Ways Toward Improving the Technology of Refractories Based on Powdered Periclase

Periclase powders available from domestic (Magnezit JSC) and foreign manufacturers are analyzed for chemical and mineralogical composition. Domestic magnesite is shown to differ from its foreign analogs in smaller values of MgO content, CaO/SiO₂ ratio, and periclase crystal size. A way toward obtaining high-quality powers involves reducing the concentration of SiO₂ in magnesite to 0.2 – 0.5% and increasing the calcination temperature to 2000 – 2100°C to prepare coarse-grained periclase with a crystal size larger than 140 m. The need for developing a technology that would enable fabrication of refractory components with tailored structural properties from periclase powder is emphasized.     

Microstructure of Periclase

The microstructure of magnesia grains obtained from coarse crystalline and cryptocrystalline magnesites and from seawater and brines is illustrated and the influence of the amount and type of impurities on the development of periclase is discussed. The factors which affect direct peri-clase-periclase bonding in basic brick are reviewed; the microstructural effects of additions of sesquioxides are shown. The complex reactions between periclase and chromite spinel are considered with reference to direct periclase-chromite bonding. The formation of secondary periclase is briefly described.     

尖晶石结合的碱性浇注料与形成尖晶石的添加剂之间的关系

阐述了碱性浇注料的性能与原位形成尖晶石的不同的添加剂之间的关系，对这些浇注料的物理性能进行了比较，结果显示添加适量的铝酸镁凝胶对尖晶石的形成有效，所有结果采用SEM，DTA，TGA和XRD的分析而获得，并证实了此性能。     

Periclase refractories from imported powders

Ten charges with different compositions were obtained from periclase refractories and used to investigate the parameters of periclase articles. The properties of articles of industrial size prepared from imported powders did not differ from those prepared from Satkinsky periclase.Translated from Ogneupory, No. 2, pp. 5 – 7, February, 1995.     

透水砖防堵技术研究与展望

透水砖的铺设能有效地降低城市的洪涝风险,是海绵城市建设的重要环节.透水砖在使用过程中,因雨水径流中颗粒物的累积效应,导致透水性能降低,使用寿命缩短.笔者综述了透水砖的孔隙结构、堵塞机理以及透水砖的防堵塞技术.透水砖的表面和内部孔隙因截留雨水径流中的颗粒物而产生堵塞,堵塞位置和程度受透水砖孔隙结构、雨水径流颗粒物性质及流...     

Periclase articles based on Korean magnesite powder

Conclusions Laboratory and technological development with the production of industrial batches at the Panteleimonovsk refractories factory and the Chasov Yar Combine established that by using Korean magnesite powder it is possible to make periclase articles meeting the demands of GOST 4689-74.Articles with positive properties were tested in the structure of open-hearth furnaces of different capacities.To increase the quality of the articles and their stabilization it is necessary to provide a specialized line, and ensure supplies of high-grade raw material, and to implement certain management and organization measures.The control and measurements department of the Panteleimonovsk refractories factory and the Chasov Yar refractories combine took part in the work.Translated from Ogneupory, No. 3, pp. 25–28, March, 1988.     

Periclase for Use in Electrical Tube Heater

Phase and structural transformations occurring in the periclase material during its extended service life in an electric tube heater are considered. The physicochemical processes involved in the overheat of the heating coil, the thermochemical aging of periclase, and the failure of the electric heater are discussed.     

工艺因素对聚轻砖性能的影响

对聚轻砖中聚苯乙烯球加入量、加入形式、不同原料对聚轻砖性能的影响进行了研究。结果表明：聚轻球的加入量可以波动在2％～9％之间,聚苯乙烯粉末加入量为1％～2．5％为宜。制品在1250℃下烧成即具有良好的性能。     

烧结粉煤灰空心砖生产工艺

介绍烧结粉煤灰空心砖生产原理及原材料选择、陈化、掺配、处理、成型、焙烧等工艺     

水泥熟料中方镁石定量分析

本文简要介绍了水泥熟料中氧化镁的定量分析方法,并采用化学方法和XRD内标法对水泥熟料中的方镁石进行定量分析,用回收率评价了该方法的准确性.结果表明:化学方法和XRD内标法定量水泥熟料中方镁石的含量是可行的,化学方法的回收率在99.40%以上,两种方法的测定结果一致.     

烧结粉煤灰空心砖的人工干燥工艺

介绍粉煤灰空心砖的人工干燥原理,干燥介质温度和湿度对坯体干燥的作用,热工参数的选择,干燥室风量与热量的测定,零压点的控制,室内温度、湿度曲线及坯体脱水收缩曲线的选择,以及干燥工艺和管理要点。     

X-Ray Diffraction Studies of Thermally Shocked Periclase

X-ray line profile analyses were used to study the effect of thermal shock on pericluse (MgO) powders of varied sieve size. Thermal shock does not produce significant microfragmentation; the crystallite size appeared to be ≥150 nm. Microstrain is very low at grain sizes < 0.10 mm, rises sharply up to ∼0.8 mm, and tends to saturate at ∼1 × 10⁻³ at sieve sizes above 3 mm.     

高掺量粉煤灰烧结砖工艺及技术装备

现将本公司研制开发的高掺量粉煤灰烧结多孔砖的工艺及技术装备作一介绍。1 粉煤灰的原料特性 粉煤灰呈细粉状的(1～50微米)球形玻璃体,通常含量70％以上,具有多孔结构,孔隙率为60％～75％,对水的吸附能力很大,往往含水率达30％,仍呈松散状态。大掺量利用粉煤灰,关键是解决尽可能高掺量的粉煤灰与胶结料混合后,如何制备满足烧结砖要求的混合料。