Novel insights into the mechanism of lime method based on calcium dioleate and mineral surface transformation

Abstract

The lime method is one of the most common flotation processes, which can achieve flotation separation of scheelite, fluorite and calcite. The large amount of calcium ions released by lime easily formed calcium dioleate colloids with fatty acid anions, which was overlooked in the classical action mechanism of the lime method. The solution chemistry calculations revealed that calcium dioleate colloid was the main action component in the pulp of lime method. The fluorite surface was covered by calcium carbonate as a result of increased surface transformation reactions, and the surface properties were similar to calcite surface. The size of calcium dioleate colloid in lime method slurry was 100–600 nm, and the amount of lime significantly affected its size and size distribution. Selective adsorption of calcium dioleate colloids occurred on the surface of scheelite, and its adsorption effect on the surface of fluorite was weakened due to surface transformation. The excellent selectivity of the lime method was explained by the selective adsorption of calcium dioleate on the surface of scheelite, which was further enhanced by the surface conversion reaction of fluorite to calcite. The new mechanism completes the classical theory by complementing the role of calcium dioleate in lime flotation.

Keywords

scheelite / lime method / calcium dioleate / surface transformation / fluorite / calcite

References

[1] YaoW, LiM-l, ZhangM, et al. . Effect of Zn2+ and its addition sequence on flotation separation of scheelite from calcite using water glass [J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2020, 588: 124394

[2] YanW-p, LiuC, AiG-h, et al. . Flotation separation of scheelite from calcite using mixed collectors [J]. International Journal of Mineral Processing, 2017, 169106-110

[3] KupkaN, RudolphM. Froth flotation of scheelite - A review [J]. International Journal of Mining Science and Technology, 2018, 28(3): 373-384

[4] ChenW, FengQ-m, ZhangG-f, et al. . Selective flotation of scheelite from calcite using calcium lignosulphonate as depressant [J]. Minerals Engineering, 2018, 119: 73-75

[5] RaiB, RaoT K, KrishnamurthyS, et al. . Molecular modeling of interactions of alkyl hydroxamates with calcium minerals [J]. Journal of Colloid and Interface Science, 2002, 256(1): 106-113

[6] FengB, LuoX-p, WangJ-q, et al. . The flotation separation of scheelite from calcite using acidified sodium silicate as depressant [J]. Minerals Engineering, 2015, 80: 45-49

[7] HuY-h, GaoZ-y, SunW, et al. . Anisotropic surface energies and adsorption behaviors of scheelite crystal [J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2012, 415: 439-448

[8] WeiZ, SunW-j, HuY-h, et al. . Structures of Pb-BHA complexes adsorbed on scheelite surface [J]. Frontiers in Chemistry, 2019, 7: 645

[9] WeiZ, HanH-s, SunW, et al. . Novel multiple ligand metal-group collectors assembled from benzohydroxamic acid and cupferron [J]. Minerals Engineering, 2023, 201108183

[10] WeiZ, HuY-h, HanH-s, et al. . Configurations of lead(II) -benzohydroxamic acid complexes in colloid and interface: A new perspective [J]. Journal of Colloid and Interface Science, 2020, 562342-351

[11] WeiZ, SunW, WangP-s, et al. . The structure analysis of metal — organic complex collector: From single crystal, liquid phase, to solid/liquid interface [J]. Journal of Molecular Liquids, 2023, 382: 122029

[12] WeiZ, HuY-h, HanH-s, et al. . Selective separation of scheelite from calcite by self-assembly of H2SiO3 polymer using Al3+ in Pb-BHA flotation [J]. Minerals, 2019, 9(1): 43

[13] WangR-l, SunW-j, HanH-s, et al. . Alcaustic starch coordination compounds: A new depressant for fine calcite [J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2022, 648129268

[14] WangR-l, SunW-j, HanH-s, et al. . A novel fine gangue depressant: Metal ions-starch colloidal depressant and its effect on ultrafine chlorite [J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2022, 655130326

[15] WeiZ, HanH-s, SunWei. A highly selective metal-organic complex collector for efficient mineral flotation [C]. Rare Metal Technology 2022, 2022, Cham, Springer: 211-223

[16] HanH-s, XiaoY, HuY-h, et al. . Replacing Petrov’s process with atmospheric flotation using Pb-BHA complexes for separating scheelite from fluorite [J]. Minerals Engineering, 2020, 145106053

[17] YongxinL, LiC-gen. Selective flotation of scheelite from calcium minerals with sodium oleate as a collector and phosphates as modifier. I. Selective flotation of scheelite [J]. International Journal of Mineral Processing, 1983, 10(3): 205-218

[18] YangX-sheng. Beneficiation studies of tungsten ores-A review [J]. Minerals Engineering, 2018, 125111-119

[19] HiçyìlmazC, Atalay, ÖzbayogluG. Selective flotation of scheelite using amines [J]. Minerals Engineering, 1993, 6(3): 313-320

[20] MartinsJ I, AmaranteM M. Scheelite flotation from tarouca mine ores [J]. Mineral Processing and Extractive Metallurgy Review, 2013, 34(6): 367-386

[21] WeiZ, SunW, HanH-s, et al. . New technology and practice of tungsten ore flotation [J]. Metal Mine, 20216072

[22] LIU Hong-wei. Study on new flotation process of refractory scheelite at room temperature [D]. Changsha: Central South University. (in Chinese)

[23] LiuH-w, XuZ-guang. Technical research on flotation of the low-grade scheelite at normal temperature by lime-based method [J]. Multipurpose Utilization of Mineral Resources, 20133335

[24] SunW-j, HanH-s, SunW, et al. . Novel insights into the role of colloidal calcium dioleate in the flotation of calcium minerals [J]. Minerals Engineering, 2022, 175107274

[25] FaK-q, JiangT, NalaskowskiJ, et al. . Interaction forces between a calcium dioleate sphere and calcite/fluorite surfaces and their significance in flotation [J]. Langmuir, 2003, 19(25): 10523-10530

[26] FaK-q, NguyenA V, MillerJ D. Interaction of calcium dioleate collector colloids with calcite and fluorite surfaces as revealed by AFM force measurements and molecular dynamics simulation [J]. International Journal of Mineral Processing, 2006, 81(3): 166-177

[27] ZhuC-y, LiG-s, XingY-w, et al. . Adhesion forces for water/oil droplet and bubble on coking coal surfaces with different roughness [J]. International Journal of Mining Science and Technology, 2021, 31(4): 681-687

[28] SunW-j, HanH-s, SunW, et al. . New insights into the role of calcium dioleate in selectively separating fluorite from calcite during cleaning process [J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2022, 648129245

[29] WangR-l, LuQ-q, SunW-j, et al. . Flotation separation of apatite from calcite based on the surface transformation by fluorite particles [J]. Minerals Engineering, 2022, 176107320

[30] ZaninM, LambertH, Du PlessisC A. Lime use and functionality in sulphide mineral flotation: A review [J]. Minerals Engineering, 2019, 143105922