Patent ID: 9560867
Date: 2017-02-07
CPC Classifications: A23L,A23V,B09B,C01G

Claim:
1. A method for removal of metal ions from rice hulls, the method comprising: 1) providing a water storage reactor, disposing a gas dispersion device at the bottom of the water storage reactor, and filling the water storage reactor with water; 2) placing the rice hulls in a bag and placing the bag in the water storage reactor, and submerging the bag in the water; 3) bubbling industrial flue gas into the water via the gas dispersion device; controlling the amount of the industrial flue gas such that about 1 g of carbon dioxide is dissolved per 100 g of water, thus generating a carbonic acid solution; 4) reacting the carbonic acid solution with metal ions in the rice hulls to yield acidified rice hulls and a precipitate; and 5) washing the acidified rice hulls to remove the precipitate and to yield washed rice hulls, and then squeezing the washed rice hulls to remove the metal ions from the washed rice hulls.