การสกัดแยกธาตุหายากเฉพาะตัวโดยวิธีการแลกเปลี่ยนไอออนเพื่อนำไปใช้ประโยชน์ในทางอุตสาหกรรม

Abstract

The aim of this engineering project is the separation of rare earths by ion exchange technique. Ion exchange technique is more efficient than solvent extraction and nitric acid precipitation technique. It generates highly pure rare earth. The purity and chemical composition of rare earths were determined by ICP-OES and X-ray fluorescence spectrometry (XRF) technique. In addition, the effect of calcination temperature (300 500 600 800 and 1,000 °C) , stirring speed (200 400 600 and 800 rpm) and precipitation temperature (28 40 60 and 80 °C) on the specific surface area, total pore volume and average pore diameter. The results show that lanthanum can be separated efficiently from other rare earths by ion exchange column. The highest purity of lanthanum was 95 %. Therefore, lanthanum was selected to study the effect of some precipitation parameters on the specific surface area, total pore volume and average pore diameter. BET Surface area technique was used to analyze the specific surface area, total pore volume and average pore diameter. It was found that at calcination temperature of 800 °C, stirring speed of 400 rpm and precipitation temperature of 28°C gave the specific surface area of 8.982 m2/g, total pore volume of 0.0157 cc/g and average pore diameter of 70.05 nanometer