Method of extracting metal ions from red mud by sonication

Abstract

A method of effectively extracting metal ions by sonication from red med that is waste remaining after extracting aluminum from bauxite. The method includes: (a) introducing, into a reactor placed in a constant-temperature tank, (1) a neutralized red mud slurry and an acidic solution or (2) red mud slurry, distilled water and an acidic solution, to form a red mud slurry, and heating the constant-temperature tank to allow the red mud slurry to react while sonicating the red mud slurry, thereby extracting metal ions from the red mud; and (b) filtering a product resulting from step (a) to provide a filtrate and a red mud residue, and separating and recovering the filtrate and the red mud residue, wherein the sonication in step (a) is performed using an ultrasonic generator by applying ultrasonic waves to an ultrasonic tip placed in the constant-temperature tank.

1 . A method of extracting metal ions from red mud by sonication, the method comprising the steps of:
 (a) introducing, into a reactor placed in a constant-temperature tank, (1) a neutralized red mud slurry and an acidic solution or (2) red mud slurry, distilled water and an acidic solution, to form a red mud slurry, and heating the constant-temperature tank to allow the red mud slurry in the reactor to react while subjecting the red mud slurry to sonication, thereby extracting metal ions from the red mud; and   (b) filtering a product resulting from step (a) to provide a filtrate and a red mud residue, and separating and recovering the filtrate and the red mud residue,   wherein the sonication in step (a) is performed using an ultrasonic generator by applying ultrasonic waves to an ultrasonic tip placed in the constant-temperature tank, and   wherein the neutralized red mud slurry or the red mud slurry and the acidic solution are mixed at a weight ratio of 1:1-1:20, and the acidic solution and distilled water are mixed at a volume ratio of 1:1-1:10.   
     
     
         2 . (canceled) 
     
     
         3 . The method of  claim 1 , wherein the ultrasonic tip is disposed between the bottom of the constant-temperature tank and the bottom of the reactor. 
     
     
         4 . (canceled) 
     
     
         5 . The method of  claim 1 , wherein the reaction in step (a) is performed at a temperature of 50-100° C. for 3 hours or more. 
     
     
         6 . The method of  claim 1 , wherein the sonication is performed at a frequency of 30-50 kHz and at a power of (i) 260-300 W or (ii) 300-500 W when the reaction is performed directly in the constant-temperature tank without a separate reactor. 
     
     
         7 . (canceled) 
     
     
         8 . The method of  claim 1 , wherein the time and temperature of the reaction in step (a) are controlled to change the composition of each of the red mud residue and the filtrate so that the red mud residue and the filtrate are used in various applications. 
     
     
         9 . (canceled)