The aim of this work was to describe the conversion of raw phosphogypsum, issued from the manufacture of H3PO4 by dissolving the phosphate rock in H2SO4, into (NH4)2SO4 and CaCO3.The thermal analysis technique was us...The aim of this work was to describe the conversion of raw phosphogypsum, issued from the manufacture of H3PO4 by dissolving the phosphate rock in H2SO4, into (NH4)2SO4 and CaCO3.The thermal analysis technique was used to estimate the yield of conversion. (NH4)2CO3 or (NH4)2CO3 with excess NH4OH or (NH4)2CO3 with NH3 gas were used in the preparation of (NH4)2SO4 from phosphogypsum. The obtained samples were separated and tested by chemical and thermogravimetric analyses, infrared spectrum and X-ray diffraction and the optimum conditions of conversion were determined. The results indicated that the yield of conversion equals to 83.37 and 86.70% in case of using (NH4)2CO3 or (NH4)2CO3 with excess ammoniarespectively, while by using NH3 gas the percentage of conversion increased to 94.2% at a flow rate of 6 ml/min. Chemical analysis, infrared spectrum and X-ray diffraction patterns of the yield, (NH4)2SO4 were nearly similar to the standard sample.展开更多
Supported γ-Al2O3 membranes without defects were prepared by the sol-gel procedure. The sol-gel method involved peptization of a boehmite (AlOOH) sol prepared from ammonium aluminium sulphate. The morphology of the s...Supported γ-Al2O3 membranes without defects were prepared by the sol-gel procedure. The sol-gel method involved peptization of a boehmite (AlOOH) sol prepared from ammonium aluminium sulphate. The morphology of the supported membranes was characterized by scanning electron microscopy (SEM) and 3D rotational microscopy. Furthermore, the effects of different preparing conditions on morphological characteristics of the membrane were also investigated. The results show that PVA is a good crack-preventing agent and the morphology of supported membranes is affected by many factors, such as Al2O3 and PVA contents of the sol, drying and sintering procedures and intrinsic defects on the substrate surface.展开更多
The dissolution kinetics of malachite was investigated in ammonia/ammonium sulphate solution. The effects of ammonia and ammonium sulphate concentration, pH, leaching time, reaction temperature, and particle size were...The dissolution kinetics of malachite was investigated in ammonia/ammonium sulphate solution. The effects of ammonia and ammonium sulphate concentration, pH, leaching time, reaction temperature, and particle size were determined. The results show that the optimum leaching conditions for malachite ore with a copper extraction more than 96.8% are ammonia/ammonium concentration 3.0 mol/L NHaOH ＋ 1.5 mol/L （NH4）2SO4, liquid-to-solid ratio 25：1 mL/g, leaching time 120 min, stirring speed 500 r/rain, reaction temperature 25 ℃ and particle size finer than 0.045 mm. The dissolution process of malachite with an activation energy of 26.75 k J/tool is controlled by the interface transfer and diffusion across the product layer. A semi-empirical rate equation is obtained to describe the leaching process and the reaction orders with respect to concentration of ammonia and ammonium sulphate are 2.983 0 and 0.941 1, respectively.展开更多
The acute toxic effects of ammonium sulphate to fresh-water catfish, Heteropneustes fossilis (H.fossilis) have been studied by determining LC50 values with 95% confidence limits, by the graphic method, the logistic me...The acute toxic effects of ammonium sulphate to fresh-water catfish, Heteropneustes fossilis (H.fossilis) have been studied by determining LC50 values with 95% confidence limits, by the graphic method, the logistic method, the Spearman and Karber method and the trimmed Spearman-Karber method. The trimmed Spearman-Karber method was found the most ideal for ammonium salt toxicity test. The flaws in the trimmed Spearman-Karber method are also discussed.展开更多
