混煤煅烧水泥熟料的热工检测分析

对TY水泥2500 t/d生产线,在水泥烧成设备和操作不调整的基础上,进行掺杂无烟煤(20％,30％,40％)燃烧的工业试验探索,并对烧成参数进一步分析.结果表明:纯烟煤和掺加20％无烟煤工况下,系统烧成状况良好,熟料产量和质量正常;当无烟煤掺入量大于20％,熟料产量逐渐下降,f-CaO含量变大,热耗迅速上升.为适应更大的掺入量,需要对冷却机附属设备及风量进行合理配置,提高二三次风温度,同时调整燃烧器操作参数来强化窑炉内的无烟煤燃烧.     

浅析烧成系统主要装备优化改造的途径

随着水泥生产技术的发展和生产线性能指标的逐步提升,原有的水泥熟料烧成装备已不能满足生产线提产和节能降耗的要求,对烧成装备的升级改造已成为水泥工业节能降耗的发展途径。在水泥烧成装备优化操作的基础上,通过分析计算,找出水泥烧成系统装备存在的主要问题和瓶颈,同时结合企业改造要求,提出对烧成系统装备可行性的优化改造方案,达到系统提高产量、降低能耗的目的。     

高岭土尾砂在日用细瓷坯料与釉料中的应用

通过正交试验，得出在１３２０℃左右烧成的日用细瓷坯料中，高岭土尾砂的最大用量为４５％，最佳用量为４０％左右；釉料中高岭土尾砂最大用量为５０％，最佳用量为４５％左右。新研制的坯料与釉料成本低廉，制品性能达到日用细瓷的要求，采用还原气氛烧成，瓷器呈白里泛青的色调，适合于青花装饰。     

陶瓷生产中的微波辅助烧成

陶瓷产品可以说是一种绝热材料,其导热率通常低于１Ｗ／ｍ·Ｋ。为满足制品烧成要求,只能提高烧成温度,并且保持规定的时间。由于试件表面温度远高于中心温度,这样容易产生热应力,使产品出现裂纹或破坏;而且,产品内部性能也不均匀。在最近１０～１５年间,人们一直在采用微波进行陶瓷烧成,这已经成为世界性的研究课题。经过使用微波单独进行烧成及用微波辅助其它工艺进行烧成等方法的试验,目前已找到了一种较实用、合理的方法,这就是微波辅助气体烧成工艺目前,微波辅助烧成工艺已经从实验室阶段走向小规模生产。在这种烧成方法中,微波被用来…     

低质坯料稀土乳浊釉低温烧成卫生瓷的研究

一、前言国家建材局编制并通过专家审议的《建筑卫生瓷工业“八五”技术进步规划》提出,在八五期间综合耗能降低15％,其中烧成能耗降低20％;并指出低温快烧工艺是降低烧成热耗和缩短烧成周期的有效手段,所以本试验采用低温烧成卫生瓷,旨在开辟卫生瓷生产的新途径。本选题除了节能降耗以外,同时还考虑到以下几点: ①长期以来我们产品釉面白度低、乳浊度不高,不得不采用优质坯用原料。这样势     

低温无铅色釉的研制

随着欧美国家对陶瓷制品铅镉溶出限量标准的提高,日用陶瓷使用无铅釉进行装饰已是大势所趋。而且,由于燃料价格的持续走高,降低烧成成本已成为多数日用陶瓷生产厂家的要求。本文应用低温烧成无铅透明釉为基础釉,在骨瓷坯体上进行了色釉装饰试验,取得了良好的试验结果。     

卫生洁具修补及二级烧成技术

1前 言 在卫生陶瓷洁具大生产中,经过一次烧成后一级品率通常为 65％左右,废品率 30％左右,其余产品则由于各种缺陷而达不到一级品的要求。为保证企业的产品质量,提高成品率,增加经济效益,产品修补和二次烧成则可以解决这些产品的问题。 所谓二次烧成修补技术,就是去掉产品经一次烧成后产生的缺陷,补上修补泥和修补釉,再把产品放回窑内高温重烧,烧成后修补的釉和泥与原坯釉熔合,产品釉面外观回复正常状态。从微观上说,经一次高温烧成后的瓷坯,存在着晶相、玻璃相、还有少量的气孔,晶相构成了坯体的骨架,玻璃相为骨架的间隙…     

