As the demand for precious metal recycling continues to grow, industrial wastewater treatment is gradually shifting away from the traditional model of simply meeting discharge standards. Instead, the industry is moving toward an integrated approach that combines pollution control, resource recovery, and water recycling.
In industries such as electroplating, PCB manufacturing, electronics processing, and precious metal refining, industrial wastewater often contains valuable metal ions, including gold and silver. How to efficiently separate, concentrate, and recover these precious metals from complex wastewater streams has therefore become an important technical challenge for the industry.
Recently, we officially launched our Gold and Silver Ion Specialty Membranes. This series of specialty membranes is specifically designed for the resource recovery treatment of industrial wastewater containing gold and silver. Through membrane separation technology, the system enables the selective retention and concentration of gold and silver ions while also providing effective separation performance for cyanide-containing wastewater streams. The technology offers a new pathway for precious metal recovery and industrial wastewater recycling.
Unlike conventional wastewater treatment processes that focus primarily on pollutant removal, YIME's gold and silver ion specialty membranes place greater emphasis on recovering valuable resources from wastewater. While reducing wastewater volume, the system concentrates precious metals that would otherwise be lost in the waste stream, creating favorable conditions for subsequent processes such as electrolytic recovery and metallurgical refining.
I. Separation and Concentration for Gold- and Silver-Containing Wastewater
Gold and silver are important precious metal resources widely used in electronics, electroplating, semiconductors, jewelry, and precision manufacturing. During industrial production, certain cleaning wastewater streams, electroplating rinse water, and process solutions may contain varying concentrations of gold ions, silver ions, and related metal complexes.
Traditional wastewater treatment methods generally rely on chemical precipitation, oxidation-reduction reactions, or adsorption processes, with the primary objective of reducing pollutant concentrations. However, for precious-metal-containing wastewater with low concentrations, large volumes, or complex chemical compositions, conventional treatment alone may result in dispersed metal resources, limited recovery efficiency, and relatively high downstream treatment costs.
YIME Gold and Silver Ion Specialty Membranes were developed specifically to address these application challenges.
The membranes utilize selective membrane separation performance to separate different components under pressure-driven operating conditions. During system operation, wastewater containing precious metal ions such as gold and silver can be progressively concentrated. Valuable metals are enriched from a large volume of wastewater into a smaller volume of concentrated solution, while part of the water and other components are separated into the permeate stream. This process helps achieve both wastewater volume reduction and valuable resource concentration.
After concentration, the high-strength gold and silver solution can be sent to an electrolytic recovery unit to obtain solid metallic gold and silver. The final permeate from the gold and silver ion concentration membrane system can also be further treated through an RO membrane system and converted into purified water for reuse in electroplating processes, reducing freshwater consumption and water waste.
Where purified water reuse is not required, the final treated water from the system can generally meet applicable discharge requirements and may be discharged accordingly.
II. Real-World Projects Demonstrate Resource Recovery Value
Industrial wastewater is often complex and subject to significant fluctuations. Therefore, the engineering value of specialty membranes cannot be evaluated solely based on laboratory data. Real-world project validation is essential for demonstrating membrane stability, separation performance, and adaptability under practical operating conditions.
Our gold and silver ion specialty membranes have already been applied in precious metal wastewater resource recovery projects in Hubei and Xinfeng, Jiangxi, providing practical validation of the product's stability, separation performance, and engineering applicability.
One of our silver recovery membrane system projects was designed with a treatment capacity of 200 m³/day. The system utilizes a multi-stage concentration process to progressively separate and enrich silver resources from silver-containing wastewater. The high-concentration silver solution is then delivered to the subsequent electrolytic recovery process.
Based on the project's operational targets, the electrolytic recovery section is designed to achieve a silver recovery capacity of up to 120 kg per month.
All core performance data are based on calculations and operational objectives from real engineering projects, providing practical reference value for similar applications.
During project implementation, we systematically summarized and optimized our gold and silver ion recovery technologies and processes. Through continuous engineering experience and process refinement, we have developed a practical set of operating procedures and incorporated relevant technologies into our intellectual property protection strategy.
Meanwhile, the preparation methods and applications of our gold and silver ion specialty membranes have successfully entered the substantive examination stage of the patent process. This further demonstrates the originality and innovative nature of the technology and reflects the reliability of our technical development capabilities.
III. How Do We Determine Whether a Project Is Suitable for On-Site Implementation?
At the early stage of a project, our team conducts wastewater sampling and water quality analysis to determine whether the wastewater is suitable for membrane concentration treatment.
We also evaluate the potential economic feasibility of the project, including the expected recovery value of precious metals and the estimated operating costs associated with water, electricity, and equipment operation.
Based on the evaluation results, both parties can further discuss technical solutions, cooperation details, commercial terms, and contract arrangements.
After the project cooperation is confirmed, we begin equipment manufacturing and the production of the required gold and silver ion specialty membranes.
Depending on the cooperation model, equipment manufacturing may also be carried out by a third-party contractor selected by the customer, with technical guidance provided by our engineering team.
After the system is completed, our technical personnel conduct commissioning and operational testing to verify actual system performance. We also provide training on basic equipment operation and recommended maintenance intervals.
Within one year after project completion, equipment and membrane products that are properly operated according to our technical guidance are covered by our warranty and maintenance service.
If equipment or membrane-related issues occur within the proper operating conditions during the warranty period, our team will provide corresponding technical support and maintenance services.
IV. Precious Metal Recovery Solutions for Multiple Industries
Gold and silver ion specialty membranes can be applied to the treatment of gold- and silver-plating rinse water and process wastewater. They are also suitable for applications in PCB manufacturing, electronics production, precious metal refining, jewelry processing, mining and mineral processing, and professional precious metal recycling.
For different projects, factors such as the concentration of gold and silver ions, the presence of cyanide, daily wastewater treatment capacity, target concentration ratio, and downstream recovery methods can all influence membrane selection and system configuration.
As green manufacturing and the circular economy continue to develop, industrial wastewater treatment is increasingly focusing not only on pollutant removal but also on the recovery of valuable metal resources and reusable water.
By integrating specialty membranes with appropriate pretreatment processes, multi-stage concentration systems, electrolytic recovery equipment, and permeate reuse systems, companies can reduce precious metal losses through wastewater discharge, lower downstream treatment loads, reduce hazardous waste disposal pressure, and promote the recycling of water resources.
Looking ahead, YIME will continue to focus on industrial wastewater resource recovery, high-value metal recycling, and membrane material innovation. Through continuous research and technological development, we aim to expand the application of specialty membrane technology across a wider range of precious-metal-related industries and contribute to more sustainable industrial resource utilization.
