Evaluation of Microwave Intensified Vanadium Bearing-High Carbonaceous Shale Acid Extraction Process

Abstract

Abstract:The microwave assisted leaching of the vanadium bearing-high carbonaceous shale process was investigated using surface response methodology (RSM) based on Box-Behnken design (BBD). The effect of important factors such as CaF 2 usage, H 2 SO 4 concentration, leaching time and microwave power, as well as the interactive coefficients, the signification of the model and factors were analyzed. With the condition of 9.8 wt % CaF 2 , 23.0 vol % H 2 SO 4 , 170.6 min and 350 W, the actual values of vanadium (V) leaching efficiency in microwave heating (MH) and conventional heating (CH) were 85.43% and 79.64%, which agreed well with the predicted values. Meanwhile, the influence order of the factors in MH and CH was CaF 2 dosage > H 2 SO 4 concentration > leaching time. Microwave was an efficacious impetus for V extraction, but the microwave power itself was not a significant factor when the temperature of leaching system was high enough. The further characterization of mineral components before and after leaching confirmed that the prior dissolving of muscovite and pyrite in MH was intensified, while both minerals were in fine grains and filled with black carbon. The selective heating of carbon and pyrite sequenced the large temperature gradient between solids and liquids, which accelerated the dissolving reaction of muscovite with CaF 2 present in MH condition.

Mineral phase and structure changes during roasting of fine-grained carbonaceous gold ores and their effects on gold leaching efficiency

“…In addition, the samples were severely sintered and obviously the liquid phase was produced during roasting. [26]. This observation is consistent with the results from XRD analysis.…”

Applied techniques for residual oil recovery from source rocks: A review of current challenges and possible developments

“…On the other hand, oil in the reservoir system can be found free within matrix pores of the well. [125] The fractionating extraction of Mohammadi et al [108] CaO, MgO, and CuO 750, 1500, and 2250 60-120 Chen et al [109] Water and glycol 750, 1250, and1750 15 Li et al [110] Ethanol, methanol, acetone, dimethylformamide (DMF), and hexane / 600-3000 Al-Gharabli et al [111] CaF 2 and H 2 SO 4 350 10-200 Wang et al [112] CaF 2 and H 2 SO 4 300 5400 Wang et al [113] Iron oxide nanoparticles 600, 800, and 1000 1800 Yang et al [114] N/A 2000 30 Li et al [115] H 2 SO 4 6000 21-600 Yuan et al [116] organic matter from source rocks, for example, may be highly dependent on the kerogen type, adsorption forces, mineralogy of the organic matter, and porosity of the matrix, which traps the organic matter deep within the intramolecular structure. [126] Various techniques that use various types of solvents, configurations, and number of fractionation steps have been reported.…”