To solve this dilemma, innovative solutions that challenge traditional waste management practices are increasingly being put into practice. Waste is no longer being seen just as something to dispose of, but as a potential resource that can be transformed into valuable commodities.

This circular approach can be particularly effective in the steel, construction and agriculture industries, which are among the largest producers of waste globally. By redefining waste, not as an end product, but as the beginning of a new value creation process, these industries have immense potential for contributing to a more sustainable future and are often at the forefront of adopting innovative waste management practices.

Construction Waste:
The construction industry is notorious for generating vast amounts of waste, from concrete and bricks to wood and metal, accounting for approximately 30% of total waste produced globally ¹. Traditionally, much of this material ends up in landfills, contributing to environmental degradation. But a shift towards recycling and repurposing construction debris is underway, using new methodologies to transform it into building materials and reducing the need for virgin resources.

1.) Concrete Repurposing: Innovative processing techniques can now crush and screen old concrete to produce aggregate for new construction projects. This not only diverts waste from landfills, but also reduces the need for quarry materials, minimising environmental impact and resource depletion.

2.) Metal Reclamation: Metals such as steel, aluminium and copper are highly recyclable. The advent of advanced sorting and processing technologies enables these metals to be efficiently separated, purified and redirected back into the manufacturing and construction pipeline.

3.) Wood Recycling: Wood waste from construction sites can be repurposed in several ways. Apart from being recycled into new building materials, it is also increasingly being used for biofuel production or converted into engineered wood products, providing an environmentally friendly alternative to landfill disposal.

Agriculture Waste: Agriculture produces enormous volumes of waste, including crop residues and animal manure. This waste, if not managed properly, can lead to an increase in greenhouse gas emissions and soil degradation. But through research and development, agricultural waste is now being converted into bioenergy, organic fertilisers and other materials, which not only improves the sustainability of farmers and agribusinesses but also opens new revenue streams for them.

1.) Biochar Production: This technology converts plant residues into biochar, a type of charcoal used to improve soil health and carbon sequestration. Agricultural waste is heated in an oxygen-limited environment, converting it into a stable form of carbon that can remain in the soil for centuries, enhancing soil fertility and reducing the need for chemical fertilisers.

2.) Biogas Generation: Anaerobic digestion can turn organic waste into biogas, a renewable energy source. Biogas plants capture methane produced during the decomposition process, which can then be used for heating, electricity or as a vehicle fuel. Not only does it provide a

clean energy source, but it also significantly reduces methane emissions, a potent greenhouse gas. Companies such as HomeBiogas ² have made biogas systems accessible for both farmers and homeowners alike, providing an alternative energy solution that saves money, reduces waste and conserves natural resources.

3.) Sustainable Materials: Agricultural waste is also being repurposed in the production of sustainable materials. For example, straw and husks can be processed into biodegradable packing solutions, while fibres from banana stems, hemp and flax are being utilised in the textile industry to create sustainable fabrics.

Steel Waste:
For each tonne of steel produced, a traditional steel plant generates around 0.6 tonnes of waste and by-products ³, including slag and dust, which at first glance seem insignificant, but are actually valuable resources that can be reused in construction and manufacturing.

1.) Slag Utilisation: Steel slag is rich in minerals and, therefore, can be used in various applications. It is increasingly being utilised as an aggregate in road construction, as a raw material in cement production ⁴ and as a soil amendment in agriculture, diverting waste from landfills and contributing to resource conservation.

2.) Dust Recycling: Dust generated during steelmaking contains valuable metals, such as zinc, that can be recovered and reused. The metals are extracted using advanced separation and processing techniques, and then fed back into the steel production process or repurposed for other applications, minimising waste and reducing the need for new raw materials.

3.) Scrap Metal Recovery: The use of scrap steel in electric arc furnace (EAF) technology is gaining traction within the steel industry, as it significantly lowers the environmental impact of steelmaking, compared to traditional blast furnace methods. Read our SWITCH article on the importance of scrap in the future of steelmaking here.

Author: Shirley Carruthers - Content Creator at ParkerSteel

References:

1. Circular Economy of Construction and Demolition Waste: A Literature Review on Lessons, Challenges, and Benefits
2. HomeBioGas
3. Destination of the waste generated by a steelmaking plant: a case study in Latin America
4. Use of Steel Slag as an Alternative to Aggregate and Filler in Road Pavements