目前我國生產防城港合成鎂鈣砂所(suo)使用(yong)(yong)的原料有(you)菱鎂石(shi)(shi)(shi)(shi)(shi)、白(bai)(bai)云(yun)石(shi)(shi)(shi)(shi)(shi)和石(shi)(shi)(shi)(shi)(shi)灰石(shi)(shi)(shi)(shi)(shi)。所(suo)采用(yong)(yong)的工(gong)(gong)(gong)藝(yi)(yi)(yi)為二步煅燒、入工(gong)(gong)(gong)合(he)(he)成工(gong)(gong)(gong)藝(yi)(yi)(yi)。即先將菱鎂石(shi)(shi)(shi)(shi)(shi)、白(bai)(bai)云(yun)石(shi)(shi)(shi)(shi)(shi)和石(shi)(shi)(shi)(shi)(shi)灰石(shi)(shi)(shi)(shi)(shi)在較低的溫(wen)(wen)度(du)下輕(qing)燒，生(sheng)產出輕(qing)燒氧(yang)化鎂、輕(qing)燒白(bai)(bai)云(yun)石(shi)(shi)(shi)(shi)(shi)和生(sheng)石(shi)(shi)(shi)(shi)(shi)灰。然后進(jin)行(xing)配料、磨細、混(hun)料、成型，最(zui)后經過高溫(wen)(wen)煅燒，煅燒出不同牌號的合(he)(he)成鎂鈣砂。具體的煅燒工(gong)(gong)(gong)藝(yi)(yi)(yi)有(you)半干法壓(ya)(ya)坯、隧(sui)道窯(yao)(yao)煅燒工(gong)(gong)(gong)藝(yi)(yi)(yi)；半干法壓(ya)(ya)球、焦(jiao)炭豎(shu)窯(yao)(yao)煅燒工(gong)(gong)(gong)藝(yi)(yi)(yi)；干法壓(ya)(ya)球、高溫(wen)(wen)燃油(you)豎(shu)窯(yao)(yao)和回轉窯(yao)(yao)煅燒工(gong)(gong)(gong)藝(yi)(yi)(yi)。

1、半干(gan)法壓坯、隧道窯(yao)煅燒工藝(yi)該(gai)煅燒工藝(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(ban)干法壓球(qiu)、焦(jiao)炭豎窯煅燒工(gong)藝

該(gai)(gai)煅(duan)(duan)燒(shao)(shao)工(gong)藝生(sheng)(sheng)產(chan)合(he)成(cheng)(cheng)鎂鈣砂是(shi)以輕燒(shao)(shao)白云石(shi)(shi)和(he)輕燒(shao)(shao)氧化鎂為原料。將輕燒(shao)(shao)白云石(shi)(shi)和(he)輕燒(shao)(shao)氧化鎂分(fen)別磨成(cheng)(cheng)細粉，計(ji)量后(hou)按比例加(jia)入輪(lun)碾(nian)機中(zhong)再加(jia)水(shui)混(hun)合(he)，混(hun)好(hao)的(de)(de)(de)合(he)成(cheng)(cheng)料在(zai)雙輥壓球機上壓成(cheng)(cheng)料球，干(gan)燥后(hou)裝(zhuang)入以焦炭(tan)或無煙煤為燃(ran)料的(de)(de)(de)豎窯內煅(duan)(duan)燒(shao)(shao)。裝(zhuang)料方式是(shi)焦炭(tan)或無煙煤和(he)料球分(fen)層裝(zhuang)入。我國遼寧(ning)省生(sheng)(sheng)產(chan)合(he)成(cheng)(cheng)鎂鈣砂的(de)(de)(de)企(qi)業中(zhong)，大部(bu)分(fen)采用(yong)該(gai)(gai)煅(duan)(duan)燒(shao)(shao)工(gong)藝。所用(yong)豎窯的(de)(de)(de)規格一般為3m×16m。該(gai)(gai)煅(duan)(duan)燒(shao)(shao)工(gong)藝簡(jian)單，產(chan)品成(cheng)(cheng)本低，但在(zai)煅(duan)(duan)燒(shao)(shao)過程中(zhong)料球和(he)焦炭(tan)混(hun)在(zai)一起，焦炭(tan)燃(ran)燒(shao)(shao)產(chan)生(sheng)(sheng)的(de)(de)(de)灰分(fen)有一部(bu)分(fen)混(hun)入到料球中(zhong)，增加(jia)了產(chan)品的(de)(de)(de)雜質含量。

