In the field of mineral resource development and utilization, gold and copper are important strategic mineral resources, and their efficient extraction has always been the core focus of industry research. With the gradual depletion of easily treatable ores, the development focus has shifted to low-grade and complex refractory ores, posing severe challenges to traditional leaching processes. Against this backdrop, sodium persulfate has demonstrated significant application potential in the industrial leaching of gold and copper by virtue of its unique chemical properties, emerging as a key reagent for intensifying leaching and improving resource utilization efficiency.
Ⅰ. Compatibility of Sodium Persulfate Properties with Leaching Processes
Sodium persulfate is a strong oxidant, and its core value lies in its ability to provide highly reactive persulfate ions under certain conditions, effectively increasing the redox potential of the system. This characteristic is highly compatible with the inherent requirements of gold and copper leaching.
In gold and copper ores, target metals often exist in insoluble forms such as sulfides. The strong oxidizing property of sodium persulfate can destroy the crystal lattice structure of these sulfides or oxidize low-valence metal ions to more soluble valence states, thereby facilitating the release of target metals from the ore matrix. In addition, sodium persulfate is relatively stable at room temperature, enabling convenient storage and transportation. Its aqueous solution maintains stable oxidation performance under industrial production conditions, allowing easy integration into existing continuous production processes.
Industrial-grade sodium persulfate has strict requirements for purity and active oxygen content, and high-quality products are the foundation for ensuring the stability of leaching results. The sodium persulfate produced by Fujian Zhanhua Chemical features high purity, low impurity content, and stable active oxygen content (purity ≥ 99%, active oxygen content ≥ 6.65%), meeting the high standards of industrial-grade products. Recognized as a National Single Champion Product by the Ministry of Industry and Information Technology, it is a powerful testament to the product's quality and performance.
Ⅱ. Mechanism of Sodium Persulfate for Improving Gold Leaching Efficiency
Gold has extremely stable chemical properties. Conventional cyanidation leaching requires sufficient oxygen to maintain an oxidizing environment, yet it typically yields low leaching rates for refractory gold ores. The addition of sodium persulfate can significantly enhance this oxidation process, achieving breakthroughs in leaching efficiency.
In the gold cyanidation leaching system, sodium persulfate plays a synergistic role in two main aspects:
It preferentially oxidizes associated sulfides in the ore (e.g., pyrite), reducing the competitive consumption of cyanide and oxygen by these "cyanide-consuming and oxygen-consuming" substances, thus allowing more leaching agent to act on gold effectively.
Its oxidation helps eliminate the passive film on the surface of gold particles, maintaining the reaction activity of the gold surface and thereby accelerating the complexation and dissolution of gold.
This synergistic effect not only improves the leaching rate and final recovery rate of gold, but also helps maintain the chemical stability of the leaching system and reduce the risk of process fluctuations.
Ⅲ. Application Advantages of Sodium Persulfate in Copper Leaching
For certain refractory copper ores, such as secondary sulfide ores or ore bodies closely associated with pyrite, traditional acid leaching or bioleaching processes may suffer from low rates and incomplete extraction. Sodium persulfate provides a solution for intensified leaching.
In acidic or ammoniacal leaching systems, sodium persulfate can directly oxidize insoluble copper sulfides (e.g., chalcocite) into soluble copper ions, or achieve indirect oxidation through intermediate media such as iron ions generated during oxidation. Its strong oxidizing capacity helps penetrate the dense encapsulation layer of ores, promoting contact between the leaching agent and internal minerals, thereby increasing the leaching rate and total leaching rate of copper. Meanwhile, the main reduction product of sodium persulfate is sulfate ions, which causes minimal interference to the leachate system and generally does not introduce difficult-to-remove impurity ions, facilitating subsequent copper solvent extraction and electrowinning processes.
Ⅳ. Comprehensive Value of Sodium Persulfate in Industrial Applications
The application value of sodium persulfate in gold and copper leaching is reflected in multiple aspects, fully aligning with the requirements for green and efficient development of the mining industry:
Strong process compatibility and low transformation cost: Usually used as an additive, it does not require large-scale modification of existing main equipment and can be directly integrated into existing leaching processes, resulting in short project implementation cycles and fast return on investment.
Significant resource benefits and expanded utilization boundaries: It greatly improves the leaching efficiency of low-grade and complex ores, expands the reserves of economically exploitable mineral resources, and enhances comprehensive resource utilization efficiency.
Outstanding environmental advantages and alignment with policy directions: Its application helps reduce the dosage of highly polluting agents such as permanganates and chlorates in traditional intensified leaching processes; moreover, the main post-reaction product is sodium sulfate, with no toxic or harmful residues, complying with the trend of green and low-carbon development in the mining industry.
Stable and reliable products ensuring continuous production: Fujian Zhanhua Chemical has deep expertise in the R&D and production of sodium persulfate. Relying on a strict production quality control system, the key performance indicators of the product remain stable, enabling it to continuously function in the complex industrial environment of gold and copper leaching and avoiding negative impacts on leaching results due to product performance fluctuations.
Ⅴ. Conclusion
With the continuous advancement of mineral processing technology, the application scenarios and mechanism research of sodium persulfate will become increasingly in-depth. Selecting stable, reliable, and high-quality sodium persulfate products is crucial to ensuring their sustained effectiveness in complex industrial environments and achieving expected economic benefits. As a professional manufacturer, Fujian Zhanhua Chemical provides a reliable raw material option for the optimization of mining leaching processes. Going forward, Zhanhua will continue to focus on the technical needs of the mining industry, promote the in-depth compatibility of products and processes, help mining enterprises achieve efficient resource utilization and green low-carbon development, and provide solid support for the security of strategic mineral resources such as gold and copper.