Phosphate Samples Research Articles

Development of a flexible technological scheme for producing complex fertilizers

The safety of fertilizers in storage, transportation in various types of transport and the effectiveness of their use in agriculture depend on their physicochemical and commercial properties. On this basis, we studied the physicochemical and commercial properties of new types of phosphorus and nitrogen-phosphorus fertilizers obtained in the process of processing samples of Karakalpakstan phosphate by mineral salt solutions, with an incomplete rate of sulfuric and nitric acid with the introduction of ammonium sulfate and nitrate. A technological scheme was developed for obtaining new types of phosphate fertilizers by decomposing the bare Karakalpak phosphate with an incomplete rate of sulfuric and nitric acids, as well as in the presence of their ammonium salts.

X-ray diffraction characterization of the untreated calcium phosphate from two Moroccan mining zones

X ray diffraction XRD analyses were performed on untreated calcium phosphate samples of the two mining zones of Morocco Benguerir and Khouribga XRD was investigated for the determination of the structure However a comparative study was carried out between the two types of phosphate to implement the observed differences Results showed that the comparison between the two samples reveals significant differences at the level of the refinement parameters crystallite size and microstrain but no changes in the crystal system

Rheological properties and small-angle X-ray scattering studies of phosphate dust obtained from baghouse collectors

Abstract Baghouse dust collectors are using in the drying unit of Beni Idir situated in Beni-Idir Khouribga city, Morocco, to retrieve phosphates particles from dust air-drying before its expulsion through the smokestacks. The phosphate dust samples used in this study were taken from the filtration chamber of the baghouse dust collectors. The first sample (S1) is untreated calcium phosphate dust, the second (S2) is the calcium phosphate dust from the outside of filter media while the third one (S3) is the calcium phosphate dust from the inside of filter media which causes clogging depth. In this paper, the rheology and the small-angle X-ray scattering (SAXS) of the three samples were investigated to elucidate the changes in terms of local structure, the viscosity, and the shear stress parameters. The rheological behavior of the dust samples was investigated for a solid mass concentration ranging from 50 to 60%, the three samples (S1) (S2) and (S3) had a solid mass concentration of C1=60%, C2=55% and C3=50% and a shear rate in the range from 1 to 1000 s−1. The results indicated that during the filtration process, the pseudo-plastic behavior of the dust phosphate changed to that of Bingham. Comparing the results of the sample’s viscosity, we found that the viscosity decreased during the process filtration. The SAXS results suggested that the dust phosphate samples possess a fractal surface structure of enormous dust particles with a rough surface interface. This new study highlights the rheological behavior of grain phosphates that could be extrapolated to other mining powder as grains material or in solution. It is important to understand the rheological characteristics of materials, their flow, and the subsequent deformation of matter as a result of the flow.

Liberation Limited Dolomite Rejection from Pebble Phosphate in Gravity Concentration

The depletion of good-quality phosphate resources, coupled by a need to supply acceptable products at a rapid rate, while meeting the specifications of fertilizer chemical plants, is of significant concern to the phosphate industry, particularly the production of concentrates with tolerable dolomite content. Tremendous efforts have been made in the past to develop an efficient and economical process that can effectively reject dolomite. However, dolomite removal continues to plague the phosphate industry due to several process-specific challenges being encountered with various beneficiation technologies. In this regard, detailed characterization of phosphate reserves is crucial to understand textural limitations and help design appropriate strategies to achieve quality products. In this paper, the development of procedures to establish dolomite rejection/francolite recovery curves for gravity preconcentration of pebble phosphate from Central Florida is described using high-speed X-ray computed tomography (HSXCT). The developed procedure is illustrated with the analysis of high MgO pebble phosphate samples (10.39 mm × 1 mm) received from South Pasture and Four Corners locations operated by the Mosaic company. The rejection/recovery curves were calculated for each sample for five different particle size classes to observe the trend in rejection/recovery with variation in particle size. In order to evaluate the reliability of the HSXCT data, analysis using the high-resolution X-ray computed tomography (HRXCT) technique was performed on one particular sample (FC-3-1). Finally, to assess the separation efficiency, the HSXCT and HRXCT rejection/recovery curves obtained were compared to experimental gravity preconcentration results reported in the literature. In this way, liberation limitations for gravity preconcentration in the processing of pebble phosphate have been established based on X-ray computed tomography analysis.