3、干(gan)法壓球(qiu)、燃油豎窯煅燒工藝

該(gai)煅(duan)(duan)(duan)燒(shao)(shao)(shao)(shao)工藝(yi)用(yong)(yong)于(yu)(yu)生(sheng)產高(gao)純(chun)度(du)(du)合成鎂鈣砂。將高(gao)純(chun)度(du)(du)輕燒(shao)(shao)(shao)(shao)氧化(hua)鎂和(he)輕燒(shao)(shao)(shao)(shao)白(bai)云石配料(liao)、混合磨(mo)細后，直接將干(gan)粉料(liao)送(song)入(ru)(ru)高(gao)壓(ya)壓(ya)球機(ji)中(zhong)干(gan)壓(ya)成球，然后再(zai)送(song)入(ru)(ru)高(gao)溫(wen)燃(ran)(ran)油(you)豎窯(yao)內(nei)(nei)煅(duan)(duan)(duan)燒(shao)(shao)(shao)(shao)。這種煅(duan)(duan)(duan)燒(shao)(shao)(shao)(shao)工藝(yi)的(de)優勢(shi)是燃(ran)(ran)料(liao)油(you)噴入(ru)(ru)到料(liao)層內(nei)(nei)，在料(liao)層內(nei)(nei)部(bu)燃(ran)(ran)燒(shao)(shao)(shao)(shao)，煅(duan)(duan)(duan)燒(shao)(shao)(shao)(shao)溫(wen)度(du)(du)高(gao)，可達到1800℃以(yi)上(shang)；燃(ran)(ran)料(liao)燃(ran)(ran)燒(shao)(shao)(shao)(shao)后不產生(sheng)灰分，對(dui)物料(liao)的(de)純(chun)度(du)(du)沒(mei)有影響。目前(qian)，國內(nei)(nei)采(cai)用(yong)(yong)該(gai)煅(duan)(duan)(duan)燒(shao)(shao)(shao)(shao)工藝(yi)生(sheng)產合成鎂鈣砂的(de)企(qi)業，只有南方(fang)一(yi)家(jia)公(gong)司。該(gai)公(gong)司燃(ran)(ran)油(you)豎窯(yao)的(de)規格為φ1.75m×11.5m，窯(yao)的(de)工作(zuo)襯用(yong)(yong)高(gao)純(chun)度(du)(du)堿(jian)性耐火制品砌筑，厚度(du)(du)為350mm。工作(zuo)襯于(yu)(yu)窯(yao)體鋼(gang)殼之間用(yong)(yong)輕質保溫(wen)磚(zhuan)砌筑。以(yi)重柴油(you)為燃(ran)(ran)料(liao)，煅(duan)(duan)(duan)燒(shao)(shao)(shao)(shao)溫(wen)度(du)(du)>1800℃。設計4排燒(shao)(shao)(shao)(shao)嘴(zui)(zui)，上(shang)下布置，間距900mm。每排設計16支燒(shao)(shao)(shao)(shao)嘴(zui)(zui)，沿圓周均(jun)布。采(cai)用(yong)(yong)無(wu)冷(leng)卻(que)燒(shao)(shao)(shao)(shao)嘴(zui)(zui)，每支燒(shao)(shao)(shao)(shao)嘴(zui)(zui)配一(yi)臺計量泵供(gong)油(you)，一(yi)次空氣由(you)羅茨風機(ji)供(gong)應(ying)。實際(ji)生(sheng)產中(zhong)使(shi)用(yong)(yong)一(yi)排燒(shao)(shao)(shao)(shao)嘴(zui)(zui)。連續裝窯(yao)和(he)出窯(yao)，全部(bu)自動化(hua)控制，生(sheng)產能(neng)力。

4、干(gan)法壓球、回轉窯煅燒(shao)工藝(yi)

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。