牡丹江合成鎂鈣砂的煅燒工藝和煅燒設備
發布日期(qi):2022-01-21 瀏覽次(ci)數:34869目前我國生產牡丹江合成鎂鈣砂所(suo)使用的(de)原料(liao)有(you)菱(ling)鎂(mei)(mei)石(shi)、白(bai)云(yun)石(shi)和(he)(he)石(shi)灰石(shi)。所(suo)采用的(de)工(gong)(gong)藝(yi)為(wei)二步煅(duan)(duan)燒(shao)(shao)、入工(gong)(gong)合成(cheng)(cheng)工(gong)(gong)藝(yi)。即先將菱(ling)鎂(mei)(mei)石(shi)、白(bai)云(yun)石(shi)和(he)(he)石(shi)灰石(shi)在較低(di)的(de)溫度下輕(qing)燒(shao)(shao),生產出(chu)輕(qing)燒(shao)(shao)氧化鎂(mei)(mei)、輕(qing)燒(shao)(shao)白(bai)云(yun)石(shi)和(he)(he)生石(shi)灰。然后進行配料(liao)、磨細、混料(liao)、成(cheng)(cheng)型,最后經過高溫煅(duan)(duan)燒(shao)(shao),煅(duan)(duan)燒(shao)(shao)出(chu)不同牌號的(de)合成(cheng)(cheng)鎂(mei)(mei)鈣砂。具體的(de)煅(duan)(duan)燒(shao)(shao)工(gong)(gong)藝(yi)有(you)半干(gan)法(fa)壓(ya)坯、隧(sui)道(dao)窯(yao)煅(duan)(duan)燒(shao)(shao)工(gong)(gong)藝(yi);半干(gan)法(fa)壓(ya)球、焦炭豎窯(yao)煅(duan)(duan)燒(shao)(shao)工(gong)(gong)藝(yi);干(gan)法(fa)壓(ya)球、高溫燃油豎窯(yao)和(he)(he)回(hui)轉窯(yao)煅(duan)(duan)燒(shao)(shao)工(gong)(gong)藝(yi)。
1、半干(gan)法壓坯(pi)、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、半干法壓(ya)球、焦炭豎窯(yao)煅燒(shao)工藝
該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)(yi)生(sheng)產合(he)成(cheng)鎂(mei)鈣砂(sha)是以輕燒(shao)(shao)(shao)(shao)白云石和輕燒(shao)(shao)(shao)(shao)氧(yang)(yang)化鎂(mei)為原料。將輕燒(shao)(shao)(shao)(shao)白云石和輕燒(shao)(shao)(shao)(shao)氧(yang)(yang)化鎂(mei)分別磨成(cheng)細粉,計(ji)量后按比(bi)例加入(ru)(ru)輪碾機中(zhong)(zhong)再加水混合(he),混好的合(he)成(cheng)料在(zai)(zai)雙(shuang)輥壓(ya)球機上(shang)壓(ya)成(cheng)料球,干燥后裝入(ru)(ru)以焦(jiao)炭(tan)(tan)或(huo)無煙煤為燃料的豎窯內煅(duan)(duan)燒(shao)(shao)(shao)(shao)。裝料方式是焦(jiao)炭(tan)(tan)或(huo)無煙煤和料球分層裝入(ru)(ru)。我國遼寧省生(sheng)產合(he)成(cheng)鎂(mei)鈣砂(sha)的企業中(zhong)(zhong),大部(bu)分采用(yong)該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)(yi)。所用(yong)豎窯的規格一(yi)般為3m×16m。該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)(yi)簡(jian)單,產品成(cheng)本低,但在(zai)(zai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)過程中(zhong)(zhong)料球和焦(jiao)炭(tan)(tan)混在(zai)(zai)一(yi)起,焦(jiao)炭(tan)(tan)燃燒(shao)(shao)(shao)(shao)產生(sheng)的灰分有一(yi)部(bu)分混入(ru)(ru)到料球中(zhong)(zhong),增加了產品的雜質含量。
3、干(gan)法壓球、燃油豎窯(yao)煅(duan)燒工藝
該煅(duan)(duan)燒(shao)(shao)(shao)工(gong)藝(yi)用(yong)于生(sheng)(sheng)(sheng)產(chan)高(gao)(gao)純(chun)度(du)合成(cheng)鎂鈣(gai)砂(sha)。將高(gao)(gao)純(chun)度(du)輕燒(shao)(shao)(shao)氧(yang)化鎂和輕燒(shao)(shao)(shao)白云石配(pei)(pei)料(liao)(liao)、混合磨細后(hou),直接將干粉料(liao)(liao)送(song)入高(gao)(gao)壓壓球機(ji)中干壓成(cheng)球,然(ran)后(hou)再送(song)入高(gao)(gao)溫燃(ran)(ran)油(you)豎窯(yao)(yao)內(nei)煅(duan)(duan)燒(shao)(shao)(shao)。這種煅(duan)(duan)燒(shao)(shao)(shao)工(gong)藝(yi)的(de)優勢是(shi)燃(ran)(ran)料(liao)(liao)油(you)噴入到料(liao)(liao)層內(nei),在料(liao)(liao)層內(nei)部燃(ran)(ran)燒(shao)(shao)(shao),煅(duan)(duan)燒(shao)(shao)(shao)溫度(du)高(gao)(gao),可達(da)到1800℃以上;燃(ran)(ran)料(liao)(liao)燃(ran)(ran)燒(shao)(shao)(shao)后(hou)不產(chan)生(sheng)(sheng)(sheng)灰分,對物料(liao)(liao)的(de)純(chun)度(du)沒有(you)影響(xiang)。目前,國內(nei)采用(yong)該煅(duan)(duan)燒(shao)(shao)(shao)工(gong)藝(yi)生(sheng)(sheng)(sheng)產(chan)合成(cheng)鎂鈣(gai)砂(sha)的(de)企業,只(zhi)有(you)南方(fang)一(yi)家(jia)公司。該公司燃(ran)(ran)油(you)豎窯(yao)(yao)的(de)規(gui)格為(wei)(wei)(wei)φ1.75m×11.5m,窯(yao)(yao)的(de)工(gong)作襯用(yong)高(gao)(gao)純(chun)度(du)堿性耐(nai)火制品砌筑(zhu),厚度(du)為(wei)(wei)(wei)350mm。工(gong)作襯于窯(yao)(yao)體鋼(gang)殼之(zhi)間(jian)用(yong)輕質保溫磚砌筑(zhu)。以重(zhong)柴油(you)為(wei)(wei)(wei)燃(ran)(ran)料(liao)(liao),煅(duan)(duan)燒(shao)(shao)(shao)溫度(du)>1800℃。設(she)計(ji)4排(pai)燒(shao)(shao)(shao)嘴,上下布(bu)置,間(jian)距900mm。每(mei)排(pai)設(she)計(ji)16支燒(shao)(shao)(shao)嘴,沿圓周(zhou)均(jun)布(bu)。采用(yong)無冷卻燒(shao)(shao)(shao)嘴,每(mei)支燒(shao)(shao)(shao)嘴配(pei)(pei)一(yi)臺計(ji)量泵(beng)供油(you),一(yi)次(ci)空氣由(you)羅茨風機(ji)供應。實際生(sheng)(sheng)(sheng)產(chan)中使用(yong)一(yi)排(pai)燒(shao)(shao)(shao)嘴。連續(xu)裝窯(yao)(yao)和出窯(yao)(yao),全(quan)部自動(dong)化控制,生(sheng)(sheng)(sheng)產(chan)能(neng)力。
4、干(gan)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。