Florida has been an important source since the 1800s; currently, the EPA notes, ... "Phosphogypsum contains appreciable quantities of uranium and its decay products, ...
In this study, phosphogypsum was used as source of calcium sulfate and the influence of its solubility (availability) on the properties of SSC was investigated. Mixtures were tested using 10 and 20% phosphogypsum calcined at either 350 or 650 °C, which were more or less soluble, respectively. The largest ettringite formations were …
Phosphogypsum is a solid waste byproduct from processing phosphate ore to make phosphoric acid that is later used in fertilizer. Phosphogypsum contains radium, which decays to form radon gas. Both radium and radon are radioactive and can cause …
Phosphogypsum has been used in agriculture as a source of calcium and sulfur for soils that are deficient in these elements. When the phosphogypsum is used as a fertilizer, it is simply spread on the top of …
The need for rare earths elements (REEs) in high tech electrical and electronic based materials are vital. In the global economy, deposits of natural REEs are limited except for countries such as China, …
1. Introduction. Phosphogypsum (signed as PG) is a by-product of the wet process to produce phosphoric acid. The main reaction equation involved is as follows [1]. (1) Ca 2 F(PO 4) 3 + 5H 2 SO 4 + 10H 2 O = 3H 3 PO 4 + 5CaSO 4 ·2H 2 O + HF↑ Approximately 4–6 tons of PG are generated per ton of phosphoric acid produced …
Radium-226, with its long half-life (1620 years), becomes the major long-term source of radioactivity in phosphogypsum. Radon-222 gas, the first decay product of Ra-226, is one of the major health concerns regarding phosphogypsum because inhalation of the radioactive gas has been linked to lung cancer (NCRP 1984). Not all of the Rn-222 …
Phosphoric acid manufacturing generates large amounts of phosphogypsum (PG); a by-product generally disposed in the surface or evacuated in the seawater without any pretreatment. Phosphogypsum may host non-negligible amounts of valuable elements such as rare earth elements (REEs), which are critical elements on …
–Natural radioactivity and metals content depend on the source of rock used and the processing conditions –Consequently, care must be taken to match a given source of phosphogypsum to the appropriate end use •Use is environmentally preferable to stacking or disposal to open waters •Regulators should be encouraged to promote beneficial ...
DOI: 10.1016/j.conbuildmat.2024.135296 Corpus ID: 267510648; Preparing sulfoaluminate cement using phosphogypsum as the only calcium oxide source: Effects of fluoride impurities @article{Yao2024PreparingSC, title={Preparing sulfoaluminate cement using phosphogypsum as the only calcium oxide source: Effects of fluoride impurities}, …
Phosphogypsum (PG) is a by-product produced during the wet process of phosphoric acid (H3PO4) production from natural phosphate rocks. Approximately 4–6 tons of PG is produced per ton of ...
Phosphogypsum, a waste product from manufacturing fertilizer, emits radon, a radioactive gas. It also contains the radioactive …
Source contribution analysis shows three sources derived from the PG deposit: PG, layered salts and gypsum + impurities (REE and U). The last source reaches the city under SW-S-SE winds accounting for a 6% of bulk atmospheric deposition. ... Phosphogypsum (PG) is the main residue of the phosphate fertilizer industry, …
Phosphogypsum (PG) is a by-product of the fertilizer industry when producing phosphoric acid from phosphate rock. For every ton of phosphoric acid produced, approximately 5.0 tons of phosphogypsum are generated. The global PG stockpile increases to 200 million tons per year [1].
EPA defines Phosphogypsum (40CFR61 Subpart R) "…as a radioactive waste product that results from processing phosphate ore to make phosphoric acid that is later used in fertilizer. Because the phosphate ore contains uranium and radium, phosphogypsum also contains these radionuclides. The radium is of particular concern because it
For a detailed characterization of the 5.7 10 6 mt phosphogypsum (PG) stack in the vicinity of Bacau city, Romania, the air dose rate (ADR) was measured in 72 points covering the stack surface, while 10 samples of stack material were collected for future analysis. Radiometric determinations showed for the ADR values varying between 364 ± 53 and …
Phosphogypsum (PG) is a radioactive industrial by-product produced in large quantities when processing phosphate ores into fertilizers. With rapid growth of high concentration phosphate and compound fertilizers production in China, PG production is increasing every year. Phosphogypsum is usually stored in such a way that it not only …
This study demonstrates the feasibility of using phosphogypsum as the sole CaO source in the preparation of calcium sulfoaluminate cement by considering its mechanical properties and the potential environmental impacts of its large-scale utilization. First, the effects of the alumina/silica ratio on the mineral phase formation, setting time ...
