1. Initial Conditions – Wastewater Issues in Coal Mining
During the extraction and processing of brown coal, a coal-water slurry is generated with a high content of solid particles. These particles are typically stored in lagoons, where they remain unused. This practice not only burdens the environment unnecessarily but also results in the loss of valuable resources.
2. ENVITES Solution – Water and Coal Dust Recycling Technology
In 2010, in cooperation with the engineering company BPO, an innovative technology was designed to enable effective separation of coal particles and their reuse, while the treated water is returned to the production process. This system was presented to the company’s management, which decided to implement the technology in its operations.
In 2011, a clarification line was installed and commissioned:
• Flow capacity: Up to 220 m³/h
• Coal recovery rate: Approximately 6,000 kg of coal dust per day
3. Technologies Used
The following key technologies were implemented as part of this project:
• Chemical preparation and dosing system: Ensures optimal dosing of reagents for effective flocculation and separation.
• Reactors: Equipment for intensive suspension processing and separation of coal particles.
• Lamella settlers: Efficient separation of solids from clarified water.
• Sludge thickeners: Minimize sludge volume by increasing its concentration before the dewatering phase.
• Filter presses: Reliable and effective dewatering of sludge.
• Belt conveyors: Used for transporting dewatered sludge during processing.
4. Benefits Achieved
The implementation of the newly designed system delivered the following benefits:
• Cost savings and efficient waste utilization: Effective separation and reuse of coal dust improved the economic performance of the entire process.
• Water recycling: Treated water is returned to the production cycle, significantly reducing fresh water consumption.
• Coal dust recovery: The recovered coal dust is reused in the final coal product, increasing its value.
• Environmental improvements: Reduced environmental impact through water recycling and minimized waste disposal.
• Return on investment: The full investment cost was recovered within just 18 months, ensuring high economic efficiency of the solution.
5. Conclusion
The introduction of the recycling technology at the coal treatment facility brought significant environmental and economic benefits. The company reduced its mining-related costs, improved environmental performance, and used water resources more effectively. The technology has proven to be highly efficient and valuable both in terms of savings and sustainability.
