浦東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:34766目前我國生產浦東合成鎂鈣砂所使用(yong)的(de)原料有(you)菱鎂石(shi)(shi)(shi)(shi)、白(bai)云石(shi)(shi)(shi)(shi)和石(shi)(shi)(shi)(shi)灰石(shi)(shi)(shi)(shi)。所采用(yong)的(de)工(gong)(gong)藝(yi)(yi)(yi)為二步煅(duan)燒(shao)(shao)(shao)、入工(gong)(gong)合成工(gong)(gong)藝(yi)(yi)(yi)。即先將菱鎂石(shi)(shi)(shi)(shi)、白(bai)云石(shi)(shi)(shi)(shi)和石(shi)(shi)(shi)(shi)灰石(shi)(shi)(shi)(shi)在較低的(de)溫(wen)度下輕燒(shao)(shao)(shao),生(sheng)產出輕燒(shao)(shao)(shao)氧化鎂、輕燒(shao)(shao)(shao)白(bai)云石(shi)(shi)(shi)(shi)和生(sheng)石(shi)(shi)(shi)(shi)灰。然后進行配料、磨細、混料、成型,最(zui)后經(jing)過高(gao)(gao)溫(wen)煅(duan)燒(shao)(shao)(shao),煅(duan)燒(shao)(shao)(shao)出不同牌號的(de)合成鎂鈣砂。具體的(de)煅(duan)燒(shao)(shao)(shao)工(gong)(gong)藝(yi)(yi)(yi)有(you)半(ban)(ban)干(gan)法壓坯、隧道窯煅(duan)燒(shao)(shao)(shao)工(gong)(gong)藝(yi)(yi)(yi);半(ban)(ban)干(gan)法壓球、焦炭豎窯煅(duan)燒(shao)(shao)(shao)工(gong)(gong)藝(yi)(yi)(yi);干(gan)法壓球、高(gao)(gao)溫(wen)燃油(you)豎窯和回轉(zhuan)窯煅(duan)燒(shao)(shao)(shao)工(gong)(gong)藝(yi)(yi)(yi)。
1、半干法壓坯、隧道窯(yao)煅燒(shao)工藝該煅燒(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(gan)法壓球、焦炭豎窯煅燒(shao)工藝
該(gai)煅(duan)燒(shao)(shao)工藝生(sheng)產(chan)合成(cheng)鎂鈣砂(sha)是以輕(qing)(qing)燒(shao)(shao)白云石和(he)輕(qing)(qing)燒(shao)(shao)氧化(hua)鎂為原(yuan)料(liao)(liao)(liao)(liao)。將(jiang)輕(qing)(qing)燒(shao)(shao)白云石和(he)輕(qing)(qing)燒(shao)(shao)氧化(hua)鎂分別磨成(cheng)細粉,計(ji)量后按比例加入輪碾(nian)機中(zhong)(zhong)再(zai)加水(shui)混合,混好的(de)合成(cheng)料(liao)(liao)(liao)(liao)在(zai)(zai)雙輥(gun)壓(ya)球(qiu)(qiu)機上(shang)壓(ya)成(cheng)料(liao)(liao)(liao)(liao)球(qiu)(qiu),干燥后裝(zhuang)入以焦炭(tan)(tan)或(huo)無煙煤(mei)為燃(ran)料(liao)(liao)(liao)(liao)的(de)豎窯(yao)內(nei)煅(duan)燒(shao)(shao)。裝(zhuang)料(liao)(liao)(liao)(liao)方(fang)式是焦炭(tan)(tan)或(huo)無煙煤(mei)和(he)料(liao)(liao)(liao)(liao)球(qiu)(qiu)分層(ceng)裝(zhuang)入。我國遼寧省生(sheng)產(chan)合成(cheng)鎂鈣砂(sha)的(de)企業中(zhong)(zhong),大部分采用該(gai)煅(duan)燒(shao)(shao)工藝。所用豎窯(yao)的(de)規格一(yi)(yi)(yi)般(ban)為3m×16m。該(gai)煅(duan)燒(shao)(shao)工藝簡單,產(chan)品(pin)成(cheng)本低,但在(zai)(zai)煅(duan)燒(shao)(shao)過程中(zhong)(zhong)料(liao)(liao)(liao)(liao)球(qiu)(qiu)和(he)焦炭(tan)(tan)混在(zai)(zai)一(yi)(yi)(yi)起,焦炭(tan)(tan)燃(ran)燒(shao)(shao)產(chan)生(sheng)的(de)灰分有一(yi)(yi)(yi)部分混入到(dao)料(liao)(liao)(liao)(liao)球(qiu)(qiu)中(zhong)(zhong),增加了(le)產(chan)品(pin)的(de)雜質含量。
