Clark Malcolm W, Despland Laure M, Lake Neal J, Yee Lachlan H, Anstoetz Manuela, Arif Elisabeth, Parr Jeffery F, Doumit Philip
School of Environment Science and Engineering, Southern Cross University, PO Box 157, Lismore NSW, 2480, Australia.
Marine Ecology Research Centre, Southern Cross University, PO Box 157, Lismore NSW, 2480, Australia.
Heliyon. 2017 Apr 17;3(4):e00294. doi: 10.1016/j.heliyon.2017.e00294. eCollection 2017 Apr.
Sugarcane bagasse ash re-utilisation has been advocated as a silica-rich feed for zeolites, pozzolans in cements and concretes, and geopolymers. However, many papers report variable success with the incorporation of such materials in these products as the ash can be inconsistent in nature. Therefore, understanding what variables affect the ash quality in real mills and understanding the processes to characterise ashes is critical in predicting successful ash waste utilisation. This paper investigated sugarcane bagasse ash from three sugar mills (Northern NSW, Australia) where two are used for the co-generation of electricity. Data shows that the burn temperatures of the bagasse in the high-efficiency co-generation boilers are much higher than those reported at the temperature measuring points. Silica polymorph transitions indicate the high burn temperatures of ≈1550 °C, produces ash dominated α -quartz rather than expected α-cristobilite and amorphous silica; although α-cristobilite, and amorphous silica are present. Furthermore, burn temperatures must be ≤1700 °C, because of the absence of lechatelierite where silica fusing and globulisation dominates. Consequently, silica-mineralogy changes deactivate the bagasse ash by reducing silica solubility, thus making bagasse ash utilisation in synthetic zeolites, geopolymers, or a pozzolanic material in mortars and concretes more difficult. For the ashes investigated, use as a filler material in cements and concrete has the greatest potential. Reported mill boiler temperatures discrepancies and the physical characteristics of the ash, highlight the importance of accurate temperature monitoring at the combustion seat if bagasse ash quality is to be prioritised to ensure a usable final ash product.
甘蔗渣灰的再利用被提倡作为一种富含二氧化硅的原料用于制造沸石、水泥和混凝土中的火山灰质材料以及地质聚合物。然而，许多论文报道，将此类材料掺入这些产品中的成功率各不相同，因为这种灰的性质可能不一致。因此，了解实际工厂中哪些变量会影响灰的质量以及了解表征灰的过程对于预测灰渣的成功利用至关重要。本文研究了来自澳大利亚新南威尔士州北部三个糖厂的甘蔗渣灰，其中两个用于热电联产。数据表明，高效热电联产锅炉中甘蔗渣的燃烧温度远高于温度测量点所报告的温度。二氧化硅多晶型转变表明，约1550℃的高燃烧温度产生的灰以α-石英为主，而不是预期的α-方石英和无定形二氧化硅；尽管存在α-方石英和无定形二氧化硅。此外，燃烧温度必须≤1700℃，因为在二氧化硅熔化和球化占主导的情况下没有焦石英。因此，二氧化硅矿物学的变化通过降低二氧化硅的溶解度使甘蔗渣灰失活，从而使甘蔗渣灰在合成沸石、地质聚合物或砂浆和混凝土中的火山灰质材料中的应用更加困难。对于所研究的灰，用作水泥和混凝土中的填充材料具有最大的潜力。所报道的工厂锅炉温度差异以及灰的物理特性，突出了如果要优先考虑甘蔗渣灰的质量以确保最终得到可用的灰产品，在燃烧部位进行精确温度监测的重要性。
