Currently, at coal-fired power plants, the process of burning produces a huge amount of ashes, usually accounting for 30-35% of the coal burned. Every year, Vinh Tan - Binh Thuan Thermal Power Plant emits millions of tons of ashes. Most of these ashes are discharged into the environment as an industrial waste without treatment and reuse of the precious waste sources. The cause of this waste is poor ash quality, lack of ash handling technology and low environmental awareness.
Therefore, studying ashes of Vinh Tan - Binh Thuan Thermal Power Plant to be able to fully utilize the ash source and to avoid affecting the environment is an urgent issue. The Vietnam Academy of Science and Technology (VAST) has assigned the project “Study on technologies to produce useful materials from ashes of Vinh Tan - Binh Thuan Thermal Power Plant” (Project Code: VAST03.02-17/18) to the Institute of Materials Science from January, 2017 to December, 2018. The project belongs to materials science guidance and is chaired by MA. Ho Ngoc Hung.
The project has implemented the solution of ash treatment in a closed, synchronous and thorough way to minimize the impact on the air environment, soil environment and water environment, in combination with full recovery and reuse of post-processed products such as: recovered coal reused as burning material; fly ash after flotation used as an additive for subsequent applications such as geopolymer concrete, pavement foundations (pavement structures) - Subbase and Base layers, additives for cement.
After two years of implementation, the project has obtained the following results:
• Building a closed, synchronous and thorough treatment technology process of ash from thermal power plant. Using the flotation method to separate three products: unburnt coal products with an amount of> 5000 Kcal/kg reused as raw materials, slag crushed as an additive for the production of cement, and fly ash used in the production of geopolymer concrete and transport works.
• Developing the technological process to produce geopolymer with 300 marks from fly ash products. Research and evaluate the ability of geopolymer concrete when immersed in the marine environment and chemicals. Casting concrete components produced for 3-way self-aligning concrete sections.
• Researching and evaluating the application and feasibility of using fly ash as an additive in transport works.
The project has published one article in a national magazine. One useful solution has been accepted. On February 27th, 2019, VAST Acceptance Council accepted the project.
Following are photos of the project:
The process of flotation of ash to recover coal and fly ash applied in the next steps
Three-way self-aligning concrete
Translated by Tuyet Nhung
Link to Vietnamese version