辉绿岩母岩→风化岩→风化土应用结果--论水泥原料的成因与烧成效果

浙江省上峰水泥厂为了降低成本、降低烧成煤耗、提高产质量,利用就近资源,做了较多的原料试验试烧工作,其中对岩浆岩石学中叫基性(SiO245％～53％)岩浆岩的辉绿岩母岩,它的风化岩,它的风化残积粘土作了系统探索,找到了应用辉绿岩的风化岩为最佳原料烧成方案。     

应用AST和纯碱提高瓷坯球磨效率的试验小结

提高球磨效率,是陶瓷生产中共同关心和急待解决的重要课题。最近我们在南京林化所和宜兴陶研所的大力支持协助下,应用AST对助磨、压滤、成型作了对比试验,取得了较为满意的效果。普瓷坯泥球磨效率提高了93％;青瓷坯泥球磨效率提高了97％;压滤水分减少了1％左右,基本满足了我厂滚压成型的要求。干坯强度也有了较为明显的提高,降低了损坯率,而对烧成白度等无影响。AST是一种很有希望的减水剂。     

生料磨的小改小革

牡丹江水泥集团烧成二分厂生料车间把提高职工创新意识,积极开展"小改小革"活动,做为内部挖潜、降低成本的一项重要举措,现举例一、二如下: (1)原有φ2.6m×13m生料磨磨头采用毛毡密封,常发生冒料、漏灰现象,不耐磨易损。经过试验,现采用皮带胶圈密封,即用耐磨皮带胶圈替代毛毡,外部淋     

Effect of wollastonite addition on sintering of hard porcelain

Hard porcelain body with wollastonite additive was produced by the slip casting method using quartz, potassium feldspar and kaolin raw materials. Wollastonite powders were added to the porcelain formulation by replacing the potassium feldspar up to 5 wt% to explore its effect on the sintering behaviour and also technological properties of as sintered end products. By means of rheological behaviour optimization of ceramic suspensions using several dispersants and sintering enhancement by wollastonite addition, hard porcelain of higher strength at lower firing temperature was obtained. By studying the effect of the additive concentration, on the firing temperatures of the hard porcelain, it is found that reducing firing temperature 25 °C without compromising its quality and thereby producing energy saving was achieved by 1 wt% wollastonite addition.     

镁质高强无铅高级日用细瓷的研究(第二代滑石质日用细瓷的研究)

通过对滑石瓷原料的优化选择、配方调整及制瓷工艺技术的改进,特别是二次烧成工艺和无铅釉的开发应用,彻底解决了长期困扰滑石瓷的难于成形、高温变形、釉面不光和铅镉危害等问题,使该瓷种的质量和水平较前有了本质的改变。这无疑为滑石瓷跻身于高档日用细瓷提供了技术支撑。     

Sugarcane Bagasse ash substituent feldspar for the production of porcelain electrical insulators

