目前我國生產保定合成鎂鈣砂所使用的(de)原料有(you)菱鎂石(shi)(shi)(shi)、白云石(shi)(shi)(shi)和石(shi)(shi)(shi)灰石(shi)(shi)(shi)。所采(cai)用的(de)工(gong)(gong)藝(yi)(yi)為二步煅(duan)燒(shao)、入工(gong)(gong)合(he)成工(gong)(gong)藝(yi)(yi)。即先將菱鎂石(shi)(shi)(shi)、白云石(shi)(shi)(shi)和石(shi)(shi)(shi)灰石(shi)(shi)(shi)在較低的(de)溫(wen)度(du)下輕(qing)燒(shao)，生產(chan)出輕(qing)燒(shao)氧化鎂、輕(qing)燒(shao)白云石(shi)(shi)(shi)和生石(shi)(shi)(shi)灰。然后進行配料、磨細、混(hun)料、成型，最(zui)后經(jing)過高溫(wen)煅(duan)燒(shao)，煅(duan)燒(shao)出不同(tong)牌號(hao)的(de)合(he)成鎂鈣砂。具(ju)體的(de)煅(duan)燒(shao)工(gong)(gong)藝(yi)(yi)有(you)半干法壓(ya)(ya)坯、隧道窯(yao)煅(duan)燒(shao)工(gong)(gong)藝(yi)(yi)；半干法壓(ya)(ya)球(qiu)、焦炭(tan)豎(shu)窯(yao)煅(duan)燒(shao)工(gong)(gong)藝(yi)(yi)；干法壓(ya)(ya)球(qiu)、高溫(wen)燃油豎(shu)窯(yao)和回轉窯(yao)煅(duan)燒(shao)工(gong)(gong)藝(yi)(yi)。

1、半(ban)干法壓坯、隧(sui)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(duan)燒(shao)工藝(yi)

該煅燒(shao)(shao)(shao)工(gong)(gong)藝生(sheng)產(chan)(chan)合(he)成(cheng)(cheng)鎂鈣砂是以(yi)輕燒(shao)(shao)(shao)白云石(shi)和輕燒(shao)(shao)(shao)氧化鎂為(wei)(wei)原料(liao)(liao)(liao)(liao)。將輕燒(shao)(shao)(shao)白云石(shi)和輕燒(shao)(shao)(shao)氧化鎂分(fen)(fen)(fen)別磨成(cheng)(cheng)細(xi)粉(fen)，計量(liang)(liang)后(hou)按(an)比例(li)加入(ru)輪碾機(ji)中再(zai)加水(shui)混合(he)，混好的合(he)成(cheng)(cheng)料(liao)(liao)(liao)(liao)在(zai)雙輥壓球機(ji)上壓成(cheng)(cheng)料(liao)(liao)(liao)(liao)球，干燥后(hou)裝入(ru)以(yi)焦炭(tan)(tan)或無煙煤為(wei)(wei)燃(ran)料(liao)(liao)(liao)(liao)的豎(shu)窯(yao)內煅燒(shao)(shao)(shao)。裝料(liao)(liao)(liao)(liao)方式是焦炭(tan)(tan)或無煙煤和料(liao)(liao)(liao)(liao)球分(fen)(fen)(fen)層裝入(ru)。我(wo)國遼寧省(sheng)生(sheng)產(chan)(chan)合(he)成(cheng)(cheng)鎂鈣砂的企業中，大部(bu)(bu)分(fen)(fen)(fen)采用該煅燒(shao)(shao)(shao)工(gong)(gong)藝。所用豎(shu)窯(yao)的規格一般(ban)為(wei)(wei)3m×16m。該煅燒(shao)(shao)(shao)工(gong)(gong)藝簡單，產(chan)(chan)品成(cheng)(cheng)本低，但在(zai)煅燒(shao)(shao)(shao)過程中料(liao)(liao)(liao)(liao)球和焦炭(tan)(tan)混在(zai)一起，焦炭(tan)(tan)燃(ran)燒(shao)(shao)(shao)產(chan)(chan)生(sheng)的灰分(fen)(fen)(fen)有一部(bu)(bu)分(fen)(fen)(fen)混入(ru)到料(liao)(liao)(liao)(liao)球中，增加了產(chan)(chan)品的雜(za)質含(han)量(liang)(liang)。

