Ash turned into material with economic value

SATURDAY, 29/05/2021 15:52:13

The treatment of ash of thermal power plants is now a hot and controversial issue in public opinion. However, Pha Lai Thermal Power JSC.’s ash treatment has become good experience for other thermal power plants to apply.

Ash of Pha Lai Thermal Power JSC. is transferred to customers

Much in demand

Pha Lai Thermal Power JSC. has two lines with at total designed capacity of 1,040 MW, generating about 455,000 tons of ash and gypsum each year.

Nguyen Van Thinh, Head of the company’s Safety and Environment Department, said at first, ash was stored in Khe Lang and Binh Giang reservoirs in Pha Lai ward with a total area of about 83.2 ha, capacity of 23.1 million m3, and storage time of around 25 years. In the reservoirs, ash was submerged under water and unable to spread into the environment.

According to Thinh, in previous years, ash treatment used to be a difficult problem, forcing the company to find an absolute and long-term solution for both environmental protection and effective production and business.

Despite the geographical advantage that the company has two big reservoirs to contain ash, ensuring no spreading into the environment, in the long run, thorough treatment of ash is a top priority towards sustainable, safe, and eco-friendly production.

Recently, all ash of Pha Lai Thermal Power JSC. has been bought by many enterprises as an input material for the production of building materials.

To date, discharged ash has been transferred to such partners as Vina Ply and Cement Co., Ltd., Song Da Cao Cuong JSC., Thien An JSC., Cao Cuong Services JSC., etc.

These companies use ash and gypsum of Pha Lai Thermal Power JSC. as materials to produce cement, concrete, unburnt bricks, tunnel bricks, etc.

One of the most important partners of Pha Lai Thermal Power JSC. in ash selling is Song Da Cao Cuong JSC. Each year, the company buys about 132,000 tons of ash and gypsum of all kinds. It has studied and built a fly ash production line with a capacity of 500,000 tons/ year.

In addition, from ash, Song Da Cao Cuong JSC. also produces AAC autoclaved lightweight bricks, dry mortar, coal, etc. Specifically, the enterprise has coordinated with Vicem Hoang Thach Cement Co., Ltd. to successfully test the use of wet fly ash as an additive in cement production, ensuring product quality and high economic efficiency, opening a new direction in cement production, contributing to thoroughly solving the thermoelectric ash problem.

Expansion needed

In November 2020, Hai Duong BOT Thermal Power Plant was officially connected to the national grid after nearly 10 years of construction.

As designed, the company annually discharges about 1.5 million m3 of ash of all kinds. All of the ash is transported in a closed conveyor belt to a yard about 75 ha in area in Le Ninh commune.

Nguyen Ngoc Chien, an employee in charge of handling the plant’s ash, said ash stored in the yard was treated in accordance with the Environmental Impact Assessment Report approved by the Ministry of Natural Resources and Environment with frequent moistening, canvas covering, or storage in tanks to limit leakage into the environment.

The Ministry of Construction’s Institute for Building Materials has verified and recognized the plant’s ash to meet standards for production of fly ash, cement additives, leveling, etc.

To date, a number of partners have contracted to buy about 50% of the ash generated annually.

“We are looking for partners to sell the remaining ash to minimize ash in the yard,” said Chien.

While the ash of Pha Lai Thermal Power JSC. is submerged under water and hardly penetrates into the environment, that of Hai Duong BOT Thermal Power Plant is exposed on the ground, much likely to pollute the environment.

As designed, the plant’s ash yard can store about 15 million tons, capable of storing the amount of ash generated in 10 years.

The use of ash as an input material for the production of building materials is the most effective and safest solution in thermoelectric ash treatment. Pha Lai Thermal Power JSC. has done well in this regard and become a model for other thermal power plants in the region.

Hai Duong BOT Thermal Power Plant has so far had a partner committed to buy 50% of the ash generated. Thus, without partners to buy the rest, a large amount of ash will be stored in the open-air yard. If the Environmental Impact Assessment Report is not strictly observed, there will be a high risk of environmental pollution.

On the other hand, thermal power plants must also take into account the prospect that ash is unfavorably sold, leading to large amounts of nonmarketable ash, to work out suitable storing and handling plans ensuring no environmental pollution and bringing about economic efficiency to enterprises and safety to the environment.



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