Sugarcane bagasse ash (SCBA) industrial waste was used to partially substitute feldspar in the production of porcelain electrical insulators from a mixture of locally available Bombawuha clay (BC), Chancho sand (CS), and mixture of Wolkite (WF) and Arerti feldspar (AF) (50:50%). The raw materials were characterized for their chemical composition, mineralogy, thermal behavior, and plasticity. The porcelain electrical insulator formulations containing various proportions of SCBA (0 wt%, 10 wt%, 15 wt%, and 20 wt%) were fired at different firing temperatures of 1200 °C, 1250 °C, and 1300 °C for 2.5 h. The fired bodies were evaluated for water absorption, apparent porosity, bulk density, flexural strength, dielectric strength, and microstructure. The results showed that SCBA had 65.06% silica (SiO₂) and had higher alkaline and iron oxide (Fe₂O₃) contents than the natural feldspars. Bombawuha clay contained kaolinite as a major mineral with a middle range plasticity index (PI = 11.2%) and the met the required purity necessary for mullite phase formation. The feldspars had a low alkali content of sodium oxide plus potassium oxide (Na₂O + K₂O) of < 6 wt %. The prepared porcelain insulator containing 10% SCBA, 50% BC, 30% mixed feldspars, and 10% CS, and fired at 1250 °C for 2.5 h exhibited a water absorption of 0.35%, flexural strength of 42.50 MPa, and a dielectric strength of 6.59 kV/mm, which satisfies the obligatory properties for quality porcelain insulators. Further, the partial replacement of feldspar by SCBA up to 10 w% lowered the firing temperature by 50 °C.     

Recycling of chromium-rich leather ashes in porcelain tiles production

Leather residues derived from shoes industry are often incinerated in winter times to warm the working ambient, giving rise to the production of chromium-rich ashes that put environmental problems on its disposal. The power of these ashes as colouring and fluxing agent for industrial porcelain tile formulations and the effects of incorporating different amounts on water absorption and bending strength were evaluated in the present work along a broad sintering temperature range of 1120–1180 °C. The experimental results revealed that the incorporation of these wastes can result in porcelain tiles with superior properties, in terms of water adsorption, density and bending strength. The results also showed the possibility of using these wastes as colouring agents to obtain broad range tonality products from cream to dark brown, depending on the added amount of leather ashes in the formulation and on the sintering temperature. The observed improvements of the final properties of the material and the ability of chromium-rich ashes to replace expensive pigments show that their incorporating in porcelain tiles formulations is a smart way of recycling this environmental dangerous leather derived waste.     

热膨胀法判定建窑黑瓷烧成温度的应用研究

以热膨胀仪判定建窑黑瓷烧成温度的研究为例,综合运用多种测试方法对建窑黑瓷标本进行了系统研究,探讨如何从建窑黑瓷胎体重烧热膨胀曲线中筛选有效转折点的问题及其转折点的形成原因。研究表明:(1)建窑黑瓷胎体重烧热膨胀曲线上有三个转折点,分别为收缩转折点、膨胀转折点和急剧收缩点。其中第一个收缩转折点是判定其古代烧成温度的关键点。(2)建窑黑瓷胎体重烧热膨胀曲线上膨胀转折点和急剧收缩点的形成皆与其胎体中大量Fe_2O_3在高温下发生分解反应有关。该研究不仅为热膨胀仪测定建窑黑瓷烧成温度的应用研究提供判定依据,也将为科学认识古陶瓷胎体重烧热膨胀曲线上多个转折点的形成机理提供数据支持。     

Effect of calcined colemanite additions on properties of hard porcelain body

Utilization of calcined colemanite as a sintering aid in hard porcelain body, prepared by slip casting route using aqueous suspension containing mixtures of kaolin, quartz and potassium feldspar, was investigated. After calcination, colemanite powders were added to the admixture of porcelain by partial substitution with potassium feldspars in the range of 0–5 wt% to discover its influences on the densification and technological properties of the final product. Through optimization of process parameters of ceramic suspensions by using appropriate dispersing agents and facilitating densification by calcined colemanite addition, hard porcelain possess high strength was obtained. When relationship between the additive concentration with temperature was established, it is found that porcelain formulations resulted in substantial reduction of firing temperature about 50 °C without compromising its quality by 1 wt% calcined colemanite addition.     

