目前我國生產宜賓合成鎂鈣砂所使(shi)用的(de)(de)原料(liao)有(you)菱鎂石(shi)(shi)(shi)、白云(yun)石(shi)(shi)(shi)和石(shi)(shi)(shi)灰石(shi)(shi)(shi)。所采用的(de)(de)工(gong)藝(yi)為二步煅(duan)(duan)燒、入工(gong)合成(cheng)(cheng)工(gong)藝(yi)。即先將菱鎂石(shi)(shi)(shi)、白云(yun)石(shi)(shi)(shi)和石(shi)(shi)(shi)灰石(shi)(shi)(shi)在較低的(de)(de)溫(wen)度下(xia)輕(qing)(qing)燒，生產出輕(qing)(qing)燒氧(yang)化鎂、輕(qing)(qing)燒白云(yun)石(shi)(shi)(shi)和生石(shi)(shi)(shi)灰。然后進行配料(liao)、磨細、混(hun)料(liao)、成(cheng)(cheng)型(xing)，最后經(jing)過高溫(wen)煅(duan)(duan)燒，煅(duan)(duan)燒出不同牌號(hao)的(de)(de)合成(cheng)(cheng)鎂鈣(gai)砂(sha)。具體(ti)的(de)(de)煅(duan)(duan)燒工(gong)藝(yi)有(you)半干法(fa)壓(ya)坯(pi)、隧道窯(yao)煅(duan)(duan)燒工(gong)藝(yi)；半干法(fa)壓(ya)球(qiu)、焦炭(tan)豎窯(yao)煅(duan)(duan)燒工(gong)藝(yi)；干法(fa)壓(ya)球(qiu)、高溫(wen)燃油豎窯(yao)和回轉窯(yao)煅(duan)(duan)燒工(gong)藝(yi)。

1、半(ban)干(gan)法壓坯(pi)、隧道窯煅(duan)(duan)燒(shao)(shao)工(gong)藝該煅(duan)(duan)燒(shao)(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(ban)干法壓球(qiu)、焦(jiao)炭豎窯煅燒工藝(yi)

該煅(duan)(duan)燒(shao)(shao)工(gong)藝生產(chan)(chan)(chan)合(he)(he)成(cheng)(cheng)(cheng)(cheng)(cheng)鎂(mei)鈣砂(sha)是(shi)以輕(qing)(qing)燒(shao)(shao)白(bai)云(yun)石(shi)和輕(qing)(qing)燒(shao)(shao)氧化(hua)鎂(mei)為原料。將輕(qing)(qing)燒(shao)(shao)白(bai)云(yun)石(shi)和輕(qing)(qing)燒(shao)(shao)氧化(hua)鎂(mei)分(fen)別磨成(cheng)(cheng)(cheng)(cheng)(cheng)細粉(fen)，計量(liang)(liang)后(hou)按比例加入輪碾機中(zhong)再加水混(hun)合(he)(he)，混(hun)好的合(he)(he)成(cheng)(cheng)(cheng)(cheng)(cheng)料在(zai)雙輥壓球機上壓成(cheng)(cheng)(cheng)(cheng)(cheng)料球，干燥后(hou)裝入以焦(jiao)炭或無(wu)煙煤(mei)為燃料的豎(shu)窯內煅(duan)(duan)燒(shao)(shao)。裝料方式是(shi)焦(jiao)炭或無(wu)煙煤(mei)和料球分(fen)層(ceng)裝入。我國遼寧省生產(chan)(chan)(chan)合(he)(he)成(cheng)(cheng)(cheng)(cheng)(cheng)鎂(mei)鈣砂(sha)的企業(ye)中(zhong)，大(da)部分(fen)采用該煅(duan)(duan)燒(shao)(shao)工(gong)藝。所用豎(shu)窯的規格一般為3m×16m。該煅(duan)(duan)燒(shao)(shao)工(gong)藝簡(jian)單(dan)，產(chan)(chan)(chan)品成(cheng)(cheng)(cheng)(cheng)(cheng)本低，但在(zai)煅(duan)(duan)燒(shao)(shao)過程中(zhong)料球和焦(jiao)炭混(hun)在(zai)一起，焦(jiao)炭燃燒(shao)(shao)產(chan)(chan)(chan)生的灰分(fen)有一部分(fen)混(hun)入到料球中(zhong)，增加了產(chan)(chan)(chan)品的雜質含量(liang)(liang)。

