中低品位磷钾伴生矿低温酸浸提钾研究
发布时间：2018-10-16 21:49
【摘要】：我国是一个农业大国,化肥的需求量十分巨大。目前,世界上生产钾肥主要开发的是可溶性钾资源。我国可溶性钾资源贫乏,但是以钾长石为主的不溶性钾资源却十分丰富。近年来,湖北省宜昌市夷陵地区发现储量丰富的磷钾伴生矿石,其主要矿物成分为钾长石、氟磷灰石、石英、白云石、黄铁矿等,P2O5含量为6~12%,K2O含量为5~9%,属于中低品位矿。采用盐酸酸浸此磷钾伴生矿,可以在较低温度下有效提取不溶性钾,同时综合利用磷、铝、钙等元素,具有重要意义。本文以宜昌市夷陵地区磷钾伴生矿为原料,研究了盐酸低温酸浸磷钾伴生矿提钾工艺。通过比较添加不同助剂后的浸出率,选择对钾浸出效果有很大促进的氟化钙作为助剂。通过单因素实验探讨了粒度、反应温度、盐酸质量分数、浸出时间、原料比、盐酸用量、搅拌速率对钾浸出率的影响。并以酸浸温度(A)、反应时间(B)、盐酸质量分数(C)和盐酸用量(D)四个工艺条件作为变量因子,以钾元素的浸出率作为评价指标Y,进行响应面实验。根据回归模型得出最佳工艺条件为:磷钾伴生矿质量为20g,磨矿时间为15min,盐酸质量分数为23%,反应温度为92℃,反应时间4h,原料比为0.2g氟化钙/g矿粉,盐酸用量为80m L,搅拌速度为500r/min。模型预测在此条件下钾元素理论浸出率为92.8%,实验验证浸出率为91.3%,模型误差为1.64%。结合磷钾伴生矿浸出实验结果与XRF、XRD及SEM-EDS等分析手段对该反应过程与机理进行了分析,得出磷钾伴生矿-氟化钙-盐酸反应具体过程为:首先,矿石中的氟磷灰石、白云石以及氟化钙等容易被酸分解的成分较快地溶解,产生细小孔道;然后,在氟离子与氢离子的共同作用下,矿石颗粒外表面的钾长石逐渐被侵蚀,同时矿石颗粒内部的钾长石也被通过孔道扩散进去的氢氟酸缓慢侵蚀。并且,由于内扩散的影响,颗粒深处的钾长石未被完全分解,夹杂在孔道之中,惰性细小颗粒也被吸附在大颗粒的孔道内。反应机理分析和计算拟合结果表明,浸出过程遵循化学反应和内扩散混合控制的未反应收缩核模型。并求得中间坪、太阳山、殷家坪地区磷钾伴生矿反应过程的表观活化能分别为34.01 k J/mol、34.40 k J/mol、30.67 k J/mol;表观速率常数分别为Km=379.2e-4090.6/T、Km=472.5e-4137.4/T、Km=115.2e-3688.8/T。最终求得混合控制动力学方程数学表达式。在20g小型实验基础上,进行了200g级、875g级、42kg级的酸浸提钾实验,基本重现了小型实验的结果,该提钾工艺无明显放大效应。
[Abstract]:Our country is a big agricultural country, the demand for chemical fertilizer is very huge. At present, the main development of potash fertilizer in the world is soluble potassium resources. The soluble potassium resources in China are poor, but the insoluble potassium resources, which are dominated by potassium feldspar, are very rich. In recent years, rich phosphate and potassium associated minerals have been found in Yiling area, Yiling City, Hubei Province. The main mineral components are potassium feldspar, fluoroapatite, quartz, dolomite, pyrite, etc. The content of P2O5 is 6 ~ 12 ~ (12) K _ 2O and the content of K _ 2O is 5 ~ 9%, which belongs to medium and low grade ore. It is of great significance to use hydrochloric acid to leach the phosphorus-potassium associated ore effectively at low temperature and to make comprehensive use of phosphorus, aluminum, calcium and other elements. In this paper, phosphorus and potassium associated minerals in Yiling area, Yichang City, were used as raw materials to study the extraction process of phosphorus and potassium associated with acid leaching of hydrochloric acid at low temperature. By comparing the leaching rate of different additives, calcium fluoride, which greatly promoted the leaching effect of potassium, was selected as the additive. The effects of particle size, reaction temperature, hydrochloric acid mass fraction, leaching time, raw material ratio, dosage of hydrochloric acid and stirring rate on the leaching rate of potassium were investigated by single factor experiments. The reaction surface experiments were carried out using the four technological conditions of acid leaching temperature (A), reaction time (B), hydrochloric acid mass fraction (C) and hydrochloric acid dosage (D) as variable factors and potassium leaching rate as evaluation index Y. According to the regression model, the optimum technological conditions are as follows: phosphorus and potassium associated ore mass is 20 g, grinding time is 15 min, hydrochloric acid mass fraction is 23, reaction temperature is 92 鈩，
本文编号：2275725
[Abstract]:Our country is a big agricultural country, the demand for chemical fertilizer is very huge. At present, the main development of potash fertilizer in the world is soluble potassium resources. The soluble potassium resources in China are poor, but the insoluble potassium resources, which are dominated by potassium feldspar, are very rich. In recent years, rich phosphate and potassium associated minerals have been found in Yiling area, Yiling City, Hubei Province. The main mineral components are potassium feldspar, fluoroapatite, quartz, dolomite, pyrite, etc. The content of P2O5 is 6 ~ 12 ~ (12) K _ 2O and the content of K _ 2O is 5 ~ 9%, which belongs to medium and low grade ore. It is of great significance to use hydrochloric acid to leach the phosphorus-potassium associated ore effectively at low temperature and to make comprehensive use of phosphorus, aluminum, calcium and other elements. In this paper, phosphorus and potassium associated minerals in Yiling area, Yichang City, were used as raw materials to study the extraction process of phosphorus and potassium associated with acid leaching of hydrochloric acid at low temperature. By comparing the leaching rate of different additives, calcium fluoride, which greatly promoted the leaching effect of potassium, was selected as the additive. The effects of particle size, reaction temperature, hydrochloric acid mass fraction, leaching time, raw material ratio, dosage of hydrochloric acid and stirring rate on the leaching rate of potassium were investigated by single factor experiments. The reaction surface experiments were carried out using the four technological conditions of acid leaching temperature (A), reaction time (B), hydrochloric acid mass fraction (C) and hydrochloric acid dosage (D) as variable factors and potassium leaching rate as evaluation index Y. According to the regression model, the optimum technological conditions are as follows: phosphorus and potassium associated ore mass is 20 g, grinding time is 15 min, hydrochloric acid mass fraction is 23, reaction temperature is 92 鈩，
本文编号：2275725
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