低品位混合型磷矿的碳热还原工艺

Carbothermal reduction process of low-grade mixed phosphate ore

以窑法工艺对云南晋宁低品位磷矿的碳热还原性能进行研究。采用4因素5水平正交实验探究反应温度、反应时间、碳过量系数、硅钙物质的量比对磷矿碳热反应还原率的影响。实验结果表明,影响磷矿还原率由大到小的顺序依次为,反应温度、碳过量系数、反应时间、硅钙物质的量比。反应温度为1 300℃、碳过量系数为2.6、反应时间为1.5 h、硅钙物质的量比为1.5时,还原率可达到最高值94.27%。同时,对云南晋宁低品位混合型磷矿用于窑法磷酸生产的适应性进行评价,表明该混合型磷矿适用于窑法磷酸生产,研究结果对低品位混合型磷矿窑法工艺具有一定指导意义。

Carbothermal reduction properties of low grade phosphate ore from Jinning,Yunnan were studied by kiln process.Four-factor and five-level orthogonal experiment was used to explore the influence of reaction temperature,reaction time,carbon excess coefficient,and Si/Ca ratio on the reduction rate of phosphate ore carbothermal reaction.The experimental results showed that the order of factors influencing the phosphate ore reduction rate was as follows:Reaction temperature,carbon excess coefficient,reaction time,Si/Ca ratio.When the reaction temperature was 1 300 ℃,the carbon excess coefficient was 2.6,the reaction time was 1.5 h,and the ratio of n(Si)/n(Ca) was 1.5,the reduction rate could reach the highest value of94.27%.Simultaneously,the applicability of Jinning,Yunnan low-grade mixed phosphate ore for kiln-process phosphoric acid production was evaluated,which showed that the mixed phosphate ore was suitable for kiln phosphoric acid production,and the research results had certain guiding significance for the low-grade mixed phosphate kiln process.