On May 28, POSCO launched a sea forest cultivation program in Ulleung Island to mark the National Ocean Day (May 31).

Earlier in the month, POSCO installed 100 Tritons* and 750 Triton blocks underwater and fostered a sea forest reaching 0.4ha in Ulleung Island. The installed Tritons have been acknowledged as artificial reefs by the Ministry of Oceans and Fisheries. The 100 Tritons were placed on the edge of the sea forest to facilitate the growth of marine algae while 750 Triton blocks were stacked up in the center, serving as a habitat and breeding ground for fish.

* Triton: The name Triton is taken after the god of the sea in Greek mythology. It is an artificial reef brand made with POSCO’s steel slag. The materials used to make Triton has proven to be safe for the environment as well as for marine life.

About 20 attendants were present at the event, including Ulleung Island Governor Byung-Soo Kim, fishermen of Ulleung Island, President of POSCO In-Hwa Chang, and RIST President Seong Yu. They inspected the sea forest site where the artificial reefs were installed.

In 2000, POSCO, together with RIST, developed an artificial reef Triton made with steel slag, a co-product of the steelmaking process. The company provided steel slags that amount to a total of 6559 Tritons free of charge. The Tritons were placed in 30 different sea forests in South Korea. In this case of Ulleung Island, POSCO not only provided the steel slag but also participated directly from the production to the installation stage.

Steel slag, the main material of Triton, has high mineral content such as calcium and iron, which are useful for marine ecosystems than general aggregates. Not only can the Triton facilitate the growth of marine algae, but it can also promote photosynthesis, thus restoring the marine ecosystem and diversifying coastal organisms as well. Also, the Triton reef can withstand typhoons and tsunamis due to its high gravity and strength and is highly resistant to seawater corrosion.

POSCO is focusing on the Triton sea forest cultivation project as one of the major Corporate Citizenship activities. The project is expected to restore the marine ecosystem and has a Blue Carbon effect since it absorbs and stores CO₂ underwater. RIST and other related organizations have revealed that sea forests are capable of storing 3 to 16 tons of carbon dioxide annually per hectare.

Ulleung Island Governor Byung-Soo Kim said, “We are glad that POSCO has stepped in to help resolve the issues of the marine ecosystem here in Ulleung Island.“ President of POSCO In-Hwa Chang explained that POSCO, as a Corporate Citizen, will actively take part in contributing to the local community with POSCO’s technology.

POSCO explored different underwater sites around Ulleung Island since December last year and selected the best location to cultivate a sea forest. In April, the company conducted a thorough investigation to understand the existing biological habitat. And finally, this month, POSCO transported the Triton to Ulleung Island and installed them underwater. POSCO and Ulleung Island will continue follow-up management — including research of water quality, supplemental planting of marine algae, and exterminating harmful organisms.

POSCO plans to develop sustainable sea fertilizer and a new type of artificial reef using steel slag. These developments are expected to contribute to restoring the marine ecosystem and also help improve the income of local fishermen.

■ The cultivation process of the Triton sea forest

What are Asphalt Roads Made of?

Asphalt roads are made of a mixture of aggregates, binders and fillers. The aggregates are typically iron and/or steel slag, sand, gravel or crushed rock, and they are bound together with asphalt itself, which is a bitumen.

Asphalt comes from natural deposits, or more commonly, as a by-product of the petroleum industry. It is a prevalent material for waterproofing, caulking and preserving, and is now most frequently used for road surfaces.

The iron and steel slag used as aggregates for asphalt roads are iron and steel by-products. Steel slag is residue from the steelmaking process, made of minerals like silica, alumina and titanium from iron sand, and combinations of calcium and magnesium oxides. During the steelmaking process, slags float on top of the molten iron, forming a barrier against oxygen and maintaining the internal temperature.

In road construction, these are the preferred aggregates as they harden well, enabling a thinner layer of pavement than what can be achieved with crushed stone aggregates. Slag is also very hardy, resistant to both weather and wear.

Steel slag is a sustainable aggregate for asphalt road production. (Source: National Slag Association)

According to the Washington State Department of Transportation’s Use of Steel Slag Aggregate in Pavements report in 2015, a high iron oxide content in steel slag aggregates creates pavement that is both hard and dense, making it a superior choice over natural aggregates such as rocks in creating hot mix asphalt.

Also, when used in bituminous pavements, slag offers the advantages of high skid-resistance, stability, resistance to rutting, fatigue resistance, deformation resistance, high cohesive strength and compatibility with typical asphalt binders. Steel slag is also used as a base course material, the material under the surface layer of an asphalt road, track or surface.

