酸度系数和烧结温度对微晶玻璃的析晶、微观形貌及性能的影响

Effect of Acidity Coefficient and Sintering Temperature on Crystallization,Microstructure and Properties of Glass-Ceramics

提钛渣制备微晶玻璃对于固体废物的无害化处理、释放大面积土地、减少天然原料的开采、改善环境污染具有重要意义。本工作以提钛渣和石英尾矿为原料,采用熔融烧结法制备高性能微晶玻璃。用差示扫描量热分析、X射线荧光光谱分析、X射线衍射分析及扫描电子显微镜等分析现代测试手段,结合性能测试,探究酸度系数(M_(k))和烧结温度对制备的微晶玻璃的物相组成、微观形貌及物理和理化性能的影响。结果表明:改变M_(k)和烧结温度使结晶相的种类和数量发生明显变化。低M_(k)有利于透辉石的生长,而高M_(k)促进钙长石的形成。M_(k)增大有助于降低微晶玻璃的熔化温度并使其在较低的烧结温度下实现致密烧结。适当的M_(k)和烧结温度有助于基体中晶体生长和气孔排除,进而促进微晶玻璃烧结并提高其理化性能。然而,较大的M_(k)或较高的烧结温度导致微晶玻璃中玻璃相增加及气孔尺寸增大,破坏其致密的微观结构并呈过烧膨胀状态。当M_(k)为1.5、烧结温度为1 190℃时,所制备的微晶玻璃具有致密的微观结构与良好的理化性能,其吸水率为0.07%,体积密度为3.05 g/cm^(3),耐酸性为96.6%,抗折强度达144 MPa,各项性能均满足工业微晶玻璃的指标。

Introduction extracted Titanium slag is a type of industrial solid waste produced when titanium is recovered from titanium-containing blast furnace slag using the high-temperature carbonization-low-temperature selective chlorination method.Currently,it can only be disposed of through simple stockpiling and burial,which endangers both the environment and human health.The use of titanium slag to prepare microcrystalline glass with excellent physical and chemical properties is of great significance for the utilization of solid waste resources and the improvement of environmental pollution.Raw material components and heat treatment systems have a significant impact on the microstructure and mechanical properties of glass ceramics.The current work is based on the chemical composition of titanium slag.high-performance glass-ceramics were prepared by melting sintering method by adding quartz tailings to increase SiO_(2) content.Our study examines how the acidity coefficient(M_(k))and sintering temperature affect the crystallization,microstructure,physical and chemical properties of microcrystalline glass.Additionally,we reveal the composition of the physical phase of glass ceramics made from titanium slag and the evolution of crystallization. These findings provide a technical foundation for the synergistic treatment of various solid wastes inthe preparation of glass ceramics.Methods Titanium slag and quartz tailings were prepared, combined, ball milled, and sieved according to the formula design, thenset aside. Weigh the required experimental raw materials, set them in a corundum crucible, heat them in a high-temperature furnacetill the glass liquid melts and clarifies, then immediately dump them into water, cold quench them into glass particles, dry them, ballmill them, and sieve them. The basic glass powder and PVA solution were uniformly mixed before being placed in a press-bar moldand pressed into blank samples, which were then sintered to produce glass ceramics sheet samples.The chemical composition of the raw materials was evaluated using X-ray fluorescence spectrometry. A thermal analyzer wasused to perform the DSC analysis simultaneously. An X-ray diffractometer was used to conduct physical phase analysis on rawmaterials and glass ceramics samples. The microstructure of the glass ceramics samples was observed using a scanning electronmicroscope (SEM), and their microscopic composition was analyzed using an energy dispersive-X-ray spectrometer (EDS).According to the principle of Archimedes, the bulk density and water absorption of each glass-ceramic sample were measured.The bending strength of glass-ceramics was tested by GB/T4741-1999 three-point bending method. JC/T 2097-2011 industrialmicrocrystalline plate’ was used to test the acid etching amount of microcrystalline glass.Results and discussion The images of the look and morphological features of the glass ceramics indicate that the samples' sinteringor fusing steadily improves with an increase in M_(k) under the same temperature settings. At M_(k)=2.4, the sample begins to soften anddistort, whereas at M_(k) =2.7, it looks to froth.The XRD spectra of the glass ceramics samples demonstrate that the type and amount of the early crystalline phases vary as theMand sintering temperature increases. Increasing the heat treatment temperature enhances the intensity of the diffraction peaks of thecrystalline phases in low M_(k) glass ceramics samples. At the same sintering temperature, the content of anorthite in glass ceramicssamples rises with increasing M_(k), while the content of diopside increases in low M_(k) and decreases in high M_(k).The surface and cross-section micro-morphology of the glass ceramics samples demonstrates that the sintering temperature istoo low and the materials do not attain the sintered state at lower With the same M_(k), the number of holes in the samples decreaseswith increasing sintering temperature. As the sintering temperature rises, big closed holes become easier to develop.The features of the glass ceramics samples, together with the results of XRD spectra and SEM photo analysis, show that Flexuralstrength and bulk density are mainly related to the type of crystalline phase, crystal content, and appropriately increase the sinteringtemperature and M_(k) is conducive to the growth of tremolite and calcium feldspar crystals in the billet and the exclusion of porosity, sothat the glass ceramics to form a flatter surface and higher mechanical-strength, which will improve the sample's This improves thesamples' densification, flexural strength, and acid resistance while also reducing water absorption. At higher acidity coefficients,increasing the SiO_(2) content in the base glass causes an increase in the liquid phase, which is beneficial for filling pores, reducing thewater absorption capacity of glass ceramics, and improving corrosion resistance under acidic conditions.Conclusions The main conclusions of this paper are summarized as follows. With the increase of M_(k) and sintering temperature, thetype and quantity of crystalline phases of glass ceramics samples will undergo high-temperature physical phase reconstruction.Within a-certain temperature range, the increase of sintering temperature can promote the growth of crystals-in glass ceramics, andthe intensity of the diffraction peaks of crystalline phases increase However, exceeding the suitable temperature will lead to thetransformation of part of the crystalline phase, low M_(k) favors the growth of diopside in glass ceramics, while high M_(k) promotes theformation of anorthite. When the M_(k) and sintering temperature are low, the glass ceramics samples are not completely sintered,-andthe conditions for crystal growth and exclusion of pores are not sufficient, as the M_(k) and the sintering temperature increase, the liquidphase appears in the matrix, which improves the conditions for crystal growth, and the crystal skeleton becomes solid, when thesintering temperature is too high or the M_(k) is too high, the glass matrix begins to melt, and the phenomenon of overcooking occurs,which-leads to an increase in the glassy phase and the expansion of pores, and makes the glass ceramics-samples have a strong andsolid crystal. skeleton. expansion, making the disjointed circular pores in the glass ceramics samples gradually increase. At M_(k) =1.5sintering temperature 1 190 ℃, with a water absorption rate of 0.07%,bulk density of 3.05 g/cm^(3), acid resistance of 96.6%, flexuralstrength of 144 MPa, and all the properties to meet the requirements of industrial glass ceramics panels.