文章摘要

Recent advances in artificial aggregate production
(人造骨料的最新进展 - 综述文章)
*Pengfei Ren as first author
 

Journal: Journal of Cleaner Production
Link: sciencedirect.com/science/article/abs/pii/S0959652620352598

 

Abstract: 
Artificial aggregates (AAs) are man-made construction material, and the properties greatly depend on its manufacturing process (e.g. granulation and hardening) and the raw materials (usually different source of wastes) used. This paper reviews the granulation process and suitable raw materials for each hardening method. Hardening methods including sintering, cold-bonding, accelerated carbonation and alkaline activation can significantly impact the final properties of the produced AAs. In general, finer material fractions are required for granulation to increase the pelletization efficiency and strength of AAs. Among the hardening methods, sintering usually gives a better physical and mechanical properties of AAs with a condition that SiO2/∑flux ratio of raw materials used should exceed 2, and (SiO2+Al2O3)/∑flux ratio of between 3.5 and 10. The cold-bonded method requires hydraulic raw materials and is restricted by a longer curing time, but this can be solved by introducing autoclaving or alkaline activation approaches to accelerate the strength gain. Post curing of AAs under a strongly alkaline solution can also effectively reduce the water absorption of aggregate by nearly 90%. The accelerated carbonation technique seems to be a green and more sustainable hardening method, as it can turn less valuable waste into strength bearing calcite and permanently store the waste CO2 through mineral carbonation. In terms of leachability, sintering can stabilize most heavy metals, while other hardening methods such as cold bonding and carbonation are only effective for stabilizing certain heavy metals.


Chinese version:
人造骨料(AAs)是人为生产的建筑材料,其性能在很大程度上取决于制造工艺(如造粒和硬化)以及所使用的原材料(通常是不同来源的废弃物)。本文对不同硬化方法的造粒工艺以及原材料进行了综述。硬化方法主要包括烧结、冷结、加速碳化和碱激发,每种方法对于人造骨料的最终性能都有显著的影响。一般来说,造粒需要更细的材料来提高造粒效率以及提高骨料的强度。在各种硬化方法中,烧结骨料的物理机械性能较好,所用原料的SiO2/∑通量比应大于2,且(SiO2+Al2O3)/∑通量比在3.5~10之间。冷结法需要材料具有一定的水化活性,而其性能受到较长养护时间的限制。但这个缺陷可以通过高压养护和碱激发的方法来加速强度的发展。在强碱性溶液中进行人造骨料的养护也能有效地降低骨料的吸水率近90%。加速碳化技术似乎是一种绿色且更可持续的硬化方法,因为它可以将价值较低的废物转化为高强度的方解石,并通过矿物碳化永久储存废弃二氧化碳。就浸出性而言,烧结法可以稳定大多数重金属,而其他硬化方法(如冷结和碳化)仅对稳定某些重金属有效。

More research team's published works: 
https://www.tcling.com/index.php?m=content&c=index&a=lists&catid=11