3、干法壓球、燃(ran)油豎窯煅燒工藝(yi)

該煅(duan)燒(shao)(shao)(shao)(shao)(shao)工藝(yi)用(yong)(yong)于生(sheng)(sheng)產(chan)高(gao)(gao)(gao)純(chun)度(du)(du)(du)(du)合成鎂鈣砂。將高(gao)(gao)(gao)純(chun)度(du)(du)(du)(du)輕燒(shao)(shao)(shao)(shao)(shao)氧化鎂和輕燒(shao)(shao)(shao)(shao)(shao)白云石配料(liao)、混合磨(mo)細后，直(zhi)接將干粉料(liao)送(song)入(ru)(ru)高(gao)(gao)(gao)壓(ya)壓(ya)球機中干壓(ya)成球，然后再送(song)入(ru)(ru)高(gao)(gao)(gao)溫(wen)(wen)燃油豎窯(yao)內(nei)(nei)煅(duan)燒(shao)(shao)(shao)(shao)(shao)。這種煅(duan)燒(shao)(shao)(shao)(shao)(shao)工藝(yi)的(de)優勢是燃料(liao)油噴入(ru)(ru)到料(liao)層內(nei)(nei)，在料(liao)層內(nei)(nei)部燃燒(shao)(shao)(shao)(shao)(shao)，煅(duan)燒(shao)(shao)(shao)(shao)(shao)溫(wen)(wen)度(du)(du)(du)(du)高(gao)(gao)(gao)，可達到1800℃以(yi)上；燃料(liao)燃燒(shao)(shao)(shao)(shao)(shao)后不產(chan)生(sheng)(sheng)灰分(fen)，對物料(liao)的(de)純(chun)度(du)(du)(du)(du)沒有(you)影響。目前，國(guo)內(nei)(nei)采(cai)用(yong)(yong)該煅(duan)燒(shao)(shao)(shao)(shao)(shao)工藝(yi)生(sheng)(sheng)產(chan)合成鎂鈣砂的(de)企業，只有(you)南方一(yi)家(jia)公(gong)司。該公(gong)司燃油豎窯(yao)的(de)規格為φ1.75m×11.5m，窯(yao)的(de)工作襯用(yong)(yong)高(gao)(gao)(gao)純(chun)度(du)(du)(du)(du)堿性(xing)耐火制品砌筑，厚度(du)(du)(du)(du)為350mm。工作襯于窯(yao)體鋼殼之(zhi)間(jian)用(yong)(yong)輕質(zhi)保溫(wen)(wen)磚砌筑。以(yi)重柴油為燃料(liao)，煅(duan)燒(shao)(shao)(shao)(shao)(shao)溫(wen)(wen)度(du)(du)(du)(du)>1800℃。設計4排(pai)燒(shao)(shao)(shao)(shao)(shao)嘴(zui)，上下布置，間(jian)距900mm。每(mei)排(pai)設計16支燒(shao)(shao)(shao)(shao)(shao)嘴(zui)，沿圓周(zhou)均布。采(cai)用(yong)(yong)無冷卻(que)燒(shao)(shao)(shao)(shao)(shao)嘴(zui)，每(mei)支燒(shao)(shao)(shao)(shao)(shao)嘴(zui)配一(yi)臺計量(liang)泵供(gong)油，一(yi)次空氣由羅茨風機供(gong)應。實際生(sheng)(sheng)產(chan)中使用(yong)(yong)一(yi)排(pai)燒(shao)(shao)(shao)(shao)(shao)嘴(zui)。連續裝(zhuang)窯(yao)和出窯(yao)，全部自(zi)動化控制，生(sheng)(sheng)產(chan)能力。

4、干(gan)法壓(ya)球、回轉窯煅燒工藝

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。