Special sands

What are special sands?

HA Special Sands

The term “special sand” covers all industrial minerals (except quartz sand) commonly used in foundries as moulding material for the manufacture of cores and moulds/dies.

Special sands include natural mineral sands, sintering and melting products produced in granular form or turned into granular form by breaking, grinding and grading processes, or inorganic mineral sands produced by other physical-chemical methods.

Special sands are different from quartz sand, particularly as regards their significantly lower thermal expansion behaviour within the temperature range of 20 – 600°C, their heat conductivity, refractoriness, and other physical characteristics.


Reasons for using special sands

Special sands are used instead of quartz sand for coremaking and mouldmaking because they are characterized by better physical-chemical properties.

Considering the casting properties to be achieved, the individual advantages of a special sand can be used: 

  • to avoid sand expansion defects, especially finning/veining;
  • to avoid the addition of gas-forming ingredients;
  • to avoid a mould-metal interface reaction;
  • to avoid metal penetration;
  • to reduce the core weight;
  • to increase the flowability of the sand;
  • to control the formation of microstructure;
  • to produce thin-walled castings.


Please contact our product management team for detailed information and further questions on our products and processes:

Tel: +34 946 730 858

Fax: +34 946 733 454

E-Mail: pm@ha-ilarduya.com