PURIFICATION OF RARE EARTH (Ce4+, La3+, Nd3+ AND Pr3+) FROM MONAZITE, BANGKA THROUGH PRECIPITATION AND TUBULAR SUPPORTED LIQUID MEMBRANE (TSLM)

• Main Author: Zamani, Fitro
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/34188
• Institution: Institut Teknologi Bandung

The demand for separation technology of rare earth elements (REEs) continuously increases in the last decades.This fact has been initiated by new govermentment policy ESDM No 1, 2012 which declares the prohibition of exporting raw material. Moreover, Chinese government policy also decreasesthe export quota of rare earth elements (REEs) for their domestic demand. Research and study of REEs separation methode on scale laboratory was performed and expected could be applied on industrial scale. The purpose on this study is to extract the Ce4+, La3+, Nd3+ and Pr3+ from the monazite sand Bangka. Prior to extracted, the total oxide of monazite is analyzed by XRF to determined the total oxide content, and it was found that the content is 57,42%. Monazite destruction was performed by the addition of NaOH in the ratio 1:1 three times. Separations of radioactive elements (uranium, thorium) were performed by deposition process at pH 2.75 and continue at pH 8 for further purificationof the REEs. The results of the process of destruction and deposition between pH 2.75 - pH 8 which were measured by XRF showed that the total content of REEs oxide tend to be increase becomes 68.61 %. REEs oxide composition as the results from the destruction using ICP OES is Ce2O3 31.91 % , 10.36 % La2O3 , Pr2O3 and Nd2O3 13.81 % to 3.46 % . Oxidation of Ce3+ to be Ce4+ was performed by adding oxalic acid and ammonium hydroxide, thencalcinedby using a furnace at a temperature of 5000C. Separation followed by Tubular Supported Liquid Membrane (TSLM) I and using the concentration of phase feedback about 1900 ppm consisting of Ce4+ 800 ppm, La3+ 460 ppm Nd3+ 421 ppm and Pr3+ 234 ppm or the composition of Ce4+ at 41.78 %, La3+at 24.02 %,Nd3+at 21.98 %and Pr3+at 12.22 %. Carrier phase using comparative D2EHPA/TBP 0.75:0.25 and separation lasted for 4 hours. TSLM optimization is performed within pH 1.5 - 3.5 of Feed phase and the results obtained at pH 3. Optimization followed by using some strong acid in the receiving phase , they areHCl , HNO3 and H2SO4. % Transport and the highest permeability was obtained, if using a receiver phase HNO3 in order Nd>Pr>Ce> La. Variations of acid concentration in the receiving phase carried out at a concentration of HNO3, 0.5 M, 1 M, 1.5 M , 2 M. The results of the permeability of the four elements do not show any specific differences.However, thetotal percentage of transport of four elements was increase in the concentration of HNO3and in phase receivers of 1.5 M. the variation of feed phase flow rate was carried out by the receiver phase flow rate of 0.36 liters per minute. Variations were performed at a flow rate of 0.24, 0.36 and 0.8 Liters per minute. The optimum condition of REEs separation wasobtained in feed fhase at pH 3 and flow rate 0.8 Liters per minute, and receiver phase ‘HNO3’ at 1.5 M. The result of TSLM I showed that feed phase contains Ce4+, La3+, Nd3+ and Pr3+, respectively for 34.99 %, 45.17 %, 11.56 % and 8.28 %,while the receiver phase, respectively for 50.58%, 11.93%, 36.76% and 0.73%. The next proxess is TSLM II which uses same feed phase as TSLM I where La3+content is high, and also keeping the separation condition as TSLM I. The total concentration of REEs in the feed phase by using TSLM II was around 1077 ppm and the produced recovery are Ce3+, La3+, and Nd3+, respectively 56.65%, 36.39%, and 87.05%.