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The Chinese Journal of Process Engineering ›› 2022, Vol. 22 ›› Issue (8): 1094-1102.DOI: 10.12034/j.issn.1009-606X.221225

• Research Paper • Previous Articles     Next Articles

Floating and sinking experiment and mechanism of calcite coating?acid reaction

Rongdong DENG*,  Dingquan XING,  Jianghui ZHOU,  Shiqi LI,  Ruiqi ZHAO   

  1. School of Zijin Mining, Fuzhou University, Fuzhou, Fujian 350108, China
  • Received:2021-07-21 Revised:2021-11-18 Online:2022-08-28 Published:2022-08-28
  • Contact: Dong RongDENG dengrongdong111@163.com

方解石包覆-酸反应浮沉试验及机理

邓荣东*, 幸鼎权, 周江慧, 李世淇, 赵睿祺
  

  1. 福州大学紫金矿业学院,福建 福州 350108
  • 通讯作者: 邓荣东 dengrongdong111@163.com
  • 作者简介:邓荣东(1986-),男,四川省自贡市人,副教授,主要从事有色金属矿的分离和硫化技术及理论,碳酸盐矿物的反浮选工艺和理论相关研究,E-mail: dengrongdong111@163.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

Abstract: Calcite, as a major gangue mineral, is often found in other calcium-bearing minerals. Froth flotation is the main method to separate calcite from other calcium minerals. However, due to the similar physicochemical characteristics of calcium-containing minerals, it is difficult to separate these minerals effectively by the conventional flotation method. Different from non-carbonate minerals, calcite has the characteristics of reacting with an acid to generate CO2 bubbles. These CO2 bubbles can effectively reduce the apparent specific gravity of calcite in a short time. Polyvinyl alcohol film has selective permeability, which can allow H+ to pass through and as a barrier to CO2 bubbles. The high polymer film can bind the generated CO2 bubbles on the surface of calcite. When there are enough CO2 bubbles, the calcite particles will float spontaneously and be separated from the calcium-containing non-carbonate minerals. The coating effect directly affects the separation effect. Therefore, it is necessary to determine conditions of appropriate coating and acid reaction to improve the effectiveness of calcite coating-acid reaction. In this work, the main factors that affect the calcite coating-acid method were systematically studied through single factor experiments and orthogonal experiments. The optimum conditions of sulfuric acid concentration, PVA type and concentration, methyl isobutyl carbinol (MIBC), and sodium dodecyl sulfonate (SDS) concentration were screened by a single factor test. The orthogonal test was carried out for three factors, acid concentration, PVA concentration, and MIBC concentration. The results showed that the coating-acid reaction method can realize the self-floating of calcite particles (1 mm). The optimum conditions of the calcite coating-acid reaction method were sulfuric acid concentration of 2.0wt%, PVA type of P139546, PVA concentration of 2.4wt%, and 40 mg/L MIBC which was conducive to the floating of calcite. Under these conditions, the floating rate of calcite was 84.9%, and the average floating time was 28.8 s. The combination of SDS and PVA can effectively improve the floating time of calcite, while the floating rate was lower than that without SDS. PVA concentration and acid concentration were the main factors affecting the calcite coating-acid reaction method.

Key words: Calcite, Coating- acid reaction, PVA, CO2 bubble, MIBC, Sodium Dodecyl Sulfonate

摘要: 本工作系统研究了硫酸浓度、聚乙烯醇(PVA)种类及浓度、甲基异丁基甲醇(MIBC)浓度和十二烷基磺酸钠(SDS)浓度对PVA包裹的方解石颗粒与稀硫酸反应时方解石上浮情况的影响,并针对酸浓度、PVA浓度和MIBC浓度三因素开展正交试验。研究结果表明,包覆-酸反应方法可实现方解石颗粒的上浮。当方解石颗粒为1 mm时的最佳包覆-酸反应条件为PVA包覆剂型号为P139546,浓度为2.4wt%、硫酸浓度为2.0wt%、MIBC用量为40 mg/L,在此条件下方解石上浮率能达到84.9%;此外,PVA浓度与硫酸浓度是影响方解石包覆-酸反应浮沉的主要因素。

关键词: 方解石, 包覆-酸反应, PVA, CO2气泡, MIBC, 十二烷基磺酸钠