Phase Composition, Structure, and Hydrolytic Durability of a Uranium-Containing Magnesium Potassium Phosphate Compound

Uranium-containing samples of magnesium potassium phosphate (MPP) compound were synthesized using a nitric acid uranium solution. Uranium is incorporated in the MPP compound in the form of potassium uranyl phosphate with the structure of metaankoleite natural mineral, K(UO2)PO4·3H2O. The differential and integral uranium leach rates, determined in accordance with GOST (State Standard) R 52 126–2003 on the 28th day of contact of the compound with water, are 1.7 × 10–6 and 2.7 × 10–6 g cm–2 day–1, respectively, and the degree of leaching is 0.014%. High hydrolytic durability of the compound with respect to uranium leaching reduces the risk of release of uranium isotopes from radioactive waste into the environment.

High speed X-ray computed tomography for plant-site analysis of pebble phosphate

The increase in demand for phosphate by agriculture and allied industries has led to an increase in production by mining and processing operations. According to an estimate by the U.S. Geological Survey, phosphate production will increase from 223 million tons in 2015 to an expected 255 million tons in 2019 (Ober, 2018). With the reduced availability of high quality resources, the phosphate industry faces a challenge to meet the ever-increasing demand. For effective utilization of existing pebble phosphate reserves, detailed particle characterization at the plant site should be useful. In this regard, high speed X-ray computed tomography (HSXCT) is being considered to achieve improved processing efficiency to meet the growing industrial demands. The current paper focuses on the demonstration and development of the HSXCT technique for plant-site characterization of the pebble phosphate resources from Florida operations.The study involves high and low MgO pebble phosphate samples obtained from Mosaic’s South Pasture and Four Corners operations. The appropriate sample preparation, operating conditions and procedures for HSXCT analysis with the VoluMax 800 system were established. Based on scanning of different sample amounts, satisfactory analysis of pebble phosphate samples has been demonstrated to be possible at a maximum scanning rate of 1 kg/min. The HSXCT data provides mineralogical and liberation analyses for quartz, dolomite and francolite with good reproducibility and good correspondence to the chemical analyses. For example, the mineral composition of each particle in a one kg sample (∼40,000 particles) can be determined in five minutes, while liberation analysis may take 15 min. Further, the statistical significance of volume grade distribution results from HSXCT analyses was assessed based on scans of replicate samples.

Hydrolytic and thermal stability of magnesium potassium phosphate compound for immobilization of high level waste

The samples of the magnesium potassium phosphate (MPP) compound have been synthesized during solidification of high level waste (HLW) surrogate. The compound consists of a main phosphate phases Mg1.1Na0.35K0.45PO4 × (4–6)H2O and MgCs0.5Na0.2K0.3PO4 × (5–6)H2O. Differential leaching rates of 239Pu, 152Eu and 90Sr from the MPP compound after heat treatment (450 °C) are 7.8 × 10−9; 1.7 × 10−7 and 8.8 × 10−6 g cm−2 day−1, respectively. The coefficient of thermal expansion of MPP compound—(11.6 ± 0.3) × 10−6 °C−1; coefficient of thermal conductivity averages 0.5 W m−1 K−1. The properties of MPP compound meet the regulatory requirements for solidified HLW.

Modification of titanium phosphate precipitated from titanylsulfate

The titanium phosphate-synthesized sol–gel method was subjected to the mechanochemical treatment in a planetary ball mill Pulverisette 6 in air or water environment or the hydrothermal treatment at 873 K or 1073 K. The properties of such modified/treated samples were examined using the XRF, XRD, TGA, static light scattering, FTIR Raman and adsorption/desorption of N2 methods. The mechanochemical treatment of xerogel samples leads to a small decrease in water contents in the sample, but the structure remains amorphous. Additionally, during milling of the sample aggregation of titanium phosphate particles and a decrease in specific surface area were observed. The hydrothermal treatment of the xerogel sample leads to a crystal product composed of titanium oxide phosphate hydrate, titanium oxide phosphate and titanium dioxide. The TGA analysis confirms the presence of titanium oxide phosphate hydrate. The hydrothermally treated titanium phosphate samples are monodispersed and have a larger specific surface area than the initial sample.

