生(sheng)產石(shi)(shi)(shi)(shi)(shi)(shi)膏(gao)(gao)的原(yuan)料主要(yao)為含(han)硫酸鈣的天(tian)(tian)然(ran)(ran)石(shi)(shi)(shi)(shi)(shi)(shi)膏(gao)(gao)(又(you)稱(cheng)生(sheng)石(shi)(shi)(shi)(shi)(shi)(shi)膏(gao)(gao))或含(han)硫酸鈣的化(hua)(hua)工(gong)副產品(pin)和磷石(shi)(shi)(shi)(shi)(shi)(shi)膏(gao)(gao)、氟石(shi)(shi)(shi)(shi)(shi)(shi)膏(gao)(gao)、硼石(shi)(shi)(shi)(shi)(shi)(shi)膏(gao)(gao)等(deng)廢渣,其化(hua)(hua)學(xue)式為CaSO4.1/2H2O,也稱(cheng)半水石(shi)(shi)(shi)(shi)(shi)(shi)膏(gao)(gao)。將(jiang)天(tian)(tian)然(ran)(ran)二(er)水石(shi)(shi)(shi)(shi)(shi)(shi)膏(gao)(gao)在不同的溫度(du)下煅(duan)燒(shao)可(ke)得到(dao)不同的石(shi)(shi)(shi)(shi)(shi)(shi)膏(gao)(gao)品(pin)種。如(ru)將(jiang)天(tian)(tian)然(ran)(ran)二(er)水石(shi)(shi)(shi)(shi)(shi)(shi)膏(gao)(gao)在107~170℃的干燥條件下加熱可(ke)得建筑石(shi)(shi)(shi)(shi)(shi)(shi)膏(gao)(gao)。
將(jiang)建筑(zhu)石膏加水(shui)(shui)(shui)(shui)后,它首先溶(rong)解(jie)于(yu)水(shui)(shui)(shui)(shui),然后生成二水(shui)(shui)(shui)(shui)石膏析出。隨(sui)著水(shui)(shui)(shui)(shui)化(hua)的(de)不(bu)(bu)斷進行(xing),生成的(de)二水(shui)(shui)(shui)(shui)石膏膠體(ti)微(wei)粒(li)不(bu)(bu)斷增(zeng)多,這些(xie)微(wei)粒(li)比原先更加細小,比表面積很大,吸(xi)附(fu)著很多的(de)水(shui)(shui)(shui)(shui)分(fen);同時漿(jiang)(jiang)(jiang)體(ti)中(zhong)的(de)自由(you)水(shui)(shui)(shui)(shui)分(fen)由(you)于(yu)水(shui)(shui)(shui)(shui)化(hua)和蒸發而不(bu)(bu)斷減少,漿(jiang)(jiang)(jiang)體(ti)的(de)稠(chou)度不(bu)(bu)斷增(zeng)加,膠體(ti)微(wei)粒(li)間的(de)黏結逐(zhu)步增(zeng)強,顆(ke)(ke)粒(li)間產生摩擦力和黏結力,使漿(jiang)(jiang)(jiang)體(ti)逐(zhu)漸失去可塑性,即漿(jiang)(jiang)(jiang)體(ti)逐(zhu)漸產生凝結。繼續(xu)水(shui)(shui)(shui)(shui)化(hua),膠體(ti)轉變成晶(jing)體(ti)。晶(jing)體(ti)顆(ke)(ke)粒(li)逐(zhu)漸長大,使漿(jiang)(jiang)(jiang)體(ti)完(wan)全失去可塑性,產生強度,即漿(jiang)(jiang)(jiang)體(ti)產生了硬(ying)(ying)化(hua)。這一過程不(bu)(bu)斷進行(xing),直至(zhi)漿(jiang)(jiang)(jiang)體(ti)完(wan)全干燥,強度不(bu)(bu)在(zai)增(zeng)加,此時漿(jiang)(jiang)(jiang)體(ti)已硬(ying)(ying)化(hua)成人(ren)造石材。
海南免膠石膏是以建筑石(shi)膏為主要(yao)原材(cai)料(liao),經加(jia)水攪拌、澆(jiao)注(zhu)成(cheng)型和(he)干燥制(zhi)成(cheng)的輕質建筑石(shi)膏制(zhi)品。生產中允許加(jia)入纖維增(zeng)強(qiang)材(cai)料(liao)或輕集料(liao),也可加(jia)入發(fa)(fa)泡劑。石(shi)膏砌塊具有隔聲(sheng)防火、施工(gong)便捷等多項(xiang)優點,是一種低碳環保、健康、符合時(shi)代發(fa)(fa)展要(yao)求(qiu)的新型墻體材(cai)料(liao)。