赛马霞石正长岩水热碱法分解反应动力学

辽宁省赛马霞石正长岩的主要矿物有钾长石、钠沸石、黑云母和白云母,其中氧化钾含量超过10%,是制取钾盐的重要原料。以氢氧化钠为碱性介质,对其进行了水热碱法分解实验。结果表明,霞石正长岩与NaOH水热分解反应的产物为羟钙霞石,分解反应属于1级反应;分解过程符合动力学方程1-(1-x)~(1/3)=kt反应的表观活化能为E_a=38.8 kJ/mol;复合反应体系中钠沸石的分解速率是影响正长岩分解反应的重要因素。     

霞石正长岩在绿色浮法玻璃中的应用研究

以霞石正长岩取代长石,按照绿色浮法玻璃的成分制备配合料并熔制玻璃。通过对熔化过程的观察和对玻璃样品有关性能测试结果的分析,讨论了霞石正长岩作为绿色浮法玻璃原料的可行性。     

霞石正长岩在仿古砖无光釉中的应用

本文介绍了在传统釉料配方工艺基础上,研究了霞石正长岩精加工粉料在仿古砖无光釉中的开发与应用,并取得较好的效果。实验证明:采用霞石正长岩精加工粉料取代部分熔块、长石类熔剂等原料,有利于提高釉面的机械强度、调整坯釉结合性、降低生产成本和提高产品优等率等。     

霞石正长岩在陶瓷釉料中的应用

霞石正长岩,在自然界中大量存在,由于其碱金属含量大,可以在釉料中代替长石使用。本文利用四川的霞石正长岩通过大量试验得到了一种对坯体适应性强,对烧成气氛不敏感的高光泽透明釉。在此釉料中加入特殊着色剂可产生小油滴斑。     

霞石正长岩的测定

分析霞石正长岩各组分的含量和铁矿物在矿石中的赋存状态。实验中采用了原子荧光光谱法对矿物进行了系统分析,并通过此方法分析矿石中的铁含量。     

霞石正长岩综合利用生产化工产品工艺计算

采用Excel软件中的迭代计算法对个旧霞石正长岩综合利用生产碳酸钠、硫酸钾、磷酸二氢钾产品进行了物料衡算,获得了个旧霞石正长岩之碳分母液处理流程中的蒸发水量及经多次循环后料液平衡时组成、产品规模及质量,为工艺参数的确定和项目的技术经济分析提供了依据.以5万t/a氧化铝为计算基准,个旧霞石正长岩综合利用生产化工产品的年生产规模为:碳酸钠1.605万t,硫酸钾634 t,磷酸二氢钾5.67万t,产品质量分数:碳酸钠94.40%,硫酸钾95.82%,磷酸二氢钾93.03%.物料衡算结果可根据计算基础数据自动调整,计算方法快捷、易于掌握.     

一种用霞石正长岩提铝硅钙渣制备硅灰石的新方法

在充分考虑了云南个旧霞石正长岩硅钙渣的物质组成特点的基础上,不添加额外的硅源和钙源,以较低的温度(800~900℃),煅烧1 h,将个旧霞石正长岩硅钙渣合成为质量分数80%~85%的硅灰石。制品符合中国行业标准DZ/T0207—2002的要求。     

霞石正长岩的开发和应用

霞石正长岩是一种新型节能陶瓷原料。用它代替长石制备坯釉料，可成功烧制日用陶瓷、美术瓷、卫生瓷、外墙砖、釉面砖产品。精选后的尾砂可生产彩色釉面砖，具有广泛的开发应用前景。     

霞石正长岩对碱-硅酸反应的影响

以霞石正长岩为代表,研究了含碱集料对碱-硅酸反应膨胀的影响。研究结果表明,80℃或150℃蒸汽养护条件下可快速检测出霞石正长岩对碱-硅酸反应的影响;霞石正长岩在混凝土中的分解反应在增加混凝土可溶碱含量的同时,反应本身还将降低孔溶液OH-浓度,因此由霞石正长岩分解析出的碱与水泥中的碱对碱-硅酸反应影响不同,只有在适当的条件下才能显著增大碱-硅酸反应膨胀。     

霞石正长岩的开发和应用

霞石正长岩是一种新型节能陶瓷原料。用它代替长石制备坯釉料,可成功烧制日用细瓷、美术瓷、卫生瓷、外墙砖、釉面砖产品。精选后的尾砂可生产彩色釉面砖,具有广泛的开发应用前景。     

Porcelain stoneware with pegmatite and nepheline syenite solid solutions: Pore size distribution and descriptive microstructure

Investigations correlating the pore size distribution-cumulative pore volume to the microstructure are used to compare the efficiency of two solid solutions of pegmatite and nepheline syenite as fluxing agents for the design of porcelainized stoneware. Particularly the fusibility of the two solid solutions was modified by adjusting the CaO content of the bodies. As results, the pegmatite based flux produced an extended viscous phase capable on embedding the crystalline phases and close open porosity as from 1175 °C. Conversely, the bodies with nepheline syenite remained relatively porous up to 1225 °C although the similar results of the mechanical strength at this temperature. The investigations on microstructure, pores size distribution and cumulative pore volume indicated almost complete reduction of the open pores in the pegmatite based bodies and the development of a band of closed pores ranged between 0.080 and 0.9 μm showing P series as a more compact structure. For the nepheline syenite based bodies, the incomplete reduction of the open pores and the relative absence of the band of pores between 0.080 and 0.9 μm were ascribed to the difference in fusibility and the viscosity of the glassy phases. These differences were interpreted in term of the differential action of CaO in Na₂O–Al₂O₃–SiO₂ and K₂O–Al₂O₃–SiO₂ on the amount and viscosity of the liquid phase formed already described in the literature.     

