You are hereSequential Elution Method
Sequential Elution Method
Sequential elution. This method was developed by the U.S. Bureau of Min es and elution is done sequentially with gold being eluted with NaClO which, being a strong oxidant, destroys the gold cyanide complex and liberates the gold. During the tests, strong base resins Amberlite IRA 400, Amberlite IRA 900, Dowex 21K, Dowex MSA-1, and Dowex SBR, were loaded with gold silver and mercury, then eluted sequentially with various eluants. Generally, all five strong base resins behaved similarly. With the first 3 hours, 100% of the mercury was eluted with 2N H2SO4. About 20% of the silver was eluted with the mercury in the case of the Dowex SBR resin; however, no gold was eluted. A subsequent elution with 200 g/l NaCl in 1N HCl removed all the remaining silver from the five resins in 6 hours with less than 10% of the gold being eluted. A final elution with 0.75% NaClO in 150 g/l NaCl plus 5% NaOH removed 93 to 98% of the gold in 9 hours. Figure 6 shows a flowsheet.
