Phosphate Fertilizer Plant Research Articles

Responses of Bambara groundnut [Vigna subterranea (L.) Verdc.] to Phosphate Fertilizer Rates and Plant Spacing and Effects on Soil Nutrient Statues in a Degraded Tropical Ultisol Agbani Enugu South East Nigeria

Responses of Bambara groundnut [Vigna subterranea (L.) Verdc.] to Phosphate Fertilizer Rates and Plant Spacing and Effects on Soil Nutrient Statues in a Degraded Tropical Ultisol Agbani Enugu South East Nigeria

Study of process mineralogy for hydrometallurgical extraction of vanadium and aluminum from bone coal

A process mineralogy study was conducted to guide the development of a process for the extraction of vanadic oxide (V2O5) and aluminum compounds from bone coal and its ash as well as the production of byproducts. Results show that to extract the targeted metals at higher recovery rates, one must find a suitable agent capable of destroying the structure of the mica and breaking down the lattices in which these metal-bearing minerals occur. For such minerals, metal extraction efficiency is usually low if the approach is simply adding an oxidant that cannot destroy the structure. In this research, a byproduct fluosilicic acid (H2SiF6 at 20 percent concentration from an operating phosphate fertilizer plant was found to be powerful and effective for the leaching of vanadium-bearing minerals such as mica. This environmentally friendly process improved the teachability of valuable constituents in the bone coal significantly, with the leaching rate of V2O5 increased to 94 percent, from 83 percent, and that of aluminum oxide (Al2O3) increased to 75 percent, from 40 percent. X-ray diffraction and chemical analyses showed that the structure of mica can be destroyed using fluosilicic acid either alone or in combination with sulfuric acid. Based on the process mineralogy study, a processingflowsheet was tested, which resulted in a final V2O5powder product with purity of 99.2 percent and an overall recovery rate of higher than 85 percent. The flowsheet consists of leaching, ion exchange and ammonium precipitation. With this process, various byproducts could also be generated, including aluminum fluoride, cryolite, aluminum sulfate, calcium sulfate, ammonium chloride, sodium chloride and cement admixtures.

Impact of a phosphate fertilizer plant on the contamination of marine biota by heavy elements.

Due to their toxicity, persistence, and bioaccumulation, metals are important marine environment pollutants, especially in low renewal rate water such as the Mediterranean Sea, receiving a lot of untreated industrial waste. The impact of a phosphate fertilizer plant on the marine biota metal contamination was studied. Several types of organisms: crabs, mussels, patella and fish were collected from two areas of the Lebanese coast, one subjected to the impact of the plant and another away from it; samples were analyzed for Zn, U, Cr, V, Mn, Ni, Co, Cu, As, Cd and Pb by ICP-MS. Higher accumulation was in crabs, patella, and mussels. Fish accumulated principally Zn, Cu, and Cd; a difference was observed between species and tissues. Cytosol metal fractionation using size-exclusion LC-ICP-MS showed principally Pb, As, Co, and Mn in the low molecular weight fraction (<1.8 Da); Cd, Zn, and Cu in the metallothionein fraction (1.8--18 k Da), and Ni in high molecular weight fraction (>20 kDa).

Assessment of committed effective dose due to the ingestion of 210Po and 210Pb in consumed Lebanese fish affected by a phosphate fertilizer plant

Ingestion of radionuclides through seafood intake is a one of the sources contributing to the internal effective dose in the human organism. In order to evaluate the internal exposure and potential risks due to 210Po and 210Pb associated with fish consumption, these radionuclides were measured in commonly consumed fish species from a clean area and an area subjected to the impact of a Lebanese phosphate fertilizer plant. The highest concentration of 210Pb was 98.7 Bq/kg fresh weight while 210Po activity concentrations varied from 3.6 Bq/kg to 140 Bq/kg. A supplementary radiation exposure was detected; the highest committed effective dose due to 210Po and 210Pb was found to be 1110 μSv/y and 450 μSv/y, respectively. Moreover, the average mortality and morbidity risks due to the fish consuming were estimated.

