目前我國生產金山合成鎂鈣砂所(suo)使用的原料(liao)有菱(ling)鎂(mei)石(shi)(shi)(shi)(shi)、白(bai)云石(shi)(shi)(shi)(shi)和(he)石(shi)(shi)(shi)(shi)灰(hui)石(shi)(shi)(shi)(shi)。所(suo)采用的工(gong)(gong)藝為(wei)二步煅(duan)(duan)燒(shao)(shao)(shao)、入工(gong)(gong)合(he)(he)成工(gong)(gong)藝。即先將菱(ling)鎂(mei)石(shi)(shi)(shi)(shi)、白(bai)云石(shi)(shi)(shi)(shi)和(he)石(shi)(shi)(shi)(shi)灰(hui)石(shi)(shi)(shi)(shi)在較低的溫度下輕燒(shao)(shao)(shao)，生產出輕燒(shao)(shao)(shao)氧化鎂(mei)、輕燒(shao)(shao)(shao)白(bai)云石(shi)(shi)(shi)(shi)和(he)生石(shi)(shi)(shi)(shi)灰(hui)。然(ran)后進行(xing)配(pei)料(liao)、磨細(xi)、混料(liao)、成型，最后經過高溫煅(duan)(duan)燒(shao)(shao)(shao)，煅(duan)(duan)燒(shao)(shao)(shao)出不同(tong)牌號的合(he)(he)成鎂(mei)鈣砂。具體的煅(duan)(duan)燒(shao)(shao)(shao)工(gong)(gong)藝有半(ban)干(gan)法(fa)壓(ya)坯、隧(sui)道窯煅(duan)(duan)燒(shao)(shao)(shao)工(gong)(gong)藝；半(ban)干(gan)法(fa)壓(ya)球(qiu)、焦炭豎窯煅(duan)(duan)燒(shao)(shao)(shao)工(gong)(gong)藝；干(gan)法(fa)壓(ya)球(qiu)、高溫燃(ran)油豎窯和(he)回轉窯煅(duan)(duan)燒(shao)(shao)(shao)工(gong)(gong)藝。

1、半干法壓坯、隧道窯煅(duan)燒(shao)工(gong)藝該煅(duan)燒(shao)工(gong)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、焦炭豎窯煅燒工藝

該(gai)煅燒(shao)(shao)(shao)工(gong)藝(yi)生產(chan)合成(cheng)(cheng)鎂鈣(gai)砂是以輕(qing)(qing)燒(shao)(shao)(shao)白(bai)云石和(he)輕(qing)(qing)燒(shao)(shao)(shao)氧(yang)化(hua)(hua)鎂為(wei)原料(liao)。將輕(qing)(qing)燒(shao)(shao)(shao)白(bai)云石和(he)輕(qing)(qing)燒(shao)(shao)(shao)氧(yang)化(hua)(hua)鎂分別(bie)磨成(cheng)(cheng)細(xi)粉，計量后(hou)按比例加入輪碾機(ji)中(zhong)(zhong)再加水混(hun)合，混(hun)好的合成(cheng)(cheng)料(liao)在雙輥(gun)壓球(qiu)(qiu)機(ji)上壓成(cheng)(cheng)料(liao)球(qiu)(qiu)，干燥(zao)后(hou)裝(zhuang)(zhuang)入以焦(jiao)(jiao)炭(tan)(tan)(tan)或無(wu)煙(yan)煤為(wei)燃料(liao)的豎窯內(nei)煅燒(shao)(shao)(shao)。裝(zhuang)(zhuang)料(liao)方式是焦(jiao)(jiao)炭(tan)(tan)(tan)或無(wu)煙(yan)煤和(he)料(liao)球(qiu)(qiu)分層裝(zhuang)(zhuang)入。我國遼寧省生產(chan)合成(cheng)(cheng)鎂鈣(gai)砂的企業中(zhong)(zhong)，大部分采(cai)用該(gai)煅燒(shao)(shao)(shao)工(gong)藝(yi)。所用豎窯的規格(ge)一般為(wei)3m×16m。該(gai)煅燒(shao)(shao)(shao)工(gong)藝(yi)簡單，產(chan)品(pin)成(cheng)(cheng)本低(di)，但在煅燒(shao)(shao)(shao)過程(cheng)中(zhong)(zhong)料(liao)球(qiu)(qiu)和(he)焦(jiao)(jiao)炭(tan)(tan)(tan)混(hun)在一起，焦(jiao)(jiao)炭(tan)(tan)(tan)燃燒(shao)(shao)(shao)產(chan)生的灰(hui)分有(you)一部分混(hun)入到料(liao)球(qiu)(qiu)中(zhong)(zhong)，增(zeng)加了產(chan)品(pin)的雜(za)質含量。

