目前我國生產濱海合成鎂鈣砂所(suo)使用的(de)(de)原料有菱鎂(mei)石(shi)(shi)(shi)、白云(yun)石(shi)(shi)(shi)和(he)石(shi)(shi)(shi)灰石(shi)(shi)(shi)。所(suo)采用的(de)(de)工藝(yi)(yi)為(wei)二步煅(duan)(duan)燒(shao)(shao)(shao)(shao)、入工合成(cheng)工藝(yi)(yi)。即先將菱鎂(mei)石(shi)(shi)(shi)、白云(yun)石(shi)(shi)(shi)和(he)石(shi)(shi)(shi)灰石(shi)(shi)(shi)在較(jiao)低的(de)(de)溫(wen)(wen)度下輕燒(shao)(shao)(shao)(shao)，生(sheng)產出輕燒(shao)(shao)(shao)(shao)氧(yang)化鎂(mei)、輕燒(shao)(shao)(shao)(shao)白云(yun)石(shi)(shi)(shi)和(he)生(sheng)石(shi)(shi)(shi)灰。然后進行配(pei)料、磨細、混料、成(cheng)型(xing)，最后經過高溫(wen)(wen)煅(duan)(duan)燒(shao)(shao)(shao)(shao)，煅(duan)(duan)燒(shao)(shao)(shao)(shao)出不同(tong)牌號的(de)(de)合成(cheng)鎂(mei)鈣砂。具體的(de)(de)煅(duan)(duan)燒(shao)(shao)(shao)(shao)工藝(yi)(yi)有半干法壓(ya)(ya)坯、隧道窯煅(duan)(duan)燒(shao)(shao)(shao)(shao)工藝(yi)(yi)；半干法壓(ya)(ya)球、焦炭豎(shu)窯煅(duan)(duan)燒(shao)(shao)(shao)(shao)工藝(yi)(yi)；干法壓(ya)(ya)球、高溫(wen)(wen)燃油(you)豎(shu)窯和(he)回轉窯煅(duan)(duan)燒(shao)(shao)(shao)(shao)工藝(yi)(yi)。

1、半干法(fa)壓坯、隧道窯煅(duan)燒工(gong)藝(yi)該煅(duan)燒工(gong)藝(yi)

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(tan)豎窯煅燒工藝

該煅(duan)燒(shao)工藝生產(chan)合(he)成(cheng)(cheng)(cheng)鎂鈣砂是(shi)以輕燒(shao)白(bai)云(yun)石和(he)輕燒(shao)氧化鎂為原料(liao)(liao)(liao)。將(jiang)輕燒(shao)白(bai)云(yun)石和(he)輕燒(shao)氧化鎂分(fen)別磨成(cheng)(cheng)(cheng)細粉，計量后按(an)比例加入(ru)(ru)輪碾機(ji)中(zhong)(zhong)再加水(shui)混(hun)(hun)(hun)合(he)，混(hun)(hun)(hun)好的(de)合(he)成(cheng)(cheng)(cheng)料(liao)(liao)(liao)在雙輥壓(ya)球(qiu)機(ji)上壓(ya)成(cheng)(cheng)(cheng)料(liao)(liao)(liao)球(qiu)，干燥后裝(zhuang)入(ru)(ru)以焦炭(tan)或(huo)無(wu)煙煤為燃(ran)料(liao)(liao)(liao)的(de)豎窯內煅(duan)燒(shao)。裝(zhuang)料(liao)(liao)(liao)方(fang)式是(shi)焦炭(tan)或(huo)無(wu)煙煤和(he)料(liao)(liao)(liao)球(qiu)分(fen)層裝(zhuang)入(ru)(ru)。我(wo)國(guo)遼寧省生產(chan)合(he)成(cheng)(cheng)(cheng)鎂鈣砂的(de)企業中(zhong)(zhong)，大部(bu)(bu)分(fen)采用(yong)該煅(duan)燒(shao)工藝。所用(yong)豎窯的(de)規格一(yi)般為3m×16m。該煅(duan)燒(shao)工藝簡(jian)單，產(chan)品成(cheng)(cheng)(cheng)本低，但在煅(duan)燒(shao)過程中(zhong)(zhong)料(liao)(liao)(liao)球(qiu)和(he)焦炭(tan)混(hun)(hun)(hun)在一(yi)起，焦炭(tan)燃(ran)燒(shao)產(chan)生的(de)灰分(fen)有一(yi)部(bu)(bu)分(fen)混(hun)(hun)(hun)入(ru)(ru)到料(liao)(liao)(liao)球(qiu)中(zhong)(zhong)，增(zeng)加了(le)產(chan)品的(de)雜質含量。

3、干法壓球、燃油豎窯煅(duan)燒(shao)工藝

該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)用(yong)(yong)于(yu)生(sheng)產(chan)(chan)高(gao)純度(du)合(he)成鎂(mei)鈣砂。將高(gao)純度(du)輕燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)氧化(hua)鎂(mei)和(he)輕燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)白云石配料(liao)(liao)、混合(he)磨細后(hou)，直接將干(gan)粉料(liao)(liao)送入高(gao)壓(ya)壓(ya)球(qiu)機中干(gan)壓(ya)成球(qiu)，然后(hou)再送入高(gao)溫燃(ran)(ran)(ran)油(you)豎窯內煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)。這種煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)的優勢(shi)是(shi)燃(ran)(ran)(ran)料(liao)(liao)油(you)噴入到(dao)料(liao)(liao)層(ceng)內，在料(liao)(liao)層(ceng)內部(bu)燃(ran)(ran)(ran)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)，煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)溫度(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)(shao)(shao)(shao)(shao)(shao)后(hou)不(bu)產(chan)(chan)生(sheng)灰分，對(dui)物料(liao)(liao)的純度(du)沒(mei)有影響(xiang)。目前，國(guo)內采用(yong)(yong)該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)工(gong)(gong)藝(yi)生(sheng)產(chan)(chan)合(he)成鎂(mei)鈣砂的企(qi)業，只(zhi)有南(nan)方一(yi)(yi)家公司。該(gai)公司燃(ran)(ran)(ran)油(you)豎窯的規(gui)格為(wei)(wei)φ1.75m×11.5m，窯的工(gong)(gong)作襯(chen)用(yong)(yong)高(gao)純度(du)堿(jian)性耐火制(zhi)品砌筑，厚(hou)度(du)為(wei)(wei)350mm。工(gong)(gong)作襯(chen)于(yu)窯體(ti)鋼殼之間(jian)用(yong)(yong)輕質保溫磚砌筑。以重柴油(you)為(wei)(wei)燃(ran)(ran)(ran)料(liao)(liao)，煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)溫度(du)>1800℃。設計(ji)4排燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴，上下(xia)布(bu)置，間(jian)距(ju)900mm。每(mei)排設計(ji)16支燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴，沿圓周(zhou)均布(bu)。采用(yong)(yong)無冷(leng)卻燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴，每(mei)支燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴配一(yi)(yi)臺計(ji)量泵供(gong)油(you)，一(yi)(yi)次空氣由羅茨風(feng)機供(gong)應。實際(ji)生(sheng)產(chan)(chan)中使用(yong)(yong)一(yi)(yi)排燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴。連續裝窯和(he)出窯，全(quan)部(bu)自動(dong)化(hua)控(kong)制(zhi)，生(sheng)產(chan)(chan)能力。

4、干法壓球、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。