Top Metal Mining Group – Water-Cooled Zero-Purge Blower Purge Dryer Delivers 7 Years of Stable Operation

Client Background

Zijin Mining Group Co., Ltd. is a large-scale mining group focused on the exploration and development of gold, copper, zinc, and other metal resources. It is one of the world‘s leading metal mining companies, ranking among the Global TOP 10 Metal Mining Enterprises. The company operates multiple large-scale mines and smelting projects in mainland China, Hong Kong, Canada, Australia, South Africa, and other countries and regions, covering the entire industrial chain from mining, mineral processing, smelting, refining, and trading.

Zijin Mining has always demanded extremely high reliability, energy efficiency, and operational stability from its equipment. Mine and smelter sites are typically located in remote areas with harsh environments (high temperature, high humidity, high dust), and production operates 24/7. Any equipment failure can lead to significant production losses. Compressed air, as a key power source for pneumatic mining equipment, automation control systems, and smelting processes, requires consistent dryness and cleanliness to ensure production efficiency and safety.

Compressed Air Applications

At Zijin Mining’s mine and smelting operations, compressed air is primarily used for:

• Underground & open-pit mining pneumatic equipment: pneumatic rock drills, air-powered loaders, pneumatic valves – requiring dry, oil-free air to prevent freezing and line blockage.
• Mineral processing: flotation machine pneumatic agitation, slurry pneumatic conveying, filter blow-off – moisture-sensitive, as high moisture affects flotation efficiency and concentrate grade.
• Smelting processes: combustion air for copper/gold smelting furnaces, dust collector reverse pulse cleaning, instrument control air – requiring stable dew point to prevent condensate from damaging precision instruments.
• Automation control systems: PLCs, pneumatic actuators, sensors – needing clean, dry instrument air.

Due to the dusty, humid mine environment, and some plants located in hot, humid southern regions, moisture in compressed air is a critical issue. The customer‘s original drying equipment suffered from high purge loss, unstable dew point, and corrosion problems.

Figure: 55Nm³/min Water-Cooled Zero-Purge Blower Purge Dryer

Pain Points (Before Cooperation)

Before partnering with us, a large copper mine and smelting base of Zijin Mining faced the following issues with its compressed air drying system:

• High Purge Air Loss: The original heatless or heated purge dryers consumed large amounts of compressed air for regeneration (15–25%), forcing compressors to run overloaded and resulting in high electricity bills.
• Unstable Dew Point: Under high-temperature, high-humidity summer conditions, the dryer outlet dew point fluctuated significantly, sometimes rising above -20°C, causing pneumatic valves to freeze and stick, and instrument lines to accumulate water.
• Equipment Corrosion: The original dryers were made of carbon steel. In the humid mine environment, internal surfaces rusted, and rust particles entered downstream equipment, causing valve wear and nozzle clogging.
• Frequent Maintenance: Desiccant degraded rapidly due to oil and moisture, requiring replacement every 1–2 years. Pneumatic valves had high failure rates due to frequent cycling, disrupting continuous production.
• High Energy Consumption: Lack of zero-purge technology meant regeneration consumed large amounts of compressed air or electric heating, conflicting with Zijin Mining‘s recent “green mine, energy conservation & emission reduction” strategy.

Our Solution

To address Zijin Mining’s core requirements of high reliability, extreme energy efficiency, corrosion resistance, and long service life, we recommended a water-cooled zero-purge blower purge adsorption dryer. This technology combines a water-cooled aftercooler and a blower purge regeneration system, specially adapted for high-temperature mine environments.

Figure: 100m³/min Desiccant Air Dryer

Core Technology: Water Cooling + Blower Zero-Purge Regeneration

• Water-Cooled Design: Equipped with a water-cooled aftercooler and a water-cooled regeneration air cooler, using the mine‘s circulating cooling water (typically ≤32°C) to cool compressed air and regeneration tail gas. This avoids the heat dissipation limitations of air-cooled systems in high ambient temperatures, ensuring stable inlet air temperature and consistent dryer efficiency regardless of environmental fluctuations.
• Blower Zero-Purge Regeneration: A blower draws ambient air, heats it to 150–200°C via electric heaters, and regenerates the saturated tower – consuming no compressed air whatsoever. Energy consumption is limited to the blower and heater, achieving over 70% energy savings compared to heatless dryers.
• Stainless Steel Construction: The towers and all air-contacting piping are made of stainless steel (304 or 316L), eliminating rust risks in the humid mine environment and ensuring clean downstream air.
• Intelligent Control: Siemens PLC with automatic control based on online dew point monitoring, optimizing regeneration cycles. Integrated remote monitoring interface allows connection to the mine‘s DCS system.

First Cooperation Equipment (2018)

• Model: Water-Cooled Zero-Purge Blower Purge Adsorption Dryer (Figure 1)
• Capacity: Sized to match the customer’s on-site compressor total flow (meeting the base‘s demand)
• Commissioning Date: 2018
• Performance Record: Continuously operated for over 7 years with pressure dew point consistently ≤ -40°C. No downtime or air quality issues caused by the dryer. The exterior and internal structure show no significant corrosion. The desiccant remains in good condition and has not been replaced to date.

Recent Additional Purchase (2025)

Based on full recognition of the equipment’s performance and after-sales service, Zijin Mining recently purchased an additional 100 m³/min blower purge dryer (Figure 2) for its capacity expansion project. The new unit features the same water-cooled zero-purge design with an upgraded control system, compatible with the existing system for flexible parallel operation.

Delivery & Installation

During the initial cooperation in 2018, our technical team conducted an on-site survey and customized the design for the hot, humid, dusty mine environment:

• Added a water-cooled precooler to reduce inlet air temperature.
• Enhanced the filtration system with additional pre-filters for oil and dust removal.
• Skid-mounted design for quick on-site installation.

Installation and commissioning took two weeks and passed customer acceptance on the first attempt. Over seven years of operation, we have provided regular remote inspections and on-site services, with excellent customer feedback.

The 2025 additional unit follows the same standard delivery process and is expected to further reduce compressed air energy consumption for the expansion project.

Results & Benefits (Based on 7 Years of Operation)

Customer Testimonial

“This water-cooled zero-purge blower purge dryer has been running continuously at our mine for over seven years since its first installation in 2018. It has never let us down. The dew point has always remained below -40°C, and the zero purge loss has saved us a significant amount in electricity bills. Based on this trust, we chose the same series again for our new expansion project. Good equipment speaks for itself.”

— Equipment Management Manager, Zijin Mining Base

Conclusion

The partnership between Zijin Mining and our company began in 2018. A single water-cooled zero-purge blower purge dryer, with over seven years of stable operation, earned the customer‘s deep trust. The recent purchase of an additional 100 m³/min unit marks a new chapter in our collaboration. Going forward, we will continue to provide efficient, reliable, and durable compressed air drying solutions for mining customers, supporting green and intelligent mine construction.