X-ray tomography study on the leaching dynamics of, and pore evolution in, large chalcopyrite ore particles during chloride leaching

IF 4.8 2区材料科学 Q1 METALLURGY & METALLURGICAL ENGINEERING

Hydrometallurgy Pub Date : 2025-08-23 DOI:10.1016/j.hydromet.2025.106556

Luis Beiza , Jochen Petersen , Lilian Velásquez-Yévenes

{"title":"X-ray tomography study on the leaching dynamics of, and pore evolution in, large chalcopyrite ore particles during chloride leaching","authors":"Luis Beiza , Jochen Petersen , Lilian Velásquez-Yévenes","doi":"10.1016/j.hydromet.2025.106556","DOIUrl":null,"url":null,"abstract":"<div><div>The dissolution of chalcopyrite (CuFeS<sub>2</sub>) in a heap leaching environment is known to progress slowly; this is mainly attributed to the formation of a product layer that inhibits the dissolution of copper from the mineral. Transporting the dissolved ions from the inner regions of the larger particles to the bulk solution through cracks and/or pores might also slow the process. Therefore, a systematic long-term study has been undertaken to determine the presence and propagation of pores, fissures or crack networks in 12–17 mm particles of a sulfide ore containing mainly quartz (SiO<sub>2</sub>), chalcopyrite and pyrite (FeS<sub>2</sub>) during its dissolution under chloride-rich heap leaching conditions. Each particle was placed in a cylindrical receptacle and flooded with 0.1 mol/L H<sub>2</sub>SO<sub>4</sub> solutions at 0, 20 and 150 g/L of chloride (as NaCl) using 0, 0.5 and 1 g/L initial cupric ion as the oxidant and leached for a period of up to 180 days at room temperature (18–22 °C). The generation of cracks and fissures and dissolution of mineral phases were observed using X-ray Computed Tomography (X-CT) at regular intervals during leaching. Additional experiments were run using 150 g/L Cl<sup>−</sup> to evaluate acidity from pH -0.4 (1.0 mol/L H<sub>2</sub>SO<sub>4</sub>) up to pH 3, as well as the effect of temperature at room temperature and 50 °C.</div><div>The results indicated that copper dissolution increased with increasing chloride concentration at room temperature and that the initial presence of cupric ions somewhat enhances the extraction. It was found that between pH 1 and 0.2 (0.1 mol/L H<sub>2</sub>SO<sub>4</sub>) at 150 g/L Cl<sup>−</sup> the dissolution is enhanced but inhibited at higher acid concentration. Low acidity (pH 3) promotes the precipitation of Fe that can block the pores and inhibit the dissolution of chalcopyrite. The X-CT scans confirmed that the gradual evolution of fissures and network of cracks over time enhanced the solution contact with the value mineral inside the particles, which then gradually disintegrated. In line with the leaching results, this effect seemed to be intensified at the higher chloride concentrations and when increasing temperature from 20 to 50 °C. The homogenous dissolution of chalcopyrite grains throughout the particle hints at the presence of galvanic coupling with pyrite grains as the key mode of chalcopyrite dissolution.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"238 ","pages":"Article 106556"},"PeriodicalIF":4.8000,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Hydrometallurgy","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0304386X25001215","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"METALLURGY & METALLURGICAL ENGINEERING","Score":null,"Total":0}

引用次数: 0

Abstract

The dissolution of chalcopyrite (CuFeS₂) in a heap leaching environment is known to progress slowly; this is mainly attributed to the formation of a product layer that inhibits the dissolution of copper from the mineral. Transporting the dissolved ions from the inner regions of the larger particles to the bulk solution through cracks and/or pores might also slow the process. Therefore, a systematic long-term study has been undertaken to determine the presence and propagation of pores, fissures or crack networks in 12–17 mm particles of a sulfide ore containing mainly quartz (SiO₂), chalcopyrite and pyrite (FeS₂) during its dissolution under chloride-rich heap leaching conditions. Each particle was placed in a cylindrical receptacle and flooded with 0.1 mol/L H₂SO₄ solutions at 0, 20 and 150 g/L of chloride (as NaCl) using 0, 0.5 and 1 g/L initial cupric ion as the oxidant and leached for a period of up to 180 days at room temperature (18–22 °C). The generation of cracks and fissures and dissolution of mineral phases were observed using X-ray Computed Tomography (X-CT) at regular intervals during leaching. Additional experiments were run using 150 g/L Cl⁻ to evaluate acidity from pH -0.4 (1.0 mol/L H₂SO₄) up to pH 3, as well as the effect of temperature at room temperature and 50 °C.

