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.

中文翻译：

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霞石正长岩添加剂对陶瓷和瓷Stone砖技术行为的影响

为了研究埃及霞石正长岩原料对瓷砖烧结性的影响，制备了四批浓度为霞石正长岩（0％，5％，10％和15％）的瓷砖。将这四批物料在1160°C至1260°C的温度下进行研磨，混合，成型，压制和烧制。在干燥，绿色状态下和在1260°C烧制后测量样品的某些技术行为；包括密度参数。相组成和微观结构研究表明，莫来石是在富含碱的玻璃状基质中烧成后刚结晶的相。焙烧批料的技术性能表明，较高的焙烧温度和较高的霞石正长岩含量产生大量的玻璃态，因此堆积密度和线性收缩率增加，烧成批的表观孔隙率和吸水率以及白度下降。得出的结论是，霞石正长岩可以成功地用作瓷砖中的助熔剂，但由于其色泽，在陶瓷体生产中不被接受。