Brown corundum fly ash (BCFA), which is the collected ash in brown corundum production, has received lots of environmental concerns due to its ultra-fine particle size and complex composition. Aiming to recycle the major elements including K, Al and Si from BCFA environmentally, this work proposed a simple and non-pollution process to utilize BCFA by water leaching, size screening and solution evaporation. The influences of water leaching conditions including leaching temperature, time and liquid-to-solid ratio was considered to optimize the K₂SO₄ recovery efficiency. Results show that the potassium sulfate content of the product is 75.7% after water leaching at 60 °C for 15 min with the liquid–solid ratio of 20:1. The wet screening and size separation with a 1 μm sieve can separate and enrich aluminum and silicon significantly. The aluminum-rich product is composed of 54.65% of alumina and 11.04% silica, with the alumina and silica ratio (A/S) of 4.95. The silicon-rich product with a particle size of less than 1 μm has a silica content of 57.57% can be used as high-value micro-sphere silica. The research results revealed in this work offers a potential and environmentally industrial treatment technique for the BCFA.

中文翻译：

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棕刚玉粉煤灰中K2SO4的回收和SiO2 / Al2O3的分离

棕刚玉粉煤灰（BCFA）是棕刚玉生产中收集的灰分，由于其超细的粒径和复杂的组成而引起了许多环境方面的关注。为了环保地回收BCFA中的K，Al和Si等主要元素，这项工作提出了一种简单且无污染的工艺，通过水浸，筛分和溶液蒸发来利用BCFA。为了优化K ₂ SO ₄，考虑了浸出条件的影响，包括浸出温度，时间和液固比。恢复效率。结果表明，在60°C水浸15分钟，液固比为20：1后，产品的硫酸钾含量为75.7％。使用1μm筛子进行湿筛和筛分可​​以显着分离和富集铝和硅。富铝产品由54.65％的氧化铝和11.04％的二氧化硅组成，氧化铝与二氧化硅之比（A / S）为4.95。粒径小于1μm的富硅产品的二氧化硅含量为57.57％，可用作高价值的微球二氧化硅。这项工作揭示的研究结果为BCFA提供了一种潜在的，环境友好的工业处理技术。