Strengthening pelletization of manganese ore fines containing high combined water by high pressure roll grinding and optimized temperature elevation system
来源期刊：中南大学学报(英文版)2014年第9期
论文作者：朱德庆 YU Wei(余为) ZHOU Xian-lin(周仙霖) 潘建
文章页码：3485 - 3491
Key words：manganese ore fines containing high combined water; pelletization; high pressure roll grinding; optimized temperature elevation system; consolidation mechanism
Abstract: Pelletization is one of useful processes for the agglomeration of iron ore or concentrates. However, manganese ore fines are mainly agglomerated by sintering due to its high combined water which adversely affects the roasting performance of pellets. In this work, high pressure roll grinding (HPRG) process and optimization of temperature elevation system were investigated to improve the strength of fired manganese ore pellets. It is shown that the manganese ore possesses good ballability after being pretreated by HPRG twice, and good green balls were produced under the conditions of blending 2.0% bentonite in the feed, balling for 7 min at 16.00% moisture. High quality roasted pellets with the compressive strength of 2711 N per pellet were manufactured through preheating at 1050 °C for 10 min and firing at 1335 °C for 15 min by controlling the cracks formation. The fired manganese pellets keep the strength by the solid interconnection of recrystallized pyrolusite grains and the binding of manganite liquid phase which filled the pores and clearance among minerals. The product pellets contain high Mn grade and low impurities, and can be used to smelt ferromanganese, which provides a possible way to use imported manganese ore fines containing high combined water to produce high value ferromanganese.
ZHU De-qing(朱德庆)1, YU Wei(余为)1, 2, ZHOU Xian-lin(周仙霖)1, PAN Jian(潘建)1
(1. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China;
2. Wuhan Iron and Steel (Group) CORP, Wuhan 430080, China)
Abstract:Pelletization is one of useful processes for the agglomeration of iron ore or concentrates. However, manganese ore fines are mainly agglomerated by sintering due to its high combined water which adversely affects the roasting performance of pellets. In this work, high pressure roll grinding (HPRG) process and optimization of temperature elevation system were investigated to improve the strength of fired manganese ore pellets. It is shown that the manganese ore possesses good ballability after being pretreated by HPRG twice, and good green balls were produced under the conditions of blending 2.0% bentonite in the feed, balling for 7 min at 16.00% moisture. High quality roasted pellets with the compressive strength of 2711 N per pellet were manufactured through preheating at 1050 °C for 10 min and firing at 1335 °C for 15 min by controlling the cracks formation. The fired manganese pellets keep the strength by the solid interconnection of recrystallized pyrolusite grains and the binding of manganite liquid phase which filled the pores and clearance among minerals. The product pellets contain high Mn grade and low impurities, and can be used to smelt ferromanganese, which provides a possible way to use imported manganese ore fines containing high combined water to produce high value ferromanganese.
Key words:manganese ore fines containing high combined water; pelletization; high pressure roll grinding; optimized temperature elevation system; consolidation mechanism