3、干法壓球、燃油豎(shu)窯(yao)煅燒工藝

該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)工(gong)藝(yi)用于生(sheng)(sheng)產(chan)高(gao)(gao)純(chun)度(du)(du)合(he)成鎂(mei)鈣砂(sha)(sha)。將高(gao)(gao)純(chun)度(du)(du)輕(qing)(qing)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)氧化鎂(mei)和輕(qing)(qing)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)白云石(shi)配料(liao)(liao)(liao)、混(hun)合(he)磨細后，直接將干粉(fen)料(liao)(liao)(liao)送入高(gao)(gao)壓(ya)壓(ya)球機中(zhong)干壓(ya)成球，然后再送入高(gao)(gao)溫(wen)燃(ran)(ran)油(you)豎(shu)窯(yao)(yao)(yao)內(nei)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)。這種煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)工(gong)藝(yi)的(de)優勢是燃(ran)(ran)料(liao)(liao)(liao)油(you)噴入到(dao)料(liao)(liao)(liao)層內(nei)，在料(liao)(liao)(liao)層內(nei)部燃(ran)(ran)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)，煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)溫(wen)度(du)(du)高(gao)(gao)，可達(da)到(dao)1800℃以上；燃(ran)(ran)料(liao)(liao)(liao)燃(ran)(ran)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)后不產(chan)生(sheng)(sheng)灰分，對物(wu)料(liao)(liao)(liao)的(de)純(chun)度(du)(du)沒(mei)有影響。目前，國內(nei)采用該(gai)煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)工(gong)藝(yi)生(sheng)(sheng)產(chan)合(he)成鎂(mei)鈣砂(sha)(sha)的(de)企(qi)業，只有南方一(yi)家公(gong)(gong)司。該(gai)公(gong)(gong)司燃(ran)(ran)油(you)豎(shu)窯(yao)(yao)(yao)的(de)規格為φ1.75m×11.5m，窯(yao)(yao)(yao)的(de)工(gong)作(zuo)襯(chen)用高(gao)(gao)純(chun)度(du)(du)堿性耐火(huo)制(zhi)品砌(qi)筑，厚度(du)(du)為350mm。工(gong)作(zuo)襯(chen)于窯(yao)(yao)(yao)體鋼殼之間用輕(qing)(qing)質保溫(wen)磚(zhuan)砌(qi)筑。以重柴油(you)為燃(ran)(ran)料(liao)(liao)(liao)，煅(duan)(duan)燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)溫(wen)度(du)(du)>1800℃。設(she)計(ji)4排燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui)(zui)，上下(xia)布置，間距900mm。每(mei)排設(she)計(ji)16支燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui)(zui)，沿圓(yuan)周(zhou)均布。采用無冷卻燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui)(zui)，每(mei)支燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui)(zui)配一(yi)臺計(ji)量泵供(gong)油(you)，一(yi)次(ci)空氣由羅茨風(feng)機供(gong)應(ying)。實際生(sheng)(sheng)產(chan)中(zhong)使用一(yi)排燒(shao)(shao)(shao)(shao)(shao)(shao)(shao)嘴(zui)(zui)。連續裝窯(yao)(yao)(yao)和出窯(yao)(yao)(yao)，全部自動(dong)化控制(zhi)，生(sheng)(sheng)產(chan)能力(li)。

4、干法(fa)壓球、回轉窯煅燒工藝

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。