Optimization of esterification reaction over niobium phosphate in a packed bed tubular reactor

Abstract The aim of this work was to investigate the effect of the calcination temperature on the textural properties, structure and acidity of niobium phosphate and the relationship between those properties and the catalytic activity for the continuous esterification reaction using oleic acid and ethanol. For this purpose, samples of niobium phosphate were prepared by calcination at 300, 350, 400, 450, 500 and 600 °C. Despite the good thermal stability presented by niobium phosphate, best results were achieved for samples pretreated at 300 °C, which presented higher acidity, surface area and catalytic activity. For this sample, the experimental conditions of temperature (from 220 to 290 °C), amount of catalyst (from 0 to 0.8 g) and ethanol:oleic acid molar ratio (from 2:1 to 14:1) were studied using design of experiments (DOE) and optimized with canonical analysis. The esterification reaction of oleic acid led to yields of esters up to 70% and conversion up to 90% at optimized conditions.

DIFFERENTIAL AND THERMAL ANALYSIS OF COMPLEX CATALYTIC SYSTEM OF TYPE хСо3(РО4)2уNi3(РО4)2

Individual phosphates of cobalt and nickel and seven new complex oxide catalytic systems based on cobalt phosphate were synthesized by modifying it with ions of Nі 2+ type xCo 3 (PO 4 ) 2 ×yNi 3 (PO 4 ) 2 with different content of both phosphates having acidic surface properties. The modern methods of analysis have studied the composition, structure and some physical and chemical parameters of all synthesized samples. The influence of the synthesis conditions on the nature of the formation of their structure and the corresponding physico-chemical and catalytic properties was studied with the help of differential-thermal analysis. It is established that for synthesized binary samples, various forms of water that are part of their composition are characteristic: adsorbed, structural, crystallization, constitutional, etc. Allocating them from the structure of catalysts in the process of heat treatment is accompanied by various effects and corresponding endo-effects. In this case, the kinetics of water thermosorption from the surface and from the volume of internal pores depends on the nature of the interaction between the molecules in the adsorption layers and water molecules on the surface. In the allocation of adsorbed water from phosphate catalysts, the change in the type of anion is not observed. However, the elimination of crystallization, and especially constitutional water, is accompanied by a rupture of chemical bonds, intense diffusion of water vapor from the lattice and rearrangement of phosphate anion. All synthesized phosphates have different curves of DTA and DTG, which are different from individual phosphates of cobalt and nickel, and with each other. It is established that on all DTG curves of K-1-K-4 samples quite significant peaks of endo-effects are observed in the region T = 473-763 K. They indicate the presence of various interactions of adsorbed aqueous layers on the surface of samples of phosphates: the layers of condensed water (I) (in the region T = 450-550 K), water in mesopores (II) (in the region T = 620-670 K), and adsorption layers of water directly on the surface of phosphates (III) (in the region T = 730-770 K). After calcining at T = 973 K and at higher temperatures, all synthesized complex catalytic phosphate systems exist in the form of anhydrous salts, which is confirmed by the data of X-ray diffraction, IR spectroscopic and chemical analyzes.

210Pb in di-calcium phosphate consumed by dairy cows

In the semiarid region of the Brazilian state of Pernambuco, the feedstuffs for dairy cattle contain the mineral supplement of di-calcium phosphate (DCP). This study was carried out to determine the concentration of 210Pb in samples of di-calcium phosphate (DCP: CaHPO4) consumed by dairy cows in Pedra and Venturosa. 210Pb concentrations ranged from 17 to 256 Bq.kg−1, and although they are below the concentrations reported in Spain (up to 2260 Bq.kg−1), they also could be considered to represent a potential risk of chemical toxicity in dairy cows.