Nearly 300 million t of phosphogypsum (PG) are produced every year as a byproduct from phosphate fertilizer production worldwide. Approximately 58% of the PG are stacked, 28% are discharged in ...
Abstract. Phosphogypsum (PG: CaSO 4 ·2H 2 O) is a waste product generated by the phosphate industry. World production of this waste exceeds 200 million tonnes per year. PG, discharged into the sea, watercourses or in wilderness stocks, contains toxic elements harmful to ecosystems and human health, including heavy …
Phosphogypsum source and compositionPhosphogypsum was collected from a phosphogypsum stack from the vicinity of Sfax, Tunisia. The major components of the phosphogypsum were SO 4 and CaO at 44.3% (w/w) and 33.6% (w/w), respectively and a high number of heavy metals which included Cd ...
The present study has estimated the impact of fugitive phosphogypsum (PG) particles on the bulk atmospheric deposition (soluble and insoluble species) of a nearby urban area (Huelva, SW Spain). The work is based on the geochemical characterization of bulk atmospheric samples collected from April 2014 to March 2017 in …
Phosphogypsum (PG) is a solid waste product generated during wet-process phosphoric acid production. Various impurities considerably reduce the purity, whiteness, and application range of PG. This ...
Phosphogypsum is the main internal source of recycled fine powder-based multi-source solid waste geopolymers, and it is the key to controlling the amount of AFt generated in the system . Therefore, the negative effect of delayed AFt on the geopolymer decreases with a decrease in the phosphogypsum content. The increase in recycled …
Phosphogypsum (PG) is a by-product of the phosphate fertilizer industry that is produced during the phosphoric acid production process. Annual global PG production ranges between 100 to 300 Mt, …
The problem of recycling and storage of phosphogypsum is topical for many countries around the world, as it is associated with environmental problems of pollution of water bodies, land, and atmosphere. Therefore, this paper analyzes the directions of phosphogypsum recycling and possible alternatives to its use. The main …
The physical properties of the material influence its application. Phosphogypsum mainly consists of silt-sized gypsum crystals. These gypsum crystals are softly aggregated, and their morphology depends on the sources of the phosphate rock and the reaction conditions of the acid attack (IAEA Technical Reports Series No. 475, 2013).
Phosphogypsum disposal was a very simple matter in the early days of the industry. If at all possible, you located your plant near the ocean or on a ... A carbon source. Carbon is needed to react with the gypsum. Carbon can come from any source,but most commonly, fuel in excess of that needed to ...
The source of calcium sulfate used for the SSC mortar was phosphogypsum. The choice of phosphogypsum was mainly motivated by its positive environmental impact, as this material is a by-product of the fertilizer industry. This type of waste is very common in Brazil and part of the phosphogypsum generated still needs a …
Phosphogypsum (PG: CaSO 4 ·2H 2 O) is a waste product generated by the phosphate industry. World production of this waste exceeds 200 million tonnes per year.
Our study aims to highlight the effects of the addition of phosphogypsum on certain fresh and hardened characteristics of geopolymer matrices based on metakaolin or fly ash. In the fresh state, workability and setting were studied by rheology and by the electrical conductivity measurement. The hardened state was characterized by XRD, …
Those phosphogypsum reuse practices, based on nonrenewable resources/energy source inputs, caused conflict between waste reduction and carbon emission reduction. This study helps construct an integrated approach for thoroughly investigating the environmental performance of an integrated system consisting of …
Phosphogypsum (PG) is the primary byproduct generated during the production of phosphoric acid, an intermediate product in phosphate fertilizer production, from calcium phosphate (apatite) ore. ... did not result from the phosphate rock itself showing that the acid used for the digestion can also be an additional source of …
It holds phosphogypsum waste, a radioactive byproduct of phosphate processing – and potential source of rare earth elements. (Serra Sowers/WUFT News) Rare Finds Scientists say Florida phosphates are significant sources of rare earth elements, highly sought for everything from cell phones to EVs.
Phosphogypsum is primarily CaSO 4 ·2H 2 O, but also contains impurities of environmental concern such as residual acids, fluoride, heavy metals and naturally-occurring radionuclides. Impurity composition within phosphogypsum can vary greatly depending on the source of phosphate rock used in phosphoric acid production.
Phosphogypsum (PG), a by-product of the phosphate industry, is high in sulfate, (SO 4 2−), which makes it an excellent substrate for sulfate-reducing bacteria (SRB) to produce hydrogen sulfide.This work aimed to optimize SO 4 2− leaching from PG to achieve a high biological reduction of SO 4 2− and generate high sulfide concentrations …
