Sains Malaysiana 48(2)(2019): 419–424

http://dx.doi.org/10.17576/jsm-2019-4802-20

Kajian Keberkesanan Pengekstrakan Torium daripada Larutan Asid Hidroklorik menggunakan Di(2-Etilheksil) Asid Fosforik (D₂EHPA)

(Effectiveness Study of Thorium Extraction from Hydrochloric Acid using Di (2-Ethylhexyl) Phosphoric Acid (D₂EHPA))

AHMAD HAYATON JAMELY MOHD SALEHUDDIN¹, ELI SYAFIQAH AZIMAN¹, CHE NOR ANIZA CHE ZAINUL BAHRI¹, MUHAMMAD AMIRUL RAFIQ AHMAD AFFENDI¹, WAN MOHD RAZI IDRIS³ & AZNAN FAZLI ISMAIL^1,2*

¹Program Sains Nuklear, Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

²Pusat Sains Terkehadapan, Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

³Pusat Sains Bumi dan Alam Sekitar, Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

Diserahkan: 25 April 2018/Diterima: 14 September 2018

ABSTRAK

Pengekstrakan torium daripada larutan akueus torium tetraklorida (ThCl4) telah dilakukan dengan menggunakan larutan organik Di-(2-etikheksil) asid fosforik dalam kerosen (D₂EHPA/K). Objektif kajian ini adalah untuk menentukan parameter kepekatan organik dalam pelarut dan masa campuran optimum yang mempengaruhi kecekapan pengekstrakan. Campuran torium - nadir bumi hidroksida ([Th-RE](OH)4) daripada sumber kepekatan monazit tempatan dilarutkan dalam asid hidroklorik (HCl) pada kepekatan 3 dan 4 molariti. Larutan akueus [Th-RE](OH)4 ini dicampurkan dengan pelarut organik D₂EHPA/K pada kepekatan berbeza iaitu 10%, 20% dan 30%. Sebatian diaduk selama 5 hingga 20 min sebelum fasa larutan akueus dan organik dipisahkan. Kepekatan torium sebelum dan selepas pengekstrakan dianalisis menggunakan Spektrometri Jisim Plasma Gandingan Teraruh (ICP-MS). Keputusan kajian mendapati peningkatan kepekatan torium dalam larutan akueus (Th-RE)OH4 dalam julat 119.40 ± 3.43 – 121.13 ± 3.18 ppm berbanding sebelumnya. Kecekapan pengekstrakan optimum bagi torium ialah 99.8%, menggunakan D₂EHPA/K pada kepekatan 30%. Keputusan kajian juga mendapati masa optimum bagi proses campuran dan pemisahan torium dalam larutan akueus kepada fasa organik masing - masing adalah 5 min. Sehubungan dengan itu, kajian ini membuktikan D2EHPA berpotensi untuk digunakan sebagai agen pengekstrakan torium daripada larutan asid hidroklorik.

Kata kunci: D₂EHPA; kerosen; monazit; pengektrakan torium

ABSTRACT

Thorium extraction from thorium tetrachloride aqueous solution (ThCl4) was performed by using organic solution of Di-(2-ethylhexyl) phosphoric acid in kerosene (D₂EHPA/K). The study aims to determine the organic concentration parameter in the solvent and the mixing time that influences the extraction efficiency. Mix thorium-rare earth hydroxide (Th-RE)(OH)4 from local monazite concentrates was dissolved in 3 M and 4 M of hydrochloric acid, respectively. The aqueous solution of (Th-RE)(OH)4 was mixed with the organic solvent D₂EHPA/K at different concentrations of 10%, 20%, and 30%, respectively. The mixture was stirred for 5 to 20 min before the aqueous and organic phase were separated. Thorium concentrations before and after extraction were analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The result indicates that thorium concentrate in aqueous solution (Th-RE)OH4 is in a range of 119.40 ± 3.43 – 121.13 ± 3.18 ppm. The highest extraction efficiency for thorium was 99.8%, extracted using D₂EHPA/K at 30% of concentration. The result indicated that the optimum mixing and separation times of thorium from aqueous solution into organic phase was 5 min, respectively. Therefore, this research proves that D₂EHPA is potentially be used as thorium extraction agent digested in hydrochloric acid.

Keywords: D₂EHPA; kerosene; monazite; thorium extraction

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*Pengarang untuk surat-menyurat; email: aznan@ukm.edu.my