Extraction of Silver from Photographic Waste Using Cocoa Husk Ash Solution

Okorosaye-Orubite K, Gbarakoro S. L.

Abstract: Silver recovery from photographic wastes (X-ray films) using cocoa husk ash solution (CHAS) as extractant has been determined in this study. Cocoa husk ash (20, 40, 60, 80 and 100g) was dissolved separately in 500ml of distilled water for 48 hours with stirring at intervals, followed by filtration. The alkaline solutions obtained were standardized by titrimetric method and used to leach the X-ray films. 100ml of 1.5M solution of sodium sulphide was added as precipitant to each beaker containing the extracts. Silver was identified using simple laboratory tests. Precipitates weighed 1.90, 2.70, 3.60, 4.10 and 6.20g with respect to quantity of ash dissolved. Analysed by Atomic Absorption Spectrophotometer model GBC 6600, silver in extracts were 56.586, 51.932, 64.185, 62.136 and 63.583mg/kg. Evidence is hereby given of another waste material that can be utilized in the extraction of silver from photographic wastes.

Keywords: Cocoa husk ash solution; photographic wastes; precipitants; silver, AAS, titrimetric