强化制粒对含铬型钒钛混合料烧结的影响

 含铬型钒钛混合料制粒效率低，料层透气性差，严重影响了其发展低温高料层烧结。在基准方案基础上，通过烧结杯试验研究了生石灰配比、混合料水分、润湿时间和制粒时间对含铬型钒钛混合料烧结的影响，并对强化制粒效果进行了观察。试验结果表明：在碱度为2.15、配碳量为3.2%(质量分数)、混合料配加生石灰为5%、水分为7.5%、消化时间为10 min，制粒时间为8 min时，平均粒径d]、拟似粒化指数GI0]、制粒效率E]、抗粉化指数B]分别由2.26 mm、66.30%、54.11%、48.15%提高到2.58 mm、80.43%、90.82%、73.53%，烧结速度、成品率、利用系数、转鼓强度分别由16.54 mm/min、70.39%、1.22 t/(m2·h)、55.36%提高到19.70 mm/min、77.94%、1.64 t/(m2·h)、59.36%。含铬型钒钛混合料对水分敏感度高，应严格控制水分波动。采用强化制粒措施，提高料层透气性，增加氧势，可提高烧结矿中铁酸钙质量分数改善其矿物组成与结构，提高产质量。

Effect of enhanced granulation on Cr-bearing vanadium and titanium magnetite sintering

Cr-bearing vanadium and titanium magnetite(V-Ti-Cr) mixture is of poor granulating efficiency and poor permeability，and has a serious impact on the development of low temperature and high material layer sintering. The effects of many parameters，including burnt lime addition，mixture moisture，wetting time and granulation time，on the sintering of V-Ti-Cr mixture were performed by sinter pot test and the effects of enhanced granulation were investigated on the basis of reference scheme .The results show that d]，GI0，E]，B] increase from 2.26 mm，66.30%，54.11%，48.15% to 2.58 mm，80.43%，90.82%，73.53%，respectively. And sintering rate，yield，productivity，strength increase from 16.54 mm/min，70.39%，1.22 t/(m2·h)，55.36% to 19.70mm/min，77.94%，1.64 t/(m2·h)，59.36%，respectively，under the conditions of 5% burnt lime addition，7.5% moisture，wetting for 10min and granulation for 8 min when the basicity of the mixture is 2.15，with 3.20% carbon. The moisture fluctuations of V-Ti-Cr mixture with a high sensitivity to moisture should be controlled strictly. The amount of calcium ferrite was increased and the mineral composition and structure of V-Ti-Cr sinter were improved，which was achieved by improving the oxygen in the bed with a higher permeability for the enhanced granulation，resulting in higher yield and quality.