The Growth Characteristics and Kinetics of Metallic Iron in Coal-Based Reduction of Jinchuan Ferronickel Slag

Abstract

As the fourth-largest industry waste residue, after iron slag, steel slag, and red mud, in China, the comprehensive utilization of nickel slag is imminent. Coal-based reduction combined with magnetic separation was considered an efficient method to extract iron from nickel slag. During the coal-based reduction of Jinchuan ferronickel slag, the growth characteristics and kinetics of metallic iron were investigated in this paper. The metallisation rate and metal iron grain size gradually increased with the reduction temperature or the reaction time, and the coal-based reduction process was divided into the rapid formation period and the aggregation growth period of the metallic phase. The granularity distribution of metallic iron obeyed the Doseresp sigmoidal function, and the activation energy of grain growth at different stages were 52.482 ± 4.448 kJ·mol−1 and 26.426 ± 3.295 kJ·mol−1, respectively. Meanwhile, a mathematical growth model of the metallic iron grains was also established.

Kinetics and Mechanism of Red Mud Carbothermic Reduction and Reduced Iron Grain Growth: An Influence of Sodium Sulfate

“…In order to describe the formal kinetics of the iron particle growth process during the solid phase carbothermic reduction of RM, the Hillert kinetic model was used. It also was previously used for the description of the iron growth process during the reduction of various iron-containing materials [39][40][41][42][43][44]. According to Hillert s theory, the grain growth process can be described by the following equation:…”