Waterjet Abrasives

Waterjet cutting is a mechanical process in which a pressurized jet of water is used to remove material from a piece and rinse away the debris. To make the cutting process more efficient, abrasive material is added to the water stream.

The pressure of a high-pressure water stream can be as high as 600 MPa, which is achieved using a hydraulic pressure intensifier and a ceramic nozzle. The stream of water is directed at the material to be cut from a 0.08–0.23 mm nozzle. The speed of the water jet might be up to four times that of the speed of sound. The method can be used to cut thick steel plates or concrete, to name a couple of examples.

 

Waterjet Materials

The most commonly used sand in waterjet cutting is garnet sand, which is a mineral-based abrasive material. As its name suggests, the main compound of garnet sand is silicate minerals of the garnet group. Due to its hardness and cubic grain shape, garnet sand is ideal for blasting. The silica contained in garnet sand is mainly in the solid, amorphous state. The availability of this grade of garnet sand has been unpredictable for a long time now, and lower-grade products have entered the market.

Finn Recycling Oy has introduced a synthetic sand made of sintered bauxite to the market, which is extremely hard (Mohs hardness 9) and free from iron and silica. In terms of specific gravity, this new sand is comparable to garnet sand, but since it is many times harder than garnet, it can also be more easily recycled.

 

Flexible and Comprehensive Sand Treatment Service

Depending on the material being cut, the waste sand generated in waterjet cutting usually contains heavy metals. Finn Recycling Oy offers waterjet cutting companies a recycling service for abrasive sand used in waterjet cutting. This sand treatment service includes collecting the used sand from the customer and then delivering new sand back to the customer.

The quality parameters of the sand are determined together with the customer:

  • pH
  • Electrical Conductivity
  • Grain Distribution
  • Loss on Ignition