Vinh Tan Power Center (view from coal port). Photo: Minh Ngoc

100% utilization of generated ash and slag

The Vinh Tan Power Center (Lam Dong Province) has been planned with three ash disposal sites, covering a total area of about 156 hectares. Currently, two disposal sites are in operation for ash and slag burial. Among them, EVN’s plants (Vinh Tan 2 and Vinh Tan 4) share a disposal site of over 38 hectares, with a storage capacity of about 8.6 million tons. Each year, the plants generate around 1.5 million tons of ash and slag. In recent years, the consumption rate of ash and slag has gradually increased, and this year it has surpassed 100%. This achievement results from the signing of long-term contracts with multiple partners, particularly the commissioning of an on-site ash and slag separation and treatment line (in cooperation with Song Da Cao Cuong Joint Stock Company), with a capacity of 700,000m³ per year.

On September 16, 2025, members of Supervisory Delegation of 15th National Assembly inspect ash and slag treatment line inside thermal power plants at Vinh Tan Power Center.

Song Da Cao Cuong Joint Stock Company, a science and technology enterprise, has partnered to process and consume ash and slag stored at disposal sites of Vinh Tan 1 (BOT), Vinh Tan 2, and Vinh Tan 4 thermal power plants. The company has completed Phase 1 investment in treating accumulated ash and slag at the sites, producing products for the domestic materials industry and for export. These include high-quality fly ash, fly ash cement, ready-mixed dry mortar, and tile and stone adhesive.

The company is also proposing to implement Phase 2 investment to produce high-quality goods following a green economy model—the first closed-loop circular economy initiative of its kind in Vietnam.

Processed ash and slag turn into high-quality materials, ready for consumption

EVN considers meeting quality standards for ash and slag as the foundation for sustainable consumption. A series of synchronized solutions has been and are being implemented, including: strict fuel control, optimizing boiler operations to reduce unburned carbon, and ensuring ash and slag meet required standards. At the same time, EVN has been making strong investments in transportation and treatment infrastructure—from upgrading internal roads, controlling dust and wastewater, to building closed pipelines to convey fly ash to ports. For example, at Vinh Tan 2 Thermal Power Plant, the port has been upgraded to handle vessels of up to 50,000DWT for export; meanwhile, at Vinh Tan 4, the internal port is also being upgraded to further increase ash and slag consumption.

About 10 years ago, the consumption rate of ash and slag at EVN’s thermal power plants nationwide was still low. However, between 2018 and 2025, remarkable progress was achieved, with the overall consumption rate during this period reaching nearly 93%. Since 2022, the rate has consistently exceeded 100%, not only processing all newly generated ash and slag but also gradually reducing accumulated stockpiles. In the first eight months of 2025 alone, EVN generated 4.57 million tons but consumed 5.31 million tons, reaching 116%. The total stockpile of ash and slag at EVN power plants is currently around 16 million tons—lower than the average two-year generation volume of about 20 million tons—thus meeting the target set by the Prime Minister under Decision No. 452/QD-TTg dated April 12, 2017, on enhancing the treatment and utilization of ash, slag, and gypsum from thermal power, chemical, and fertilizer plants as materials for construction production and works.

“A positive signal”

On September 16, during the supervisory program of the National Assembly delegation on “the implementation of policies and laws on environmental protection since the Law on Environmental Protection 2020 took effect” at the Vinh Tan Power Center, Mr. Le Quang Huy—Chairman of the National Assembly’s Committee on Science, Technology and Environment—highly praised the ash and slag treatment models at Vinh Tan 2 and Vinh Tan 4 Thermal Power Plants. He emphasized that this is a positive signal for Vietnam’s circular economy: “It can be said that this is a typical example of ash and slag utilization, where the byproducts of coal-fired thermal power plants are recycled back into high-value finished products for international export, delivering both economic and environmental benefits.”

Concluding remarks by Mr. Le Quang Huy, Chair of National Assembly’s Committee on Science, Technology and Environment, at visit to Vinh Tan Power Center, September 16, 2025

EVN’s President and CEO Nguyen Anh Tuan reports to National Assembly’s Oversight Delegation during working session on September 16, 2025. Photo: Minh Ngoc

According to EVN, although fly ash and slag from Vinh Tan 2 and Vinh Tan 4 Thermal Power Plants have been certified as meeting technical standards and regulations, and have been assessed by experts and scientists as being of good quality—suitable for the production of building materials, cement additives, concrete, or non-fired bricks—the consumption of ash and slag at Vinh Tan Power Center still faces difficulties due to long transportation distances and the limited promotion of ash utilization for landfilling and construction materials.

Therefore, EVN has proposed that the National Assembly and the Government soon establish mechanisms to encourage the reuse of ash and slag in the production of non-fired bricks, filling materials, roadbeds, and for export; with priority application in transportation, construction, and landfilling projects in Lam Dong and Khanh Hoa provinces. In addition, EVN recommends adjusting the Technical Guidance under Decision No. 216/QD-BXD (March 28, 2019), to encourage project owners to use ash and slag as filling materials, and to promptly issue detailed guidelines on norms, unit prices, construction methods, and acceptance procedures.

Translator: Vân Ly