ISSN 2594-357X
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The Formation of return fines not only reduces productivity but also affects moisture and fuel additions when they return to blending. Previous researches mainly focus on the effects of parameters, such as temperature and basicity, on the formation rate of return fines, and their size or addition on sintering. However, the formation mechanism hasn't been clearly and deeply studied. By analyzing mineralization, two main breaking forms of sintered body are summarized in this paper, then the experiments are conducted to study the effects of corresponding factors namely liquid fluidity, pore and mineral properties in bonding phase so that the formation mechanism of return fines is unveiled. The results show that: (1). Essence of failure in effective bonding is insufficient bonding interface due to low liquid fluidity, which can be ascribed to two reasons: low segregated basicity or heat shortage, and significant decrease in proper primary liquid fluidity caused by excessive assimilability of nuclei.(2)Low self-strength of bonding phase is primarily related to weak structure and high internal stress of minerals. When the pores in bonding phase matrix have macroporous and thin-walled structure, it has the most negative impact on the strength, high porosity and their uneven distributions in SFCA also reduce the strength of bonding phase. Besides, SFCA decrease or large pieces of hematite entrainment in SFCA caused by basicity segregation reduces self-strength of bonding phase.
The Formation of return fines not only reduces productivity but also affects moisture and fuel additions when they return to blending. Previous researches mainly focus on the effects of parameters, such as temperature and basicity, on the formation rate of return fines, and their size or addition on sintering. However, the formation mechanism hasn't been clearly and deeply studied. By analyzing mineralization, two main breaking forms of sintered body are summarized in this paper, then the experiments are conducted to study the effects of corresponding factors namely liquid fluidity, pore and mineral properties in bonding phase so that the formation mechanism of return fines is unveiled. The results show that: (1). Essence of failure in effective bonding is insufficient bonding interface due to low liquid fluidity, which can be ascribed to two reasons: low segregated basicity or heat shortage, and significant decrease in proper primary liquid fluidity caused by excessive assimilability of nuclei.(2)Low self-strength of bonding phase is primarily related to weak structure and high internal stress of minerals. When the pores in bonding phase matrix have macroporous and thin-walled structure, it has the most negative impact on the strength, high porosity and their uneven distributions in SFCA also reduce the strength of bonding phase. Besides, SFCA decrease or large pieces of hematite entrainment in SFCA caused by basicity segregation reduces self-strength of bonding phase.
Palavras-chave
Iron ore; Sintering; Return fines; Formation mechanism.
Iron ore; Sintering; Return fines; Formation mechanism.
Como citar
Zhu, Juan;
Wu, Sheng-li;
Shi, Xin;
Zhang, Guo-liang;
Liu, Xin-liang;
Fan., Jia-xin.
STUDY ON FORMATION MECHANISM OF RETURN FINES IN
SINTERING PROCESS
,
p. 437-449.
In: 42º Seminário de Redução de Minério de Ferro e Matérias-primas / 13º Seminário Brasileiro de Minério de Ferro / 6th International Congress on the Science and Technology of Ironmaking,
Rio de Jabeiro,
2012.
ISSN: 2594-357X
, DOI 10.5151/2594-357X-22112
