目前我國生產文昌合成鎂鈣砂所使(shi)用的(de)原料(liao)有菱(ling)鎂(mei)(mei)石(shi)(shi)(shi)(shi)、白(bai)云石(shi)(shi)(shi)(shi)和(he)(he)石(shi)(shi)(shi)(shi)灰(hui)石(shi)(shi)(shi)(shi)。所采用的(de)工(gong)(gong)(gong)(gong)藝為二(er)步煅(duan)(duan)燒(shao)(shao)、入(ru)工(gong)(gong)(gong)(gong)合(he)成工(gong)(gong)(gong)(gong)藝。即先將菱(ling)鎂(mei)(mei)石(shi)(shi)(shi)(shi)、白(bai)云石(shi)(shi)(shi)(shi)和(he)(he)石(shi)(shi)(shi)(shi)灰(hui)石(shi)(shi)(shi)(shi)在較(jiao)低的(de)溫(wen)度下(xia)輕(qing)(qing)燒(shao)(shao)，生產出(chu)輕(qing)(qing)燒(shao)(shao)氧(yang)化(hua)鎂(mei)(mei)、輕(qing)(qing)燒(shao)(shao)白(bai)云石(shi)(shi)(shi)(shi)和(he)(he)生石(shi)(shi)(shi)(shi)灰(hui)。然(ran)后進行配料(liao)、磨細、混(hun)料(liao)、成型(xing)，最后經(jing)過高(gao)溫(wen)煅(duan)(duan)燒(shao)(shao)，煅(duan)(duan)燒(shao)(shao)出(chu)不同牌號的(de)合(he)成鎂(mei)(mei)鈣砂(sha)。具體的(de)煅(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)(gong)藝有半干法(fa)壓坯(pi)、隧道窯煅(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)(gong)藝；半干法(fa)壓球、焦(jiao)炭豎窯煅(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)(gong)藝；干法(fa)壓球、高(gao)溫(wen)燃油豎窯和(he)(he)回轉窯煅(duan)(duan)燒(shao)(shao)工(gong)(gong)(gong)(gong)藝。

1、半干法壓坯、隧道(dao)窯煅(duan)(duan)燒工藝(yi)該煅(duan)(duan)燒工藝(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、焦炭豎窯煅燒工藝

該煅(duan)燒(shao)(shao)(shao)(shao)工藝生產(chan)合成(cheng)(cheng)(cheng)(cheng)鎂鈣(gai)砂(sha)是(shi)以輕(qing)燒(shao)(shao)(shao)(shao)白云(yun)石和(he)輕(qing)燒(shao)(shao)(shao)(shao)氧化鎂為(wei)(wei)(wei)原料(liao)。將(jiang)輕(qing)燒(shao)(shao)(shao)(shao)白云(yun)石和(he)輕(qing)燒(shao)(shao)(shao)(shao)氧化鎂分(fen)別磨成(cheng)(cheng)(cheng)(cheng)細(xi)粉，計量(liang)后(hou)按比例加(jia)入(ru)輪碾機中(zhong)再(zai)加(jia)水混(hun)合，混(hun)好的合成(cheng)(cheng)(cheng)(cheng)料(liao)在雙(shuang)輥壓(ya)球機上壓(ya)成(cheng)(cheng)(cheng)(cheng)料(liao)球，干燥后(hou)裝入(ru)以焦(jiao)(jiao)炭或無煙煤(mei)為(wei)(wei)(wei)燃料(liao)的豎窯(yao)內煅(duan)燒(shao)(shao)(shao)(shao)。裝料(liao)方式是(shi)焦(jiao)(jiao)炭或無煙煤(mei)和(he)料(liao)球分(fen)層裝入(ru)。我國遼寧省生產(chan)合成(cheng)(cheng)(cheng)(cheng)鎂鈣(gai)砂(sha)的企(qi)業(ye)中(zhong)，大部分(fen)采(cai)用(yong)該煅(duan)燒(shao)(shao)(shao)(shao)工藝。所用(yong)豎窯(yao)的規格一般為(wei)(wei)(wei)3m×16m。該煅(duan)燒(shao)(shao)(shao)(shao)工藝簡單，產(chan)品成(cheng)(cheng)(cheng)(cheng)本低，但在煅(duan)燒(shao)(shao)(shao)(shao)過程中(zhong)料(liao)球和(he)焦(jiao)(jiao)炭混(hun)在一起(qi)，焦(jiao)(jiao)炭燃燒(shao)(shao)(shao)(shao)產(chan)生的灰分(fen)有一部分(fen)混(hun)入(ru)到料(liao)球中(zhong)，增加(jia)了產(chan)品的雜質含(han)量(liang)。

