Meikap B C, Purohit N K, Mahadevan V
Department of Chemical Engineering, National Institute of Technology (NIT), Deemed University, Rourkela 769 008, India.
J Colloid Interface Sci. 2005 Jan 1;281(1):225-35. doi: 10.1016/j.jcis.2004.08.084.
Indian high-ash coal contains alpha-silica components of the mineral matter. When coal is transported in the form of a slurry, alpha-silica adds to the settling properties of coal and enhances erosion of pipelines. As such any technique that will contribute to changing the characteristics of mineral matter by selective demineralization is bound to supplement the knowledge of coal slurries in the science of rheology. One such method is the use of a novel microwave technology, which changes the alpha-silica to less harmful beta-silica. Thus microwave-treated coal slurry facilitates enhanced flow characteristics and abates the erosion problem in pipeline transport as well as in coal-slurry injection furnaces. This paper reports on the rheological study of closely sized coal particles of medium-volatile, low-ash, low-moisture cleans and high-ash rejects with and without microwave treatment. Viscosity of suspensions of microwave-treated coal was found to be less than that of untreated coal, in the case of both cleans and rejects. Microwave pretreatment thus reduces the viscosity and the pumping cost and opens a new outlook for pipeline transport. An attempt has been made to quantify the improvement of rheological characteristics due to microwave pretreatment.
印度高灰分煤含有矿物质中的α-二氧化硅成分。当煤以煤浆形式运输时，α-二氧化硅会增加煤的沉降特性，并加剧管道的侵蚀。因此，任何有助于通过选择性脱矿改变矿物质特性的技术都必然会补充流变学中关于煤浆的知识。一种这样的方法是使用新型微波技术，它能将α-二氧化硅转变为危害较小的β-二氧化硅。因此，经微波处理的煤浆有助于改善流动特性，并减轻管道输送以及煤浆注入炉中的侵蚀问题。本文报道了对中等挥发分、低灰分、低水分精煤和高灰分尾煤的粒度相近的煤颗粒进行微波处理和未处理时的流变学研究。结果发现，无论是精煤还是尾煤，经微波处理的煤悬浮液的粘度都低于未处理的煤。因此，微波预处理降低了粘度和泵送成本，并为管道运输开辟了新前景。已尝试量化微波预处理对流变特性的改善。
