Introduction Phosphogypsum is an industrial by-product of the phosphatic fertilizer industry that has received attention because of its acidity, fluoride content, heavy metal content and low level radioactivity (Rutherford et al. 1994).
WhatsApp: +86 18221755073Phosphogypsum is waste with the main component CaSO 4 ·2H 2 O (90% calculated as dry mass), but containing a variety of impurities of phosphate rock origin. Among the impurities, the most significant concern is the high fluorine content (0.3–1.8%), which restricts the application of this waste product.
WhatsApp: +86 18221755073Phosphogypsum, a typical by-product in the phosphorus chemical industry, could generate a large amount of leachate containing phosphate and fluoride in the process of rainfall and long-term …
WhatsApp: +86 18221755073This study discusses fluoride removal efficiency from phosphogypsum (PG) on lab-scale experiment matrix designed by Box-Behnken method. Temperature, solid/liquid ratio, and time were introduced as ...
WhatsApp: +86 18221755073phosphogypsum, sodium fluoride, calcium fluoride, sodium sulfate, wet conversion. 1. Introduction. Phosphogypsum (PG) is an acidic by-product resulted during the production of phosphoric acid by the wet process. This latter can be expressed by the following chemical reaction [1]: ... Generally, the content of these impurities is similar to that ...
WhatsApp: +86 18221755073The release of unacceptable fluoride levels by phoshogypsum on contact with water is a major impediment in its usage to manufacture building products because excess fluoride consumption causes dental and skeletal fluorosis. This paper examines the efficacy of fly ash pozzolanic reactions in controlling fluoride release by phosphogypsum.
WhatsApp: +86 18221755073The resource utilization of phosphogypsum is confronted with great challenge. Of all the different methods for phosphogypsum resource utilization, using phosphocypsum to fabricate calcium fluoride (CaF 2 ) is an effective resource utilization method. In this work, high-quality nano-calcium fluoride was successfully prepared in aqueous solution using calcined phosphogypsum by …
WhatsApp: +86 18221755073The thermal treatment method involves the transformation or decomposition of fluorides in phosphogypsum under high-temperature conditions, thereby reducing the fluorine content in phosphogypsum and subsequently mitigating the impact of fluorine on its properties.
WhatsApp: +86 18221755073The MP-BC exhibited 133 mg/g maximum fluoride adsorption capacity, and the adsorption rate of fluoride in actual phosphogypsum leachate by MP-BC can reach 97.23%. Furthermore, chemical precipitation was the primary adsorption mechanism. Also, the MP-BC can effectively promote fluoride ion conversion into calcium fluoride.
WhatsApp: +86 18221755073Phosphogypsum (PG)-based cemented paste backfill (PCPB) is a promising avenue for the large-scale disposal of PG. However, the toxicity and low strength of PCPB …
WhatsApp: +86 18221755073The presence of impurities from raw materials directly affects the crystal shape control, process, and product performance of high-strength α-hemihydrate gypsum (α-HH,α-CaSO 4 •0.5H 2 O) from industrial by-product phosphogypsum (PG). In this work, effect of sodium fluoride on the crystal regulation of high-strength α-HH using calcium sulphate …
WhatsApp: +86 18221755073In this present paper, the main existence form and phase distribution of trace fluoride in phosphogypsum was investigated by the combination of X-ray photoelectron spectroscopy …
WhatsApp: +86 18221755073Research has proved that the use of modified materials can not only effectively reduce the soluble phosphorus and F-content in PG, but also promote the hydration reaction. ... Control of fluoride pollution in cemented phosphogypsum backfill by citric acid pretreatment. Materials, 16 (19) (2023), 10.3390/ma16196493. Google Scholar [13]
WhatsApp: +86 18221755073The high concentration of fluoride and phosphate in phosphogypsum leachate is harmful to the environment and ecosystem. ... To sum up, ASC is a competitive candidate to treat wastewater with high fluoride and phosphate content, such as phosphogypsum leachate. Graphical abstract. Download: Download high-res image (331KB) Download: Download full ...
WhatsApp: +86 18221755073The MP-BC exhibited 133 mg/g maximum fluoride adsorption capacity, and the adsorption rate of fluoride in actual phosphogypsum leachate by MP-BC can reach 97.23%. …
WhatsApp: +86 18221755073Skip to search form Skip to main content Skip to account menu. Semantic Scholar's Logo. Search 224,403,091 papers from all fields of science ... {Highly efficient recovery of phosphate and fluoride from phosphogypsum leachate: Selective precipitation and adsorption.}, author={Mengxuan Zhao and Xiaodi Li and Junxia Yu and Fei Li and Li Guo and ...
