摘要
以硅锰渣为主要原料,采用熔渣冷却析晶一步法(铸石浇铸法),在 800、900、1000 和 1050℃四个不同晶化温度,分别制备了规格为ϕ100 mm×20 mm的铸石样品CT-800、CT-900、CT-1000 和CT-1050,通过构建实验装置,测试了熔渣在成型和热处理全过程中心与边缘温度变化规律,并结合X射线衍射(XRD)、差示扫描量热分析(DSC)、扫描电子显微镜和能谱(SEM-EDS)等手段,分析了不同晶化温度对铸石中心和边缘的温差、析晶与物理性能的影响规律.研究表明:以硅锰渣为主要原料在 900～1050℃保温析晶可以制备出满足天然花岗岩建筑板材标准(GB/T18601-2009)的铸石,晶相为辉石、黄长石以及硫化锰.CT-1000 和CT-1050 铸石析出更多和更大尺寸的晶相,存在微观孔隙和宏观缩孔,降低了其力学性能.CT-900具有最佳性能,而CT-800 以玻璃相为主,热处理后发生断裂.在本实验条件下,最大温差(32℃)发生在把熔渣倒入模具的凝固成型阶段,且晶化温度越低,温差越大.CT-1000 和CT-1050 析晶阶段存在的大量析晶放热导致温差二次增大,延长了中心和边缘温度一致的时间.硫化锰是高温熔融态下析出晶相,易于氧化分解,快速冷却的边缘存在更多硫化锰相.黄长石较辉石在更高的温度下析出,较高的晶化温度处理样品和相同晶化温度下样品的中心部分均存在相对更多的黄长石相.
Abstract
Direct preparation of glass-ceramics from slag is an efficient way to use the"slag"and"heat"of the slag,making this preparation a sought-after research topic.To prepare glass-ceramics using the Petrurgic method,this paper used silico-manganese slag as the main raw material,along with chromite and serpentine as modifiers.The Petrurgic method is a heat treatment process involving controlled crystallization during slag cooling to form glass-ceramics.The prepared glass-ceramic samples had a diameter of 100 mm and a height of 20 mm.Various tests and analyses such as X-ray diffraction(XRD),differential scanning calorimetry(DSC),scanning electron microscopy with energy dispersive X-ray spectroscopy,flexural strength,compressive strength,water absorption,and bulk density were performed on the samples.The influence of different heat treatment regimens on the phase composition and properties of silico-manganese slag microcrystalline glass was discussed.Additionally,the study investigated the temperature variation inside the glass-ceramic samples,and the results indicated that by modifying the slag and annealing it at 700℃ after cooling to the crystallization temperature,microcrystalline glass meets the performance requirements of natural granite.The temperature range of 900-1050℃was found to be associated with the crystallization of the augite phase,while the temperature range of 1000-1050℃ was related to the crystallization of the akermanite phase.With improvements in the heat treatment system,the amount of akermanite phase precipitation will increase,and the grain will become coarser than before.At 900℃,the grain growth of the microcrystalline glass was not as significant as that of the samples annealed at 1000℃ and 1050℃,and the lack of excessive crystallization led to fewer defects inside the glass-ceramics.After studying the temperature profile data,it was observed that during the heat treatment process at 1000-1050℃,inconsistent crystallization between the inner and outer parts of the sample resulted in a temperature gradient from the center to the edge.After studying the temperature profile data,it was observed that during the heat treatment process at 1000-1050℃,inconsistent crystallization between the inner and outer parts of the sample resulted in a temperature gradient from the center to the edge.However,at 900℃,the temperatures of the central and edge regions remained consistent during the crystallization stage.For the heat treatment at 800℃,the slag temperature quickly decreased below 900-1050℃,making crystallization difficult.The overall trend of the temperature difference between the central and side parts of the sample was similar for all four heat-treatment conditions.After casting the slag into the mold,temperature gradients were formed within the sample.These formations do not affect the types of crystalline phases that precipitate;however,they do affect the quantity of crystallization.
基金项目
内蒙古乌兰察布市"揭榜挂帅"资助项目(2022JB002)
维普
万方数据