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Published in Elaine A. Moore, Lesley E. Smart, Solid State Chemistry, 2020
For method 1, chlorine gas is produced as a byproduct. It could be recycled and reacted with arsenic to produce AsCl3. It could however simply become a waste material (Principle 1). The production of chlorine means that not all materials used are incorporated in the product (Principle 2). Chlorine gas is harmful to health. At 1–3 ppm, it produces mild irritation, but the toxicity increases with concentration and at 1000 ppm, it is lethal within minutes. Chronic low-level exposure may lead to impairment of the lung. Gallium is considered mildly toxic, but can cause irritation when inhaled. AsCl3 is carcinogenic and toxic when inhaled or ingested (Principle 3).
Environmental, Health, and Safety Issues
Published in William C. Dickinson, Paul N. Cheremisinoff, Solar Energy Technology Handbook, 2018
Philip E. Mihlmester, John B. Thomasian, Michael R. Riches
Gallium is extracted as a by-product from zinc and aluminum ores. Aluminum ore is the most probable future source of gallium for photovoltaic cells [28]. A significant increase in gallium production will result in large amounts of alumina sludge, as well as possible contamination of surface water with mercury and caustic or acidic effluents [29]. The quantity of solid alumina waste that would arise is estimated at between 55,000 and 109,000 metric tons per year per 1 GW equivalent of GaAs photocells [26].
Photovoltaics
Published in Sheila Devasahayam, Kim Dowling, Manoj K. Mahapatra, Sustainability in the Mineral and Energy Sectors, 2016
Venkata Manthina, Alexander Agrios, Shahzada Ahmad
Gallium used in CIGS has an annual production of 430 metric tons in 2014, a 26% increase from 2013. Gallium is extracted from the metal ores such as bauxite and zinc processing in ppm concentrations. Metal production has to be increased significantly to produce more gallium for solar power generation. Gallium use in integrated circuits and optoelectronic devices (LEDs, laser diodes, and photodetectors) account to 80% of the consumption and is more required for these applications.
Exploring a promising technology for the extraction of gallium from coal fly ash
Published in International Journal of Coal Preparation and Utilization, 2022
Jing Huang, Yingbin Wang, Guanxuan Zhou, Yu Gu
Coal is widely used as an energy source in electricity generation and steel production due to its massive reserves and cheap cost (Vejahati, Xu, and Gupta 2010). Over the past few decades, the amount of coal fly ash (CFA) has sharply increased as nonvolatile residues in China (Yao et al. 2015). Trace elements especially gallium in CFA have attracted attentions (Dai et al. 2018; Pan et al. 2019). With the development of optoelectronics, aerospace, and telecommunication, the supply and demand of gallium have gradually increased in recent years (Shao et al. 2018). The annual production of gallium is about 600 tons (Eheliyagoda et al. 2019). Gallium is a dispersed trace element, which is mainly recycled from bauxite or coal and is a by-product of zinc production (Qin et al. 2015). There are no gallium mines in China. Based on the fact that bauxite supply falls short of demand, CFA is a promising alternative source for extracting gallium (Gutierrez, Pazos, and Coca 1997). In fact, gallium is retained in CFA during burning and has a high enrichment factor (Fang and Gesser 1996). Therefore, finding a low cost and high efficient method for extracting gallium is an important step toward the high-value-added utilization of CFA.
Precious and critical metals from wasted LED lamps: characterization and evaluation
Published in Environmental Technology, 2022
Marcelo Pilotto Cenci, Frederico Christ Dal Berto, Bianca Wurlitzer Castillo, Hugo Marcelo Veit
All PCBs contained the critical element gallium, in which is frequently used in PCBs’ integrated circuits, in the form of gallium arsenide (GaAs) [41]. Gallium is considered irreplaceable for current technological applications in advanced semiconductors due to low energy consumption and high computation speed [42], and, therefore, may also be considered a target element for PCBs’ recycling routes. Other critical elements found in all brands were barium, antimony, and magnesium. Cobalt was present above the limit of quantification, only in the brands L1 and L2. The toxic element lead was not found in detectable concentrations in PCBs, which suggests the correct replacement of lead-based solders with eco-friendlier ones. The toxic element arsenic was found in the PCBs of all brands (concentrations between 0.01% and 0.02%) and is possibly related to GaAs material, along with gallium. No detectable amount of cadmium was found in the PCBs of the LED lamps.
Behaviors of Adsorption and Elution on Amidoxime Resin for Gallium, Vanadium, and Aluminium Ions in Alkaline Aqueous Solution
Published in Solvent Extraction and Ion Exchange, 2021
Qi Zheng, Chunlin He, Jiejie Meng, Toyohisa Fujita, Chunhui Zheng, Wei Dai, Yuezhou Wei
Gallium (Ga), as an important element of the main group metals, is mainly used in the fields of electronic, chemical, new energy, instrument industries, and medicine production.[1–4] Currently, 80% Ga is used for semiconductor manufacturing,[5] and with the rapid development of downstream firms of Ga, especially the semiconductor, and the solar cell industries will demand Ga steadily in the future. Ga is produced as a by-product from bauxites, sulphidic zinc ores, and coal.[6–8] Bauxite is now the most important resource of Ga; almost 90% of Ga is extracted from bauxite.[9] Additionally, some amount of vanadium (V) is always present in bauxite[10,11] and residues of mineral oil processing including crude oil.[12] When bauxite is leached by the Bayer process, Ga and V are leached into Bayer liquor together with aluminum (Al).[13]