宜昌地区含钾中低品位磷矿石的选矿工艺研究

发布时间：2018-05-28 00:06

  本文选题：胶磷矿 + 钾长石　； 参考：《武汉工程大学》2015年硕士论文

【摘要】：磷、钾作是植物生长必需的营养元素,对农作物的生命代谢起着十分重要的作用。我国多氮少磷缺钾的现象严重,使化肥工业受到资源限制,极大制约了我国农业发展。同时,我国磷矿大多是中低品位磷矿或共生矿,开发利用上存在较大的技术难题。我国储有大量的中低品位磷矿和难溶性钾矿,大力开发和利用这些资源是促进我国化肥工业发展的必由之路。宜昌地区拥有丰富的含钾磷矿,此含钾磷矿具有磷钾伴随而生的特性,磷、钾资源可进行综合回收,具有较大的经济优势。经济合理地开发利用这一资源,对我国含钾磷矿的综合利用具有重要的意义。本文首先对宜昌地区含钾中低品位磷矿的矿物组成、形貌、粒度及嵌布特征进行了研究,而后基于矿石特性,进行了浮选研究。主要结论如下:(1)此含钾中低品位磷矿石中主要有用矿物为胶磷矿、钾长石,脉石矿物为石英、白云石及黄铁矿。其中有用组分P2O5含量为20.92%,K_2O含量为4.59%。矿石中胶磷矿为隐晶质集合体呈纹层状分布;长石多呈不规则粒状结构,部分为板状晶体形态,大部分次生成绢云母呈微细鳞片状结构;石英呈不规则粒状结构零散分布。(2)在磨矿细度-0.074 mm 93.64%,药剂用量为碳酸钠6 kg/t、水玻璃3 kg/t、TSM-46 1.8 kg/t,浮选时间5 min,浮选温度20±1℃时,经过一次粗选,P2O5品位由20.92%提升至27.72%。通过精选、扫选实验进一步富集磷、钾后,得到精矿P2O5品位31.84%、P2O5回收率70.53%,尾矿K_2O品位9.53%、K_2O回收率52.80%的选矿指标。(3)对原矿及浮选后的矿样进行粒度筛析,发现在相同的浮选工艺参数下,浮选后的磷精矿和钾精矿中,矿物粒级越细,浮选回收率越高;不同粒级矿物的磷精矿、钾精矿与原矿的回收率无明显差异。对比粗粒级物料和细粒级物料的磷精矿、钾精矿品位发现,分选效果随着物料粒级的增大而变差。(4)以单矿物浮选实验为依据,对浮磷后的K_2O品位为9.41%的钾精矿(即磷尾矿)进行浮选实验,在pH值约为2,十二胺浓度为3×10-4 mol/L时K_2O品位提升至10.94%,游离的石英降至4.76%;pH值约为8,N-十二烷基-1,3-丙二胺浓度为4×10-4mol/L时K_2O品位提升至10.53%,游离的石英降至2.57%。两种捕收剂基本能除去钾精矿中的石英。(5)经分析,造成脱硅实验后精矿中K_2O回收率较低、尾矿中K_2O品位较高的原因可能有如下三点:第一,由于胺类捕收剂主要以静电力作用于矿物表面,而长石石英表面电荷机理基本相同,仅靠物理吸附为主的胺类捕收剂,可能会因缺乏选择性而分离效果较差;第二,实际入选矿物中含大量泥质及铁质杂质,长石大多被绢云母交代,而强酸性条件下会优先浮选出云母,因此造成精矿中杂质较多而K_2O含量低;第三,实际入选矿物中细粒级长石含量较多,而细粒级长石会吸附在粗粒级石英表面,使浮选尾矿中含有细粒级长石,造成尾矿中K_2O含量较高。
[Abstract]:Phosphorus and potassium are essential nutrients for plant growth and play an important role in crop life and metabolism. The phenomenon of nitrogen, low phosphorus and potassium deficiency is serious in China, which limits the chemical fertilizer industry and restricts the development of agriculture in China. At the same time, the phosphate rock in China is mostly low grade phosphate ore or cogeneration ore, so there are some technical problems in exploitation and utilization. There are a large number of low and medium grade phosphate ores and insoluble potassium ores in China. It is the only way to promote the development of chemical fertilizer industry in China to develop and utilize these resources vigorously. In Yichang area, there are abundant potassium bearing phosphate rock, which has the characteristics of phosphorus and potassium accompanying, phosphorus and potassium resources can be comprehensively recovered, which has a great economic advantage. Developing and utilizing this resource economically and reasonably is of great significance to the comprehensive utilization of potash-bearing phosphate ore in China. In this paper, the mineral composition, morphology, granularity and inlay characteristics of medium and low grade phosphate rock containing potassium in Yichang area were studied firstly, and then flotation was carried out based on the ore characteristics. The main conclusions are as follows: (1) the main useful minerals in the medium and low grade potassium bearing phosphate rock are galactophosphate, potassium feldspar, gangue mineral quartz, dolomite and pyrite. The content of useful component P2O5 is 20.92 and the content of K2O is 4.59. In the ore, the colloidal phosphate rock is a cryptocrystalline aggregate with lamellar distribution, the feldspar is mostly of irregular granular structure, some of them are plate-shaped crystals, and most of the secondary sericite is of fine scale structure. When the grinding fineness is 0.074 mm 93.64 mm, the dosage of sodium carbonate is 6 kg / t, the dosage of sodium silicate is 3 kg / t, the floatation time is 5 min, the flotation temperature is 20 卤1 鈩，

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