Study of fluoride content in some commercial phosphate fertilizers

Fluoride levels in seven commercial phosphate fertilizers (four single superphosphate samples, two diammonium phosphate samples, and one ammonium nitrophosphate sample) were analyzed independently at three laboratories employing the techniques of ion chromatography and ion-selective electrode. The results were consistent for aqueous solutions containing 100 mg L−1 (ppm) of fertilizer. The average values of fluoride from four different studies varied from 0.140 ± 0.006–1.33 ± 0.158% (w/w) for the seven fertilizer samples. The [P2O5]/[F] ratios (w/w) were computed for all the seven samples and the values were in the range of 13.79–328.57. By comparing these values with the average [P2O5]/[F] ratio in phosphate rock, it was inferred that 3–75% of fluoride originally present in rock remained in the fertilizers. IR spectral data revealed a small peak at 716 cm−1 – indicative of SiF62− – in the sample containing lowest fluoride which may be on account of fluoride stripping of intermediate phosphoric acid with reactive silica in this case. Considering 15 MMT (million metric tons) of annual consumption of phosphate fertilizers in India, the incremental load of fluoride in agricultural fields was estimated to be 127,650 ± 14,550 MTy−1 based on the grand average fluoride content of 0.851 ± 0.097% (w/w). While a part of this fluoride would likely get discharged into oceans through run-off, the remainder may persist in the soil, some amount may accumulate in vegetation, and a part might find its way into fresh water bodies, thereby aggravating the fluoride problem in the Country. The problem of non-point source pollution can be reduced by eliminating fluoride at source, and utilizing the recovered fluoride as feedstock. This could, in principle, satisfy the entire requirement of the fluorochemicals industry in India. Environmental costs need to be factored in while making an assessment of the viability of fluoride recovery and reuse in this manner compared to production from virgin sources of fluoride.

Thermoluminescent response of differently doped lithium magnesium phosphate (LiMgPO4, LMP) crystals to protons, neutrons and alpha particles

Differently doped lithium magnesium phosphate crystals have been investigated with respect to their thermoluminescent properties. The LiMgPO4 crystals with Tb, B, Eu, Er, Tm, Y rare-earths elements were grown by the micro pulling down method. Different radiation qualities, such as protons of different energies, neutrons and alpha particles, have been used for samples irradiation. Thermoluminescent sensitivity to ionizing radiation, dose-response characteristics and relative thermoluminescence efficiency have been evaluated for all radiation qualities and compared for all analyzed crystal samples. It was found that the radio-sensitivity of the studied compound varies within several orders of magnitude depending on the applied doping ion and its concentration. The highest response was measured for the samples doped with thulium ions. In this case, the signal amplitude was about 3 times higher as compared to the standard LiF:Mg,Ti samples in the form of cold-pressed and sintered pellets. The dose-response of the studied LiMgPO4 crystals was found to be linear up to kGy range, regardless of the applied dopant and its concentration. An interesting behavior was observed in case of relative efficiency vs. linear energy transfer dependence. For protons of different energies the analyzed samples show a similar behavior as the reference LiF:Mg,Ti samples, showing a maximum efficiency evaluated for 20 MeV particles. The response of LiF-based samples for alpha particles decreases significantly to the value of around 0.08. The response of the analyzed lithium magnesium phosphate samples also decreases, but the decrease is not so significant in this case. This probably corresponds to the wide linear dose-response range and also indicates that the local signal saturation effects occur in this material in the range of much higher doses as compared to the reference LiF-based samples.

The aid of calorimetry for kinetic and thermal study

Phosphoric acid, a non-renewable chemical, is used in different industries. Production of this chemical from natural phosphate can be done by two routes: wet process and thermal process. The nature of the natural phosphate, i.e., its chemical composition, plays an important role in the kinetics and thermodynamics of phosphoric acid production. Thus, the establishment of a kinetic model, based on reaction mechanism, for the dissolution of natural phosphate is cumbersome due to the presence of impurities. Besides, one should use an online analytical method because the dissolution reaction is fast. The dissolution of two natural phosphates with different percentages of phosphorus pentoxide (P2O5), phosphate samples (28 mass% of P2O5) from Gafsa region (Tunisia) and phosphate samples (18 mass% of P2O5) from Cheketma-Kasserine region (Tunisia), was studied from a kinetic and thermal aspect. Experiments were performed by using a Tian—Calvet calorimeter. Two acid solutions were used for the dissolution: one with phosphoric acid (S1) and the other a mixture of phosphoric and sulfuric acid (S2). For both natural phosphates, it was found that in case of using S1 solution the heat released due to the dissolution was lower than in case of using solution S2. This difference was explained by the precipitation of monohydrate sulfate calcium to its dihydrate form. By using a granulometry distribution lower than 500 μm, heat released during the dissolution of both phosphates by S1 was similar, i.e., − 230 J g−1, and the same observation was done by using S2 solution, i.e., between − 300 and − 350 J g−1. We have demonstrated that granulometry distribution plays an important role, and by using a granulometry lower than 120 μm for Cheketma-Kasserine region phosphate, the heat released during the dissolution was higher, i.e., − 400 J g−1 with solution S2. Avrami model was found to describe the precipitation of calcium sulfate, and three distinguished domains were obtained by using Gafsa region phosphate compared to two domains with Cheketma-Kasserine region phosphate.