3、干法壓(ya)球、燃(ran)油豎窯(yao)煅(duan)燒(shao)工藝
該(gai)煅燒(shao)(shao)(shao)工藝用(yong)(yong)(yong)(yong)于生(sheng)產(chan)高(gao)純(chun)度(du)(du)(du)(du)合成鎂鈣砂。將(jiang)高(gao)純(chun)度(du)(du)(du)(du)輕燒(shao)(shao)(shao)氧化(hua)鎂和輕燒(shao)(shao)(shao)白云(yun)石配料(liao)(liao)、混合磨細后,直接將(jiang)干粉料(liao)(liao)送(song)入(ru)高(gao)壓壓球機中(zhong)干壓成球,然(ran)后再(zai)送(song)入(ru)高(gao)溫(wen)燃(ran)(ran)(ran)油豎(shu)窯(yao)內煅燒(shao)(shao)(shao)。這種煅燒(shao)(shao)(shao)工藝的(de)(de)優勢是燃(ran)(ran)(ran)料(liao)(liao)油噴入(ru)到(dao)料(liao)(liao)層(ceng)內,在料(liao)(liao)層(ceng)內部燃(ran)(ran)(ran)燒(shao)(shao)(shao),煅燒(shao)(shao)(shao)溫(wen)度(du)(du)(du)(du)高(gao),可達到(dao)1800℃以上;燃(ran)(ran)(ran)料(liao)(liao)燃(ran)(ran)(ran)燒(shao)(shao)(shao)后不產(chan)生(sheng)灰分,對(dui)物料(liao)(liao)的(de)(de)純(chun)度(du)(du)(du)(du)沒(mei)有(you)(you)影響。目前,國內采(cai)用(yong)(yong)(yong)(yong)該(gai)煅燒(shao)(shao)(shao)工藝生(sheng)產(chan)合成鎂鈣砂的(de)(de)企業,只有(you)(you)南方一(yi)(yi)(yi)家公司。該(gai)公司燃(ran)(ran)(ran)油豎(shu)窯(yao)的(de)(de)規格為(wei)φ1.75m×11.5m,窯(yao)的(de)(de)工作襯(chen)用(yong)(yong)(yong)(yong)高(gao)純(chun)度(du)(du)(du)(du)堿性耐火制品砌筑,厚度(du)(du)(du)(du)為(wei)350mm。工作襯(chen)于窯(yao)體(ti)鋼殼之(zhi)間用(yong)(yong)(yong)(yong)輕質保溫(wen)磚砌筑。以重柴油為(wei)燃(ran)(ran)(ran)料(liao)(liao),煅燒(shao)(shao)(shao)溫(wen)度(du)(du)(du)(du)>1800℃。設計(ji)4排(pai)(pai)燒(shao)(shao)(shao)嘴,上下(xia)布(bu)置,間距(ju)900mm。每排(pai)(pai)設計(ji)16支燒(shao)(shao)(shao)嘴,沿圓周均(jun)布(bu)。采(cai)用(yong)(yong)(yong)(yong)無冷卻(que)燒(shao)(shao)(shao)嘴,每支燒(shao)(shao)(shao)嘴配一(yi)(yi)(yi)臺計(ji)量泵供油,一(yi)(yi)(yi)次空氣(qi)由(you)羅茨風機供應。實際生(sheng)產(chan)中(zhong)使用(yong)(yong)(yong)(yong)一(yi)(yi)(yi)排(pai)(pai)燒(shao)(shao)(shao)嘴。連(lian)續裝窯(yao)和出窯(yao),全部自動(dong)化(hua)控制,生(sheng)產(chan)能力(li)。
4、干法壓球、回轉窯(yao)煅(duan)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。