Measurement and evaluation of natural radioactivity in …

2015-6-1 · Phosphogypsum (PG) is a by-product waste of phosphoric acid (H 3 PO 4 )/phosphate fertilizers manufacture where phosphate ore attacked …

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Request to Use Phosphogypsum in Government Road …

2020-10-14 · On October 14, 2020, the EPA approved The Fertilizer Institute''s request to use phosphogypsum in government road construction projects subject to certain terms and conditions. Under Clean Air Act (CAA) regulations, EPA may approve a request for a specific use of phosphogypsum if it is determined that the proposed use is at least as protective ...

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Long‐term effects of lime and phosphogypsum on soil …

2020-10-21 · Lime and phosphogypsum applications are well-established practices in weathered soils, and their surface application under no-till (NT) can affect soil physical attributes and C and N fractions. This study determined the long-term (10-yr) effects of lime and phosphogypsum applications to the soil surface on soil C and N fractions of a tropical ...

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Imminent Failure of Phosphogypsum Stack in Tampa Bay …

2021-4-3 · ST. PETERSBURG, Fla.— Manatee County officials have issued evacuation orders for the area surrounding Florida''s Piney Point in anticipation of the imminent catastrophic collapse of a phosphogypsum stack retention pond holding up to 700 million gallons of wastewater. It has been reported that 22,000 gallons a minute are being discharged from the holding pond to …

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Radiation and Phosphogypsum

Radiation and Phosphogypsum. • Both natural gypsum and phosphogypsum contain radioactivity, but phosphogypsum contains more. • In the manufacture of phosphoric acid, the acid is filtered through cloth to remove solids. The radium is filtered out with the solids. The solid portion is known as phosphogypsum. • Phosphogypsum produced in ...

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Natural radioactivity in phosphates, phosphogypsum and …

The process of leaching of the radioisotopes from phosphogypsum was discussed. A method for the direct alpha counting of 226Ra thin source, elaborated by the deposition of Ra from aqueous solutions on manganese oxides film deposited on polyvinyl support, have been developed and applied for the determination of 226Ra in natural water samples. ...

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Phosphate, phosphoric acid and phosphogypsum …

phosphogypsum samples have been crushed, and pulverized to a ne powder with particles< 50–100 μ m, then dried for 24 h at 105 °C, nally they were cooled and stored in a

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The using of waste phosphogypsum and natural gypsum …

Phosphogypsum is a by-product of chemical reaction whereby sulfuric acid is reacted with phosphate rock to produce the phosphoric acid needed for fertilizer production. PG has used as set controller in the manufacture of Portland cement, as a raw material for clinker, as a secondary binder with lime and cement and in production of artificial ...

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(PDF) The using of waste phosphogypsum and natural …

2008-6-1 · Phosphogypsum (PG) is a by-product of the production of fertilizers from phosphate ores, and it contains some harmful substances to the environment. Thus, it is necessary to stabilize/solidify ...

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NaturalGPS GPS Trackers

2019-11-10 · Access your NaturalGPS account on any device or computer; Obtain reports as frequently as every 30 seconds; Accelerometer logic facilitates efficient battery usage. For an object that moves once every week, expect 12-24 months per battery charge; Installation takes 1-3 minutes and setting up a NaturalGPS account is even quicker

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EPA Approves Use of Phosphogypsum in Road Construction

2020-10-14 · Phosphogypsum is a byproduct material of phosphate fertilizer production. It is regulated for the presence of radium-226, a naturally occurring radioactive substance that produces radon gas, a hazardous air pollutant. The Clean Air Act requires the disposal of phosphogypsum in stacks, except for limited agricultural and research uses.

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Assessment of Natural Radioactivity in Phosphate Ore, …

2012-9-11 · The radionuclides present in phosphate ore, phosphogypsum and soil samples in the vicinity of a phosphate fertilizer plants in Nigeria were identified and their activity concentration determined to assess the potential radiation impact on the environment due to fertilizer production. The mean activity concentration of 238U, 232Th, and 40K radionuclides in …

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Natural radioactivity in phosphates, phosphogypsum and …

2001-1-1 · The radiological impact of this radioactivity, varies with the mineralogical nature of the phosphates ( Table 2) ( Scholten & Timmermans, 1996) and requires a special care, especially in Morocco where these are important mines of phosphates and phosphogypsum. This country is contributing about two-thirds of the phosphates commercialised worldwide.

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Phosphogypsum Stacks

There are currently about 1 billion tons of phosphogypsum stacked in 24 stacks in Florida and about 30 million new tons are generated each year. Other areas of the world, however, looked at phosphogypsum as a valuable raw material and developed processes to use it in chemical manufacture and construction materials.

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NORM in Phosphogypsum

Weigh 0.5 g of phosphogypsum into a microwave container and add 15 mL conc. HNO 3 (65 %) Add 30 mg Pb 2+ and about 0.05 ( 232 U, 225 Ra) to 0.5 Bq ( 209 Po) tracer. Digest at 120 °C for 15 min and at 150 °C for 25 min at 1000 W. …

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Plasticity, Swell-Shrink, and Microstructure of …

2016-7-21 · The study involved utilization of an industrial waste, Phosphogypsum (PG), as an additive to lime stabilization of an expansive soil. Three lime dosages, namely, initial consumption of lime (ICL), optimum lime content (OLC), and less than ICL (LICL), were identified for the soil under study for stabilizing the soil. Along with lime, varying doses of PG were added to the soil …

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Difference Between Gypsum and Phosphogypsum

2020-2-28 · The key difference between gypsum and phosphogypsum is that gypsum is a naturally occurring form of calcium sulfate, whereas phosphogypsum is a synthetic form of calcium sulfate.More specifically, gypsum is a rock-forming, soft crystal obtained by mining or quarrying, but phosphogypsum is a by-product during the production of superphosphate from …

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Subpart R: National Emission Standards for Radon …

2022-6-24 · Phosphogypsum is a solid waste byproduct 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 decays to form radon, a cancer-causing, radioactive gas.