The results indicated that copper dissolution increased with increasing chloride concentration at room temperature and that the initial presence of cupric ions somewhat enhances the extraction. It was found that between pH 1 and 0.2 (0.1 mol/L H₂SO₄) at 150 g/L Cl⁻ the dissolution is enhanced but inhibited at higher acid concentration. Low acidity (pH 3) promotes the precipitation of Fe that can block the pores and inhibit the dissolution of chalcopyrite. The X-CT scans confirmed that the gradual evolution of fissures and network of cracks over time enhanced the solution contact with the value mineral inside the particles, which then gradually disintegrated. In line with the leaching results, this effect seemed to be intensified at the higher chloride concentrations and when increasing temperature from 20 to 50 °C. The homogenous dissolution of chalcopyrite grains throughout the particle hints at the presence of galvanic coupling with pyrite grains as the key mode of chalcopyrite dissolution.

查看原文本刊更多论文

大黄铜矿颗粒在氯化物浸出过程中浸出动力学及孔隙演化的x射线层析成像研究

已知黄铜矿（CuFeS2）在堆浸环境中的溶解过程缓慢；这主要是由于产物层的形成抑制了铜从矿物中的溶解。将溶解的离子从较大颗粒的内部区域通过裂缝和/或孔隙运输到整体溶液中也可能减缓这一过程。因此，对一种含石英（SiO2）、黄铜矿和黄铁矿（FeS2）为主的硫化矿石在富氯化物堆浸条件下溶蚀过程中，在12-17 mm颗粒中孔隙、裂隙或裂纹网络的存在和扩展进行了系统的长期研究。将每个颗粒置于圆柱形容器中，分别以0、20和150 g/L氯化钠（NaCl）和0、0.5和1 g/L初始铜离子为氧化剂，分别注入0.1 mol/L H2SO4溶液，在室温（18-22℃）下浸出180天。在浸出过程中，利用x射线计算机断层扫描（X-CT）定期观察裂缝和裂隙的产生以及矿物相的溶解。另外，用150 g/L Cl -评价pH -0.4 （1.0 mol/L H2SO4）到pH 3的酸度，以及室温和50℃温度的影响。结果表明，在室温条件下，铜的溶出度随氯离子浓度的增加而增加，铜离子的初始存在对萃取有一定的促进作用。结果表明，在pH 1 ~ 0.2 （0.1 mol/L H2SO4）和150 g/L Cl−浓度下，溶解度有所提高，但酸性浓度越高，溶解度越低。低酸度（pH 3）促进铁的析出，铁的析出可以堵塞孔隙，抑制黄铜矿的溶解。X-CT扫描证实，随着时间的推移，裂缝和裂缝网络的逐渐演变增强了溶液与颗粒内部价值矿物的接触，然后逐渐分解。与浸出结果一致，在较高的氯化物浓度下，当温度从20°C增加到50°C时，这种效果似乎得到了加强。黄铜矿颗粒在整个颗粒中的均匀溶解表明黄铁矿与黄铁矿的电偶联是黄铜矿溶解的关键模式。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Hydrometallurgy 工程技术-冶金工程

CiteScore

9.50

自引率

6.40%

发文量

144

审稿时长

3.4 months

期刊介绍： Hydrometallurgy aims to compile studies on novel processes, process design, chemistry, modelling, control, economics and interfaces between unit operations, and to provide a forum for discussions on case histories and operational difficulties. Topics covered include: leaching of metal values by chemical reagents or bacterial action at ambient or elevated pressures and temperatures; separation of solids from leach liquors; removal of impurities and recovery of metal values by precipitation, ion exchange, solvent extraction, gaseous reduction, cementation, electro-winning and electro-refining; pre-treatment of ores by roasting or chemical treatments such as halogenation or reduction; recycling of reagents and treatment of effluents.