钒渣和石灰石同步混磨对钙化提钒效果的影响

Effect of simultaneous grinding of vanadium slag and limestone on vanadium extraction by calcification

采用轮碾机对钒渣和石灰石粉实施同步混磨,得到混磨混合料,并与搅拌混合的普通混合料相比较,考察两种混合料的粒度分布、粉末形貌及混匀度,分析焙烧温度和钙钒比对不同预处理混合料焙烧转化率的差异,研究混磨预处理对熟料酸浸过程初始pH值、酸耗及浸出时间的影响。结果表明:在相同的钙钒比下,混磨预处理能显著提高混合料的焙烧转化率;钙钒比为0.6时,混磨后的混合料在870℃下焙烧转化率比普通混合料高约2%;在同一转化率水平下,采用混磨预处理可降低石灰石用量,钙钒比为0.4的混磨混合料在870℃下的焙烧转化率为90.18%,与钙钒比为0.6的常规混合料焙烧转化率(90.76%)相当;在酸浸过程中,混磨混合料经焙烧所得熟料浸出初始pH值较常规熟料低,耗酸量减少约13%,且可缩短浸出时间。混磨预处理可以降低生产成本、提高生产效率,具有一定的应用前景。

An experiment was designed to intensify the grinding and mixing of vanadium slag and limestone powder using a kind of wheel mill.The obtained material was compared with the ordinary mixture using agitation mixing method.The size distribution,powder morphology and mixing degree of two kinds of mixtures were investigated.The effects of calcination temperature and calcium vanadium ratio(m(CaO)/m(V_(2)O_(5)))of the mixture on the roasting conversion were analyzed.The initial pH value,acid consumption and leaching time difference owing to agitation mixing during the leaching course were also studied.The results show that the mixed grinding pretreatment can significantly improve the roasting conversion of the mixture under the same calcium vanadium ratio.When the value of m(CaO)/m(V_(2)O_(5))is 0.6,the calcination conversion of the mixture after mixed grinding at 870℃is about 2%higher than that of the ordinary mixture.At the same conversion level,the amount of limestone can be reduced by using mixed grinding pretreatment.The calcination conversion of the mixed grinding mixture with m(CaO)/m(V_(2)O_(5))of 0.4 at 870℃is 90.18%,which is equivalent to 90.76%of the conventional mixture with m(CaO)/m(V_(2)O_(5))of 0.6.During the acid leaching process,the initial pH value of the clinker obtained by roasting the mixed grinding mixture is lower than that of the conventional clinker,the acid consumption is reduced by about 13%,as well as the leaching time can be significantly shortened.The mixed grinding pretreatment can reduce the production cost and improve the production efficiency,which has a certain application prospect.