Impacts of hazardous air pollutants emitted from phosphate fertilizer production plants on their ambient concentration levels in the Tampa Bay area

The concentrations and distribution of hazardous air pollutants (HAPs) metals emitted from four phosphate fertilizer plants in Central Florida, as well as their environmental and health impacts, were investigated. It was hypothesized that the modern control devices employed in the plants would lower the exposure, if any, to an acceptable level. The dominant HAP metals emitted from the stacks of these plants were identified to be Mn, Cr, Ni, and Se. The ambient concentrations at six receptors (Zephyrhills, Plant City, Tampa, Lakeland, Tower Dairy, and Sydney) downwind the plants estimated by AERMOD revealed the maximum ground level concentrations were lower than the European Communities and USEPA standards. Source apportionment estimated by the chemical mass balance (CMB) model indicated that marine (45.5 ± 17.1 %) and geological (17.3 ± 10.6 %) were the top two contributors for 26 elements, while the phosphate fertilizer plants contributed only 1.14 ± 0.55 %. Unexpectedly, the maximum ground-level risks for Cr from plant A (1.3 × 10−6 ± 8.4 × 10−8) and plant D (1.1 × 10−6 ± 6.7 × 10−8) were slightly higher than the general guideline of 1 × 10−6, but they occurred within the facility limit. No other metals approached levels of concern for non-cancer risks. One possible source for Cr emissions from these plants may be stainless steel milling balls used in the production process. Sensitivity analysis of the meteorological data in 2001–2005 showed only 7.7 % variation in the corresponding risk. Overall, phosphate fertilizer plants make minor contribution to the ambient levels of HAP metals compared to other sources for the general population in the Tampa Bay area, although more in-depth investigation into the Cr emissions is recommended.

External gamma radiation levels and natural radioactivity in soil around a phosphate fertilizer plant at Mumbai

Fertilizers containing phosphate have been used worldwide in increasing quantities in order to replenish natural nutrients, which are being continuously depleted from the soil by virtue of farming activities. Phosphate rocks together with potassium ores and nitrogenous compounds are the main raw materials used for industrial fertilizer production. Rock phosphate ore processing and disposal of phosphogypsum contribute to enhanced levels of natural radionuclides in the environment. The levels of naturally occurring radionuclides such as 238U, 232Th, 226Ra and 40K in soil samples collected around a phosphate fertilizer plant were estimated. Radium equivalent activity, external hazard index and external dose rate due to natural gamma background at various locations around the plant were also measured.

Natural radioactivity assessment of a phosphate fertilizer plant area

Rock phosphate ore processing and disposal of phosphogypsum contribute to enhanced levels of natural radionuclides in the environment. The concentration of naturally occurring radionuclides in soil, rock phosphate and phosphogypsum samples collected around a phosphate fertilizer plant were determined. Also the external background gamma levels were surveyed.238U, 232Th, 226Ra and 40K activities in soil samples were 21–674Bq/kg, 11–44Bq/kg, 22–683Bq/kg and 51–295Bq/kg respectively. The external background gamma radiation levels in the plant premises were ranging from 48 to 133 nGy/h.

FERTILIZERS PotashCorp to lay off more than 1,000 workers amid global price declines

Potash Corp. of Saskatchewan, a leading producer of potassium, phosphate, and nitrogen fertilizers, says it will reduce its workforce by 18%, or approximately 1,045 employees. The firm is taking the action because of lower-than-anticipated fertilizer demand from the developing world. The market’s softness is a change from 2012, when high prices for agricultural commodities boosted prices and earnings at fertilizer companies. More than half of PotashCorp’s employee cuts will come from operations in Saskatchewan and New Brunswick, where the company plans to reduce production of potash, a mined salt that is largely potassium chloride. Other layoffs will affect workers at phosphate and nitrogen fertilizer plants in Florida, North Carolina, and Trinidad. Prices for potash have dropped by almost 23% compared with a year ago, according to a recent report from NPK Fertilizer Advisory Service. Analysts say the breakup in July of Belarus Potash Co., a cartel of producers in Belarus ...

Determination of uranium concentration in urine of workers in an Iraqi phosphate mine and fertilizer plants

Precise determination of uranium concentration in human urine is quite important in assessment of occupational and public exposure to uranium. In the present work, a pulsed dye nitrogen laser-induced kinetic phosphorescence analysis (KPA) was used to determine uranium in urine of Iraqi phosphate mine and fertilizer plant workers and in the population living near the mining region. A total of 92 urine samples were collected from workers of the Akashat phosphate mine, the Al-Qaim fertilizer complex, and the Akashat residential region. Uranium concentration in urine of all samples ranged between 0.49 to 5.26 μg L−1 with a total average of 1.47 ± 0.01 μg L−1. For comparison, all samples were also analyzed using a completely different technique; the nuclear fission track analysis using CR-39 SSNTD. Both techniques were capable of such measurements, although not with an equal degree of uncertainty. KPA technique is found to be more suitable for analysis of urine samples having high concentrations of uranium.

