Preparation of glasses and glass-ceramics prerared from sewage sludge and incinerator ash.

虽然我们只有有限的堆填区可供弃置这些废物，但每年仍会产生大量废物。如何处理这些废弃物，使其成为有价值的材料，是一个重要而紧迫的问题。污泥经除水和有机物后，其主要成分为无机SiO_2-CaO-Al_2 O_3-Fe_2O_3。在本研究中，将污泥和焚烧炉灰在1350-1450 ℃下熔融，冷却后得到玻璃。结果表明，这些玻璃具有与铝硅酸盐玻璃相似的组成和性质，但具有强烈的黑色和完全不透明。用化学试剂制备的相同组成的玻璃与用废物制备的玻璃相比，不那么不透明。颜色的来源被推断为碳，硅或一些硫化物化合物。模拟结果表明，只要玻璃中含有极细的不透明颗粒，即使小于分析检测值，玻璃也能完全不透明，在pH 7 -10的溶液中，废物玻璃的化学稳定性几乎与窗玻璃相同。但在酸性溶液中的耐久性略低于窗玻璃，微晶玻璃有可能比母玻璃更强。为了制备出性能优良的微晶玻璃，必须采用合适的晶核剂。结果发现，FeS促进从废物的玻璃的结晶。

A huge amount of waste suhstances are generated each year, although we have only limited landfill sites available to disposal of these waste. It is an important and urgent problem how to deal with these waste and how to reuse as valuable materials. The main components of the sewage sludge are inorganic SiO_2-CaO-Al_2O_3-Fe_2O_3 after removal of water and organic substamces. The incinerator ash also has similar compositions.In the present study, the sewage sludge and incinerator ash were melted at 1350-1450ﾟC and after cooling, glasses were obtained. It was shown that these glasses have similar compositions and properties to these of aluminosilicate glasses.However, these glasses have strong black color and completely opaque. The glasses of the same compositions prepared from chemical reagents were not so opaque, compared with those from wastes. Color origins were deduced to be carbon, silicon or some sulfide compounds. By simulation, it was shown that, even small amounts less than analytic detection, the glasses can be completely opaque if very fine opaque particles are distributed in the glasses.It was shown that the glasses from waste have almost same chemical durability as the window glasses in the solution of pH7-10. But in the acidic solution, the durability was slightly less than that of window glasses.The glass-ceramics have possibility to being stronger than the mother glasses. In order to prepare excellent glass-ceramics, proper crystal nucleation agents are necessary. It was found that FeS promotes crystallization of the glasses from waste.