【作者】 郭辉；

【导师】 应建康；

【作者基本信息】 四川大学 ， 化学工艺， 2002， 硕士

【摘要】 用中和料浆浓缩法生产磷铵时，料浆的粘度过大，大量的中和热不能有效的利用，而且料浆的含水量难以浓缩降到20％以下，使以后的干燥工序，设备生产强度低，能耗大。针对这一问题，本文提出酸性磷铵料浆浓缩生产新工艺，并对酸性料浆的流变性行为进行了研究。 文章先对开阳磷矿磷酸中和过程料浆物性进行研究，实验结果表明：湿法磷酸氨化中和过程中，酸性料浆的粘度随中和度变化较大，在中和度为0.52左右存在粘度最低点，过了这一点后，料浆粘度随中和度急剧升高。在0.89达到一个高点。而后缓慢降低致1.01后，粘度又随中和度渐渐上升。当酸性料浆含水量逐渐降低时，随磷铵晶体的析出，料浆逐渐由牛顿型流体向非牛顿型流体转变，剪切变稀的现象逐渐明显。而另一方面确定了酸性料浆粘度与温度之间的关系。 同时研究了在酸性料浆中加入一定的降摩阻剂和分散剂对料浆粘度的影响。实验发现：加入聚乙二醇料浆粘度有明显的改善，在聚乙二醇浓度为0.08％时，酸性料浆粘度有最小值。 通过模拟湿法磷酸实验，重点研究了磷铵料浆中所含杂质对酸性料浆粘度的影响。研究结果得出酸性磷铵料浆在低含水量时，所含镁的影响随含水量的减少而急剧增加；铁的作用比镁要小，且其浓度超过某一值后，对料浆粘度影响随其含量变化很小；铝的影响则更小。同时对钙、氟等杂质的影响作了简略研究。通过所获数据发现酸性料浆的流变特性，并对流变特性参数与镁、铁、铝三杂质含量之间进行拟合，获得了不同含水量条件下杂质对酸性料浆影响的流变方程。更多还原

【Abstract】 "Slurry-concentrated method" to product ammonium phosphate can’t utilize the concentration heat effectually. At the same time the viscosity of slurry is very high. The concentration of water can’t drop to 20%, the drying process consumes lots of energy. Work intensity of drying equipment is too low. To solve these questions, this paper bring out a new technique, "acidic slurry-concentrated method ", and study the rheological behavior of the acidic slurry.In this paper, firstly the rheological character of acidic ammonium phosphate slurry was studied. The result showed the relations between the value of neutralization and the viscosity of slurry. When the value of neutralization was 0.52, the viscosity of slurry is the lowest. With the decreasing of the concentration of water, the viscosity increased, the flow showed shear thinning, the non-Newtonian characters appearing. In addition, the exponential relationship between viscosity and the temperature is observed.Secondly influences of the additives were investigated. After adding the additives into the slurry, the fluidity of the slurry changed. Some additives such as polyglycol can make the viscosity of slurry descend.Thirdly the effect of impurities in the simulating wet-process phosphoric acid on the rheological behavior of the acidic ammoniated slurry has been studied. The result showed the viscosity has very important relations with the impurity and confirmed the impurities in the wet -process phosphate slurry could affect the fluidity of the acidic slurry, especially "Mg2+". After theregression analysis of the data, several mathematical models expressing the effects of the impurities on the rheological behavior were obtained .更多还原