan)(duan)燒(shao)(shao)(shao)工藝;干(gan)(gan)法(fa)壓(ya)球(qiu)、高溫燃油豎窯(yao)和(he)回(hui)轉窯(yao)煅(duan)(duan)燒(shao)(shao)(shao)工藝。
1、半干法壓坯、隧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(gong)藝
該煅燒(shao)工藝生(sheng)(sheng)產(chan)(chan)合(he)成(cheng)鎂鈣砂是以輕(qing)(qing)燒(shao)白(bai)云(yun)(yun)石(shi)和(he)輕(qing)(qing)燒(shao)氧化鎂為(wei)(wei)原料(liao)(liao)(liao)。將輕(qing)(qing)燒(shao)白(bai)云(yun)(yun)石(shi)和(he)輕(qing)(qing)燒(shao)氧化鎂分別磨成(cheng)細粉,計量(liang)后按比例加入輪碾機(ji)中(zhong)(zhong)再(zai)加水混(hun)合(he),混(hun)好的(de)合(he)成(cheng)料(liao)(liao)(liao)在(zai)雙輥壓球機(ji)上(shang)壓成(cheng)料(liao)(liao)(liao)球,干燥后裝入以焦(jiao)炭或無煙(yan)煤為(wei)(wei)燃料(liao)(liao)(liao)的(de)豎窯(yao)(yao)內煅燒(shao)。裝料(liao)(liao)(liao)方式是焦(jiao)炭或無煙(yan)煤和(he)料(liao)(liao)(liao)球分層裝入。我國遼(liao)寧(ning)省生(sheng)(sheng)產(chan)(chan)合(he)成(cheng)鎂鈣砂的(de)企業中(zhong)(zhong),大(da)部分采(cai)用該煅燒(shao)工藝。所用豎窯(yao)(yao)的(de)規格一般(ban)為(wei)(wei)3m×16m。該煅燒(shao)工藝簡(jian)單,產(chan)(chan)品(pin)成(cheng)本低,但在(zai)煅燒(shao)過程中(zhong)(zhong)料(liao)(liao)(liao)球和(he)焦(jiao)炭混(hun)在(zai)一起,焦(jiao)炭燃燒(shao)產(chan)(chan)生(sheng)(sheng)的(de)灰分有(you)一部分混(hun)入到料(liao)(liao)(liao)球中(zhong)(zhong),增加了產(chan)(chan)品(pin)的(de)雜(za)質含量(liang)。
3、干法壓球、燃(ran)油豎(shu)窯煅(duan)燒(shao)工(gong)藝
該煅(duan)(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)用(yong)(yong)(yong)(yong)于生(sheng)(sheng)(sheng)產高(gao)(gao)純度合成鎂(mei)鈣砂(sha)。將(jiang)高(gao)(gao)純度輕燒(shao)(shao)(shao)(shao)氧化鎂(mei)和(he)輕燒(shao)(shao)(shao)(shao)白云石配(pei)料(liao)(liao)(liao)、混合磨細后(hou)(hou),直接將(jiang)干粉料(liao)(liao)(liao)送入高(gao)(gao)壓(ya)壓(ya)球機(ji)中(zhong)干壓(ya)成球,然后(hou)(hou)再送入高(gao)(gao)溫(wen)燃(ran)油豎(shu)(shu)窯(yao)(yao)(yao)內煅(duan)(duan)燒(shao)(shao)(shao)(shao)。這種煅(duan)(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)的(de)(de)優勢是燃(ran)料(liao)(liao)(liao)油噴入到料(liao)(liao)(liao)層(ceng)內,在料(liao)(liao)(liao)層(ceng)內部燃(ran)燒(shao)(shao)(shao)(shao),煅(duan)(duan)燒(shao)(shao)(shao)(shao)溫(wen)度高(gao)(gao),可(ke)達到1800℃以(yi)上;燃(ran)料(liao)(liao)(liao)燃(ran)燒(shao)(shao)(shao)(shao)后(hou)(hou)不產生(sheng)(sheng)(sheng)灰分(fen),對(dui)物料(liao)(liao)(liao)的(de)(de)純度沒有影響(xiang)。目前,國內采用(yong)(yong)(yong)(yong)該煅(duan)(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)生(sheng)(sheng)(sheng)產合成鎂(mei)鈣砂(sha)的(de)(de)企業,只有南方一(yi)(yi)家公司。該公司燃(ran)油豎(shu)(shu)窯(yao)(yao)(yao)的(de)(de)規格為(wei)φ1.75m×11.5m,窯(yao)(yao)(yao)的(de)(de)工(gong)(gong)作(zuo)(zuo)襯用(yong)(yong)(yong)(yong)高(gao)(gao)純度堿性耐火(huo)制品砌(qi)筑(zhu),厚(hou)度為(wei)350mm。工(gong)(gong)作(zuo)(zuo)襯于窯(yao)(yao)(yao)體鋼殼(ke)之間用(yong)(yong)(yong)(yong)輕質保溫(wen)磚砌(qi)筑(zhu)。以(yi)重柴油為(wei)燃(ran)料(liao)(liao)(liao),煅(duan)(duan)燒(shao)(shao)(shao)(shao)溫(wen)度>1800℃。設(she)計(ji)(ji)4排(pai)燒(shao)(shao)(shao)(shao)嘴,上下布置,間距900mm。每排(pai)設(she)計(ji)(ji)16支(zhi)燒(shao)(shao)(shao)(shao)嘴,沿(yan)圓周均布。采用(yong)(yong)(yong)(yong)無冷卻燒(shao)(shao)(shao)(shao)嘴,每支(zhi)燒(shao)(shao)(shao)(shao)嘴配(pei)一(yi)(yi)臺計(ji)(ji)量泵供油,一(yi)(yi)次空氣(qi)由(you)羅茨風機(ji)供應。實際生(sheng)(sheng)(sheng)產中(zhong)使用(yong)(yong)(yong)(yong)一(yi)(yi)排(pai)燒(shao)(shao)(shao)(shao)嘴。連續裝窯(yao)(yao)(yao)和(he)出窯(yao)(yao)(yao),全部自動化控(kong)制,生(sheng)(sheng)(sheng)產能力。
4、干法壓球、回(hui)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。