目前我國生產寧河合成鎂鈣砂所使用(yong)的(de)(de)(de)原料(liao)有菱(ling)(ling)鎂石(shi)、白(bai)云石(shi)和石(shi)灰(hui)石(shi)。所采用(yong)的(de)(de)(de)工(gong)(gong)(gong)藝為二(er)步煅(duan)燒(shao)(shao)(shao)、入工(gong)(gong)(gong)合成(cheng)工(gong)(gong)(gong)藝。即先將菱(ling)(ling)鎂石(shi)、白(bai)云石(shi)和石(shi)灰(hui)石(shi)在較低的(de)(de)(de)溫(wen)度下(xia)輕燒(shao)(shao)(shao)，生產(chan)出(chu)(chu)輕燒(shao)(shao)(shao)氧化鎂、輕燒(shao)(shao)(shao)白(bai)云石(shi)和生石(shi)灰(hui)。然后進行(xing)配料(liao)、磨(mo)細(xi)、混料(liao)、成(cheng)型，最后經過高溫(wen)煅(duan)燒(shao)(shao)(shao)，煅(duan)燒(shao)(shao)(shao)出(chu)(chu)不同(tong)牌號的(de)(de)(de)合成(cheng)鎂鈣砂。具體(ti)的(de)(de)(de)煅(duan)燒(shao)(shao)(shao)工(gong)(gong)(gong)藝有半干法(fa)(fa)壓坯、隧道窯(yao)(yao)煅(duan)燒(shao)(shao)(shao)工(gong)(gong)(gong)藝；半干法(fa)(fa)壓球(qiu)、焦(jiao)炭豎(shu)窯(yao)(yao)煅(duan)燒(shao)(shao)(shao)工(gong)(gong)(gong)藝；干法(fa)(fa)壓球(qiu)、高溫(wen)燃油(you)豎(shu)窯(yao)(yao)和回轉窯(yao)(yao)煅(duan)燒(shao)(shao)(shao)工(gong)(gong)(gong)藝。

1、半干法壓(ya)坯、隧道窯煅(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、焦炭豎窯(yao)煅燒(shao)工(gong)藝

該(gai)(gai)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)生(sheng)(sheng)產(chan)合(he)成(cheng)鎂鈣砂是(shi)以(yi)輕燒(shao)(shao)(shao)(shao)白云(yun)石和輕燒(shao)(shao)(shao)(shao)氧化鎂為原料(liao)。將輕燒(shao)(shao)(shao)(shao)白云(yun)石和輕燒(shao)(shao)(shao)(shao)氧化鎂分別磨(mo)成(cheng)細(xi)粉，計量(liang)(liang)后(hou)按比例(li)加入輪碾(nian)機中(zhong)再加水混合(he)，混好(hao)的(de)(de)合(he)成(cheng)料(liao)在(zai)雙輥壓(ya)球(qiu)(qiu)機上壓(ya)成(cheng)料(liao)球(qiu)(qiu)，干燥后(hou)裝(zhuang)入以(yi)焦(jiao)炭(tan)(tan)或無煙(yan)煤(mei)為燃料(liao)的(de)(de)豎窯(yao)內(nei)煅(duan)燒(shao)(shao)(shao)(shao)。裝(zhuang)料(liao)方式是(shi)焦(jiao)炭(tan)(tan)或無煙(yan)煤(mei)和料(liao)球(qiu)(qiu)分層裝(zhuang)入。我(wo)國(guo)遼(liao)寧省生(sheng)(sheng)產(chan)合(he)成(cheng)鎂鈣砂的(de)(de)企業中(zhong)，大部分采用該(gai)(gai)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)。所用豎窯(yao)的(de)(de)規格一般為3m×16m。該(gai)(gai)煅(duan)燒(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)簡(jian)單(dan)，產(chan)品(pin)成(cheng)本低(di)，但在(zai)煅(duan)燒(shao)(shao)(shao)(shao)過(guo)程中(zhong)料(liao)球(qiu)(qiu)和焦(jiao)炭(tan)(tan)混在(zai)一起(qi)，焦(jiao)炭(tan)(tan)燃燒(shao)(shao)(shao)(shao)產(chan)生(sheng)(sheng)的(de)(de)灰分有一部分混入到料(liao)球(qiu)(qiu)中(zhong)，增(zeng)加了(le)產(chan)品(pin)的(de)(de)雜質含量(liang)(liang)。

