钾矿石用于磷炉造渣助熔机理研究

发布时间：2018-06-03 15:55

本文选题：助熔剂 + 钾矿石　；参考：《昆明理工大学》2017年硕士论文

【摘要】：黄磷是众多行业的基础原料,其生产过程由电提供热量,用碳还原磷矿石获得单质磷,再经洗涤、精制生产黄磷,采用硅石作助熔剂以降低炉渣排渣温度。通常情况下,电炉操作温度在1350～1450℃之间,吨产品磷电耗在13000～15000kW·h,因电炉容量、操作水平及原料品质而异,因此,黄磷生产是高能耗限制产业;我国可溶性钾资源短缺,而以钾长石为代表的难溶性钾资源丰富,作为农业生产大国,钾肥是必不可少的。本文在电炉法生产黄磷原理的基础上,提出用钾矿石替换硅石作为磷炉造渣助熔剂,利用其可形成更低共熔物的特点,在降低黄磷生产能耗的同时,回收随尾气升华的氧化钾制备钾肥,缓解了钾肥的短缺,为综合利用电炉法黄磷和钾矿石开辟一条新的途径。为便于研究含钾矿石替换硅石助熔效果,在充分认识电炉法黄磷生产熔渣形成机理的基础上,实验用CaO代替磷矿石,将助剂化学纯SiO2、硅石、钾长石和霞石正长岩与CaO在不同酸度值下混合均匀,测定其熔融温度、粘度,对高温下不同助熔剂磷炉造渣机理进行了初步探讨;为了验证助熔剂替换的优越性,将不同助熔剂与焦炭、磷矿石进行高温反应,测定其磷的转化率、钾的气化率以及残渣的高温流动性。对CaO-硅石和CaO-钾矿石体系的热力学研究表明,钾矿石可以降低磷炉造渣助熔的反应温度。通过不同助熔剂体系下的熔融性研究可知:与传统的硅石助熔相比,化学纯SiO2助熔的熔点升高49.5℃,钾长石助熔的熔点降低73.5℃,霞石正长岩降低257.2℃。在相同反应温度和时间下,通过高温体系摊开面积对不同助熔体系的炉渣流动度进行研究,结果表明:SiO2体系推开面积是硅石的0.49倍,钾长石体系是硅石助熔体系的1.54倍,霞石正长岩-CaO体系是硅石-CaO体系的7.49倍。结合XRD和TG-DSC分析表征可知,SiO2-CaO、硅石-CaO和钾长石-CaO体系在900℃时已有CaSiO3和Ca2SiO4生成,SiO2-CaO体系在1300℃硅酸钙盐的衍射峰强度较强,而硅石-CaO体系在1300℃已有少量玻璃体形成,衍射图谱特征峰以CaSiO3为主,钾长石-CaO体系在1000℃有CaAl2Si2O8和Ca2Al2SiO7生成,在1300℃时残余硅酸钙盐和硅铝酸钙盐熔融形成液态,衍射峰以KAlSiO4为主,霞石正长岩-CaO体系在900℃时就有Ca2Al2SiO7和Ca12Al14O33形成,1200℃图谱以KAlSi04为主,1250℃时体系由晶态变为非晶态。由此可知,钾矿石可以降低黄磷生产的熔点,而钾矿石中霞石正长岩助熔效果又优于钾长石。在上述研究的基础上,对不同助熔剂-焦炭-磷矿石体系高温反应后磷的转化率进行研究,结果表明:在1300℃时硅石-磷矿石-焦炭体系磷的转化率为30.85%,钾长石助熔体系在1100℃和1300℃时分别为38.7%和89.62%,霞石正长岩体系在1100℃时为86.56%。对钾矿石-焦炭-磷矿石体系钾的气化率的研究可知,由于K2O易升华,用钾长石和霞石正长岩助熔磷炉造渣时,在1100℃钾的气化率分别为81.57%和98.57%。对不同助熔剂-焦炭-磷矿石体系反应残渣流动温度的测定结果表明:钾长石助熔时在1300℃下残渣流动温度为1405℃,而霞石正长石在1100℃时反应残渣的流动温度为1401.7℃。对残渣进行XRD表征,1300℃时,SiO2助熔体系仍以Ca5(PO4)3F和SiO2特征峰为主,硅石体系有少量硅酸钙盐生成,钾长石体系有少量玻璃体生成,霞石正长岩体系由晶态转为非晶态。故用钾矿石替换硅石生产黄磷可以提高磷的转化率,降低反应温度,同时联产钾肥。
[Abstract]:Yellow phosphorus is the basic raw material in many industries, its production process is supplied by electricity, the phosphate rock is reduced by carbon to obtain phosphorus, and then by washing, refining production of yellow phosphorus and using silica as a flux to reduce slag discharge temperature. In general, the operating temperature of the electric furnace is between 1350~1450 and 13000 to 15000kW. H. Capacity, operation level and raw material quality are different. Therefore, the production of yellow phosphorus is a high energy consumption restriction industry. The soluble potassium resources in China are short and the potassium feldspar as the representative of the difficult soluble potassium resources is rich. As a big agricultural production country, potash fertilizer is essential. In this paper, on the basis of the principle of producing yellow phosphorus in the electric furnace method, the replacement of silica with potassium ores is proposed. As a phosphorus furnace slag flux, it can make use of the characteristics of the lower eutectic, while reducing the energy consumption of the yellow phosphorus production, recovering potassium oxide from the sublimation of the tail gas, alleviating the shortage of potassium fertilizer, opening up a new way for the comprehensive utilization of the yellow phosphorus and potassium ores in the electric furnace method. On the basis of fully understanding the formation mechanism of the slag in the production of yellow phosphorus in the electric furnace, the experiment used CaO to replace the phosphorus ore. The chemical pure SiO2, silica, potassium feldspar and nepheline syenite and CaO were mixed uniformly under different acidity values, and the melting temperature and viscosity were measured, and the mechanism of the slag formation of different flux in the high temperature was preliminarily discussed. The