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Study on the Physicochemical Properties of Burnt Lime for the Iron and Steel Refining.

钢铁精炼用生石灰理化性质的研究。

基本信息

批准号：
60550476
负责人：
MITSUO Toshiharu
金额：
$ 1.15万
依托单位：
Kumamoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1986
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-60550476/
关键词：
Pretreatment of hot metal Ladle refining Desulfurization of molten iron Dephosphorization of molten iron Flux for refining Burnt lime for refining Limestone for iron and steel making 生石灰の滓化

项目摘要

Several properties of limestones and their burnt limes were investigated on six commercially available limestones for the iron and steel refining. Additional experiments were carried out to study the relationships between hydration reactivity of burnt limes and reactivity to molten iron and fluxing property to molten slags.1. For the hydration reactivity test, the early value after 1 minute indicates closer relationship to the reactivity with molten iron than the value after 10 minutes which has been widely used in steelmaking practice. In other words, large scatter in early value of hydration reactivity was observed even for soft burnt lime, but the reactivity to molten iron increased with increasing of the early value.2. High early value of hydration reactivity was obtained for the limestone having large grain size in spite of relatively low temperature calcination almost independent of calcination conditions. On the other hand, low early value was obtained for the limestone having small grain size by relatively low temperature calcination, and it was improved by high temperature calcination or holding for a long time.3. It was found out that the factor controlling the early value of hydration reactivity and reactivity to molten iron was not the microstructure of burnt lime surface but macro crack of 1 <mu> m order in width.4. The formation of crack of 1 <mu> m order in width depends on the grain size of limestone and the calcination conditions (calcination temperature and holding time), and it may be attributed to micro grain growth of burnt lime by sintering.5. The relationship between the early value of hydration reactivity and fluxing property to molten slag may consist with the reactivity to molten iron. However, more examinations may be required to make it clear.

以六种市售的钢铁冶炼用石灰石为原料，研究了石灰石及其煅烧石灰的若干性质。另外，还研究了煅烧石灰的水化反应性与其对铁水的反应性和对熔渣的助熔性的关系.对于水化反应性试验，1分钟后的早期值比炼钢实践中广泛使用的10分钟后的值表明与铁水的反应性的关系更密切。也就是说，即使是软生石灰，其水化反应活性的早期值也存在较大的分散性，但其对铁水的反应活性随着早期值的增大而增大.尽管煅烧温度较低，但大粒径石灰石的水化反应活性早期值较高，几乎与煅烧条件无关。粒径较小的石灰石，较低温度煅烧得到的早期值较低，高温煅烧或长时间保温可以提高早期值.研究发现，控制水化反应性和铁水反应性早期值的因素不是生石灰表面的微观结构，而是宽度为1 m量级的宏观裂纹<mu>. 1 m数量级裂纹的形成<mu>与石灰石的粒度和煅烧条件（煅烧温度和保温时间）有关，可能是生石灰烧结后的微观晶粒长大所致.水化反应性早期值与熔渣熔化性的关系可能与铁水反应性的关系一致。但是，可能需要进行更多的检查才能弄清楚。