利用熔态二次镍渣制备微晶铸石

Preparation of cast stone from molten secondary nickel slag

为了寻求二次镍渣的资源化利用,开展以二次镍渣为原料制备微晶铸石的研究。首先对试验原料进行物化分析,并借助CaO-MgO-Al2O3-SiO2四元相图,进行配比优化试验;然后对其热处理制度进行研究,确定了最佳的核化、晶化温度及保温时间,并测定其性能指标;最后采用XRD、IR红外光谱、DSC、SEM及EDS等对其结构和微观进行分析,并结合力学性能测试研究热处理制度对其性能的影响及其析晶机理。结果表明:采用配比为二次镍渣89%、石英砂6%、氧化铝4%、氧化锆0.5%、氟化钙0.5%,在均化温度1500℃、保温300 min条件下得到过冷却熔态镍渣,然后在核化温度730℃和晶化温度980℃时,分别保温60 min进行热处理,冷却后得到微晶铸石,最后测得其抗压和抗折强度分别为894.3 MPa和174.8 MPa,冲击韧性为2.82 kJ/m^(2),耐磨性为0.025 g/cm^(2)、耐酸碱度分别为99.5%和99.2%。

In order to seek the resource utilization of secondary nickel slag,the preparation of cast stone with molten secondary nickel slag(MSNS)as the main raw material was carried out.Firstly,the material was analyzed by physicochemical method,and the optimum ratio test was carried out by using CaO-MgO-Al2O3-SiO2 phase diagram.Then,the heat treatment system was studied to determine the optimal nucleation and crystallization temperature and holding time,and the performance indexes were determined.Finally,XRD,IR,DSC,SEM and EDS were used to test and analyze the structure and microstructure.Combined with the mechanical properties test,the effect of heat treatment on the properties of microcrystalline cast stone and its crystallization mechanism were explored.The results show that,cast stone is prepared by mixing 89%molten secondary nickel slag,6%quartz sand(QS),4%alumina,0.5%zirconia and 0.5%calcium fluoride.The supercooled molten nickel slag is obtained at the homogenization temperature of 1500℃and holding for 300 min.Then,when the nucleation temperature is 730℃and the crystallization temperature is 980℃,both holding time of them are 60 min.After cooling,the microcrystalline cast stone is obtained.Finally,its compressive and flexural strength are measured to be 894.3 MPa and 174.8 MPa,respectively,impact toughness(IT)is 2.82 kJ/m^(2),wear resistance(WR)is 0.025 g/cm^(2),acid and alkali resistance(AAR)are 99.5%and 99.2%,respectively.