Technological breakthroughs

TURNING BY-PRODUCTS INTO RESOURCES: THE GREEN TRANSFORMATION STORY FROM DAP-VINACHEM

Every year, Vietnam’s cement industry still imports over 3 million tons of gypsum for production. Meanwhile, at DAP - Vinachem JSC (Hai Phong), phosphogypsum (PG)—a by-product generated during fertilizer production—has, for many years, mostly been stored at disposal sites or transferred to units that require processing.

Since 2024, this situation has begun to change as DAP-Vinachem invested in an on-site PG processing line at the plant, producing material that meets Vietnamese standards for use as a cement additive. Instead of stopping at the fertilizer production stage, by-products are reintroduced into the industrial value chain, helping to form a domestic raw material source for the building materials sector.

Solving the Phosphogypsum Problem

During phosphoric acid production, all DAP plants generate phosphogypsum. As fertilizer output increases, the amount of PG generated also rises accordingly. DAP-Vinachem is no exception to this trend.

For many years, the company cooperated with external units to receive and process PG. However, as production expanded, the volume of by-products increased, placing pressure on storage sites and raising management costs. Meanwhile, environmental protection and efficient resource use have become more pressing requirements.

In terms of composition, PG contains a high content of calcium sulfate—the main raw material for gypsum used in the cement industry. However, this material still contains some impurities such as P₂O₅ and fluoride, so it needs to be treated before use. Faced with the dual need to reduce storage pressure and utilize generated by-products, DAP-Vinachem invested in an on-site PG processing line to create material that meets technical standards before entering the market.

Forming a Linkage Chain with the Cement Industry

The processing line went into operation in 2024 with stages of washing, neutralizing, and cleaning PG. This process helps recover residual P₂O₅ and fluoride while controlling the product’s technical specifications.

After treatment, PG meets Vietnamese Standard TCVN 11833:2017 for gypsum used as a cement additive. From DAP-Vinachem, the material is transferred to Dinh Vu Gypsum JSC and Truong An Hai Phong Investment JSC for further processing into finished gypsum before being supplied to cement plants. The two companies currently have a combined processing capacity of over 1.3 million tons per year.

The linkage among businesses has formed a relatively complete supply chain. DAP-Vinachem processes PG to standard; processing companies further refine the product; and cement plants gain an added domestic raw material source, replacing part of imported gypsum.

Thanks to early-stage processing, PG is no longer just stored but becomes an input for another production sector.

Increasing Value from By-products

Utilizing PG brings many benefits to enterprises. First, it reduces pressure on storage sites and allows for more efficient exploitation of by-products generated during production.

For the cement industry, having an additional domestic gypsum source helps companies be more proactive in securing raw materials and reduces dependence on imports amid volatile international markets.

This model also shows that industrial by-products can completely become raw materials if processed with appropriate technology. This approach aligns with the trend of circular economy development, where resources are used more efficiently and the life cycle of materials is extended through multiple production chains.

Towards Green Production

For the chemical industry, green transformation is not only about investing in modern equipment or reducing emissions, but also about using resources generated during production more efficiently.

Investing in a PG processing line helps DAP-Vinachem gradually solve its by-product problem while supplementing raw materials for the domestic building materials sector. This is also one of the solutions that reduces the amount of waste to be stored, improves resource efficiency, and promotes the circular economy model.

From a by-product mainly managed at storage sites, phosphogypsum has now become a raw material for cement production after proper treatment. This demonstrates that with investment in technology and a change of approach, industrial by-products can create new value, contributing to the company’s green and sustainable development goals.