目前我國生產大慶合成鎂鈣砂所(suo)使用的原料有菱鎂(mei)(mei)石(shi)、白云石(shi)和石(shi)灰(hui)石(shi)。所(suo)采(cai)用的工(gong)(gong)藝為二步煅燒、入工(gong)(gong)合(he)成(cheng)(cheng)工(gong)(gong)藝。即(ji)先(xian)將(jiang)菱鎂(mei)(mei)石(shi)、白云石(shi)和石(shi)灰(hui)石(shi)在較低的溫度(du)下輕(qing)燒，生產出輕(qing)燒氧化鎂(mei)(mei)、輕(qing)燒白云石(shi)和生石(shi)灰(hui)。然后進行配料、磨細、混料、成(cheng)(cheng)型，最后經過高溫煅燒，煅燒出不同牌(pai)號的合(he)成(cheng)(cheng)鎂(mei)(mei)鈣(gai)砂(sha)。具體(ti)的煅燒工(gong)(gong)藝有半(ban)干法(fa)壓(ya)坯、隧(sui)道窯(yao)(yao)煅燒工(gong)(gong)藝；半(ban)干法(fa)壓(ya)球(qiu)、焦炭豎(shu)窯(yao)(yao)煅燒工(gong)(gong)藝；干法(fa)壓(ya)球(qiu)、高溫燃(ran)油豎(shu)窯(yao)(yao)和回轉(zhuan)窯(yao)(yao)煅燒工(gong)(gong)藝。

1、半(ban)干法壓坯、隧道窯煅(duan)燒(shao)工(gong)藝(yi)該煅(duan)燒(shao)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、焦炭豎窯(yao)煅燒工藝(yi)

該煅燒(shao)(shao)(shao)工(gong)(gong)藝(yi)(yi)生產合(he)成鎂鈣砂是以(yi)(yi)輕(qing)(qing)燒(shao)(shao)(shao)白云(yun)石(shi)和輕(qing)(qing)燒(shao)(shao)(shao)氧(yang)化(hua)鎂為原料(liao)。將輕(qing)(qing)燒(shao)(shao)(shao)白云(yun)石(shi)和輕(qing)(qing)燒(shao)(shao)(shao)氧(yang)化(hua)鎂分(fen)別磨成細粉，計量后按比例加入(ru)(ru)(ru)輪碾機中(zhong)(zhong)(zhong)再(zai)加水混合(he)，混好的(de)合(he)成料(liao)在(zai)(zai)雙(shuang)輥壓(ya)球機上壓(ya)成料(liao)球，干燥后裝入(ru)(ru)(ru)以(yi)(yi)焦炭(tan)或(huo)(huo)無煙煤(mei)為燃料(liao)的(de)豎窯(yao)內(nei)煅燒(shao)(shao)(shao)。裝料(liao)方式是焦炭(tan)或(huo)(huo)無煙煤(mei)和料(liao)球分(fen)層裝入(ru)(ru)(ru)。我國遼寧省(sheng)生產合(he)成鎂鈣砂的(de)企業中(zhong)(zhong)(zhong)，大部分(fen)采用(yong)(yong)該煅燒(shao)(shao)(shao)工(gong)(gong)藝(yi)(yi)。所用(yong)(yong)豎窯(yao)的(de)規格一般為3m×16m。該煅燒(shao)(shao)(shao)工(gong)(gong)藝(yi)(yi)簡單，產品成本低，但在(zai)(zai)煅燒(shao)(shao)(shao)過程中(zhong)(zhong)(zhong)料(liao)球和焦炭(tan)混在(zai)(zai)一起(qi)，焦炭(tan)燃燒(shao)(shao)(shao)產生的(de)灰分(fen)有一部分(fen)混入(ru)(ru)(ru)到料(liao)球中(zhong)(zhong)(zhong)，增加了產品的(de)雜質(zhi)含量。

3、干法壓球(qiu)、燃油豎窯煅燒工藝(yi)

該(gai)煅燒(shao)(shao)(shao)(shao)(shao)(shao)工藝(yi)(yi)用(yong)于生(sheng)(sheng)產(chan)(chan)高(gao)純度(du)(du)(du)合成(cheng)(cheng)鎂鈣砂(sha)(sha)。將高(gao)純度(du)(du)(du)輕燒(shao)(shao)(shao)(shao)(shao)(shao)氧化(hua)鎂和輕燒(shao)(shao)(shao)(shao)(shao)(shao)白云(yun)石(shi)配(pei)料(liao)(liao)、混合磨細后，直接將干(gan)粉(fen)料(liao)(liao)送(song)入(ru)高(gao)壓(ya)壓(ya)球機中(zhong)(zhong)干(gan)壓(ya)成(cheng)(cheng)球，然(ran)后再送(song)入(ru)高(gao)溫燃(ran)油(you)豎(shu)(shu)窯(yao)內(nei)煅燒(shao)(shao)(shao)(shao)(shao)(shao)。這種煅燒(shao)(shao)(shao)(shao)(shao)(shao)工藝(yi)(yi)的優(you)勢是燃(ran)料(liao)(liao)油(you)噴入(ru)到料(liao)(liao)層內(nei)，在料(liao)(liao)層內(nei)部燃(ran)燒(shao)(shao)(shao)(shao)(shao)(shao)，煅燒(shao)(shao)(shao)(shao)(shao)(shao)溫度(du)(du)(du)高(gao)，可達(da)到1800℃以(yi)上(shang)；燃(ran)料(liao)(liao)燃(ran)燒(shao)(shao)(shao)(shao)(shao)(shao)后不產(chan)(chan)生(sheng)(sheng)灰分，對物料(liao)(liao)的純度(du)(du)(du)沒有影響。目前，國內(nei)采(cai)(cai)用(yong)該(gai)煅燒(shao)(shao)(shao)(shao)(shao)(shao)工藝(yi)(yi)生(sheng)(sheng)產(chan)(chan)合成(cheng)(cheng)鎂鈣砂(sha)(sha)的企(qi)業(ye)，只有南(nan)方一(yi)(yi)家(jia)公司(si)(si)。該(gai)公司(si)(si)燃(ran)油(you)豎(shu)(shu)窯(yao)的規(gui)格為φ1.75m×11.5m，窯(yao)的工作襯用(yong)高(gao)純度(du)(du)(du)堿性(xing)耐火制品砌(qi)筑，厚(hou)度(du)(du)(du)為350mm。工作襯于窯(yao)體鋼殼(ke)之間(jian)用(yong)輕質保溫磚(zhuan)砌(qi)筑。以(yi)重柴油(you)為燃(ran)料(liao)(liao)，煅燒(shao)(shao)(shao)(shao)(shao)(shao)溫度(du)(du)(du)>1800℃。設計(ji)4排燒(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui)(zui)(zui)，上(shang)下布置，間(jian)距900mm。每(mei)排設計(ji)16支(zhi)燒(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui)(zui)(zui)，沿圓周(zhou)均布。采(cai)(cai)用(yong)無冷卻燒(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui)(zui)(zui)，每(mei)支(zhi)燒(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui)(zui)(zui)配(pei)一(yi)(yi)臺(tai)計(ji)量泵(beng)供(gong)油(you)，一(yi)(yi)次空氣由羅茨風機供(gong)應。實際(ji)生(sheng)(sheng)產(chan)(chan)中(zhong)(zhong)使用(yong)一(yi)(yi)排燒(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui)(zui)(zui)。連(lian)續裝窯(yao)和出窯(yao)，全部自動化(hua)控制，生(sheng)(sheng)產(chan)(chan)能力。

4、干(gan)法(fa)壓球、回轉(zhuan)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。