Speciation of As(III) and As(V) in some Ghanaian Gold Tailings by a Simple Distillation Method

Abstract

As(III) and As(V) in goldtailings and river-bedsediments from Obuasi were determined by distillationof arsenic as AsCl₃. Results yielded 3750±426 mg kg^-1 (45.2%) for As(V) and 3050±66 mg kg^-1 (36.7%) for As(III) in the tailings. In the river-bed sediments, one spot yielded: As(III) 0 mg kg^-1 (0%) and As(V) 1447±51 mg kg^-1 (100%), whilst a second spot yielded: As(III) 0 mg kg^-1 (0%) and As(V) 2976±51 mg kg^-1 (100%). Using arsenic oxide standards, the recovery of As(III) and As(V) in the trioxide were 94.8 and 0.6% respectively. In a mixture of the two oxides, the recovery of As(III) was 87.6% with practically no interference from As(V). Total As content of the tailings was determined by neutron activation analysis (NAA) to be 8305±75 mg kg^-1.