Recycling fly ash into valuable resource: sustainable path towards circular economy

The rate of fly ash utilisation has steadily increased over the years, to 84% in 2021 from 37.5% in 2018. During 2022–2023, many plants managed to consume 100% of the daily fly ash produced while also processing a significant portion of long-stored stockpiles.

A view of the Song Hau 1 thermal power plant project (Photo: VNA)
A view of the Song Hau 1 thermal power plant project (Photo: VNA)

Hanoi (VNA) – With coordinated mechanisms and policies of the Government, active efforts from ministries and localities, and initiatives from businesses, fly ash is gradually being recycled into valuable materials and products, helping tackle environmental challenges while actively supporting a circular economy and sustainable development.

From waste to material

According to the Ministry of Industry and Trade (MoIT), Vietnam currently has 31 coal-fired power plants that generate fly ash. All of these plants have developed and implemented treatment and consumption plans in compliance with regulations. The rate of fly ash utilisation has steadily increased over the years, to 84% in 2021 from 37.5% in 2018. During 2022–2023, many plants managed to consume 100% of the daily fly ash produced while also processing a significant portion of long-stored stockpiles.

Vu Ngoc Hung from the MoIT’s Industrial Safety Techniques and Environment Agency, stated that coal-fired power plants have basically completed standardisation and certification of fly ash in accordance with national technical regulations. As a result, fly ash now meets the requirements for use as a cement additive, construction material, filling material, or mineral additive for concrete products.

Data from the Vietnam Electricity Group (EVN) and its subsidiaries also show that thanks to coordinated measures, the rate of fly ash utilisation has risen significantly over the years, from 33% in 2015 to 100% since 2022, including the consumption of stockpiled fly ash from storage sites.

In the first eight months of 2025, a total of 4.57 million tonnes of fly ash and slag was generated, including 3.77 million tonnes of fly ash, 0.76 million tonnes of bottom ash, and 43,700 tonnes of gypsum. Consumption reached 5.31 million tonnes, equivalent to 116% of the generated volume, surpassing the average consumption level of 2024.

The Ministry of Construction noted that the consumption of coal-fired fly ash has been rising sharply, gradually keeping pace with production. By early this year, the cumulative nationwide consumption of coal-fired fly ash had surpassed 100 million tonnes.

Assoc. Prof. Dr. Luong Duc Long, former Director of the Vietnam Institute for Building Materials, said that if properly managed, fly ash from coal-fired power plants is a valuable raw material for cement, concrete, and non-fired brick production. In many applications, especially as a mineral additive, fly ash enhances fineness, strength, and water resistance of products while contributing to environmental protection.

Companies that consume fly ash have reported stable market demand in recent years. Using fly ash as a raw material not only helps conserve natural resources such as sand and stone but also significantly reduces landfill waste. This is considered a prime example of a circular economy model in the energy and construction materials industries.

Currently, many localities have been using coal-fired fly ash as filling material, generally without technical issues. By the end of 2024, the national cumulative consumption of coal-fired fly ash had exceeded 100 million tonnes, with approximately 55% or 55 million tonnes used for land filling. Large-scale application of fly ash for filling helps reduce pressure on storage sites and create a stable and sustainable consumption pathway.

Towards 100% fly ash utilisation

At the Duyen Hai thermal power plants, fly ash is gradually becoming a valuable commodity. Fly ash storage sites are strictly managed in line with technical procedures, ensuring environmental safety before recovered for use as a production raw material. The plant reported that its fly ash consumption rate has now reached approximately 99%.

To achieve the goal of 100% fly ash utilisation by 2026, the company is collaborating with the Vietnam Institute for Building Science and Technology to maintain sampling, evaluation, and testing of coal-fired fly ash for filling materials in accordance with standards and regulations. It continues to monitor and effectively implement existing contracts while actively seeking additional consumption partners.

Experts said it is necessary to soon complete the system of standards and regulations, creating a comprehensive and consistent legal framework that gives businesses and investors confidence in using fly ash.

