Page 28 - Mines and Minerals Reporter eMagazine - Volume October 2021

TECHNOLOGY

MECHANISM FOR

SUSPENSION

MAGNETIZATION

ROASTING OF

IRON ORE USING

STRAW-TYPE

BIOMASS

REDUCTANT

Yue Cao a,b,c , Yongsheng Sun a,b,c,* , Peng Gao a,b,c , Yuexin Han
, School of Resources and Civil Engineering,
a,b,c , Yanjun Li a,b,c a
Northeastern University, Shenyang 110819, China, Nation-
b
al-local Joint Engineering Research Center of High-efficient
Exploitation Technology for Refractory Iron Ore Resources,
Shenyang 110819, China, State Key Laboratory of Rolling and
c
Automation, Northeastern University, Shenyang 110819, China

Abstract

s an alternative reductant for fossil fuel in the future, straw-type biomass contributes to emission reduction and green
utilization in the suspension roasting process. In this study, the influences of the roasting time, roasting temperature
Aand dose of straw-type biomass after suspension magnetization roasting (SMR) and separation were investigated. The
optimal conditions were determined to be a roasting time of 7.5 min with a straw-type biomass dose of 20 wt% and a roasting
temperature of 800 c, in which an iron grade of 71.07% and recovery of 94.17% were obtained for the iron concentrate. The
0
maximum saturation magnetization under optimal conditions was 35.05 Am2g 1, and the gaseous regulation of the biomass
revealed that cumulative reducing gas volume was 293.93 mL at the optimal roasting time of 450 s. The transformation of
hematite to magnetite was detected by X-ray diffraction (XRD). During microstructure evolution, the outer layer consisting of
fissures and tiny holes continuously deepened toward the core.

Introduction refractory iron ore lacks the appropriate treatment because
of its properties such as low iron grade, complex composi-
tion and fine-grained granularity [2,3]. During the process
The rapid depletion of high-grade iron ores, as well as the tre- of suspension magnetization roasting (SMR), refractory iron
mendous demand of iron and steel industries, has given rise ore phases can transform into magnetite, which is effectively
to the urgent need for global attention on the effective utili- separated by the low-intensity magnetic separation methods
zation of refractory iron ore [1]. In China, a large reserve of [4–6]. Because of magnetic differences, excellent index

* Corresponding author at: School of Resources and Civil Engineering, Northeastern University, Shenyang 110819, China.

26 MINES & MINERALS REPORTER / OCTOBER 2021