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利用磷矿石、钾长石同步提取磷和钾的基础研究
【作者】 丁楠；
【导师】 夏举佩；
【作者基本信息】 昆明理工大学 ， 化学工程， 2010， 硕士
【摘要】 我国的磷矿资源丰富,高品位的富矿却越来越少。随着磷化工的快速发展以及对磷矿石的无序开采和严重浪费,我国的高品位磷矿石的储量正在锐减,中低品位磷矿石的资源化应用技术开发问题已成为制约磷化工企业发展的关键。与此同时,我国由于可溶性钾资源储量严重不足致使钾肥仍依赖进口。然而我国的非水溶性钾资源储量却十分丰富而且分布广泛,以钾矿石为原料单一生产可溶性钾肥,由于能耗高、经济效益差而推广困难。本文将钾长石提钾和中低品位磷矿石的利用相结合,同步提取有效磷和有效钾,实现钾长石与磷矿资源的合理利用,具有重大的经济价值和科学意义。本文以磷矿粉、焦炭和钾长石为主要原料,经研磨、计量、混合,在高温下焙烧。以磷的反应率和钾的溶出率为主要指标,考察了还原剂用量、焙烧温度、焙烧时间、摩尔钙硅比、助剂种类及助剂添加量对反应指标的影响。本文通过实验研究得出以下结论：(1)在磷矿粉-焦炭体系中,磷的反应率随还原剂添加量的增加而提高,当还原剂用量为磷矿质量的45%时,适宜的焙烧温度为1250℃C,焙烧时间2.0h,此时磷的反应率最大,为86.97%。(2)在确定出磷矿粉-焦炭体系反应条件的基础上,加入钾长石到体系中。通过考察摩尔钙硅比对实验结果的影响,得出：当钙硅比为2.0时枸溶性钾的生成率最高为54.64%,此时磷的反应率为82.83%。(3)通过正交实验,得出磷矿粉-焦炭-钾长石反应体系的优方案为：焙烧温度1250℃C、焙烧时间1.5小时、钙硅比2.0和还原剂用量为磷矿粉质量的40%。(4)在磷矿粉-焦炭-钾长石反应体系优方案的基础上,具体考察助熔剂种类及掺量对磷矿粉-焦炭-钾长石体系钾溶出率的影响。结果表明：钾的反应率随着助剂用量的增加而提高。在助剂添加量相同的情况下,确定最优的助熔剂为CaCl2,添加量为钾长石质量的40%适宜。(5)最终研究结果表明,磷矿粉-焦炭-钾长石体系中,钙硅比选择2.0、焙烧温度为1250℃C、焙烧时间1.5小时,助熔剂CaCl2添加量为钾长石质量的40%,磷的反应率平均为90%,钾的总反应率>96%,以气态的形式挥发逸出的>93%,炉渣中钾含量仅占0.18%,避免了传统矿石提钾的水萃工艺流程长、能耗高的缺点。
【Abstract】 The phosphorous ore resources of our country are abundant, but high-rich grade ores are few. As the fast development of the phosphorus chemical industry and phosphorus ore exploited disorderly and wasted seriously, the reserve volume of premium phosphorous ore of our country are falling sharply, the utilization of middle or low grade phosphorous ore has already become the key of industrial development, which restrict the development of phosphorous chemical industry. Meanwhile, in China, serious lacking of soluble potassic resource, potassic fertilizer still depends on import. However, the reserve volume of insoluble potassium resource in our countries is very abundant and widespread. Because the high consumption of energy and poor benefits, the popularization of potassic fertilizer, which are prepared solely based on potassium ore, become very difficult. Using combination of the K-feldspar potassium extraction with the uses of middle or low grade phosphorus of ore, soluble potassium salt and phosphoric salt are produced synchronously, the rational utilization of K-feldspar and phosphorus ore resource has come true, which has great economic value and scientific meaning.This text use ground phosphate rock, coke and potash feldspar as main materials, through grinding, measuring and mixing, then roast under the high temperature. Regard reactivity ratio of phosphor and dissolving rate of potassium as the major indicator, it also investigates reductant consumption, calcination temperature, roasting time, mol-ration of silicon divided calcium, assistant kind and assistant addition level impacting on reaction index.Through the experiment, conclusions can be listed as follows:(1) In the ground phosphate rock-coke system, with the increase of the addition level of reductant consumption and reactivity ratio of phosphorus have improved, when reductant consumption is 45% of the phosphorous ore, the suitable calcination temperature is 1250℃and roast time is 2.0 hour, at this moment,86.97% is the greatest rate to the reactivity ratio of phosphor.(2) On the basis of determining the ground phosphate rock-coke system reaction condition, adding the K-feldspar to the system. Through investigating the impact of on the experiment, result is obtained:when mol-rate of calcium and silicon is 2.0, 54.64% is the highest rate as the intersection of soluble potassium citrate. At this moment, the reactivity ratio of phosphor is 82.83%.(3) Through orthogonal, the excellent scheme of the ground phosphate rock-coke-K-feldspar reaction system is:calcination temperature is1250℃, roast time is 1.5 hour, calcium/silicon ratio is 2.0, and reductant consumption is 40% of the phosphorous ore.(4) On the basis of excellent scheme of reaction system of ground phosphate rock-coke-potash feldspar, influence of producing rate to potassium on flux type and dosage to ground phosphate rock-coke-potash feldspar system is investigated specifically. The result shows:with the increase of the addition level of assistant consumption, the reactivity ratio of potassium have improved. Under the situation of identical addition of assistant, confirming optimal flux is CaCl2, suitable addition level is 40% of the K-feldspar quality.(5) The ultimate consequence point out:for the reaction system of phosphate rock-coke-potash feldspar, calcium/silicon ratio is 2.0, calcination temperature is 1250℃, roast time is 1.5 hour, and reductant consumption is 40% of the phosphorous ore, then the reactivity ratio of phosphor exceed 90%, the total reactivity ratio of potassium near 96%, and the 93% of total potassium is escaped on gaseous state. The potassium content is only 0.18% in remainder. This circuit can simplify the extract course with water or citrate acid, and reduce the consumption of energy comparatively.