25.05.2021, 14:31

Promoting treatment and use of ash, slag from thermal power plants

 

Illustrative image    

NDO - In recent years, following the directions of Government, the Prime Minister, ministries, branches and localities, the treatment and use of ash, slag and gypsum from thermal power plants have achieved certain results.


Some factories have used all of the generated ash and slag and a part of the backlog ash and slag. According to statistics from Electricity Vietnam (EVN), by the end of 2020, the total volume of ash and slag in their coal-fired power plants was more than 8.5 million tonnes, of which more than 7.1 million tonnes was fly ash, nearly 1.4 million tonnes was slag, and 120,000 tonnes was gypsum.

The total volume of ash and slag treated and used was 7.1 million tonnes, reaching nearly 83.5% of the generated volume (it reached 68.85% in 2019). Some thermal power plants have made great efforts in treating and using ash and slag, typically Duyen Hai 1 and Duyen Hai 3 in Tra Vinh province, with a consumption rate of 83.36% (only 65% in 2019).

EVN has directed and guided units to analysis ash and slag when there is a plan to change the input coal fuel source, ensuring the appropriate level of standard and regulation conformity corresponding to the type of used fuel.

Up to now, all EVN thermal power plants have signed short-term and long-term ash consumption contracts with partners.

However, this process also faces many difficulties, for example at the Vinh Tan Power Centre in Binh Thuan province, transportation is difficult because it is far from the consumer market, so the use of ash and slag as materials for ground leveling and filling is more feasible.

Besides, the ash and slag of the Vinh Tan 2 and Vinh Tan 4 thermal power plants, although conforming to regulations to be used as materials for ground leveling and filling, it cannot replace traditional materials in traffic projects due to legal proceedings.

In relation to the ash and slag in the Duyen Hai Thermal Power Plant’s yard, EVN and Power Generation Corporation 1 have agreed to hand it over to the Tra Vinh Provincial People's Committee to use for public welfare purposes. However, the problem is that the legal documents do not provide for giving away products or selling assets without collecting money.

Promoting the treatment and use of ash and slag from thermal power plants is very important, taking advantage of raw materials to produce building materials, traffic works, and making practical contributions to environmental protection. The Government and relevant ministries and agencies have assessed that, due to various reasons, the treatment and use of ash, slag and gypsum have not met the set targets; and consumption has not been balanced with emissions. Large amounts of ash, slag and gypsum are being stored in factory yards and continue to increase, with many landfills only capable of storing them for a few years.

In order to overcome limitations and speed up the treatment and consumption of ash and slag, recently, the Prime Minister issued Directive 08/CT-TTg on promoting the treatment, use and consumption of ash and slag; asking the Ministry of Construction and related agencies to coordinate with the relevant agencies in order to not only continue researching new applications for ash, slag and gypsum, but also to complete the formulation of technical standards, regulations and instructions on the treatment and use of ash, slag and gypsum as raw materials for construction and to direct cement factories to increase their use of ash, slag and gypsum as additives.

At the same time, the Ministry of Natural Resources and Environment has been assigned to promulgate guidance for the treatment of ash, slag and gypsum in the production of building materials, considering the use of ash, slag and gypsum for the production of building materials as well as regulating the process of treating ash, slag and gypsum; monitoring and inspecting environmental protection, and implementing the commitments in its environmental impact assessment report.

The Prime Minister also asked the Ministry of Science and Technology to continue to prioritise and support the implementation of scientific and technological tasks in the research and use of ash, slag and gypsum as raw materials for production industries.

The instruction also requires localities to prioritise research topics on using ash and slag as raw materials for the production of building materials; encouraging enterprises in the locality to participate in the treatment and use of ash and slag; adopt policies to encourage the treatment of ash and slag; and create favorable conditions for enterprises handling and using ash and slag to access emission sources.

The owner of the emission facility must be responsible for treating and consuming the generated ash and slag generated in the production process, having effective solutions to fulfill the commitments in the environmental impact assessment report and the law on environmental protection.


TUNG LAM