In vitro Evaluation of Porous borosilicate, borophosphate and phosphate Bioactive Glasses Scaffolds fabricated using Foaming Agent for Bone Regeneration

In this work, glasses within the borosilicate borophosphate and phosphate family were sintered into 3D porous scaffolds using 60 and 70 vol. % NH4(HCO3) as a foaming agent. All scaffolds produced remained amorphous; apart from one third of the glasses which crystallized. All produced scaffolds had porosity >50% and interconnected pores in the range of 250–570 µm; as evidenced by µCT. The in-vitro dissolution of the scaffolds in SBF and changes in compression were assessed as a function of immersion time. The pH of the solution containing the borosilicate scaffolds increased due to the typical non-congruent dissolution of this glass family. Borophosphate and phosphate scaffolds induced a decrease in pH upon dissolution attributed to the congruent dissolution of those materials and the large release of phosphate within the media. As prepared, scaffolds showed compressive strength of 1.29 ± 0.21, 1.56 ± 0.63, 3.63 ± 0.69 MPa for the borosilicate, borophosphate and phosphate samples sintered with 60 vol. % NH4 (HCO3), respectively. Evidence of hydroxyapatite precipitation on the borosilicate glass scaffolds was shown by SEM/EDS, XRD and ICP-OES analysis. The borophosphate scaffolds remained stable upon dissolution. The phosphate scaffolds were fully crystallized, leading to very large release of phosphate in the media.

Reflectance spectroscopy and ASTER based mapping of rock-phosphate in parts of Paleoproterozoic sequences of Aravalli group of rocks, Rajasthan, India

This paper applies reflectance spectroscopy and Advanced Space borne thermal emission reflection radiometer (ASTER) data processing to delineate dolomite-hosted rock phosphate around Udaipur City, Western India, using visible-near infrared (VNIR) and short wave infrared (SWIR) bands of the ASTER sensor. A number of ASTER image spectra and field spectra (resampled to ASTER bands) of pure dolomite and rock phosphate are compared and found to be consistent in terms of the presence of absorption minima at 2.3 µm for dolomite and the absence of the same feature in the spectra of the rock-phosphate. Before attempting spectral mapping, ASTER SWIR band data are clipped using the spatial extent of host rock; which has been prepared from the reference geological map and consequently updated using VNIR-SWIR derived image enhanced products at selected part of the study areas. Two sub-pixel spectral methods namely adaptive coherence estimator (ACE) and matched filtering (MF) methods are applied to ASTER SWIR bands to delineate rock-phosphate-rich zones within dolomite. The output images of the above algorithms are integrated in a principal component (PC) image to delineate phosphate pixels. A principal component; which has similar sign of Eigen vector loading for ACE and MF abundance image is used to delineate rock phosphate within dolomite. The results are validated in the field using a qualitative colorimetric method and also by comparing image spectra of spectrally anomalous zone with the ASTER resampled laboratory spectra of rock phosphate samples. A number of sporadic but important patches of phosphate rich zones in addition to the main surface exposures of the Jhamar Kotra Mine are confirmed in the field. The proposed method is a novel application of spectral mapping of phosphate deposits in dolomitic and carbonatic rocks and present approach of ASTER data processing can be used to delineate phosphate rich zones occurring within similar geological provinces in any parts of the world.

Investigation of the leaching behavior of components of the magnesium potassium phosphate matrix after high salt radioactive waste immobilization

The samples of the magnesium potassium phosphate (MPP) matrix have been synthesized during solidification of the simulator of acid intermediate level waste. The main phase of the obtained samples corresponds to MgK1−x(NH4)xPO4 × 6H2O. The behavior of the matrix components during leaching with bidistilled water according to the semi-dynamic test GOST R 52126-2003 has been studied. The high hydrolytic stability of the MPP matrix to leaching of 137Cs, 90Sr, 239Pu and 241Am exceeding the stability of the cement matrix has been shown. It has been found that the components leaching process is controlled by various mechanisms due to the formation of the salts with different solubility.

