Rice Husk (Hull) Ash (RHA)

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Avocado Engineering supplies Rice Husk Ash (RHA) for various industrial applications. We work in corporation with our business partner and producer to supply high quality rice husk ash (RHA) in the powder or granulated forms.

Rice husk ash (or rice hull ash) is produced in a controlled high temperature process. The as-produced ash is mainly composed of amorphous silica with low carbon content. Rice husk ash (RHA) is a green product, which is produced from agricultural residues. RHA is a super-pozzolanic material with silica content over 85%. Rice husk ash can be an alternative material for silica fume (micro-silica).

RHA specification and composition including XRD is provided here. The material on offer is mainly composed of amorphous silica with low carbon and moisture content.

Applications of RHA:

RHA can be used in a variety of industries with the highest applications in the steel plants and in special blends of cement and concrete admixtures. Following are some of the applications of the rice husk ash:

  1. RHA is an excellent insulator. RHA is also used for example in steel industry as the slag suppression material for insulation of molten metal in the tundish and ladle in slab caster. It is an eco-friendly material that reduces the cost of the operation. As an insulator on the molten metal, it maintains the temperature and does not let the system cool down quickly, which reduces the breakdown time of the casting.
  2. Green concrete, where RHA is used as a substitute for cement.
  3. Blended cements.
  4. High performance concrete (HPC) blends to provide high workability and very high early strength and long term durability. RHA is an excellent material in the production of special cement and concrete mixes, high performance concrete, high strength, low permeability concrete, for use in bridges, marine environments, nuclear power plants, etc. Addition of rice husk ash to concrete lowers the heat of hydration by as much as 30% and prevents the formation of cracks during casting. High performance concrete materials can be obtained by a reaction between calcium hydroxide and silica in the RHA to produce calcium silicate hydrate (CSH or C-S-H), which is the main product of hydration of Portland cement, primarily responsible for the strength in cement-based materials.
  5. Refractory materials such as in refractory bricks for long furnaces.
  6. Ceramic glaze.
  7. Insulator.
  8. Roofing shingles.
  9. Waterproofing chemicals: RHA has excellent water resistance (impermeability) properties. It reduces the water penetration by as much as 60% .
  10. Oil spill absorbent.
  11. Specialty paints.
  12. Flame retardants.
  13. Carrier for pesticides.
  14. Insecticides and bio-fertilizers.

Types of available materials:

RHA is available in two main types: Powder form and granulated cylindrical shapes (2-8 mm in diameter). Granulated RHA is mainly used as the steel tundish insulant. Particle size of the powder form material can be engineered according to the user requirements. For example, 325 mesh and 140 mesh can be supplied for concrete applications.

Packaging and logistics:

We are able to supply the material in a range of packaging options depending on the user preferences. For example, some users prefer 10 kg bags, 25 kg bags or bulk/jumbo bags. We can supply materials on pallets (fumigated or non-fumigated, IPPC or non-IPPC), depending on the destination country. For example, Australian companies require IPPC pallets.

Should you have any inquiries for the supply of this material, please contact us using the below form:


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