How To Reuse Pistachio Shells?

Empty pistachio shells are useful for recycling in several ways.

Practical uses include:

• As a fire starter; kindling to be used with crumpled paper;
• To line the bottom of pots containing houseplants for drainage and retention of soil for up to two years.
• As a mulch for shrubs and plants that require acid soils, as a medium for orchids.
• As an addition to a compost pile designed for wood items that take longer to decompose than leafy materials.
• Shells from salted pistachios can also be placed around the base of plants to deter slugs and snails.
• Many craft uses for the shells include holiday tree ornaments, jewelry, mosaics and rattles.
• Research indicates that pistachio shells may be helpful in cleaning up pollution created by mercury emissions. (S)

Pistachio Shells powder

Also, Pistachio Shells in powder shape have for different applications.

To process the pistachio shell powder, the raw material, the pistachio shell, is ground and sieved either into fine powders or coarser granules.

Pistachio Shell Granules in Personal Care

Pistachio shells have characteristic beige to white color. Therefore, the powder is very light, in some instances even similar to natural marble granules. This unique hue makes pistachio shell granules a versatile bio-based ingredient. As a sought after natural ingredient, pistachio shell granules are mainly used by cosmetic formulators as a

• skin abrasive or exfoliator in body, face, hand, foot, lip and scalp scrubs
• dental abrasive to enhance the mechanical cleaning effect of toothpaste
• whitening agent, i.e. for vegan and all-natural face powders and makeup foundations
• rheology modifier in solid and semi-liquid formulae (e.g. creams, balms, decorative cosmetics)
• carrier for pigments, aromas, and perfumes
• substrate for biodegradable glitter
• soap texturizer or as peeling grains in soap making

Mechanical Properties and Material Science Applications of Pistachio Shell Powder

Due to the hardness of the pistachio shell (approx. 3.5 according to Mohs), a variety of micron ranges are possible. More and more manufacturers of conventional plastics and wood-based materials seek a top-quality, bio-based ingredient as a replacement for synthetic microparticles to create innovative materials. This includes:

• Composites (e.g. wood-plastic composites): in many instances, the pistachio shell powders are powerful substitutes for polyethylene or polyurethane fillers. Besides, lightweight applications benefit from the relatively low density of pistachio shell powder.
• MDF panels (medium-density fibreboards): especially for surface claddings, furniture, artworks, and decorative finishes.
• Paints, resins, glues, and inks, also for nature-inspired 3D printing of biomaterials, medical parts such as implants, auto parts, shipbuilding, and aviation components, stationery and ceramic objects. (S)

Source: “Agnet west”, “Biopowder”