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The using of waste phosphogypsum and natural gypsum …

2008-6-1 · Phosphogypsum is a by-product of chemical reaction whereby sulfuric acid is reacted with phosphate rock to produce the phosphoric acid needed for fertilizer production. PG has used as set controller in the manufacture of Portland cement, as a raw material for clinker, as a secondary binder with lime and cement and in production of artificial ...

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Potential Uses of Phosphogypsum and Associated Risks: …

4) Phosphogypsum has been used commercially in North Carolina as a fill and sub-base in roads crossing swampy areas. 5) A mixture of phosphogypsum (13 percent) and concrete was used to pave 1,670 m2 (2,000 yd2) of driveways and parking areas at the Florida Institute of Phosphate Research in Bartow, Florida.

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Measurement and evaluation of natural radioactivity in …

2015-2-15 · The present work is directed to characterize the phosphogypsum (PG) wastes by means of in situ atmospheric radon measurements, gross-alpha and gamma-ray spectrometry measurements. The average radon concentrations in three locations: Valea Calugareasca, Navodari and Turnu Magurele are 21.88 ± 3.19, 26.56 ± 2.90 and 33.43 ± 3.64 (Bq × m−3), …

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Characterization of phosphate rock and phosphogypsum …

Since the establishment of the coastal industrial complex in Gabes city (Gulf of Gabes, SE Tunisia), hundred million tons of untreated phosphogypsum have been discharged in the open sea causing serious environmental problems. To better understand the dynamic and behavior of phosphate/phosphogypsum c …

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Natural radioactivity in phosphate rock, phosphogypsum …

2005-5-1 · Phosphate deposits are generally characterized by enhanced radionuclide concentrations compared to natural levels. The mining and processing of this phosphate ore redistribute radionuclides throughout the environment and introduce them into phosphoric acid and phosphogypsum. Phosphoric acid is the starting material for triple superphosphate (TSP), …

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Dehydration behaviour of a natural gypsum and a …

1999-7-5 · It was decided to investigate the degree of dehydration of a naturally occurring gypsum and a phosphogypsum at various isothermal conditions between 90°C and 140°C in a first effort to simulate milling conditions. By far the largest source of gypsum is from the manufacture of phosphoric acid by the reaction of phosphate rocks with sulphuric ...

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Phosphogypsum

Phosphogypsum is a waste by-product from the processing of phosphate rock in plants producing phosphoric acid and phosphate fertilizers, such as superphosphate. The wet chemical phosphoric acid treatment process, or ''wet process'', in which phosphate ore is digested with sulfuric acid, is widely used to produce phosphoric acid and calcium sulfate, mainly in dihydrate form (CaSO 4 …

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Phosphogypsum, the composition and application of

2019-9-26 · Phosphogypsum, the composition of the formula: Phosphogypsum – a fertilizer used for plastering of soils. Phosphogypsum contains at least 80% of gypsum (CaSO4·2H2O) in the form of small crystals and 0.4% water-soluble phosphorus oxide, which is its beneficial components. It also contains soluble impurities (sulfuric acid, phosphoric acid ...

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PHOSPHOGYPSUM ANALYSIS: TOTAL CONTENT AND …

2012-6-26 · phosphogypsum is classified as TENORM (Technologically Enhanced Naturally Occurring Radioactive Material), that is, a solid waste containing naturally occurring radioactive elements from the rock matrix. Environmental impact studies should assess the existing site and conditions and evaluate the anticipated impacts on the environment itself by ...

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(PDF) Natural radionuclides content and radon …

2014-9-1 · In this paper, phosphogypsum (PG) with the content of ²²⁶Ra of about 500 Bq kg⁻¹ was used as a clay additive in mass ratios of (0–40) % and its influence on the radiological and ...

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Phosphate, phosphoric acid and phosphogypsum natural …

2021-6-5 · The concentrations of 238U, 226Ra, 232Th and 40K maintained in phosphate rock (PR), phosphoric acid (PA) and phosphogypsum (PG) samples and its possible radiation hazards, have been measured. The radionuclides in phosphate rock have been redistributed unsymmetrically between phosphoric acid and phosphogypsum during the production process. …

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Project Phosphogypsum: The Effect of Phosphogypsum on …

2022-7-17 · Phosphogypsum is a waste product of the phosphate fertilizer industry. Accumulation of phosphogypsum is a growing environmental problem in Florida and all over the world. As more man-made fertilizer is produced to meet the agricultural needs of a growing world population, phosphogypsum stacks continue to rise and pose an environmental hazard in ...

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Comparative adsorption studies of cadmium ions on …

2021-9-1 · It is apparent from Fig. 3 that the natural clay particles are mostly irregular in shape and the clay has a porous surface, which is a favorable condition for Cd(II) adsorption. On the contrary, the phosphogypsum presents a relatively different surface morphology. The phosphogypsum particles have a length of between 10 and 200 μm and a defined crystalline …

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