USE OF NEPHELINE SYENITE IN FLOOR-TILE AND WALL-TILE BODIES*

The physical properties of wall-tile bodies and floor-tile bodies are described. The wall-tile bodies are fluxed respectively with nepheline syenite; feldspar; talc and feldspar; talc and syenite; talc, pyrophyllite, and syenite; and talc, pyrophyllite, and feldspar. Floor-tile bodies, developing at lower temperatures, may be formulated with nepheline syenite. The greater refractoriness of American clays used in these bodies, as compared to English clays, is compensated for by the increased fluxing action of nepheline syenite.     

LOW-TEMPERATURE VITREOUS BODIES*

The properties of a series of low-temperature bodies predominately comprised of clays and nepheline syenite are described. These bodies have a higher alumina content than the usual typical pottery bodies because of the high alumina content of nepheline syenite and clays and also because flint is introduced only in small amounts.     

湖北随州硬玉质的变霓霞正长岩的岩石矿物特征及应用研究

随州硬玉质变霓霞正长岩的岩石组织结构、矿物赋存状态、矿石可选性和玻璃陶瓷原料应用试验研究表明：该资源具有易采易进两大优点,矿石经单一磁选的精矿可作玻璃和陶瓷的原料;同时已反复试验证实该资源可烧成原矿用量达90％的釉面墙地砖。     

Effect of Nepheline Syenite Additives on the Technological Behavior of Ceramics and Porcelain Stoneware Tiles

To study the effect of the Egyptian nepheline syenite raw materials on the sinterability of the ceramic tiles, four batches with concentrations of nepheline syenite (0, 5, 10 and 15%) were prepared. The four batches were ground, mixed, shaped, pressed and fired at temperatures from 1160 °C to 1260 °C. Some technological behaviors of the samples were measured in dry, green state and after firing at 1260 °C; including densfication parameters. Phase composition and microstructural studies refered that mullite was the newly crystallized phase after firing set in a glassy matrix enriched in alkalis. Technological properties of the fired batches revealed that the higher firing temperature and higher nepheline syenite contents produced larger amounts of glassy phase, and consequently bulk density and linear shrinkage increased, while apparent porosity and water adsorption as well as whiteness of fired batches decreased. It is concluded that nepheline syenite could be successfully used as flux in ceramic tiles, while it is not accepted in the production of porcelain bodies because of their coloration.

     

Nepheline syenite-talc low temperature vitrified bodies

Compositions in the system, talc-nepheline syenite-quartz-china clay (Kaolinite) were studied. The content of nepheline syenite was kept constant, 25%, while talc was added in the range of 5–15% at the expense of quartz. This study extended the range of fusible talc/nepheline mixes from 15 to 28%. The content of talc dissolved in the glassy phase is limited to 3–4%. Addition of talc to the compositions caused the dissolution of mullite and increased the glassy phase. The addition of nepheline syenite counteracts the effect of talc on the thermal expansion coefficient of the bodies.     

EFFECT OF REFRACTORY MILL ADDITIONS ON MOLTEN APPARENT VISCOSITIES OF STEEL GROUND-COAT ENAMELS*

A viscosimeter of the rotating-cylinder type was used to determine the effect of refractory mill additions on the molten apparent viscosity of steel ground-coat enamel. A blend of three commercial frits was used as the base enamel to study the effect on molten viscosity of various amounts of silica, feldspar; and nepheline syenite. Results indicated that silica imparted the greatest increase in molten viscosity. Additions of feldspar and nepheline syenite of 9% or less increased the molten viscosity about the Same amount. With, however, a 12% addition of refractory, feldspar was more effective for increasing molten viscosity than nepheline syenite.     

Crystallisation of processed nepheline syenite–magnesite glasses

Abstract

Transparent glasses were prepared from processed nepheline syenite–magnesite mixtures. Incorporation of TiO₂ in the base glasses changes the glass colour from white to amber or dark brown. Translucent porcelainous glass ceramics with white, creamy and a variety of bluish colorations were obtained in glasses containing non-magnetic nepheline syenite. However, dark marblelike glass ceramics were developed in glasses containing middling and tailing nepheline syenite. Aluminium diopside [Ca(Mg,Al)(Si,Al)₂O₆], nepheline, forsterite, magnesium titanate MgTi₂O₅ and hematite were developed by heat treatment of these glasses. SEM micrographs tend to show fine and uniform bulk with increasing Fe₂O₃ contents in the parent glass ceramic samples, however addition of TiO₂ enhances nucleation and the microstructure becomes of evenly good uniform fine structure in the sample with lowest iron content.     

Microstructural Evolution in Clay-Based Ceramics I: Single Components and Binary Mixtures of Clay, Flux, and Quartz Filler

Microstructural evolution on heating kaolinite clay, quartz, nepheline syenite, and soda–lime–silica (SLS) glass to various temperatures to 1300°C was investigated in quenched and slowly cooled samples by XRD, thermal analysis and SEM, and by in situ XRD. In the individual components, the expected behavior was observed and in SLS glass, devitrification led to crystallization of cristobalite, quartz, devitrite, and wollastonite, which dissolved at 900°–1000°C. Significant effects of each component on microstructural evolution in the others were often observed in binary mixtures. For example, in SLS glass and quartz mixtures, devitrification of SLS glass to form cristobalite was delayed and two forms of cristobalite with different morphologies were identified. Albite and plagioclase crystallized on heating kaolin clay and SLS glass mixtures, decreasing the alumina content available for mullite formation. Melting of nepheline syenite promoted reaction with the clay, including accelerated phase dissolution. SLS glass accelerated dissolution of nepheline syenite and prevented leucite formation.