MINRES: A description of waste materials and construction products
Definition of mineral waste For the purposes of this project, mineral wastes include naturally occurring minerals derived from mining and quarrying. However, mineral wastes are not necessarily derived from minerals extraction and the definition also includes oxides, silicates, phosphates, carbonates, sulfates, aluminates and related compositions derived from industrial processes. The MINRES materials include the following categories: - Quarry wastes
- Ashes
- Industrial process residue (hazardous and non hazardous)
- Dredgings and gully waste
- Excavation materials, trench arisings
- MSW treatment residues
The following minerals/materials/material types are specifically excluded from the main focus of the project: - The WRAP waste materials: paper, timber, plastics, container glass and rubber (except for ash derived from them) and post-consumer plasterboard.
- Wastes that already have applications as coarse and sand sized aggregates (except manufactured aggregates made by processing wastes which are included)
- Non-mineral materials (organics), metals and liquids.
The main generic waste sources for the project are listed below. WASTE SOURCES |
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| Waste type | Sources | Types of materials |
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| | ISSA | Sewage sludge incinerators | Fine ash |
| | Paper sludge ash | Paper mill sludge incinerators | Fine ash |
| | Steelworks by-products | Steel works | Steel slag fines, other dusts and residues |
| | MSW ash | Municipal solid waste incinerators | Coarse and fine ash |
| | Foundry by-products | Metal foundries | Sand, other dusts, residues and slags |
| | FGD gypsum | Coal burning power stations with FGD systems. Other industrial processes also produce by-product gypsum | Gypsum |
| | Pulverised fuel ash (pfa) | Coal burning power stations | Pulverised fuel ash |
| | Colliery spoil | Aggregate by-product from coal extraction | Aggregates. Burnt or unburnt types |
| | Biomass ash | Power stations burning biomass (eg meat and bonemeal, straw) | Fine and coarse ash |
| | Quarry by-products | Crushed rock and gravel quarries | Crush rock fines, silts, sands, scalpings |
| | Residues from the water industries | Water treatment | Sewage sludge, water treatment residues |
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Construction products The project focuses primarily on the following construction products/product groups: - Ceramic products (bricks)
- Cement manufacturing
- Aerated concrete products
- Manufactured concrete products
- Acoustic and thermal insulation products (mineral wool)
- Plasterboard
- Manufactured aggregates- (dense and lightweight)
This group includes common and facing fired clay bricks produced by extrusion or moulding. The findings will also be relevant to other heavy clay products such as tiles, paving and pipes or architectural masonry. Cement manufacturing The project has focussed on alternative raw materials for the manufacture of common (or Portland cement-based) cements. Materials which contribute to the cement clinker composition and/or provide alternative fuels for the cement kiln are included. Pozzolanic mineral additions to the ground cement clinker are mentioned, as are low carbon alternatives to Portland cement. Aerated concrete (aircrete) Aerated concrete products are produced from a slurry which is foamed (using finely divided aluminium metal), cut into blocks and autoclaved. Aircrete products include standard or “jumbo” blocks but other components are also available. Industrial by-products such as pulverised fuel ash are already commonly used in the manufacture of aircrete. Manufactured concrete products Includes a wide range of factory produced concrete products such as aggregate concrete blocks (dense and lightweight), paving slabs, kerbs, culverts, pipes etc. A range of manufacturing techniques, including wet and dry mix technologies are employed in their manufacture. Acoustic and thermal Insulation products Mineral wool insulation (manufactured from igneous rock and various industrial by-products) is the main focus in this project used as acoustic and thermal insulation. Plasterboard Includes a range of board products comprising a gypsum core, with facing paper. Plasterboards are used in applications such as lining ceilings, construction of partition walls or dry-lining. Produced from a gypsum slurry in a continuous process, plasterboard is also known as gypsum wallboard. Manufactured aggregates The project primarily considers manufactured aggregates made from fine particle sized materials by sintering. However cold bonded aggregates made by treatment with carbon dioxide or plastic/quarry waste composite aggregates can be produced and are briefly considered.
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