VietNamNet Bridge - In developed countries, 90 percent of ash and slag from plants is treated and recycled into materials useful for industry. In Vietnam, the figure is 10 percent.

The 20 thermal power plants and fertilizer and chemical plants produce 20 million tons of ash and slag a year. About 20 million tons of untreated ash and slag have been left on open ground. Vietnam needs thousands of hectares of land every year to store the ash and slag.

The big volume of ash and slag puts pressure on the environment and land resources. Meanwhile, plants are facing the risk of having to stop production if they don’t have land to store waste.

Scientists say the waste is still useful. It can be recycled into cement additives, lightweight aggregates, precast concrete and unburned bricks. With high technology, it can serve as material to recollect metals and plastics. 

In Vietnam, fly ash has been used as an additive for mass concrete for hydropower dam works, applying roller compacted concrete (RCC) technology.

Calculations found that cement and building material plants, and transport and irrigation works, now have a big demand for ash, slag and gypsum. They can consume all the volume of ash and slag generated by thermal power and chemicals plants. 

In Vietnam, fly ash has been used as an additive for mass concrete for hydropower dam works, applying roller compacted concrete (RCC) technology.

While Vietnamese enterprises have to import gypsum for domestic production, thermal power plants now throw ash and slag away. At some thermal power plants in coastal areas, workers spray sea water into ash and slag grounds to prevent dust, thus making the ash and slag salty and unusable. 

Luong Duc Long, head of the Building Material Institute, said that Vietnamese enterprises rarely use the ash and flag from thermal power plants for several reasons. 

In other countries, enterprises understand how to reuse waste. In Japan, for example, enterprises receive $30 for every ton of fly ash they use to recycle any kind of building material. If enterprises make products using recycled materials, their products will have a ‘green label’.

Meanwhile, in Vietnam, not all enterprises know that waste can be used to make products instead of natural materials. Not all of them know how to use the waste in the most effective way. And more importantly, they cannot see the benefits of using the waste.

The government of Vietnam has launched a program on developing unburned building materials. At least 25 percent of unburned materials must be used instead of burned materials by 2015.

However, a survey of the Building Material Institute showed that the figure was only 18 percent in 2015.

related news

Thermopower plants’ fate questionable as Vietnam tries to reduce greenhouse gas emissions Thermopower plant projects double attractive

Nam Mai