Silica Extraction


Silica From Rice Husk Ash (RHA)

AGI MILLTEC, as a market leader, strives for continuous improvement to serve customers better and to provide good value for their money. Disposal of rice husk is one of the major challenges faced by millers all over India. India produces around 25 million tons of rice husk every year. Rice husk when burnt in the boiler as fuel, generates ash known as rice husk ash (RHA). While RHA is environmental waste, it contains 60% to 80% amorphous silica, which is useful in various industries.

As an expansion and diversification strategy, AGI MILLTEC has introduced a high-efficiency precipitated silica extraction technology from rice husk ash. The equipment for the extraction plants are designed locally, at AGI MILLTEC. AGI MILLTEC batch processing plants operate at 2 tons per day silica extraction capacity. Along with silica, there are other by-products like carbon and sodium carbonate from RHA that are useful in various industries. This product is currently in its pilot phase.

Benefits of Precipitated silica from rice husk ash

  • Precipitated silica from rice husk ash is from a bio source and is non-toxic.
  • Precipitated silica is extracted from waste hence nullifying the raw material cost.
  • Any industry that uses rice husk as fuel for cogeneration can benefit from this technology.

Utilization of rice husk

  • Rice husk can be combusted in a boiler to generate steam for cogeneration and process requirement.
  • The ash generated can be stored for silica extraction.
  • The steam generated is utilised in a steam turbine which generates electricity. Electricity generated is consumed for mill requirements.

Data on Rice husk

  • One ton of paddy milled generates 200 kg of husk
  • 200 kg of husk give 50 kg of ash
  • The ash contains 60~80% Silica (i.e.) 40 kg silica per ton of paddy

Uses of Precipitated silica in products 

  • Rubber reinforcement (Tyre industry)
  • Plastic reinforcement
  • Agriculture (Animal food)
  • Food, Healthcare, Cosmetics
  • Catalyst; Coatings
  • Pulp and Paper processing

Process Flow Diagram


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