Selective Extraction and Pre-Concentration of Some Radioactive Elements In the Processed Egyptian Monazite Solution Before Their Spectrophotometric Determination

Abstract

The separation and accurate spectrophotometric determination of uranium, thorium and some rare earth elements in black sand Egyptian monazite grade 97% from Rashid area was studied. Problems encountering the spectrophotometric technique in rock and minerals analysis are mainly referring to spectral interference. So, to solve these problems solvent extraction was used to preconcentrate the studied elements prior to their determination. N-Methyl-N,N,N-trioctylammonium chloride in kerosene was firstly used for extraction and separation of uranium and thorium from Egyptian monazite sample. The operating extraction and stripping conditions of U in the present study have been experimentally optimized. It was found that, U can be selectively extracted by using 0.5 M N-Methyl-N,N,N-trioctylammonium chloride in kerosene at a phase ratio O/A of 1:1 at room temperature, pH=1 for 30 minutes contact time and 5 minutes settling time. Two Moles of Na2CO3 is used for uranium stripping at room temperature for 15 minutes. Then, U was determined spectrophotometrically in the stripped solution by Arsenazo III dye. The selective extraction of thorium from uranium raffinate was investigated and several factors affect the efficiency of extraction.