The Environmental Benefits of Steel and Steel Slag

Base course material containing iron and steel slag as well as asphalt mixture containing iron and steel slag were designated as a procurement item under the Green Procurement Law. These materials are recognized as items with environmental benefits. The use of slag minimizes environmental impact as it saves energy and conserves resources.

Steelmakers need to actively find ways to reuse steel by-products to reduce their overall waste. For example, POSCO is dedicated to reusing by-products of steel making as it has a strong commitment to environmentally friendly practices. In 2016, POSCO recycled 98.4 percent of its steelworks-generated by-products, 77 percent of which was blast furnace slag and steelmaking slag.

In fact, 88 percent of POSCO’s blast furnace slag is turned into granulated blast furnace slag for cement material. POSCO carefully tests all of its steel slag products before clearing them for reuse, ensuring that every market item is suitable for its intended application.

Hot slag, or steel waste, is poured into piles to cool before being used for asphalt road construction.(Source: Fractum)

While POSCO works to improve its recycling capabilities, manufacturing and other industries are starting to see the benefits of steel and iron slag. These materials are being used everywhere, from rail ballast to artificial ocean reefs.

Steel slag is far from industrial waste, as POSCO’s efforts show. This steelmaking by-product has serious potential, now and in the future, and is a highly versatile, easily-used material for road making and other applications.

Demand for sustainable materials is on the rise in flourishing industries such as construction and manufacturing. Steelmakers like POSCO who put by-products to full use and invest in research to apply them to different industries will share the economic benefits and play a vital role towards greener business practices in the coming future.

This waste can lead to environmental pollution and, as such, many efforts have been made over the past two decades to decrease the waste and upcycle the byproducts. As a result of this growing environmental awareness, steel slag is now highly regarded as a recycled material that can reduce environmental impact due to its resource-conservation and energy-saving properties.

What’s Steel Slag?
Slag, also known as steel aggregate, is the primary byproduct of steelmaking. The residue is comprised of minerals such as silica, alumina and titanium from ironsand, as well as other combinations of calcium and magnesium oxides derived from other raw materials.

During smelting, slagging agents and fluxes are added to the blast furnace or steelmaking furnace to remove impurities from the iron ore, steel scrap and other ferrous feeds. The slags secure the liquid metal from outside oxygen and maintain temperature by forming a lid. Being lighter than the liquid metal, the slag floats and can be removed with ease. All steel slag products are then rigorously tested before being released on the market to ensure that they will not adversely affect the environment, and that they are suitable for the application in which they will be used.

How Its Used
Slag is being used extensively for various applications throughout the world including Brazil, Australia, China, throughout the European Union and the United States. In fact, it is estimated that 7 to 7.5 million metric tons (7.7 to 8.3 million tons) of steel slag is used each year in the United States alone for a range of applications.

Because of its hydraulic property and the large bearing capacity it can provide, steel slag is often used as a road base course material. With high particle density and hardness, this slag has superior wear resistance, which makes it an excellent aggregate for asphalt concrete. Steel slag, when used in the asphalt layer, also makes roads safer to drive on by offering better skid resistance.

Moreover, due to its high angle of shearing resistance, high particle density and large weight per unit volume, steel slag is also used as a material for civil engineering works, ground improvement materials and cement. In fact, the use of slag to replace some of the Portland cement in concrete reduces the carbon footprint of concrete production, and generally improves the quality of the material.

Other applications of slag include rail ballast, soil conditioner, sewage treatment and even artificial ocean reefs. Through these applications, steel slag prevents landfill waste, reduces carbon dioxide emissions and helps preserve natural resources, among other environmental benefits. The sale of these byproducts is also economically sustainable, generating revenue for steel producers and forming the foundation of a profitable worldwide industry.

The widespread public awareness on the environmentally friendly features of steel slag, among other steel waste materials, has led to the significant increase in the recycling capabilities of steelmakers like POSCO, as well as the steel industry’s ongoing efforts to expand the utilization of these byproducts. As innovative technology developments and synergies with other industries continue to bring the steel industry closer to its goal of zero waste, the upcycling of byproducts such as steel slag remains the best possible solution for now.

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At the Forefront of Korea’s Marine Ecology Conservation: POSCO Volunteers for Clean Ocean 

POSCO Volunteers for Clean Ocean, established on November 25, 2009, is an organization committed to saving Korea’s waters. Its activities, carried out by members with professional experience in scuba diving, are varied: cleaning waters and beaches near company processing plants in Pohang and Gwangyang, aiding regional fisheries, lifesaving and salvaging sunken ships are all part of POSCO Volunteers for Clean Ocean’s efforts to protect and preserve Korea’s waters. In addition, the volunteer organization symbolizes the POSCO Green Environment Spirit by actively participating in marine conservation initiatives alongside various organizations in collaborative events such as Water Day and Oceans Day.

Passion? Check. Professionalism? Check.  

