普洱合成鎂鈣砂的煅燒工藝和煅燒設備
發布日(ri)期:2022-01-21 瀏(liu)覽次數:34787目前我國生產普洱合成鎂鈣砂所(suo)(suo)使用的(de)(de)原(yuan)料有菱(ling)(ling)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(suo)(suo)采(cai)用的(de)(de)工(gong)(gong)(gong)藝為二步煅(duan)(duan)(duan)燒(shao)(shao)、入工(gong)(gong)(gong)合成工(gong)(gong)(gong)藝。即先將菱(ling)(ling)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(jiao)低(di)的(de)(de)溫(wen)(wen)度下輕燒(shao)(shao),生產出輕燒(shao)(shao)氧化鎂、輕燒(shao)(shao)白(bai)云石(shi)(shi)(shi)(shi)和生石(shi)(shi)(shi)(shi)灰。然后進行配料、磨(mo)細、混(hun)料、成型,最(zui)后經過高溫(wen)(wen)煅(duan)(duan)(duan)燒(shao)(shao),煅(duan)(duan)(duan)燒(shao)(shao)出不同牌(pai)號的(de)(de)合成鎂鈣砂。具體(ti)的(de)(de)煅(duan)(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)藝有半干法(fa)壓坯、隧(sui)道窯(yao)煅(duan)(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)藝;半干法(fa)壓球、焦炭豎(shu)窯(yao)煅(duan)(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)藝;干法(fa)壓球、高溫(wen)(wen)燃油豎(shu)窯(yao)和回(hui)轉(zhuan)窯(yao)煅(duan)(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)藝。
1、半干法壓坯、隧道窯(yao)煅(duan)燒工藝該煅(duan)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(ya)球、焦炭(tan)豎窯煅(duan)燒工藝
該(gai)煅(duan)燒(shao)(shao)工(gong)藝生(sheng)產合成鎂(mei)鈣砂(sha)是以(yi)輕(qing)燒(shao)(shao)白(bai)云石和輕(qing)燒(shao)(shao)氧(yang)化鎂(mei)為原料(liao)。將輕(qing)燒(shao)(shao)白(bai)云石和輕(qing)燒(shao)(shao)氧(yang)化鎂(mei)分別(bie)磨成細(xi)粉(fen),計量后(hou)(hou)按(an)比例加(jia)入輪(lun)碾機中再加(jia)水(shui)混合,混好的合成料(liao)在(zai)雙輥壓球機上壓成料(liao)球,干燥后(hou)(hou)裝入以(yi)焦炭(tan)或無煙煤為燃料(liao)的豎窯(yao)內煅(duan)燒(shao)(shao)。裝料(liao)方式是焦炭(tan)或無煙煤和料(liao)球分層裝入。我國(guo)遼寧省生(sheng)產合成鎂(mei)鈣砂(sha)的企業中,大(da)部分采用(yong)該(gai)煅(duan)燒(shao)(shao)工(gong)藝。所用(yong)豎窯(yao)的規格一(yi)般為3m×16m。該(gai)煅(duan)燒(shao)(shao)工(gong)藝簡(jian)單,產品成本低,但在(zai)煅(duan)燒(shao)(shao)過程中料(liao)球和焦炭(tan)混在(zai)一(yi)起,焦炭(tan)燃燒(shao)(shao)產生(sheng)的灰分有(you)一(yi)部分混入到(dao)料(liao)球中,增加(jia)了產品的雜質含(han)量。
3、干(gan)法壓球、燃油(you)豎窯煅(duan)燒工藝
該煅(duan)燒(shao)工(gong)藝用(yong)(yong)(yong)于(yu)生產高(gao)純(chun)(chun)度(du)(du)合成(cheng)鎂鈣(gai)砂。將高(gao)純(chun)(chun)度(du)(du)輕(qing)燒(shao)氧(yang)化(hua)鎂和輕(qing)燒(shao)白云石配料(liao)(liao)(liao)、混合磨細后,直接(jie)將干粉料(liao)(liao)(liao)送入高(gao)壓壓球機(ji)中干壓成(cheng)球,然后再送入高(gao)溫燃(ran)油(you)(you)(you)豎窯(yao)內(nei)煅(duan)燒(shao)。這(zhe)種煅(duan)燒(shao)工(gong)藝的(de)優勢是燃(ran)料(liao)(liao)(liao)油(you)(you)(you)噴入到料(liao)(liao)(liao)層內(nei),在料(liao)(liao)(liao)層內(nei)部燃(ran)燒(shao),煅(duan)燒(shao)溫度(du)(du)高(gao),可達到1800℃以上(shang);燃(ran)料(liao)(liao)(liao)燃(ran)燒(shao)后不(bu)產生灰分,對(dui)物(wu)料(liao)(liao)(liao)的(de)純(chun)(chun)度(du)(du)沒(mei)有影響。目前,國內(nei)采(cai)用(yong)(yong)(yong)該煅(duan)燒(shao)工(gong)藝生產合成(cheng)鎂鈣(gai)砂的(de)企業,只(zhi)有南(nan)方一(yi)(yi)家公司。該公司燃(ran)油(you)(you)(you)豎窯(yao)的(de)規格(ge)為(wei)(wei)φ1.75m×11.5m,窯(yao)的(de)工(gong)作(zuo)襯(chen)用(yong)(yong)(yong)高(gao)純(chun)(chun)度(du)(du)堿性(xing)耐(nai)火制(zhi)品砌筑,厚度(du)(du)為(wei)(wei)350mm。工(gong)作(zuo)襯(chen)于(yu)窯(yao)體鋼殼之(zhi)間(jian)用(yong)(yong)(yong)輕(qing)質保溫磚砌筑。以重柴油(you)(you)(you)為(wei)(wei)燃(ran)料(liao)(liao)(liao),煅(duan)燒(shao)溫度(du)(du)>1800℃。設計4排(pai)燒(shao)嘴,上(shang)下布(bu)置(zhi),間(jian)距900mm。每排(pai)設計16支燒(shao)嘴,沿圓周(zhou)均布(bu)。采(cai)用(yong)(yong)(yong)無(wu)冷卻(que)燒(shao)嘴,每支燒(shao)嘴配一(yi)(yi)臺計量(liang)泵供油(you)(you)(you),一(yi)(yi)次(ci)空氣由羅茨風機(ji)供應(ying)。實際生產中使用(yong)(yong)(yong)一(yi)(yi)排(pai)燒(shao)嘴。連續裝窯(yao)和出窯(yao),全部自動化(hua)控制(zhi),生產能力(li)。
4、干法壓(ya)球(qiu)、回轉窯煅燒工(gong)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。