@article{han_sagzhanov_pan_hassas_rezaee_akbari_mensah-biney_2022, title={Direct Extraction of Lithium from alpha-Spodumene by Salt Roasting-Leaching Process}, ISSN={["2168-0485"]}, DOI={10.1021/acssuschemeng.2c04402}, abstractNote={In recent years, several methods have been reported to extract lithium (Li) from spodumene. However, the majority of them still require the transformation of the naturally occurring spodumene phase (α) to the more reactive crystalline phase (β) by calcination at 1100 °C. To address the economic drawbacks and high greenhouse gas emission of this phase transformation, this study aimed to directly extract Li from α-spodumene. Nine reagents of alkali metals (Group IA), alkaline earth metals (Group IIA), and ammonium (NH4+) salts were examined for roasting and phase transformation of α-spodumene to water- or acid-soluble phases. For this purpose, sequential roasting, water leaching, and acid leaching were performed. The leaching recovery results showed that the order of roasting efficacy of the three reagent categories is Group IA > Group IIA > > NH4+. 71 and 88% of water leaching and total leaching recovery values, correspondingly, were achieved by the NaOH roasting–water leaching–acid leaching process, under the nonoptimized conditions of a roasting temperature of 320 °C, an NaOH: spodumene ratio of 1.5:1, and a roasting time of 2 h. Thermodynamics analysis by FactSage demonstrated that α-spodumene was decomposed to Na2SiO3, Na4SiO4, NaAlO2, and Li3NaSiO4 by NaOH and to NaAlSiO4, Na2SiO3, and Li3NaSiO4 by Na2CO3. Eh-pH diagrams calculated by HSC Chemistry revealed that despite the low solubility of lithium silicates in water, they dissolve at high pH (>12.5), explaining the high water leaching recovery of Li. In future studies, the optimization of the process parameters will be conducted to maximize the Li recovery in water leaching, while recovering other valuable elements as byproducts.}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Han, Shihua and Sagzhanov, Daulet and Pan, Jinhe and Hassas, Behzad Vaziri and Rezaee, Mohammad and Akbari, Hamid and Mensah-Biney, Robert}, year={2022}, month={Sep} }
 @article{rezaee_han_sagzhanov_hassas_slawecki_agrawal_akbari_mensah-biney_2022, title={Microwave-assisted calcination of spodumene for efficient, low-cost and environmentally friendly extraction of lithium}, volume={397}, ISSN={["1873-328X"]}, DOI={10.1016/j.powtec.2021.11.036}, abstractNote={To utilize the advantages of microwave-assisted calcination over conventional heating, this work studied the effect of microwave power on phase transformation and leachability of spodumene. X-ray diffraction (XRD) and scanning electron microscope (SEM) were utilized to characterize the phase transformation and structural changes of spodumene calcined by both microwave and conventional heating methods. Results showed that the effect of microwave power on both phase transformation and leachability of spodumene is significant. The optimum lithium recovery through the microwave calcination-acid roasting-leaching process reached 97% at 2.0 kW microwave power, comparable with that of conventional heating. Besides a more rapid, less energy-consuming, and free greenhouse-gas-emission calcination, microwave heating also resulted in lower recovery values of Fe, Na, and Ca in the leaching process, gaining an advantage in downstream purification processes. The microwave temperature profiles of spodumene, and characterization results confirmed that α-spodumene started to transfer into γ- and β-spodumene at around 900 °C.}, journal={POWDER TECHNOLOGY}, author={Rezaee, Mohammad and Han, Shihua and Sagzhanov, Daulet and Hassas, Behzad Vaziri and Slawecki, Tania M. and Agrawal, Dinesh and Akbari, Hamid and Mensah-Biney, Robert}, year={2022}, month={Jan} }
 @article{akbari_ackah_mohanty_2020, title={Performance Optimization of a New Air Table and Flip-flow Screen for Fine Particle Dry Separation}, volume={40}, ISSN={["1939-2702"]}, DOI={10.1080/19392699.2017.1389727}, abstractNote={ABSTRACT The mining industry has seen increased efforts toward achieving dry mineral separation owing to current and projected water scarcity and environmental problems associated with conventional wet processing methods. Commercially available dry coal separation technologies such as air tables and air jigs have proven effective in cleaning only the +6.35 mm while the −6.35 mm comprised of coal and impurities is discarded or used without further cleaning. To address this issue, a new density-based dry separator named SIU Airtable was developed. The main objective of this study was to evaluate the fine coal (6.35 × 1 mm) dry cleaning performance of the developed air table. The study also sought to evaluate the dry screening performance of the Liwell flip-flow screen to achieve efficient size separations at 1 and 2 mm. Two different Illinois No. 6 coal samples were used to optimize the new air table by varying its operating variables. The analysis of separation efficiency showed similar trends for both coal samples based on the cut point density (SG50) and probable error (Ep). Additionally, separation efficiency was significantly higher for the 6.35 × 3.36 mm size fraction and reduced when the size range was broadened to 6.35 × 1 mm. Product coal ash of 13.8–14.5% and tailings ash of 52.9–59.7% were achieved from the feed ash of 31–36%. Screening experiments on the Liwell flip-flow screen showed an efficiency of 88.7% and 85.1% achieved for the 1-mm and 2-mm polyurethane panels, respectively.}, number={9}, journal={INTERNATIONAL JOURNAL OF COAL PREPARATION AND UTILIZATION}, author={Akbari, Hamid and Ackah, Louis and Mohanty, Manoj}, year={2020}, month={Sep}, pages={581–603} }
 @article{akbari_ackah_mohanty_2018, title={Development of a new fine particle dry separator}, volume={35}, ISSN={["0747-9182"]}, DOI={10.19150/mmp.8289}, abstractNote={Dry coal cleaning has generated renewed interest in scientific and coal mining communities alike due to water scarcity in many parts of the world and the numerous tailings ponds that have resulted from traditional wet coal preparation methods. Commercially available dry separation technologies such as air tables and air jigs are mostly effective in cleaning coarse coal with particle size larger than 6.35 mm. The smaller-than-6.35 mm fraction, which might be up to 20 to 40 percent of raw coal, is sent to the clean coal or tailings streams in a dry separation plant without any cleaning. The main objective of this study is to develop, design and fabricate a new density-based dry separator to effectively clean fine coal in the size range of smaller than 6.35 mm to larger than 1 mm.A difficult-to-clean coal sample with particle size smaller than 6.35 mm and flat-shaped shales as main rocks were used in this study. Using a laboratory-scale fluidization bed, the optimum air flow rate for fluidization of fine particles in air tables was found, which was much less than that for coarse coal. The perforations diameter and open area of the separating deck of the air table were also found to be critical for fine particle separation. These findings led to the development of a new air table named SIU Airtable for cleaning fine coal sized smaller than 6.35 mm and larger than 1 mm. The new air table has a unique air distribution and fluidization system for fine particles, along with adjustable vibration frequency and direction. It also has an optional extended section to lower the moisture content of high-moisture fine coal using part of the fluidization air. The experiments showed that an ash rejection of about 49 percent could be achieved with a combustible recovery of around 89 percent, indicating suitable separation. Furthermore, increasing ash rejection to 70 percent gives a combustible recovery of 72 percent, indicating that the separation performance of the new air table is close to the fine coal washability data.}, number={2}, journal={MINERALS & METALLURGICAL PROCESSING}, author={Akbari, H. and Ackah, L. A. and Mohanty, M. K.}, year={2018}, month={May}, pages={77–86} }