3、干法壓球(qiu)、燃(ran)油豎窯(yao)煅燒工藝

該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工(gong)(gong)(gong)藝(yi)用于生(sheng)(sheng)(sheng)產(chan)(chan)高純度(du)(du)合成鎂鈣(gai)(gai)砂。將高純度(du)(du)輕燒(shao)(shao)(shao)(shao)(shao)(shao)氧化鎂和輕燒(shao)(shao)(shao)(shao)(shao)(shao)白云石(shi)配料(liao)(liao)、混合磨細后，直接將干(gan)粉(fen)料(liao)(liao)送入高壓(ya)(ya)壓(ya)(ya)球機中(zhong)干(gan)壓(ya)(ya)成球，然后再(zai)送入高溫(wen)燃(ran)(ran)油豎窯(yao)內(nei)(nei)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)。這(zhe)種煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工(gong)(gong)(gong)藝(yi)的(de)優勢是燃(ran)(ran)料(liao)(liao)油噴入到料(liao)(liao)層內(nei)(nei)，在料(liao)(liao)層內(nei)(nei)部燃(ran)(ran)燒(shao)(shao)(shao)(shao)(shao)(shao)，煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)溫(wen)度(du)(du)高，可達到1800℃以(yi)上(shang)；燃(ran)(ran)料(liao)(liao)燃(ran)(ran)燒(shao)(shao)(shao)(shao)(shao)(shao)后不產(chan)(chan)生(sheng)(sheng)(sheng)灰分，對物料(liao)(liao)的(de)純度(du)(du)沒有影響。目前，國內(nei)(nei)采用該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)工(gong)(gong)(gong)藝(yi)生(sheng)(sheng)(sheng)產(chan)(chan)合成鎂鈣(gai)(gai)砂的(de)企(qi)業(ye)，只有南方一(yi)(yi)家公司(si)。該(gai)公司(si)燃(ran)(ran)油豎窯(yao)的(de)規(gui)格(ge)為φ1.75m×11.5m，窯(yao)的(de)工(gong)(gong)(gong)作襯(chen)(chen)用高純度(du)(du)堿性(xing)耐火制(zhi)品砌筑，厚度(du)(du)為350mm。工(gong)(gong)(gong)作襯(chen)(chen)于窯(yao)體鋼殼之間用輕質保溫(wen)磚砌筑。以(yi)重柴油為燃(ran)(ran)料(liao)(liao)，煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)溫(wen)度(du)(du)>1800℃。設(she)計4排(pai)燒(shao)(shao)(shao)(shao)(shao)(shao)嘴，上(shang)下(xia)布(bu)(bu)置，間距900mm。每排(pai)設(she)計16支燒(shao)(shao)(shao)(shao)(shao)(shao)嘴，沿(yan)圓(yuan)周均(jun)布(bu)(bu)。采用無冷卻燒(shao)(shao)(shao)(shao)(shao)(shao)嘴，每支燒(shao)(shao)(shao)(shao)(shao)(shao)嘴配一(yi)(yi)臺(tai)計量泵供(gong)油，一(yi)(yi)次(ci)空氣由羅茨風(feng)機供(gong)應。實際生(sheng)(sheng)(sheng)產(chan)(chan)中(zhong)使用一(yi)(yi)排(pai)燒(shao)(shao)(shao)(shao)(shao)(shao)嘴。連續裝窯(yao)和出窯(yao)，全(quan)部自動(dong)化控制(zhi)，生(sheng)(sheng)(sheng)產(chan)(chan)能(neng)力。

4、干法(fa)壓(ya)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。