In Situ Arsenic Remediation Complicated by Carbonate

Remediation of dissolved arsenic (As) in groundwater at levels as high as 38mg/L with pH values close to 1 and Fe and Al concentration of thousands of mg/L was attempted at a former phosphate fertilizer plant. Adsorption of As onto naturally occurring ferrihydrite was considered to be the dominant process that would reduce dissolved arsenic concentrations. Remediation was not completely effective because bicarbonate released from CaCO3 used as the neutralizing agent competed with As for adsorption sites on ferrihydrite. Dissolved carbonate concentration was higher than normal because CO2 gas was trapped in the groundwater. Field tests of the effectiveness of groundwater aeration showed that removing excess CO2 from the aquifer and reducing bicarbonate concentration has the potential to reduce dissolved As to the required level.

A Study of Heavy Metals in the Dust Fall around Assiut Fertilizer Plant

A study of an environmental assessment of dust fall and the associated heavy metal contents was conducted during the period from the first of March 2011 to the end of February 2012 at adjoining area of a phosphate fertilizer plant. Around the industrial area 8 dust fall stations were established and one of them was built upwind far from pollution activities to be taken as a control sample. Dust fall samples collected monthly weighed and then prepared to be analyzed through Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS) to obtain heavy metal concentration. Meteorological parameters influencing the distribution of dust fall such as wind speed and direction, temperature, humidity, rain fall and pressure were determined. Results showed that deposition flow rates were 38.2. 47.5, 57.7, 44.3, 39.4, 38.2, 42.7 and 5.9 g/m2·month for the sites No., 1, 2, 3, 4, 5, 6, 7 and 8 respectively, and were compared with the findings of other investigators of like industrial areas worldwide. Levels of heavy metal As, Cu, Pb, Zn, Cd, and Hg in the deposited dust fall were 3.30, 26.46, 22.33, 235.00, 4.53 and 3.80 μg/g respectively. Enrichment coefficients of the heavy metals in the dust fall were found to be significant and reached the values 1.81, 0.90, 0.85, 0.65, 0.41 and 0.35 for zinc, lead, cadmium, copper, mercury and arsenic respectively. The paper ends with results and recommendations suggesting a methodology to remediate the investigated area polluted with heavy metals and control measures for the fertilizer plant to reduce pollution into the surrounding environment.

Assessment of Natural Radioactivity in Phosphate Ore, Phosphogypsum and Soil Samples Around a Phosphate Fertilizer Plant in Nigeria

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 (238)U, (232)Th, and (40)K radionuclides in phosphate ore samples were 616 ± 38.6, BDL (Below Detection Level) and 323.7 ± 57.5 Bq kg(-1) respectively. For the phosphogypsum, 334.8 ± 8.8, 4.0 ± 1.4, and 199.9 ± 9.3 Bq kg(-1) respectively and for soil samples range from 20.5 ± 7.3 to 175.7 ± 10.5 Bq kg(-1) for (226)Ra, 15.5 ± 1.5 to 50.4 ± 0.6 Bq kg(-1) for (232)Th and 89.5 ± 8.1 to 316.1 ± 41.3 Bq kg(-1) for (40)K respectively. The mean absorbed dose rate was 71.4 nGy h(-1). The mean annual effective dose was 86 μSv.

Natural radioactivity in cultivated land in the vicinity of a phosphate fertilizer plant in Nigeria

Natural radioactivity in soil and vegetable samples in cultivated land in the vicinity of an active phosphate fertilizer plant in Kaduna, Nigeria was carried out to assess the potential radiological impact of the plant on its immediate environment. The activity counting was carried out using sodium iodide gamma spectrometry. The annual committed effective dose for two vegetables in the farmlands due to uranium (238U) and thorium (232Th) was assessed. The mean activity concentration of radionuclides in the soil samples ranges from 20.5±7.3 to 31.6±4.1Bqkg−1 for 226Ra, 19.6±1.6 to 53.2±3.7Bqkg−1 for 232Th and 203.9±6.3 to 253.6±9.5Bqkg−1 for 40K. The annual intake of 238U and 232Th from consumption of okra were 1.9Bqkg−1 and 5.22Bqkg−1 and for tomatoes 2.66Bqkg−1 and 5.1Bqkg−1 respectively. The committed effective doses from consumption of okra and tomatoes were 0.1μSvy−1 and 0.12μSvy−1 respectively.

