scholarly journals Nitrogen-phosphate Fertilizers Based on Activation of Phosphorite Powder with Partially Ammoniated Mix of Phosphoric and Sulphuric Acids

Author(s):  
A. A. Rasulov ◽  
Sh. S. Namazov ◽  
B. E. Sultonov

In this article obtaining complex nitrogen-phosphate fertilizers based on activation of phosphorite powder with partially ammoniated mix of phosphoric and sulphuric acids have been studied. In order to reduce the foaming of the process, for the first time a partially ammoniated mix of acids was used. The optimal technological parameters for activation phosphorite powder with partially neutralized mixes of sulphuric and phosphoric acids are the followings: the mix of sulphuric and phosphoric acids with a ratio of SО3:Р2О5 = 1.2; рН of acids – 2.5; weight ratio of ammonium sulphate-phosphate slurry towards phosphorite powder is 100 : 20; temperature is 60°С; duration is 30 min.  The composition nitrogen-phosphate fertilizers obtained in optimal condition contains (wt., %): N – 11.55; Р2О5total -24.61; Р2О5acceptable by citric acid -21.66; Р2О5 acceptable by EDTA -20.24; Р2О5water-soluble  -13.02; CaOtotal -13.59; СаОacceptable by citric acid -11.43. In that condition, granulated products of nitrogen-phosphate can be produced with high strength. The advantage of offered promising technology concludes in reduction two times expenditure of the most expensive ammonia in comparison with ammonium sulphate production and an increase in gross domestic product.

Author(s):  
Gulnoza Kodirova ◽  
Israiljon Shamshidinov ◽  
Boxodir Sultonov ◽  
Rikxsitilla Najmiddinov ◽  
Bakhodir Mamurov

Fluoride compounds have the most harmful effects on the environment. The main source of fluoride in the soil is phosphorus-containing fertilizers. Purification of wet-process phosphoric acid (WPPA) from fluorine will significantly reduce its content in phosphorous-containing fertilizers and improve the quality of the resulting products. The aim of the study is to reduce the content of fluorine and sulfates in the wet-process phosphoric acid by introducing calcium carbonate, dolomite or phosphorite into the finished extraction pulp before filtration and obtaining high-quality calcium and magnesium-containing phosphate fertilizers based on it. Phosphates were determined by differential photometric, fluorine – ionometric, calcium, magnesium, aluminum, and iron-complexometric, and sulfates-by weight methods. For the first time, scientifically-based data were obtained on the simultaneous reduction of the content of fluorine and sulfates in WPPA from phosphorites of Central Kyzylkum and the production of calcium-magnesium phosphate fertilizers based on it. Optimal technological parameters of the process of simultaneous defluorination and desulfatation of  WPPA from Central Kyzylkum phosphorites with calcium carbonate, dolomite and washed burnt phosphoconcentrate (WСPC) were found by introducing them into the second section of the extractor, into the finished extraction pulp in the amount of 100% for sulfate binding and 100-150% for fluorine binding, as well as obtaining high-quality products based on purified WPPA. The degree of transition of fluorine to the gas phase and phosphogypsum at a rate of 100-150% of calcium oxide for fluorine binding is 86.2-89.4% and its content in the wet-process phosphoric acid decreases from 1.18% to 0.22-0.29%. At the same time, the SO3 content in the acid decreases from 1.21% to 0.24-0.26%. The filtration rate of the sulfate-phosphate pulp varies slightly and is 807.6-812.6 kg/m2·h by dry residue.


Author(s):  
D.M. Vanderwalker

Aluminum-lithium alloys have a low density and high strength to weight ratio. They are being developed for the aerospace industry.The high strength of Al-Li can be attributed to precipitation hardening. Unfortunately when aged, Al-Li aquires a low ductility and fracture toughness. The precipitate in Al-Li is part of a sequence SSSS → Al3Li → AlLi A description of the phases may be found in reference 1 . This paper is primarily concerned with the Al3Li phase. The addition of Zr to Al-Li is being explored to find the optimum in properties. Zirconium improves fracture toughness and inhibits recrystallization. This study is a comparision between two Al-Li-Zr alloys differing in Zr concentration.Al-2.99Li-0.17Zr(alloy A) and Al-2.99Li-0.67Zr (alloy B) were solutionized for one hour at 500oc followed by a water quench. The specimens were then aged at 150°C for 16 or 40 hours. The foils were punched into 3mm discs. The specimens were electropolished with a 1/3 nitric acid 2/3 methanol solution. The transmission electron microscopy was conducted on the JEM 200CX microscope.


Alloy Digest ◽  
2012 ◽  
Vol 61 (5) ◽  

Abstract Tungum alloy combines an unusually high strength-to-weight ratio, with ductility, excellent corrosion resistance, and good fatigue properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming. Filing Code: Cu-806. Producer or source: Tungum Ltd.


Alloy Digest ◽  
1997 ◽  
Vol 46 (9) ◽  

Abstract Sandvik Ti-3Al-2.5V Grade 9 titanium-aluminum alloy offers excellent corrosion resistance, especially to chloride media, and has a high strength-to-weight ratio, which is especially suitable for use in aerospace applications. Tubing can be produced having a CSR (contractile strain ratio) that enhances the fatigue endurance limit. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength as well as fatigue. It also includes information on corrosion resistance as well as forming, machining, and joining. Filing Code: TI-109. Producer or source: Sandvik.