3、干法壓球、燃油豎窯煅燒工(gong)藝

該煅(duan)燒(shao)(shao)(shao)工(gong)(gong)藝(yi)用(yong)于生產高(gao)(gao)純度(du)合成鎂鈣砂(sha)。將高(gao)(gao)純度(du)輕(qing)燒(shao)(shao)(shao)氧(yang)化(hua)鎂和輕(qing)燒(shao)(shao)(shao)白云石配料(liao)(liao)、混合磨細后(hou)，直接(jie)將干粉料(liao)(liao)送(song)入高(gao)(gao)壓壓球(qiu)(qiu)機(ji)中干壓成球(qiu)(qiu)，然(ran)后(hou)再送(song)入高(gao)(gao)溫(wen)(wen)燃(ran)油(you)豎(shu)窯內(nei)煅(duan)燒(shao)(shao)(shao)。這種煅(duan)燒(shao)(shao)(shao)工(gong)(gong)藝(yi)的優(you)勢是燃(ran)料(liao)(liao)油(you)噴(pen)入到(dao)料(liao)(liao)層內(nei)，在料(liao)(liao)層內(nei)部燃(ran)燒(shao)(shao)(shao)，煅(duan)燒(shao)(shao)(shao)溫(wen)(wen)度(du)高(gao)(gao)，可達到(dao)1800℃以上；燃(ran)料(liao)(liao)燃(ran)燒(shao)(shao)(shao)后(hou)不產生灰分，對物料(liao)(liao)的純度(du)沒有影響。目前，國內(nei)采用(yong)該煅(duan)燒(shao)(shao)(shao)工(gong)(gong)藝(yi)生產合成鎂鈣砂(sha)的企業(ye)，只有南方一家(jia)公司(si)。該公司(si)燃(ran)油(you)豎(shu)窯的規格為(wei)φ1.75m×11.5m，窯的工(gong)(gong)作(zuo)襯(chen)用(yong)高(gao)(gao)純度(du)堿(jian)性(xing)耐火制品砌(qi)筑，厚度(du)為(wei)350mm。工(gong)(gong)作(zuo)襯(chen)于窯體(ti)鋼(gang)殼之(zhi)間(jian)(jian)用(yong)輕(qing)質保(bao)溫(wen)(wen)磚砌(qi)筑。以重柴油(you)為(wei)燃(ran)料(liao)(liao)，煅(duan)燒(shao)(shao)(shao)溫(wen)(wen)度(du)>1800℃。設計(ji)4排燒(shao)(shao)(shao)嘴，上下布置(zhi)，間(jian)(jian)距(ju)900mm。每排設計(ji)16支(zhi)燒(shao)(shao)(shao)嘴，沿圓周均布。采用(yong)無冷(leng)卻燒(shao)(shao)(shao)嘴，每支(zhi)燒(shao)(shao)(shao)嘴配一臺(tai)計(ji)量泵供(gong)油(you)，一次空氣由羅茨風(feng)機(ji)供(gong)應。實際生產中使用(yong)一排燒(shao)(shao)(shao)嘴。連續裝窯和出窯，全(quan)部自動(dong)化(hua)控制，生產能力。

4、干法壓球、回轉窯煅(duan)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。