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The objective of this program is to determine how retorting process parameters affect the partitioning of Hg, As, Se, and Cd from raw o11 shale to spent shale, shale oil, retort water, and offgas. For each of the elements, the objective of this study is to 1) determine the distribution coefficients for each product stream; 2) identify the chemical forms in water, gas, and oil streams, with particular emphasis on inorganic or organometallic species known to be or suspected of being carcinogenic, toxic, or otherwise harmful; 3) investigate the mechanism(s) responsible for mobilization into each product stream for toxic or labile chemical forms identified in item 2 are mobilized into each product stream; and 4) the effect of retorting rate, maximum retorting temperature, and retorting atmosphere on items 1 and 3. A Green River shale from Colorado and a New Albany shale from Kentucky were heated at 1 to 2°C/min and at l0°C/min to maximum temperatures of 500 and 750°C under a nitrogen sweep gas. The product streams were analyzed using a variety of methods including Zeeman atomic absorption spectroscopy, microwaveinduced helium plasma spectroscopy, x-ray fluorescence, instrumental neutron activation analysis, high-pressure liquid and silica gel column chromatography, and mercury cold vapor atomic absorption. The results obtained using these analytical methods indicate that the distribution of mercury, arsenic, and selenium in the product stream is a function of oil shale type, heating rates, and maximum retorting temperatures.

This report describes and discusses the design, construction, calibration and operations of the Pacific Northwest Laboratory (PNL) 6-kg retort. Use of this retort will help determine the distribution and speciation of Hg, As, Se, and Cd compounds as a function of retorting parameters in shale oil, retort water, and offgas. The first test consisted of heating the oil shale to 500"C with a 100% nitrogen (N 2) sweep gas. Results of this test demonstrated that the system operates as designed; only two minor modifications were necessary to achieve satisfactory operation of the retort.

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