Alloy Digest ◽  
1954 ◽  
Vol 3 (8) ◽  

Abstract Donegal DC-50 is a precipitation hardening stainless steel having high strength-weight ratio. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: SS-17. Producer or source: Donegal Manufacturing Corporation.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1048
Author(s):  
Belén Díaz ◽  
X. Ramón Nóvoa ◽  
Carmen Pérez ◽  
Sheila Silva-Fernández

This research emphasizes the importance of the acid cleaning prior to the phosphate development on high-strength steel rods. It compares the phosphate properties achieved after different acid-pickling conditions. The most common inorganic acids were considered in this study. Additionally, taking into account the environmental and safety concerns of these acids, the assessment of a less harmful organic acid is presented. This study revealed significant differences in the coating morphology and chemical composition whereas no great changes were found in terms of the coating weight or porosity. Thus, hydrochloric and sulfuric acid promote the growth of a Fe-enriched phosphate layer with a less conductive character that is not developed after the pickling with phosphoric acid. The phosphate developed after the citric acid pickling is comparable to that developed after the inorganic acids although with a porosity slightly higher. The temperature of the citric acid bath is an important parameter that affects to the phosphate appearance, composition, and porosity.


2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110090
Author(s):  
Sudip Banerjee ◽  
Prasanta Sahoo ◽  
J Paulo Davim

Magnesium matrix nanocomposites (Mg-MNCs) are high grade materials widely used in aerospace, electronics, biomedical and automotive sectors for high strength to weight ratio, excellent sustainability and superior mechanical and tribological characteristics. Basic properties of Mg-MNCs rely on type and amount of reinforcement and fabrication process. Current study reviews existing literatures to explore contribution of different parameters on tribological properties of Mg-MNCs. Effects of particle size and amount of different reinforcements like SiC, WC, Al2O3, TiB2, CNT, graphene nano platelets (GNP), graphite on tribological behaviour are discussed. Incorporation of nanoparticles generally enhances properties. Role of different fabrication processes like stir casting (SC), ultrasonic treatment casting (UST), disintegrated melt deposition (DMD), friction stir processing (FSP) on wear and friction behaviour of Mg-MNCs is also reviewed. Contributions of different tribological process parameters (sliding speed, load and sliding distance) on wear, friction and wear mechanism are also examined.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1421
Author(s):  
Armin Yousefi ◽  
Saman Jolaiy ◽  
Reza Hedayati ◽  
Ahmad Serjouei ◽  
Mahdi Bodaghi

Bonded patches are widely used in several industry sectors for repairing damaged plates, cracks in metallic structures, and reinforcement of damaged structures. Composite patches have optimal properties such as high strength-to-weight ratio, easiness in being applied, and high flexibility. Due to recent rapid growth in the aerospace industry, analyses of adhesively bonded patches applicable to repairing cracked structures have become of great significance. In the present study, the fatigue behavior of the aluminum alloy, repaired by a double-sided glass/epoxy composite patch, is studied numerically. More specifically, the effect of applying a double-sided composite patch on the fatigue life improvement of a damaged aluminum 6061-T6 is analyzed. 3D finite element numerical modeling is performed to analyze the fatigue performance of both repaired and unrepaired aluminum plates using the Abaqus package. To determine the fatigue life of the aluminum 6061-T6 plate, first, the hysteresis loop is determined, and afterward, the plastic strain amplitude is calculated. Finally, by using the Coffin-Manson equation, fatigue life is predicted and validated against the available experimental data from the literature. Results reveal that composite patches increase the fatigue life of cracked structures significantly, ranging from 55% to 100% for different applied stresses.


2021 ◽  
pp. 089270572199789
Author(s):  
S Gohar ◽  
G Hussain ◽  
A Ali ◽  
H Ahmad

Honey Comb Sandwich Structures (HCSS) have numerous applications in aerospace, automobile, and satellite industry because of their properties like high strength to weight ratio, stiffness and impact strength. Fused Deposition Modeling (FDM) is a process which, through its flexibility, simple processing, short manufacturing time, competitive prices and freedom of design, has an ability to enhance the functionality of HCSS. This paper investigates the mechanical behavior (i.e. flexural, edgewise compression and Interfacial bond strength) of FDM-built HCSS. The influence of face/core material was examined by manufacturing four types of specimens namely ABS core with Composite (PLA + 15% carbon fibers) face sheets, ABS core with PLA face sheets, TPU core with composite face sheets and TPU core with PLA face sheets. To measure the effect of face sheets geometry, raster layup was varied at 0°/90° and 45°/−45°. The mechanical characterization revealed that an optimum combination of materials is ABS core with composite face sheets having raster layup of 0°/90°. This study indicates that HCSS with complex lamination schemes and adequate mechanical properties could be manufactured using FDM which may widen the applications of FDM on an industrial scale.


2020 ◽  
Vol 29 (1) ◽  
pp. 186-194
Author(s):  
V. Balaguru ◽  
Visvalingam Balasubramanian ◽  
P. Sivakumar

AbstractNowadays, ultra-high hard armor (UHA) steels are employed in armor tracked vehicle (ATV) construction because of their high hardness, high strength to weight ratio, and excellent toughness. UHA steels are usually welded using austenitic stainless steel (ASS) welding consumables, to avoid hydrogen-induced cracking (HIC). The use of ASS consumables to weld the above steel was the only available remedy because of higher solubility of hydrogen in the austenitic phase. In this investigation, an attempt was made to investigate the effect of ASS consumables (with different Creq/Nieq ratio) on solidification mode, impact toughness and microstructural characteristics of shielded metal arc (SMA) welded UHA steel joints. The welded joints were characterised based on impact toughness properties, hardness, and microstructural features. As the ferrite number increases with an increase in Creq/Nieq ratio result in different solidification mode (A, FA, F). It is also found that ferrite number of weld metal has appreciable influence on impact toughness and has inversely proportional relationship with impact toughness of the welded joints.


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