3、干(gan)法壓球、燃油豎窯煅燒(shao)工藝(yi)

該(gai)煅(duan)(duan)燒(shao)(shao)(shao)工(gong)藝用于(yu)生(sheng)(sheng)產高(gao)純(chun)(chun)度(du)合(he)成鎂(mei)鈣砂。將高(gao)純(chun)(chun)度(du)輕(qing)燒(shao)(shao)(shao)氧化(hua)鎂(mei)和輕(qing)燒(shao)(shao)(shao)白(bai)云石配料(liao)(liao)、混合(he)磨細(xi)后(hou)(hou)，直接將干粉料(liao)(liao)送入高(gao)壓(ya)壓(ya)球機中(zhong)干壓(ya)成球，然后(hou)(hou)再送入高(gao)溫(wen)(wen)燃(ran)(ran)油(you)豎(shu)(shu)窯(yao)(yao)內煅(duan)(duan)燒(shao)(shao)(shao)。這(zhe)種煅(duan)(duan)燒(shao)(shao)(shao)工(gong)藝的(de)優勢是燃(ran)(ran)料(liao)(liao)油(you)噴入到(dao)料(liao)(liao)層(ceng)內，在料(liao)(liao)層(ceng)內部燃(ran)(ran)燒(shao)(shao)(shao)，煅(duan)(duan)燒(shao)(shao)(shao)溫(wen)(wen)度(du)高(gao)，可達到(dao)1800℃以(yi)(yi)上；燃(ran)(ran)料(liao)(liao)燃(ran)(ran)燒(shao)(shao)(shao)后(hou)(hou)不產生(sheng)(sheng)灰分，對(dui)物料(liao)(liao)的(de)純(chun)(chun)度(du)沒有影響(xiang)。目前，國(guo)內采(cai)用該(gai)煅(duan)(duan)燒(shao)(shao)(shao)工(gong)藝生(sheng)(sheng)產合(he)成鎂(mei)鈣砂的(de)企業，只有南方一(yi)(yi)(yi)家(jia)公司。該(gai)公司燃(ran)(ran)油(you)豎(shu)(shu)窯(yao)(yao)的(de)規(gui)格為(wei)φ1.75m×11.5m，窯(yao)(yao)的(de)工(gong)作襯用高(gao)純(chun)(chun)度(du)堿性耐火(huo)制(zhi)品砌(qi)筑，厚度(du)為(wei)350mm。工(gong)作襯于(yu)窯(yao)(yao)體鋼殼之間用輕(qing)質保溫(wen)(wen)磚砌(qi)筑。以(yi)(yi)重(zhong)柴(chai)油(you)為(wei)燃(ran)(ran)料(liao)(liao)，煅(duan)(duan)燒(shao)(shao)(shao)溫(wen)(wen)度(du)>1800℃。設計4排燒(shao)(shao)(shao)嘴，上下(xia)布(bu)置，間距900mm。每排設計16支燒(shao)(shao)(shao)嘴，沿圓(yuan)周均布(bu)。采(cai)用無冷卻燒(shao)(shao)(shao)嘴，每支燒(shao)(shao)(shao)嘴配一(yi)(yi)(yi)臺計量泵供油(you)，一(yi)(yi)(yi)次空(kong)氣由羅茨風(feng)機供應。實際生(sheng)(sheng)產中(zhong)使用一(yi)(yi)(yi)排燒(shao)(shao)(shao)嘴。連續裝(zhuang)窯(yao)(yao)和出(chu)窯(yao)(yao)，全部自動(dong)化(hua)控制(zhi)，生(sheng)(sheng)產能力。

4、干(gan)法(fa)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。