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过程工程学报 ›› 2020, Vol. 20 ›› Issue (2): 222-229.DOI: 10.12034/j.issn.1009-606X.219305

• 过程与工艺 • 上一篇    下一篇

硫酸溶液中方解石表面CO2气泡的生长过程

马 麟1， 邓荣东1,2*， 幸鼎权1， 陈泓希1， 范兴颖1， 黄汀怡1   

  1. 1. 福州大学紫金矿业学院，福建 福州 350108 2. 福州大学紫金矿业集团矿产资源综合利用联合研发中心，福建 福州 350108
  • 收稿日期:2019-09-20 修回日期:2019-11-15 出版日期:2020-02-22 发布日期:2020-02-19
  • 通讯作者: 邓荣东 313957363@qq.com
  • 基金资助:
    方解石反应浮选过程中CO2气泡的原位束缚及其机制研究;方解石表面CO2气泡的生长动力学研究

Growth process of CO2 bubbles on calcite surface in sulfuric acid solution

Lin MA1, Rongdong DENG1,2*, Dingquan XING1, Hongxi CHEN1, Xingying FAN1, Tingyi HUANG1   

  1. 1. School of Zijin Mining, Fuzhou University, Fuzhou, Fujian 350108, China 2. Zijin Mining Group Joint Research Center for Comprehensive Utilization of Mineral Resources, Fuzhou University, Fuzhou, Fujian 350108, China
  • Received:2019-09-20 Revised:2019-11-15 Online:2020-02-22 Published:2020-02-19
  • Contact: DENG Rong-dong 313957363@qq.com

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摘要： 用高速摄像仪对方解石与硫酸反应产生CO2气泡的过程进行了系统研究，分析了硫酸浓度和方解石颗粒尺寸对CO2气泡产生量、气泡生长速率、脱附直径、数量分布、方解石颗粒表观比重及方解石与硫酸反应后的表面形态等的影响。结果表明， CO2气泡在方解石表面的生长非常迅速，在反应时间一定时，CO2气泡产生量与硫酸浓度成反比，浓度越高产生的气泡越少，且随硫酸浓度增加，气泡生长速率越来越大，而脱离直径越来越小。绝大部分生成的CO2气泡会迅速脱离方解石表面。随着反应进行，硫酸浓度越高，相同时间内方解石表面可统计气泡数量越少，但在表面残留CO2气泡的直径越大。酸浓度过高不利于CO2气泡在方解石表面的吸附。方解石与硫酸反应后表面粗糙度增加，可增大表面对气泡的吸附作用。

关键词: 方解石, CO2气泡, 气泡生长过程, 浮选, 表观比重

Abstract: Calcite is one of the most common gangue minerals in mineral processing. The efficient separation of calcite from valuable minerals has long been a focus and challenge in the field of mineral processing, and especially in the processing of calcium-containing minerals such as scheelite, fluorite, and apatite. In acidic pulp, calcite could react with hydrogen ions to form CO2 bubbles, which are sometimes beneficial for minerals separation. The process of CO2 bubble generation by the reaction between calcite and sulfuric acid was systematically studied using high-speed camera in this work. The effect of sulfuric acid concentration and calcite particle size on CO2 bubbles production, bubble growth rate, detachment diameter, quantity distribution, apparent specific gravity of calcite particles and surface morphology after reaction of calcite with sulfuric acid were investigated. When calcite encountered acid, CO2 bubbles generated immediately on the surface of calcite. Once grew to a certain size, these bubbles would detach quickly from the calcite surface. When sulfuric acid concentration was in the range of 1.0wt%?2.0wt%, CO2 bubbles production on the calcite surface was inversely proportional to sulfuric acid concentration. The higher the concentration, the less CO2 bubbles was produced, and the faster the reaction terminated. As sulfuric acid concentration increased, the bubble growth rate increased and the detachment diameter reduced. The surface of the calcite would always adsorb CO2 bubbles during the reaction time, resulting in a smaller apparent weight of calcite and the change of surface properties of calcite. Calcium sulfate crystals were formed by the reaction of calcite with sulfuric acid, which prevented the further reaction of calcite with acid. The apparent specific gravity of calcite varied with the particle size, but only at small values of 6?7 seconds. The research of this work provided a fundamental basis for the separation of calcite from other non-carbonate minerals.

Key words: Calcite, CO2 bubbles, bubble growth process, flotation, apparent specific gravity