REWAS 2022: Poster Session: On-Demand Poster Session
Program Organizers: Camille Fleuriault, Eramet Norway

Monday 8:00 AM
March 14, 2022
Room: Energy & Environment (including REWAS 2022 Symposia)
Location: On-Demand Room


The Research Status and Progress on the Utilization of Coal Fly Ash: A Review: Joseph Nyarko-Appiah1; Wenzhou Yu1; Peng Wei1; Hao Chen1; 1Chongqing University
    Coal fly ash (CFA), solid waste from the thermal power plant, is gaining attention as an alumina content substitute, but its production has long been considered to be problematic in environmental management. Many researchers have proposed and developed utilization technologies that can help solve these problems by utilizing large amounts of the CFA. This review aims at pointing out aspects for CFA utilization, one aspect of the utilization technology that has had a great impact on the material society is how it affects the environment and the other is the recovery of rich minerals. The current research status, progress and future scope of research on CFA will be reviewed in this paper based on comprehensive research data. More research is required to provide a better understanding of the reaction mechanism and economic advantages of CFA. This paper review provides existing opportunities to motivate researchers to be involved in this study.

Recovery of Rare Earth Elements from Nd-Fe-B Magnet through Selective Chlorination Using Zinc Chloride: Kyung-Hwan Lim1; Chan Uk Choi1; Gyeonghye Moon2; Tae-Hyuk Lee1; Jungshin Kang1; 1Korea Institute of Geoscience and Mineral Resources; 2HANNAE For T
    A novel selective chlorination process using zinc chloride was investigated for the selective recovery of rare earth elements from a Nd-Fe-B magnet. An Nd-Fe-B magnet powder and zinc chloride mixture in an alumina crucible was positioned in a gas-tight quartz tube. This quartz tube was placed in an electric furnace preheated to 1000 K for 1.5 – 5 h for the reactions. After the experiments, a mixture of metallic iron and neodymium chloride was produced owing to the selective chlorination of rare earth elements in the magnet powder. In addition, the chlorination efficiencies of neodymium, dysprosium, and praseodymium were 96.5 %, 57.2 %, and 97.6 %, respectively, under the certain conditions. Therefore, it was demonstrated that the novel selective chlorination using zinc chloride developed in this study is feasible for the efficient recycling of Nd-Fe-B magnets.

KIGAM Technology for the Recovery of NdFeB Waste Magnet and Manufacturing Scraps: Kyeong Woo Chung1; Ho-sung Yoon1; Chul-joo Kim1; Rina Kim1; Byunchul Lim2; 1Korea Institute of Geoscience and Mineral Resources; 2SungLim Rare Earth Metal Co. Ltd.
    At KIGAM, the pilot plants have been developed and demonstrated two processes for recycling NdFeB waste magnets and manufacturing scraps. The former process uses thermal oxidation as a pretreatment before. The latter does caustic digestion and the thermal oxidation process. About 35% of the iron in feed was co-leached with REEs upon leaching of thermally oxidized products. Therefore, the separation process of REEs and non-REEs was carried out using the double-salt precipitation method to produce a high purity REEs solution applicable for solvent extraction. Instead, the leaching yield of iron upon leaching of caustic digestion and thermal oxidation products showed a value of 0.01%. Thus the high purity REEs solution was obtained and directly applied to solvent extraction. Finally, REEs-compounds of 99.9% or above could be obtained by solvent extraction using mixer settler and precipitation from raffinate and stripping solutions.

Recovery of Lithium from Black Cathode Active Materials of Discarded Lithium-ion Batteries (LIBs): Pankaj Choubey1; Rukshana Parween1; Rekha Panda1; Om Shankar Dinkar1; Manis Kumar Jha1; 1CSIR-National Metallurgical Lab
    Lithium (Li) is the lightest energy critical element used in manufacturing of active cathode material of LIBs. Thus, consumption of lithium is constantly increases in the LIBs. Meanwhile, LIBs becomes obsolete when reached its end-of-life and results in generation of huge amount of spent LIBs. Present study reports the roasting and leaching process for selective recovery of Li from active cathode material. At first, cathode material was roasted to study different process parameters viz. roasting temperature, time and mass ratio to optimize the condition to convert lithium cobalt oxide cathode materials into water soluble lithium complex. It was found that cathode material converted into lithium sulfate at 750 °C in two hours maintaining mass ratio of LiCoO2/ Na2SO4: 1/ 0.5. Subsequently, 96.7% Li was leached from roasted product at 80 °C in de-ionized water within two hours. Further, Li can be precipitated as lithium carbonate using sodium carbonate.

