Foundry sand (also known as casting sand) consists primarily of clean, uniformly sized, high-quality silica sand that is bonded to form moulds for ferrous (iron and steel) and nonferrous (copper, aluminium, brass) metal castings.
The most common casting process used in the foundry industry is the sand cast system. Virtually all sand cast moulds for ferrous castings are of the green sand type. Green sand consists of high-quality silica sand, bentonite clay (as the binder), water and coal (a carbonaceous mould additive to improve casting finish).
The type of metal being cast determines which additives and what gradation of sand is used. The production of foundry sand requires specialist screening and classification systems and involves detailed analysis of feed material and sand grade specifications.
We manufacture the full range of equipment required on a foundry sand processing plant and the modular nature of our equipment ensures:
- Maximum process efficiency – careful attention to all material transfer points maximises retention of material and water within the circuit and ensures maximum product yield.
- Minimal footprint – the clever integration of several processing phases throughout our modular equipment range minimises the space required to accommodate your plant and reduces overall project costs through the reduction in associated works to prepare concrete pads onto which your plant will be installed.
- Rapid Deployment – our modular equipment range takes significantly less time to install than the traditional stick build / static plant approach. This ensures you are up and running in the shortest possible time.
- Minimal environmental impact – by choosing our water recycling and tailings management system you will achieve up to 95% water recycling from your wet processing plant and also significantly reduce the space required to accommodate your silica sand plant.
Where is foundry sand used?
Ferrous (iron & steel) industries account for the majority of foundry sand used for castings.
The automotive industry and its suppliers are also major consumers of foundry sand. Typically, around 1 tonne of foundry sand is required for each tonne of iron or steel casting produced.
Recycling foundry sand
The recycling of non-hazardous, spent foundry sand can save energy, reduce the need to mine virgin materials and may reduce costs for both producers and end users of foundry sand. Recycled foundry sand typically finds use in construction applications but can also be used in the following ways:
- Feedstock for the manufacturing of Portland cement
- Partial replacement for fine aggregate in asphalt mixtures
- Sand required for masonry mortar mix
An individual analysis of the spent foundry sand in terms of physical and chemical properties is required in order to determine the potential for recycling of foundry sand and its suitable applications.