Experimental investigation on molten slag granulation for waste heat recovery from various metallurgical slags

• Published in: Applied thermal engineering Vol. 103; pp. 1112 - 1118
• Main Authors: Liu, Junxiang, Yu, Qingbo, Zuo, Zongliang, Duan, Wenjun, Han, Zhicheng, Qin, Qin, Yang, Fan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 25.06.2016
• Subjects: Dry granulation; High-temperature; Metallurgical slags; Rotary cup; Waste heat; Dry granulation; High-temperature; Metallurgical slags; Waste heat; Rotary cup
• ISSN: 1359-4311
• DOI: 10.1016/j.applthermaleng.2016.05.011

•Dry granulation technology can be applied to various metallurgical slags granulation.•The length of molten slag ligament in granulation for high viscosity slag was long.•There was small change in mean diameter for low viscosity and surface tension slag granulation.•The particle size tended to be uniform with an increase in rotating speed. Metallurgical slags, discharged at high temperature range, are produced as by-products in metallurgical processes. In order to reuse waste energy in molten metallurgical slags, the dry granulation and waste heat recovery technology is a popular technology, compared to water quenching granulation. In the study, the solid particle diameter and size distributions of metallurgical slags with different viscosity and surface tension by dry granulation were investigated. The results indicated that the length of molten slag ligament in granulation for ferroalloy slag, with high viscosity, was long. And there was small change in mean diameter of solid particles with an increase in rotating speed for metallurgy slag with low viscosity and surface tension. The semi-empirical relations, based on the experimental data, can be applied to calculate mean diameter of solid particles for different kinds of metallurgical slags. For blast furnace slag and ferroalloy slag granulation, the main mass fraction peak was located in the range of 2.44–3.14mm. For copper slag granulation, the main mass fraction peak moved to the range of small diameter with an increase in rotating speed.