Electrofilter powder (EP) is a residue generated in large amounts during the calcination of aluminium hydroxide in the Bayer process. The production of high temperature structural insulator (HTSI) using EP is proposed. Different tests were made using different proportions of the starting materials, although the optimal mixture contained (in wt%) 52% EP, 14.7% silica fume (or quartz), 12% refractory aluminous cement and 21.3% water. Besides, 900 cm³ of polystyrene flakes were added to the mixture to promote a fine structure of pores. The brick was formed using manual mixing and vibration compacting in silicone molds. Then, it was dried at 100°C for 24 h, and after that, subjected to pre-sintering by heating up to 1050°C, and finally it was sintered at 1400° or 1450°C for 2 h. At the end of the process, the brick comprised 63% mullite, 24% anorthite and 13% corundum, with the following properties: density values within 0.75 and 0.80 g.cm⁻³, thermal conductivity values within 0.25 and 0.29 W.m⁻¹.K⁻¹, compressive strength values higher than 3.5 MPa, total porosity in the range 75–79% and overheat stability at 1400°C for 24 h with no appreciable dimensional changes.

电滤粉（EP）是拜耳法氢氧化铝在煅烧过程中大量产生的残留物。提出了使用 EP 生产高温结构绝缘体 (HTSI)。使用不同比例的起始材料进行了不同的测试，尽管最佳混合物包含（重量百分比）52% EP、14.7% 硅粉（或石英）、12% 耐火铝水泥和 21.3% 水。此外，900 厘米³聚苯乙烯薄片被添加到混合物中以促进孔隙的精细结构。砖是在硅胶模具中使用手动混合和振动压实形成的。然后在100℃下干燥24小时，然后加热到1050℃进行预烧结，最后在1400℃或1450℃下烧结2小时。在工艺结束时，砖由 63% 莫来石、24% 钙长石和 13% 刚玉组成，具有以下特性：密度值在 0.75 和 0.80 g.cm ^{-3 之间}，热导率值在 0.25 和 0.29 Wm ^{-1 之间}。 K ^-1，抗压强度值高于 3.5 MPa，总孔隙率在 75-79% 范围内，并且在 1400°C 下过热稳定性 24 小时，没有明显的尺寸变化。