More transparency needed in VN ash and slag market
Thanh Dai Phu My JSC in Hai Phong City began treating slag from steel mills in August 2015 when the treatment plant in Ba Ria – Vung Tau became operational.
More than 85 percent of its after-treatment products are cement additives which are provided to tens of cement plants throughout the country.
More than 12 percent of the products are used as building materials to replace natural stone, provided to projects in industrial zones.
Following initial success, Thanh Dai Phu My built another plant to recycle by-products in metallurgy in Nam Cau Kien Industrial Zone in Hai Phong City.
The biggest advantage of the treatment plant is that steel slag can be fully re-used. The by-products from steel mills can be processed into materials to replace natural materials to make useful products, friendly to the environment. The output products are provided to industrial zones and neighboring areas and to reduce natural mineral exploitation.
|More than 85 percent of its after-treatment products are cement additives which are provided to tens of cement plants throughout the country.|
Thanh Dai Phu My uses modern technology to create products which can be used as input materials for other industries, such as metallurgy, cement and building materials, so no secondary waste is generated. The water used during the production process circulates through sedimentation tank systems and is brought back, so no waste water is produced.
“With the technology, we are sure that the plant won’t cause negative impact on the environment during the industrial waste treatment process. The recycling and full reuse of steel slag will bring benefits to three parties (owners of waste, treatment company and users),” he said.
Experts, after considering the national power development plan by 2020, estimate that the total amount of ash and slag from coal-fired power plants may reach 29 million tons by 2025.
The ash and slag could be input materials for mining additives for cement or unburned bricks, or used to partially replace clinker and clay.
The ash and slag market in Vietnam has taken shape with many companies collecting ash and slag in large quantities for reuse in cement and unburned brick production.
The coal-fired power plants belonging to the Electricity of Vietnam have signed contracts on selling ash and slag to Son La and Trung Son hydropower plants, which use ash and slag to make dams.
However, Dai said there is unhealthy competition in the market. Many enterprises don’t have ash and slag treatment technology, but have joined the ash and slag treatment market. They just want to use the metal contained in slag, and bury untreated slag, which causes pollution.
LNG could replace coal in the power sector at a higher cost but would cause less pollution.