Elution of metal ions from chelating resin using amino acid eluant

The method of any preceding claim wherein the amino acid compound comprising an amino acid functional group represented by Formula (I):

The method of any preceding claim wherein the amino acid compound is represented by Formula (II):

• wherein R1 and R2 are independently selected from:
• hydrogen and an alkyl group having from 1 to 6 carbon atoms which may be unsubstituted or substituted with at least one of:
• amine, amino acid, carboxylic acid, hydroxyl, thiol and a ring structure, or R1 and R2 may collectively form a ring structure.

The method of any preceding claim wherein the amino acid compound is selected from at least one of:

• iminodiacetic acid and ethylenediaminetetraacetic acid.

The method of any preceding claim wherein the amino acid compound is selected from at least one of:

• alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, ornithine, phenylalanine, proline, selenocysteine, serine, taurine, threonine, tryptophan, tyrosine and valine.

The method of any preceding claim wherein the eluant excludes ammonia and mineral acids.

The method of any preceding claim wherein the metal ions comprise copper ions.

The method of any preceding claim wherein the metal ions comprise iron ions.

The method of any preceding claim further comprising the steps of:

• (a) passing a product liquor solution which contains metal ions through the bed of resin which is selective for loading the metal ions, (b) passing the eluant through the bed to at least partially remove the metal ions from the chelating resin and create a metal-rich eluate, and (c) electro-winning the metal-rich eluate to produce electro-won metal and a metal-depleted eluate, and (d) combing at least a portion of the metal-depleted eluate with the product liquid solution and repeating steps (a), (b) and (c).