POSCO Volunteers for Clean Ocean has 780 passionate members, 270 of whom hold certified licenses for skin and scuba diving. The high level of professionalism makes it possible for the volunteers to engage in collaborative lifesaving efforts with other organizations such as the Coast Guard.

In August last year, POSCO Volunteers for Clean Ocean was shown on the popular KBS environmental documentary <Environment Special> displaying the Korean flag at Dokdo after removing the starfish that were damaging the ecosystem. Dokdo, a small island located in the East Sea, bears great significance to Korea as the nation has been in continuous debate with Japan over which country is the rightful owner. Such passionate activities were made possible by regular meetings and training: the organization meets every Saturday to preserve Korea’s oceans such as collaborating with regional schools and local residents to improve the coastal environment and ecology.

Introducing the Various Activities of POSCO Volunteers for Clean Ocean

POSCO Volunteers for Clean Ocean working to purify the ocean water at a beach near Pohang

POSCO Volunteers for Clean Ocean visits Bal-san ri Dong-hae myun, Pohang during Global Volunteer Week

Cleaning up the coastline and getting rid of organisms that harm the marine ecology at Myodo Island in Yeosu. 

Interview: POSCO Volunteers for Clean Ocean President Jong-bin Park on the Organization and its Future

“We will focus on recovering the marine ecosystem and make a tangible contribution to the fishing economy.”

I remember the early days of the POSCO Volunteers for Clean Ocean when some fishers were concerned about the impact our activities might have on their farms. Recently, however, local communities are competing to invite us as we have demonstrated over time our contribution in recovering the marine ecosystem. Local governments are inviting us to various environmentalist events, which helps us establish our corporate image as a core volunteer group as well as leading to more opportunities to participate in joint efforts to improve regional communities.

Our next plan is to raise awareness of eco-friendly steel material by integrating them into our volunteer activities. Recently, our members installed the artificial steel reef “Triton” in the waters of Guman-yi ri Dae-bo myun. We were surprised to see the marine ecosystem recovering rapidly due to the swift growth of marine algae following the installment of Triton. We also plan to make efforts to improve the fishing economy.

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What is Triton?

‘Triton’ was named after a sea-god from ancient Greek mythology, who controlled all ocean. The key to Triton was something called a Steel Slag. It is a by-product of molten metal from melting iron ore, soft coal, limestone—the three ingredients for producing steel—in extremely high temperature. Steel Slag is an eco-friendly resource that can be widely used for many purposes such as cement, manures, and aggregates. POSCO’s ‘Triton’ is a low-carbon fish reef using such Steel Slag. It creates a healthy environment for marine life to flourish, by attracting the accession of marine plants in the area. [/box]

We hope that our readers were able to feel POSCO Volunteers for Clean Ocean’s passion for marine ecology preservation through this post. POSCO Volunteers for Clean Ocean will continue in its endeavors to save the waters of Korea.

What is Triton—the artificial fish reef?

‘Triton’ was named after a sea-god from ancient Greek mythology, who controlled all ocean. The key to Triton was something called a Steel Slag. It is a by-product of molten metal from melting iron ore, soft coal, limestone—the three ingredients for producing steel—in extremely high temperature.

Steel Slag is an eco-friendly resource that can be widely used for many purposes such as cement, manures, and aggregates. POSCO’s ‘Triton’ is a low-carbon fish reef using such Steel Slag.

Since 2000, POSCO started research on ways to restore marine life by collaborating with Research Institute of Industrial Science & Technology (RIST), and ‘Triton’ is the result of this project. Triton consists dominantly of steel, which is a necessary element for mixing photosynthesis and protein. It creates a healthy environment for marine life to flourish, by attracting the accession of marine plants in the area. Thanks to the installment of Tritons, sea forests were restored healthily. These sea plants then help to decrease carbon dioxide due to their ability to store about 10-20 tons of carbon dioxide every 1ha per year during the process of photosynthesis.

 Not only in the southern sea of Korea, but Triton has made sea forests in parts of the east sea. The priceless sea forest created in the southern sea, was progressed by POSCO MOU pilot project with the Ministry of Maritime Affairs and Fisheries. After 18 months of making the sea forest, the amount of contrast in the bedrock biomass in the area have increased more than ten times its original state, and the incomes for fishermen have also increased.

POSCO Reaches Out Globally In Preserving and Restoring Marine Life

Towards the future, POSCO aims to build mutually cooperative relationships for constructing fishery resources with the Ministry for Food, Agriculture, Forestry and Fisheries. Furthermore, POSCO plans to establish seventeen more sea forests with Triton until 2014. In addition we will try our best to restore the coral reef forests in Indonesia along with protection of marine life in other parts of the world as well. POSCO’s deep concern for the marine affairs will continue.