Innovative Applications Of Symbiotic Products From The Steel Industry Support Marine Regeneration
In coastal Areas of South Korea, artificial reefs made of steel slag have been used to create undersea forests to provide new habitats and breeding grounds for fish populations.
The seabed environment along the coast of South Korea is deteriorating due to desertification, a process that has destroyed Marine life and is directly linked to climate change and environmental pollution.
More than 60 percent of Marine plants have been destroyed along 220 kilometers of the country's eastern coastline. The desertification of undersea forests, which are made up of algae, including seaweed and kelp, is leading to the destruction of ecosystems, with severe impacts on fish populations.
With South Korea's fishing catches dwindling, the country's Ministry of Marine Fisheries launched a planting program in 2009 with the goal of creating 54,000 hectares of undersea forest by 2030.
A necessary symbiotic product
In 2000, the research arm of PoSCO, South Korea's largest steel company, teamed up with the Korea Institute of Industrial Science to study using steel slag to create artificial reefs. Steel slag is a kind of symbiotic product produced in the manufacturing process of steel. It is produced after separating impurities from molten steel. Because steel slag is a dense, rock-like material, it has traditionally been used as a paving material, a construction aggregate or an agricultural soil additive.
Posco's research team realized that steel slag is rich in natural minerals, including calcium and iron, which play an important role in the growth of Marine plants. The result was an artificial reef called Triton® Block, which has been placed in 30 different underwater forests in Korea.
Triton® Blocks are made up of 85% steel slag aggregate and 15% steel slag cement and water. Since 2007, more than 29,000 blocks, which are heavy enough to withstand activities such as typhoons or tsunamis, have been dropped into more than 7,500 reefs. Before the blocks can be placed on the ocean floor, they need to be implanted with Marine algae to help regenerate large areas of previously barren coastline.
Posco is committed to sustainable development by providing free steel slag to local reef manufacturers in order to reduce production costs for the company. In addition, Pohang processes 13,500 tons of steel slag every year to ensure a stable supply of reefs to coastal areas in need.