Many businesses have also proposed the Government and relevant ministries to consider mechanisms to support transportation costs and encourage the expansion of fly ash applications.

Hung said that the MoIT is continuing to study and improve mechanisms and policies to promote the development of the environmental industry, with priority given to supporting the production and consumption of recycled products made from fly ash.

As technical, transportation, and policy barriers are gradually removed, fly ash will truly become a “secondary resource,” importantly contributing to the construction materials industry and emission reduction goals./.

VNA

See more

According to the Hanoi Department of Agriculture and Environment, air quality index (AQI) readings have at times reached poor and very poor levels. (Photo: VNA)

Hanoi targets 20% reduction in PM2.5 levels

Hanoi has affirmed its commitment not to trade environmental protection for economic growth. The city is moving to establish low-emission zones (LEZs) as a core measure to control emissions and promote green, sustainable urban development.

A waste collection area. (Photo: VNA)

Ca Mau approves investment policy for waste-to-energy plant

The waste-to-energy plant is planned for construction in Dat Moi commune, covering a total area of about 20 hectares. It will have a waste treatment capacity of approximately 600 tonnes of household waste per day and a power generation capacity of 6MW.

Ice coats the summit of Fansipan in the northern province of Lao Cai in the early morning of December 25. (Photo: Published by VNA)

Peak Fansipan blanketed in ice on Christmas Day

With temperatures hovering between 1 and 3 degrees Celsius, frost and ice covered the summit area, creating an ideal condition for tourists eager to admire icy scenery, clouds and experience a Christmas atmosphere amid a sea of cold mist.

Illustrative image (Photo: nhandan.vn)

20 trailblazing companies in national green ESG rankings honoured

In 2025-2026, the “For a Green National Environment” programme will pivot around six tasks that merge expertise with broad social outreach, including targeted communications, "Journey to Net Zero" conferences and trainings, ESG surveys and announcements, a "National Green Ambassador" contest, a "Green Fashion" design competition, and the rollout of "National Green Station" models focused on zero-waste living.

Air pollution in Hanoi. (Photo: VNA)

Hanoi to launch 5,000 public electric bicycles

In a move to reduce air pollution and promote green mobility, Hanoi has approved a plan to deploy 5,000 public electric bicycles, alongside restrictions on petrol- and diesel-powered vehicles in the city’s central area.

Official heritage plaque i sinstalled on the 12 recognised Shan Tuyet tea trees in Dong Phuc commune. (Photo: VNA)

Thai Nguyen: 12 ancient Shan Tuyet tea trees win national heritage status

The recognition honours the biological, cultural and historical values of these centuries-old Shan Tuyet tea trees – natural treasures deeply woven into the livelihoods, traditions and identity of local ethnic communities. The title affirms the community’s commitment to preserving and promoting the value of this iconic local tea variety.

Sarus cranes at Tram Chim National Park (Photo: VNA)

Return of sarus cranes: Hope takes wing in Dong Thap wetland

Beneath the wide Mekong Delta sky, Tram Chim National Park is racing against time, pouring heart and science into a decade-long (2022–2032) plan to rescue the Eastern sarus crane – an elegant, scarlet-headed bird listed as endangered on the International Union for the Conservation of Nature (IUCN) Red List and a living emblem of both the park and all of Dong Thap province

French Ambassador Olivier Brochet speaks at the press conference in Hanoi on December 11 to mark the 10th anniversary of the Paris Agreement on climate change and highlighting the COP30 outcomes. (Photo: VNA)

International community ready to support Vietnam in energy transition, climate response

In a video message to the press conference, UN Resident Coordinator in Vietnam Pauline Tamesis said the UN is ready to support Vietnam in building a pipeline of projects capable of absorbing financing mobilised under the Political Declaration on establishing the Just Energy Transition Partnership (JETP), as well as from global climate finance sources, including the Green Climate Fund and the Loss and Damage Fund.