INFLUENCE OF DIFFERENT FEED PHOSPHATE ON MECHANICAL PROPERTIES OF SWINE BONE TISSUE

The function of the highly complex structure such as the human skeletal system is possible by the appropriate construction and properties of bone tissue. Bone tissue, due to its design, is a material that continuously adapts its mechanical properties and structural response to the smallest change in load condition. Bone should be viewed as a twophase composite material, consisting of a collagen matrix with low elasticity and HA crystals with high elasticity modulus. The main mineral components of these crystals are Ca and P. The degree of digestibility of P compounds is affected by many factors, which include, type of feed, breed and species of animals, amount of vitamins and probiotics, and the ratio of Ca vs. P. The primary feed used in swine feeding is grain, which is also the main source of P that has in the form of phytate. This form of phosphorus is very difficult absorb as molecules of phytic. Consequently, in neutral pH phytate forms sparingly soluble complexes with amino acids, sugars and divalent metal cations, thus reducing its absorption. Amount of P supplied with the feed, even when supplemented by microbial phytase, does not cover the requirements of extensively growing pigs. The most frequently commercial products which are intended to supplement deficiencies are 1, 2 and 3-calcium, calcium-sodium, sodium-calcium-magnesium. Studies in literature (Jongbloed, 2000) present that the best results in swine nutrition is obtained when one or disodium phosphate is used. The main goal of this study was to determine the mechanical properties and elemental content of bone tissue derived from pigs fed with forage with different amounts of Ca and P. In addition, the study was to determine the fodder value of the new dicalcium phosphate feed (n-DCP) produced by the Gda sk Phosphate Fertilizer Plants' Fosfory Ltd. according to patent No. P-369805, when compared to monocalcium phosphate, calcium and sodium.

Effect of planting date and phosphorus fertilizer on growth and yield of green pods on pea plant Pisum sativum L.

Research carried out in the Technical Institute / Mosul , during autumn season 2007 and 2008 to study the effect of three sowing date 15/ 10 , 30/10 , 14/11, and three levels of phosphate fertilizer 10, 20, 30 kg P2O5 / donum addition to the treatment comparison (without fertilization) in the vegetative growth and yield of green pods of peas variety Mammoth Melting Sugar and experience in the factorial design sectors as random , full data has been recorded : plant height, number of branches, mild and dry weight of shoot , number of days to lighten 50% of flowers , number of pods / plant, length of pod, number of seeds in the pod, yield per plant, and the total yield per unit area. The results indicated that early sowing date 15/10 led to a significant increase of all the qualities compared with the late date 14/11 except number of seeds per pod, resulting in added phosphate fertilizer 30 kg P2O5 to increase significant in all the studied traits compared with the treatment comparison. The effect of interference results indicated that early sowing date 15/10 and adding phosphate fertilizer level at 30 kg P2O5 resulted in a significant increase of all studied traits, and by 67.5%, 45.5%, compared with the delayed sowing date and without phosphate fertilizer plant holds the two strands of one sum up the total unit area respectively .

Electrodeposition of Silicon from Fluorosilicic Acid Produced in Iraqi Phosphate Fertilizer Plant

The availability, low toxicity, and high degree of technological development make silicon the most likely material to be used in solar cells, the cost of solar cells depends entirely on cost of high purity silicon production. The present work was conducted to electrodeposite of silicon from K2SiF6, an inexpensive raw material prepared from fluorosilicic acid (H2SiF6) produced in Iraqi Fertilizer plants, and using inexpensive graphite material as cathode electrode. The preparation of potassium fluorosilicate was performed at (60 o C) in a three necks flask provided with a stirrer ,while the electro deposition was performed at 750 o C in a three-electrodes configuration with melt containing in graphite pot. High purity potassium fluorosilicate (99.25%) was obtained at temperature (60 o C), molar ratio-KCl/H2SiF6(1.4) and agitation (600 rpm). Spongy compact deposits were obtained for silicon with purity not less than (99.97%) at cathode potential (�0.8 V vs. Pt), K2SiF6 concentration (14% mole percent) with grain size (130 µm) and level of impurities (Cu, Fe and Ni) less than (0.02%).

Electrodeposition of Silicon from Fluorosilicic Acid Produced in Iraqi Phosphate Fertilizer Plant

Electrodeposition of Silicon from Fluorosilicic Acid Produced in Iraqi Phosphate Fertilizer Plant

Radioactivity and fluoride contamination derived from a phosphate fertilizer plant in Egypt

