X‐ray radiation monitor for measuring solids content in fluid fine tailings

Abstract

The extraction of bitumen from oil sands produces fluid fine tailings (FFT) consisting mainly of water, sands, clay, and residual bitumen. Generally, devices with radioactive sources are used to measure the variation of FFT density or solids concentration inline, but to date there is no suitable device for in situ monitoring in tailings storage facilities such as large tailings ponds. In this study, an alternative method using highresolution spectrometry based on a low radiation intensity source and a cadmium telluride (CdTe) detector was used to measure the solids content in tailings samples based on X-ray attenuation. The radiation source used in the experiment was a 1 μCi 133 Ba. GEANT4, a Monte Carlo-based simulation code that calculates the transmission of radiation through matter, was used to simulate the results of this study and build calibration curves that can determine the solids content concentration based on measured sample composition. Experiments and simulations were performed on various concentrations of both actual FFT samples from tailings facilities and kaolin as a model material. Good agreement between the experimental and simulation results was observed, paving the way for a potential real-time solids content measurement system that could be deployed over large areas to measure the settling of FFT in tailings ponds.Abbreviations: FFT, fluid fine tailings; ICP-MS, inductively coupled plasma-mass spectrometry; wt%, weight percent.

Low intensity gamma-ray monitor for in-situ solids fraction measurements in liquids

“…Data can be recorded continuously for hundreds of hours without interruptions as the system is fully automated. Software is used to analyse the pulse height spectral data and compare with predetermined calibration curves in order to determine the solids content based on the data [22]. For oil sand settling ponds, a wireless link could be used to transfer this data to a remote location for analysis and for use in monitoring and process control [5].…”

“…There are two standard gamma-ray techniques which are used for solids content profile measurements. One is through transmission of gamma rays [3][4][5][6][7][8] and the other one is the backscattered gamma ray method [9].…”

“…If the number of high strength sources installed in one zone is large, then there would be a safety concern about level of radiation and also there are concerns about misuse or even loss of a radioactive source. A major concern with previous gamma ray transmission and backscatter techniques is that a source with high radiation activity will be required which can impose health risks and safety concerns [5][6][7][8]. In earlier reported work, mainly Thallium doped NaI was used as a Scintillator material with photomultiplier tubes and a Cs137 source was used.…”