Quality of commonly used fertilizers collected from different areas of Bangladesh

Total 54 fertilizer samples were randomly collected from the markets of four districts ofBangladeshto assess nutrient and heavy metal (Cd, Cr & Pb) contents in different fertilizers. The chemical analyses of fertilizers were conducted at the Department of Agricultural Chemistry,BangladeshAgriculturalUniversity, Mymensingh. Nutrient status of fertilizers was determined using the standard procedures and heavy metals in the fertilizer extract were analyzed using Atomic Absorption Spectrophotometer (AAS). Nitrogen (N) content in urea collected from different areas ranged from 41.37 to 46.27%. Biuret content of the collected urea samples varied from 1.40 to 2.80%, where the maximum allowable limit (MAL) is 1.50%. Among the six urea samples, biuret content exceeded the MAL in five samples. Phosphorous (P) content in most of the triple superphosphate (TSP) samples was higher than the specified amount. Out of eight samples, only two samples contained less than 20% P. Out of eight diammonium phosphate (DAP) samples, only three samples contained lower amount of P than the specified amount and five samples contained lower amount of N than the specified amount. Chromium content in all theDAPsamples were much higher than the MAL. Potassium (K) content in all five collected muriate of potash (MoP) samples were lower than the specified amount with an average of 45.81% K. The concentration of sulphur (S) in fertilizer samples in the investigated area varied from 16.50 to 21.60%. Out of six magnesium sulphate samples, five samples contained lower than the specified amount (9.5%) of Mg. The concentration of boron (B) in solubor samples varied from 13.55 to 19.56%, which are lower than the standard limit (20.90%). The concentration of zinc (Zn) in all the collected zinc sulphate heptahydrate samples had lower amount of Zn than the standard limit (23%). Only one out of six collected copper sulphate samples, met the specified limit of Cu (25.40%). Total 42 fertilizer samples (77.80%), out of 54, had less than the specified amount of nutrients. Heavy metals like Pb and Cr content exceeded the MAL in 67% and 47% of collected fertilizer samples, respectively. Cadmium content was below the detectable limit of flame in AAS in all the samples. In order to minimize the impact of fertilizer adulteration on food security and safety, continuous monitoring of fertilizer quality is required.J. Bangladesh Agril. Univ. 15(2): 219-225, December 2017

Novel multifunctional of magnesium ions (Mg++) incorporated calcium phosphate nanostructures

Magnesium ions incorporated calcium phosphate was synthesized by wet chemical route and followed by microwave assisted method. XRD analysis was confirmed that the presence of calcium phosphate (hydroxyapatite). TEM analysis was exhibited rod-like morphology. XRF results were showed the percentage of calcium, phosphate, magnesium and oxygen. There was a slight blue shift observed in magnesium ions based samples. Higher magnesium (0.1 Mg-HAp) was revealed the greater discharging time with capacitance voltage (0.55 V). Magnesium based calcium phosphate was showed prolonged rate of drug release. At higher frequency, the Nyquist plot was showed the electrochemical behavior, however at lower frequency, revealed mass transfer process. Magnesium ions tailor the specific capacitance of calcium phosphate. Therefore, magnesium ions based phosphate samples could be an outstanding multifunctional candidate for drug release and supercapacitor applications.

The structure of tributyl phosphate solutions: Nitric acid, uranium (VI), and zirconium (IV)

Diffusion, rheology, and small angle neutron scattering (SANS) data for organic phase 30 v/v % tributyl phosphate (TBP) samples containing varying amounts of water, nitric acid, and uranium or zirconium nitrate were interpreted from a colloidal perspective to give information on the types of structures formed by TBP under different conditions. Taken as a whole, the results of the different analyses were contradictory, suggesting that these samples should be treated as molecular solutions rather than colloids. This conclusion is supported by molecular dynamics (MD) simulations showing the existence of small, molecular aggregates in TBP samples containing water and nitric acid. Interpretation of TBP and nitric acid diffusion measurements from a molecular perspective suggest that nitric acid and metal species formed are consistent with the stoichiometric solvates that have traditionally been considered to exist in solution.