PRACTICAL ASPECTS OF OXIDE COPPER RECOVERY WITH ALKYL HYDROXAMATES

Alkyl hydroxamates are well known collectors for oxide copper minerals as evidenced by the large amount of published literature. Our studies on a wide variety of copper ores from around the world have shown tha t alkyl hydroxamates will recover most of the ''floatable'' oxide copp er minerals from an ore. They are available commercially, and they off er many advantages over alternative technologies for oxide copper reco very. In spire of this, the full potential of hydroxamates has not bee n exploited in the industry. The objective of this paper is to provide relevant practical aspects and guidelines to facilitate successful ap plication of hydroxamates in operating plants. A critical analysis of the available information and data, based on several case studies, flo tation testing, and microscopic analysis indicates that alkyl hydroxam ates can effectively recover well-defined oxide minerals of copper, bu t not copper occurrences such as Cu-bearing goethite (often misidentif ied as cuprite) which report as Acid Soluble copper in chemical assays . Prior to any flotation testing with hydroxamates, it is necessary to assess the various modes of occurrence of Acid Soluble copper using m icroscopic and microprobe analysis. (C) 1998 Elsevier Science Ltd. All rights reserved.