superiority of the substitution of fluxing agent, the reaction of different flux with coke and phosphate rock at high temperature, the conversion rate of phosphorus, the gasification rate of potassium and the high temperature fluidity of the residue. The thermodynamic study on the system of CaO- silica and CaO- potassium ore shows that the potassium ore can reduce the reaction temperature of the smelting of the phosphorus furnace and through the different flux body. Compared with the traditional silica fusion, the melting point of the chemical pure SiO2 fusion is increased by 49.5 degrees C, the melting point of the potash feldspar is reduced by 73.5, and the nepheline syenite is reduced by 257.2 degrees C. The results of the slag flow degree of the different melting system are studied by the open area of the high temperature system at the same reaction temperature and time. The area of SiO2 system is 0.49 times as high as silica, 1.54 times as high as silica, and 7.49 times of nepheline syenite -CaO system. SiO2-CaO, silica -CaO and potassium feldspar -CaO system has been formed at CaSiO3 and Ca2SiO4 at 900, and SiO2-CaO system is at 1300 centigrade of silicic acid. The diffraction peak intensity of calcium salt is strong, while the silica -CaO system has a small number of vitreous body formation at 1300 C, the characteristic peak of the diffraction pattern is CaSiO3, the -CaO system of potassium feldspar has CaAl2Si2O8 and Ca2Al2SiO7 at 1000, and the residual calcium silicate salt and calcium aluminosilicate salt melt into liquid at 1300 C, the diffraction peak is KAlSiO4 mainly, nepheline syenite -Ca The O system has Ca2Al2SiO7 and Ca12Al14O33 at 900 C. The 1200 c map is dominated by KAlSi04, and the system changes from crystal to amorphous state at 1250 C. Thus, potassium ores can reduce the melting point of yellow phosphorus production, and the effect of nepheline syenite in the potassium ore is better than that of potassium feldspar. The conversion rate of phosphorus after high temperature reaction was studied. The results showed that the conversion rate of phosphorus in the silica phosphate rock coke system was 30.85% at 1300 and 38.7% and 89.62% at 1100 and 1300, respectively, and the nepheline syenite system was gasified by 86.56%. for potassium ore coke phosphate rock system at 1100 C. The results of the study show that the flow temperature of K2O Yi Shenghua, with potassium feldspar and nepheline syenite phosphate smelting furnace, was 81.57% and 98.57%., respectively, at 1100 C and 98.57%., respectively, to determine the flow temperature of the reaction residue of the different flux coke phosphate rock system, indicating that the flow temperature of the residue at 1300 C was 1405, while that of the potassium feldspar at 1300. At 1100 C, the flow temperature of the reacting residue is 1401.7. The residue is characterized by XRD. At 1300, the SiO2 fusion system is still dominated by Ca5 (PO4) 3F and SiO2 characteristic peaks, a small amount of calcium silicate in the silica system, a small amount of vitreous formation in the potassium feldspar system and the crystallization of the nepheline syenite system from crystalline to amorphous. The production of yellow phosphorus by silica can increase the conversion rate of phosphorus, reduce the reaction temperature, and simultaneously produce potassium fertilizer.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ126.317

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