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›› 2014, Vol. 14 ›› Issue (2): 258-265.

• 过程与工艺 • 上一篇    下一篇

硼精矿加压碱解制备水合偏硼酸钠

殷保稳 秦士跃 张亦飞 张懿   

  1. 中国科学院过程工程研究所湿法冶金清洁生产技术国家实验室 中国科学院过程工程研究所 中国科学院过程工程研究所 中国科学院过程工程研究所
  • 收稿日期:2013-12-20 修回日期:2014-01-17 出版日期:2014-04-20 发布日期:2014-04-20
  • 通讯作者: 殷保稳

Preparation of Hydrated Sodium Metaborate from Boron Concentrate via Pressure Alkaline Leaching

YIN Bao-wen QIN Shi-yue ZHANG Yi-fei ZHANG Yi   

  1. Institute of Process Engineering, Chinese Academy of Sciences Institute of Process Engineering,Chinese Academy of Sciences Institute of Process Engineering,Chinese Academy of Sciences Institute of Process Engineering, Chinese Academy of Sciences
  • Received:2013-12-20 Revised:2014-01-17 Online:2014-04-20 Published:2014-04-20
  • Contact: YIN Bao-wen

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被引次数

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摘要： 采用NaOH-H2O体系加压溶出硼精矿制备水合偏硼酸钠．正交实验结果表明，影响硼溶出的因素顺序为，碱浓度>时间>液固比>温度. 考察了初始NaOH溶液浓度、液固比、反应时间、反应温度、矿石粒度和搅拌速度对硼溶出的影响，最优条件[初始NaOH浓度25%(w)、液固比4:1(w)、反应时间2 h、反应温度140℃、搅拌速度500 r/min、高压釜表压0.2 MPa]下，硼转化率达95.91%. 湿硼泥经三级逆流浆化洗涤(各级洗涤温度90℃、洗水与湿硼泥质量比3:1、时间1 h)可实现Na2O和B2O3的高效回收，烘干的终硼泥Na2O和B2O3含量分别为0.35%和0.45%(w)，含42.91%(w) MgO的终硼泥可作为提镁的优质原料. 溶出液添加CaO苛化并高温放置陈化脱色除杂，再降温至25~30℃，恒温结晶6 h后抽滤，结晶率大于70%，晶体用无水乙醇、饱和偏硼酸钠溶液洗涤，40℃烘干12 h，物相为NaB(OH)4，纯度约为90%.

关键词: 硼精矿, NaOH, 溶出, 逆流浆化洗涤, 结晶, 偏硼酸钠

Abstract: Pressure alkaline leaching was used to prepare hydrated sodium metaborate from boron concentrate in NaOH-H2O system. Orthogonal experiments indicated that the most significant influential factor was NaOH concentration, and order of the factors was initial NaOH concentration > reaction time > mass ratio of liquid to solid > temperature. The effects of initial NaOH concentration, reaction time, temperature, mass ratio of liquid to solid, stirring speed and particle size of ore on leaching of boron were examined. Under the optimal conditions (mass fraction of NaOH of 25%, mass ratio of liquid to solid of 4:1, reaction temperature of 140℃, time of 2 h, stirring speed of 500 r/min and gauge pressure of 0.2 MPa), 95.91% of boron was leached out. Na2O and B2O3 in wet boric sludge could be effectively recycled by three-stage countercurrent slurry washing (washing temperature of 90℃, mass ratio of liquid to solid of 3:1, and time of 1 h), dropping to 0.35% and 0.45%, respectively. Final boric sludge containing 42.91% MgO was good raw material for extraction of Mg. After purification, the leachate was crystallized isothermally at 25~30℃ for 6 h and the crystallization rate reached over 70%. Washed with anhydrous ethanol and saturated sodium metaborate solution and dried under 40℃ for 12 h, reulting crystal was analyzed by XRD and proved to be NaB(OH)4, its purity was nearly 90%.

Key words: boron concentrate, sodium hydroxide, leaching, countercurrent slurry washing, crystallization, sodium metaborate

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