Influence of mineralogical composition of applied ball clays on properties of porcelain tiles

Relations between quality of ball clays applied in raw materials batches for manufacture of porcelain tiles, and physical properties and microstructure of obtained tiles, were investigated. Studied clays constituted 35% of the batch, while the other components were unchangeable. Stoch index, new IR 3620/3700 index and XRIR index (Stoch index multiplied by IR 3620/3700 index), were proposed to take into account crystallinity of kaolinite and contents of illite and smectites in studied clays. Relationship between XRIR index value of clay, and water absorption and abrasion resistance of the obtained ceramic material, was found. Water absorption of the tile is also correlated with grain size distribution and bending strength of used clay. Optimal ball clay for porcelain tile production should exhibit: Stoch index - min. 4.3; IR 3620/3700 index - min. 1.2; XRIR index - min. 4.8; grain size median - max. 0.27 μm; bending strength after drying - min. 8.0 MPa.     

Firing process and colouring mechanism of black glaze and brown glaze porcelains from the Yuan and Ming dynasties from the Qingliang Temple kiln in Baofeng,Henan, China

Black glaze and brown glaze porcelains were an important part of ancient Chinese iron-based high temperature glazes. The excavation of black glaze and brown glaze porcelains from the Yuan and Ming dynasties at the Qingliang Temple kiln site in Baofeng, Henan, China, in 2014, enriched the firing history of this kiln site and history of Chinese ceramics. In this study, black glaze and brown glaze porcelain samples from the Qingliang Temple kiln site from the Yuan and Ming dynasties were selected and analysed via optical microscopy, laser Raman spectroscopy, focused ion beam scanning electron microscopy combined with EDS and energy dispersive X-ray fluorescence to determine their microscopic morphology, microzone composition, microstructure and chemical composition. Moreover, the main wavelength range of the brown glaze porcelain samples were measured by UV–Vis–NIR spectrophotometer systems. The main conclusions of this study are as follows. The brown glaze porcelain from the Yuan and Ming dynasties at the Qingliang Temple kiln site has two different colour layers, with the surface is brown and the bottom is black. The presence of a glass phase and α-Fe₂O₃ phase in the black glaze porcelain samples, and a rare ε-Fe₂O₃ phase in the brown glaze porcelain samples. The brown colour was a result of ε-Fe₂O₃ precipitation, whilst the black base layer also enhanced the brown-colouring effect. Different glaze formulations were used for brown glazed porcelain, some of which were similar to those used for black glaze porcelain and derived from the transformation of black glaze porcelain through different firing atmospheres and cooling rates. Although the formula of the brown glaze porcelain samples exhibited differences, the main wavelength difference was not large, was within the 645–682 nm range and belonged to the visible red region.     

Effect of soda-lime glass on sintering and technological properties of porcelain stoneware tiles

The feasibility of waste glass recycling in ceramic tile production was assessed with special reference to fully vitrified products (porcelain stoneware). Soda-lime float or container glass was introduced, in replacement of sodic feldspar, in typical porcelain stoneware bodies (up to 10 wt.%) that underwent a laboratory simulation of tilemaking process, with a technological and compositional characterization of both fired and unfired tiles. Soda-lime glass had no significant effect on semi-finished products, but it influenced remarkably the firing behaviour, increasing shrinkage and closed porosity, decreasing open porosity and bulk density, and lowering mechanical and tribological performances. Waste glass promotes a more effective melting of quartz and a partial dissolution of mullite, leading to a more abundant and less viscous liquid phase, which accelerates the sintering kinetics. In conclusion, soda-lime glass can be used in small amounts (5% or less) with tolerable modifications of technological behaviour and performances of porcelain stoneware tiles.     

Effect of microstructure on cutting processability of porcelain tile subjected to different firing cycles

The fast firing technique is one of the most important ways to save energy consumption and improve production efficiency in the porcelain tile industry. In the actual production, excessively short firing cycle time easily causes the cutting edge defects. This work examines the effect of microstructure on cutting processability of a representative composition of a commercial porcelain tile fired at 1200 °C with two different firing cycles as follows: 40 min and 60 min. The phase composition and microstructure were investigated by using a combination of techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM). The result indicated that it was beneficial to extend firing cycle (from 40 min to 60 min) for the cutting processability of porcelain tiles, which was due to the formation of positive microstructures such as secondary mullite needles and small-volume residual quartz.