Cancelled
Selective Separation of Molybdenum from Leaching Solution of Spent Catalyst by Solvent Extraction with TBP: Kunpeng Shi1; yanfang huang1; guihong han1; Shengpeng Su1; 1Zhengzhou University
    Separation and recovery of molybdenum and vanadium from leaching solution of spent catalyst is of great significance for resource utilization of spent catalyst. In this work, selective separation of molybdenum was comprehensively investigated by tributyl phosphate (TBP) with the emphasis on the hydrochloric acid concentration, TBP concentration, reaction time, and oil-water ratio. The results indicated that molybdenum was effectively extracted by 40% (v/v) TBP. More than 95.2% molybdenum was extracted, while the extraction percentage of vanadium was negligible under the optimal conditions (hydrochloric acid concentration of 2 mol/L, reaction time of 10 min and phase ratio (O/A) of 1/2). Furthermore, the molybdenum in loaded organic phase can be stripped using 0.1 mol/L sodium hydroxide, which achieves the selective separation of molybdenum and vanadium.

Recycling of Automobile Discarded Ceramic Converters for Pt-group Metals’ Recovery through Pressure CN-leaching: Sadia Ilyas1; Hyunjung Kim1; Rajiv Srivastava2; 1Jeonbuk National University; 2Dai Hoc Duy Tan
    Recycling of automobile catalytic converters was studied using the cyanidation at an elevated temperature and pressure that dissolving Pt-group metals (PGMs) followed by their liquid-liquid separation with ionic-liquid Cyphos IL101. PGMs were efficiently dissolved by autoclaving of the spent catalysts sample preconditioned in 2.0 M NaOH solution at 90 C for 60 min duration. The cyanide used in the study was metabolically produced by Chromobacterium violaceum. Under the optimized autoclave leaching process at temperature 150 C, pO2 200 psi, and time 120 min; approximately 90% PGMs’ could be dissolved. The residual cyanide can be subjected to the biodegradation within the bacterial life-cycle.

Fe-Si Alloy Preparation and Alumina Extraction from Red Mud and Silica Fume via Vacuum Carbothermal Reduction: Peng Wei1; Wenzhou Yu1; Hao Chen1; Joseph Emmanuel Nyarko-Appiah1; 1Chongqing University
    With the increasing awareness of environmental protection, the disposal of solid waste such as red mud (RM) and silica fume (SF) has attracted widespread attentions. In this study, a novel method by recycling RM and SF simultaneously was proposed for preparing Fe-Si alloy and extracting alumina. The process is mainly composed of vacuum carbothermal reduction and magnetic separation. The results show that Fe-Si alloy was successfully synthesized during the vacuum carbothermal reduction and it was effectively separated during the magnetic separation. Additionally, after the magnetic separation, the non-magnetic portion mainly contains alumina and it can be a potential raw material to produce alumina by the Bayer process. This process could recycle RM and SF simultaneously, and almost no waste residue was generated. Therefore, it provided a clean and sustainable route for synergistic recycling of RM and SF.

Geopolymers Made of Construction and Demolition Waste: Current Trends and Perspectives: Angelica Cardoza Herrera1; Henry Colorado1; 1Universidad de Antioquia
    A literature review of the research of geopolymers from construction and demolition wastes mostly from the last 5 years (2015-2020) is presented and classified in three different study areas (Energy - Business, Management and Accounting - Environmental Sciences). The investigation initially analyzes the environmental impact from these recycled-based materials, while a second part it focuses on the experimental design and formulations of these geopolymers including their manufacturing methods. finally, the mechanical properties obtained by different authors are summarized. The systematic review was conducted using the Scopus Data Base. The perspectives of this environmental solution were also analyzed.

Advanced Process of Waste Glass Bottle for the Production of Recycled Glass Aggregate and Cullet: Hoon Lee1; Hansol Lee1; Kwanho Kim1; 1Korea Institute of Geoscience and Mineral Resources
    In Korea, ~20% of waste glass bottles are buried in landfill every year. Many studies have been conducted to utilize this waste in foamed glass and cement production. However, more research is needed to find efficient methods to convert the waste to valuable materials, such as recycled fine aggregates. In this study, we designed an integrated crushing-grinding-separation process involving additional crushing equipment to handle large amounts of waste glass bottles and determined whether the products met recycled fine aggregate quality standards. Waste glass bottles were crushed to a size less than 10 mm using a pilot-scale shredder and roll, hammer, and vertical shaft impact (VSI) crushers. We found that the VSI crusher is the most suitable equipment, in terms of crushing performance and ease of operation, to convert the glass bottles to recycled fine aggregates. The crusher generated products exhibiting aspect ratios less than those of natural sand in most particle sizes. The proposed process is a promising way to convert glass wastes to recycled aggregates. We expect that incorporating optical-sorting-based techniques into the process will further increase the recycling rate of waste glass bottles, even from a mix of bottles with different colors.