钒渣加NaOH-Na2CO3造块焙烧条件对块样孔隙率和铬提取率影响  

Effect of roasting conditions of the pellets made of vanadium slag and mixture of NaOH-Na2CO3 on the porosities of roasted pellets and the vanadium extractions

作　　者：方孝红 沈少波[1] 李娜[1] 侯全起 张政 FANG Xiaohong;SHEN Shaobo;LI Na;HOU Quanqi;ZHANG Zheng(School of Metallurgical and Ecological Engineering,Beijing University of Science and Technology,Beijing 100083,China)

机构地区：[1]北京科技大学,冶金与生态工程学院,北京100083

出　　处：《四川冶金》2020年第1期11-16,共6页Sichuan Metallurgy

摘　　要：将钒渣粉和NaOH-Na2CO3混合物粉末混合造块、焙烧、水浸,以提取钒渣中的铬。块样中NaOH-Na2CO3混合物和钒渣重量比固定为0.5。实验结果表明:通过改变NaOH-Na2CO3添加物中NaOH/(Na2CO3+NaOH)摩尔比R,制得不同孔隙率的焙烧块样。焙烧块样孔隙率主要决定于添加的NaOH-Na2CO3混合碱的熔点;混合碱的熔点越低,焙烧块样孔隙率越高。在相同焙烧实验条件下,摩尔比R为0.9的焙烧块样表面有平均粒径0.5 mm的大孔,摩尔比R为0(仅加Na2CO3)的焙烧块样表面几乎看不到大孔,两者孔隙率分别为30%和6%,铬提取率分别为74%和44%。Na2CO3焙烧块样坚硬,难以破碎,而NaOH-Na2CO3焙烧块样易破碎,利于后续水浸提铬。其余焙烧条件相同,优化的R值为0.9,优化的焙烧温度为800℃,优化的焙烧时间为2h。在此优化条件下,焙烧块样体积增大为原来的2.14倍,焙烧块样孔隙率达到最大值30%,铬提取率也达到最大值74%。总体而言,钒渣烧结块样孔隙率与铬提取率之间有密切的正相关性。Some powders of a vanadium slag were mixed with the powders of NaOH-Na2CO3 mixture to make some pellets.The pellets thus obtained were roasted and then leached with water to extract chromium in this work.The weight ratio of added NaOH-Na2CO3 mixture to vanadium slag was fixed at 0.5 for each sample.It was found through experiments that the roasted pellets with different porosities were made by adjusting the mole ratio R of added NaOH/(Na2CO3+NaOH)mixture.The pellet porosity was mainly determined by the melting point of added NaOH-Na2CO3 mixture.The lower the melting point,the larger pellet porosity.Under the same roasting conditions,some larger holes with an average diameter of 0.5 mm were presented on the roasted pellet with an addition of NaOH-Na2CO3 mixture having a R value of 0.9,while no large holes were visible on the roasted pellet with only addition of Na 2 CO 3(R=0).The porosities of the roasted pellets with R values of 0.9 and 0 were 30% and 6%,respectively,and the vanadium extractions were 74% and 44%,respectively.The only Na2CO3 added roasted pellet was very hardanddifficult to break,while the NaOH-Na2CO3 added pellets were easily broken,which was beneficial for the subsequent water leaching and the chromium extraction.The remaining roasting conditions were the same,the optimized R value,roasting temperature and roasting time were 0.9,800℃ and 2 h,respectively.Under these optimized conditions,the volume of the roasted pellet thus obtained was increased by 2.14 times and both thepellet porosity and Cr extraction reached the maximums of 30%and 74%,respectively.In general,there is a close positive correlation between the vanadium slag porosity and the chromium extraction.

关 键 词：钒渣 提铬 块样焙烧 NaOH-Na2CO3混合添加物 焙烧块样孔隙率 

分 类 号：TF802.67[冶金工程—有色金属冶金]