低硅铁尾矿微晶泡沫玻璃的耐酸碱性研究

Research on Acid and Alkali Resistance of Foam Glass-ceramics From Low-silicon Iron Ore Tailings

以商洛市大西沟低硅铁尾矿和废玻璃粉为主要原料,以Na_(2)B_(4)O_(7)·5H_(2)O作为助溶剂,CaCO_(3)和Na_(3)PO_(4)·12H_(2)O分别作为发泡剂和稳泡剂,TiO_(2)和CaF_(2)作为复合晶核剂,采用熔融-烧结工艺制备微晶泡沫玻璃。借助XRD、TG-DSC、SEM等测试手段,研究了微晶泡沫玻璃的物相、显微结构以及耐酸碱性能测试前后的失重率、力学性能。结果表明,基础玻璃配合料分别在800℃、950℃和1050℃进行发泡、核化、晶化后,制得了以标准透辉石为主晶相、易变辉石和白硅钙石为次晶相的钙铁硅型微晶泡沫玻璃。形貌分析发现,其内部分布着大量孔径不一、平均尺寸小于2.0 mm的封闭式气孔。抗腐蚀测试24 h后,试样的耐酸耐碱失重率仅为0.11%和0.17%,抗压强度仍保持在37.1 MPa和36.8 MPa,且在H_(2)SO_(4)中表现出比NaOH溶液中更优异的抗腐蚀性能。铁尾矿的大量掺入以及复合晶核剂的复配对微晶泡沫玻璃优异的耐酸碱腐蚀性起主导作用。

The foam glass ceramics were prepared by fusion-sintering process with low silicon iron tailings collected from Daxigou tailings pond in Shangluo and waste glass powder as the main raw materials,Na_(2)B_(4)O_(7)·5H_(2)O as co-solvent,CaCO_(3) and Na_(3)PO_(4)·12H_(2)O as foaming agent and foam stabilizer,respectively,TiO_(2) and CaF_(2) as composite nucleating reagents.By virtue of XRD,TG-DSC and SEM,the phase,microstructure,acid and alkali resistance weight loss rate and mechanical properties of foam glass-ceramic before and after corrosion resistance test were studied.Results show that the closed-pore structured calciumferrosilicon foam glass-ceramic with the standard diopside as the main crystal phase and the pigeonite and bredigite as the secondary crystal phase were prepared at 800℃for foaming,950℃for nucleation and 1050℃for crystallization.After a 24 h-running test for corrosion resistance,the acid and alkali resistance weight loss rates of the samples were only 0.11%and 0.17%,the compressive strength remained at 37.1 and 36.8 MPa,respectively.Besides,the tested samples displayed the better corrosion resistance in H_(2)SO_(4) than that in NaOH solution.The utilization of high-incorporation iron tailings and compound nucleating agents for foam glassceramics were mainly responsible for the excellent corrosion resistance in acid and alkali solution.