WhatsApp: +86 18221755073Soil fluoride pollution due to small and large scale industrial plants and phosphogypsum (PG) as a by-product of a chemical fertilizer production plant (CFPP) in Bandırma district in Turkey was ...
WhatsApp: +86 18221755073Our results exhibit that the contents of soluble phosphorus and fluoride ions in phosphogypsum washed with circulating water are 0.017 % and 0.006 % respectively, which reach the Chinese national standard. ... The content of soluble ions are found to be 0.017 % and 0.006 % for fluoride ions and PG ions respectively. Download: Download high-res ...
WhatsApp: +86 18221755073Phosphogypsum (PG) is a type of synthetic gypsum generated during the production of phosphoric acid. ... cadmium, chromium, fluoride, zinc, antimony, copper (U.S. Environmental Protection Agency, 1990), which may ... to the annual effective dose due to airborne contamination from phosphogypsum wallboard with enhanced radium content used as an ...
WhatsApp: +86 18221755073The fluoride was tested by a fluoride ion detector (PF-202, INESA Scientific Instrument Co., Ltd, Shanghai, China) with a detection limit from 10 −1 to 10 −6 mol/L. To eliminate the influence of fluoro complex, sodium acetate (CH 3 COONa) or HCl was applied to modify the pH values of leachates from 5 to 7. The remained residues after ...
WhatsApp: +86 18221755073The modified phosphogypsum biochar (MP-BC) was prepared by mixing the modified phosphogypsum (MPG) with pineapple peel in proportion and applied to the removal of fluoride from wastewater.
WhatsApp: +86 18221755073Second, compared to the P—phosphor element, the content of F—fluoride in phosphogypsum is relatively low. Existing data show that the P/F mass ratio usually fluctuates between 0.7 and 9, indicating significant regional differences in the samples. Meanwhile, the technical difficulty of removing relatively low concentrations of F elements ...
WhatsApp: +86 18221755073Phosphogypsum (PG) is a solid waste generated during the wet process of phosphoric acid, the utilization of which is hindered by impurities.Herein, natural gypsum and limestone were replaced by PG as the only source of CaO for the production of sulfoaluminate cement (SAC). The effects of fluoride impurities such as NaF, CaF 2, and Na 2 SiF 6 on the …
WhatsApp: +86 18221755073This study investigates the impact of initial fluoride content (IFC) in PG samples on the strength and leaching behavior of PCPB to establish appropriate pretreatment standards. …
WhatsApp: +86 18221755073Phosphogypsum, a typical by-product in wet process phosphoric acid with enormous production and high content of phosphorus and fluorine, can offer significant possibilities as a second resource. Thus, developing green and effective technologies for removing and recycling phosphate and fluoride from phosphogypsum leachate is greatly important ...
WhatsApp: +86 18221755073Our results exhibit that the contents of soluble phosphorus and fluoride ions in phosphogypsum washed with circulating water are 0.017 % and 0.006 % respectively, which reach the Chinese national standard. Meanwhile, the washing water can be used again for washing PG after CDI treatment, so as to achieve the purpose of water recycling and water ...
WhatsApp: +86 18221755073Phosphogypsum (PG) is an industrial solid waste inevitably generated from the wet process of phosphoric acid production (Cai et al., 2021; Ennaciri et al., 2020).Based on previous statistics, the overall utilization rate of PG is only 15%, representing that the majority of PG is stockpiled in the ground and without any type of isolation (Zhang et al., 2012a).
WhatsApp: +86 18221755073The high concentration of fluoride and phosphate in phosphogypsum leachate is harmful to the environment and ecosystem. Thus, there is a need to develop feasible materials or technologies to remove both fluoride and phosphate in acidic phosphogypsum leachate. In this study, sulfoaluminate cement (SC) was used to simultaneously remove fluoride and phosphate in …
WhatsApp: +86 18221755073The MP-BC exhibited 133 mg/g maximum fluoride adsorption capacity, and the adsorption rate of fluoride in actual phosphogypsum leachate by MP-BC can reach 97.23%. ... An X-ray fluorescence spectrometer (XRF, ZSX Primus III +, Japan) was used to measure the component elements and content in materials. A fully automatic specific surface area ...
WhatsApp: +86 18221755073Phosphogypsum (PG) is an industrial waste residue produced during the wet process of phosphoric acid production in the phosphorus chemical industry. ... [34], reducing the dissolved Ca 2+ content and fluoride removal efficiency of the PG. Therefore, maintaining a relatively low solution temperature (20 ℃) is beneficial for fluoride ions removal.
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