Thursday, October 7, 2010

Recovery of uranium for non-conventional Malaysian sources

In this topic, we will learn that the security of uranium fuel supply is an important aspect for countries which that using nuclear power energy. The alternative sources of uranium are identified from the present conventional uranium mines with respect to the present of high demand for nuclear power and uranium. Futhermore, this topic will also describes about the material such as Xenotime(YPO4) which is a yttrium phosphate mineral is a recovered by product from tin mining industry. Unlike another rare earth mineral called monazite, there is higher content of uranium in Xenotime as to that of thorium. For our knowledge, there are about 1-2% U3O8 found in this material and the highest compared to the other tin by product minerals.

The process that we called a “hydrometallurgy” was developed by researcher to produce uranium and yttrium oxide concentrates. This process involved alkaline fusion, acid leaching and frictional precipitation stages. The inclusion fractional precipitation stage in the process enables to separate yttrium from the uranium. Previously, the uranium contaminated organic DEHPA was sent to Malaysian Nuclear Agency for storage and disposal when the Asian Rare Earth plant in Lahat Datu, Perak was closed in year 1996. As we can know that, DEHPA was used as a solvent extraction solvent for separation of light and heavy rare earth elements. There is about 31,500 liters of this waste and EDXRF analysis show that the uranium content is 990 ppm and the total rare earth content is 25,890 ppm present in this waste.

Hence, the distribution coefficient and separation factors for these elements were determined so as to conduct an efficient stripping process. The Malaysian tin by product minerals are also known to be contaminated with radioactive elements. For our general information, the uranium content in Malaysian Zircon mineral ranges from 0.06-0.18% U3O8 and Malaysian ilmenite from 0.01-0.07% U3O8. As this radioactive elements is found to be contaminated both of the surface  as well as in the crystals, physical and chemical processes were developed to remove them.