The environmental pollution caused by the wastewater from a phosphate fertilizer plant in Egypt was investigated. The concentrations of radionuclides and fluoride in phosphate fertilizer (raw materials, end products and by-products) and other types of fertilizer samples were measured. The concentrations of these elements were also measured in environmental samples (water, sediment and plant) collected from the proximity of outlet of wastewater discharge pipes of the phosphate fertilizer company. The fluoride concentration was ranged from 0.03 to 0.25 mg/g, 0.002 to 0.006 mg/g, 0.42 to 1.88 mg/g and 0.44 to 7.3 mg/l for phosphate fertilizer, other types of fertilizer, sediment and water samples, respectively. The activity concentrations of 226Ra were ranged from 244 to 1312 Bq/kg, 0.6 to 12.1 Bq/kg, 15.4 to 33.8 Bq/kg, 0.06 to 1.3 Bq/l and 8.9 to 17.3 Bq/kg for phosphate fertilizer, other types of fertilizer, sediment, water and plant samples, respectively. The 232Th activity concentrations were ranged from 0.7 to 24 Bq/kg, 0.7 to 14.5 Bq/kg, 10.4 to 19.3 Bq/kg, 0.02 to 0.16 Bq/l and 2.0 to 29.8 Bq/kg for these samples, respectively. Also, the 40K activity concentrations were ranged from 2.1 to 1.4 Bq/kg, 2.1 to 5313 Bq/kg, 128 to 281 Bq/kg, 0.14 to 0.6 Bq/l and 686 to 977 Bq/kg for these samples, respectively. Low content of 137Cs was determined in only two phosphate fertilizer samples (F2 and F3; mean 1.3 Bq/kg) and in most of sediment samples (with range 1.0–2.4 Bq/kg). The radium equivalent, as a radiation hazard index, was ranged from 284 to 1316, 9.6 to 432 and 47 to 70 Bq/kg for phosphate fertilizer, other types of fertilizer and sediment samples, respectively. The results indicated that the wastewater polluted with fluoride produced from the phosphate fertilizer company may be affecting the environment. The radioactivity content measurements indicated that the environment may be slightly affected with low concentrations of 226Ra and 232Th isotopes due to the discharged wastewater from the phosphate fertilizer industry. On the other hand, the results of comparison studies for radioactivity concentrations are also presented and discussed.

Minimization of Artifacts in Sulfuric Acid Mist Measurement Using NIOSH Method 7903

NIOSH Method 7903 employs a silica gel tube for sulfuric acid mist measurement in workplaces. However, SO2 gas present in the sample volume can be transformed into sulfate in the sampling process causing an artifact that is reported as sulfuric acid. A sampling train incorporating a honeycomb denuder system was applied for field sampling at seven phosphate fertilizer plants to evaluate its use for reducing the artifact sulfate concentration while preserving the actual sulfuric acid mist concentration. The denuder system was designed to remove SO2 gas before the air entered the silica gel tube and to monitor SO2 concentration at the same time. A deactivation model was also applied to correct for the presence of the artifact. The denuder system had 95.7 +/- 6.8% collection efficiency for SO2 gas, and the impact of sulfate aerosol on SO2 collection was negligible. SO2 concentrations at the seven plants ranged from 34 ppb to 5.6 ppm. The honeycomb denuder system and the deactivation model were shown to reduce the artifact sulfate concentration by 70% and 39%, respectively. However, they were still higher than the sulfate aerosol concentration measured by a cascade impactor. One possible reason is the residual sulfate in the glass fiber filter and the silica gel.

An assessment of the chemical composition of precipitation and throughfall in rural-industrial gradient in wet subtropics (southern Brazil)

The chemical composition of bulk precipitation and throughfall were analyzed, during a 1-year period (2002), in rural-urban-industry gradients with similar forest cover (Eucalyptus spp.) in southern Brazil (Rio Grande and Porto Alegre cities). Values of pH varied from 5.0-5.1 in rural to 5.4-6.1 in industrial sites, and were intermediate in urban sites. The major ions in bulk precipitation were Na+, Cl-, NH+(4), NO-(3), and PO(3-)(4), and concentrations increased in urban and industrial sites. Principal component analysis identified the local main anthropogenic sources. Estimated annual amounts of dry deposition were generally greater in both industrial and urban sites than in rural sites. Areas close to industrial activity showed greater S and N total deposition (10.4-10.9 and 20.2-30.6 kg/ha, respectively) than in urban (3.4-7.3 and 14.6-24.1 kg/ha) and in rural (1.7-2.6 and 8.9-12.1 kg/ha) sites. Annual deposition of Ca and P varied from 0.6 and 3.0 kg/ha in rural to 45.4 and 32.4 kg/ha in industrial sites, maximum values being observed closed to the phosphate fertilizer plant of Rio Grande. Deposition in urban and industrial sites may be balanced by the alkaline cations, as bulk precipitation pH varied from 5.4 to 6.1, and was greater than in rural sites (5.0-5.1).