PEP Integrated Test D Run Report Caustic and Oxidative Leaching in UFP-VSL-T02A

Abstract

This report was supported by many dedicated staff involved in laboratory experiments, sampling, data acquisition, and technical reviews. Individuals on the operations and sampling crew are especially recognized for supporting the Pretreatment Engineering Platform Project by working unpredictable, long, and off-hour shifts for the 10 months of PEP operations. The tests and reports could not have gotten this far without their extraordinary effort. The authors gratefully acknowledge the help and support of the following staff:

SRNL Review And Assessment Of WTP UFP-02 Sparger Design And Testing

“…Testing was conducted to evaluate the caustic leaching process; observations relative to risk of plugging provided secondary -or opportunistic --data. 21,22,23,24 The simulant used in this testing contained boehmite, gibbsite, chromium oxyhydroxide, sodium oxalate, filtration simulant, and supernate. This simulant was selected to investigate caustic leaching, oxidative leaching, and washing.…”

Pretreatment Engineering Platform Phase 1 Final Test Report

“…A run sheet specifying all process control parameters, transfer volumes, transfer rates, process times, and endpoints had been developed, reviewed, and approved, and the information from the run report was incorporated into the Test Instruction. The Test Plans, Test Instructions, and procedures used for Integrated Test D are in Sevigny et al (2009).…”

“…As described in more detail in Sections 4.3 and 4.5 of Sevigny et al (2009) (the run report for Integrated Test D), two batches of solids-concentrated simulant were processed during Integrated Test D. The caustic leaching processing included in-line addition of NaOH reagent in the filter-loop, heat-up to leaching temperature (85°C), and digestion at constant temperature. The simulant that underwent caustic leaching in Integrated Test D included the Cr component.…”

“…This very low Integrated Test D loop flow rate during the post-oxidative-leach wash contributes to the low normalized filter flux seen in Figure 10.14. However, it is important to note that the decrease in flow rate observed towards the end of Integrated Test D was because of management direction in an attempt to minimize air entrainment (see Sevigny et al 2009 for details). (Figure 10.14), Integrated Tests A and B showed similar rates, both starting fairly high and smoothly decreasing ranging from 0.34 down to 0.13 GPM/ft 2 .…”

“…The heated IW rinse left a film on the wall that can be seen in Figure 13.5 and Figure 13.6. In the cleanout of Tank T02A, the vessel was drained of process slurries and then cleaned with nitric acid during the prototypic filter cleaning (see Section 13.5 and Sevigny et al 2009 for a more detailed description). After the completion of Integrated Test D, 2-M nitric acid was placed in Tank T02A to conduct the prototypic ultrafilter cleaning ).…”