[Objective] To understand the application effects of urea ammonium chloride fertilizer on maize production. [Methods] A field plot experiment was conducted to study the effects of urea ammonium chloride of different f...[Objective] To understand the application effects of urea ammonium chloride fertilizer on maize production. [Methods] A field plot experiment was conducted to study the effects of urea ammonium chloride of different fertilization patterns on summer maize yield and yield components. [Results] Urea ammonium chloride had a long fertilizer effect and the same yield-increasing effect with urea, which could im- prove the agronomic traits and economic traits of maize apparently and the applica- tion of urea ammonium chloride with nutrient reduction of 40% （namely just use urea ammonium chloride equaled 60% pure nitrogen）, had the same yield-increasing effect with urea of traditional fertilization patterns, and input-output ratio was high and the economic benefit was remarkable. [Conclusion] To provide scientific theoretical direc- tion for large area popularization and application of urea ammonium chloride.展开更多
In this study, a new method of synthesis of polyethylene glycol supported potassium tribromide （PEG KBr3） and its application in acylation and bromination reactions are reported. Ammonium persulphate oxidizes I（Br ...In this study, a new method of synthesis of polyethylene glycol supported potassium tribromide （PEG KBr3） and its application in acylation and bromination reactions are reported. Ammonium persulphate oxidizes I（Br to the corresponding tribromide which is entrapped by polyethylene glycol leading to stable PEG KBr3. The reagent is proved to be highly efficient for the acylation of variety of alcohols and bromination of activated aromatic substrates. The method is a mild, one pot reaction and involves no use of toxic reagents.展开更多
文摘The aim of this work was to describe the conversion of raw phosphogypsum, issued from the manufacture of H3PO4 by dissolving the phosphate rock in H2SO4, into (NH4)2SO4 and CaCO3.The thermal analysis technique was used to estimate the yield of conversion. (NH4)2CO3 or (NH4)2CO3 with excess NH4OH or (NH4)2CO3 with NH3 gas were used in the preparation of (NH4)2SO4 from phosphogypsum. The obtained samples were separated and tested by chemical and thermogravimetric analyses, infrared spectrum and X-ray diffraction and the optimum conditions of conversion were determined. The results indicated that the yield of conversion equals to 83.37 and 86.70% in case of using (NH4)2CO3 or (NH4)2CO3 with excess ammoniarespectively, while by using NH3 gas the percentage of conversion increased to 94.2% at a flow rate of 6 ml/min. Chemical analysis, infrared spectrum and X-ray diffraction patterns of the yield, (NH4)2SO4 were nearly similar to the standard sample.
基金the National Natural Science Foundation of China (NSFC 20503015)
文摘Supported γ-Al2O3 membranes without defects were prepared by the sol-gel procedure. The sol-gel method involved peptization of a boehmite (AlOOH) sol prepared from ammonium aluminium sulphate. The morphology of the supported membranes was characterized by scanning electron microscopy (SEM) and 3D rotational microscopy. Furthermore, the effects of different preparing conditions on morphological characteristics of the membrane were also investigated. The results show that PVA is a good crack-preventing agent and the morphology of supported membranes is affected by many factors, such as Al2O3 and PVA contents of the sol, drying and sintering procedures and intrinsic defects on the substrate surface.
基金Project(2007CB613601) supported by the National Basic Research Program of ChinaProject(10C1095) supported by the Foundation of Hunan Educational Committee,China
文摘The dissolution kinetics of malachite was investigated in ammonia/ammonium sulphate solution. The effects of ammonia and ammonium sulphate concentration, pH, leaching time, reaction temperature, and particle size were determined. The results show that the optimum leaching conditions for malachite ore with a copper extraction more than 96.8% are ammonia/ammonium concentration 3.0 mol/L NHaOH ＋ 1.5 mol/L （NH4）2SO4, liquid-to-solid ratio 25：1 mL/g, leaching time 120 min, stirring speed 500 r/rain, reaction temperature 25 ℃ and particle size finer than 0.045 mm. The dissolution process of malachite with an activation energy of 26.75 k J/tool is controlled by the interface transfer and diffusion across the product layer. A semi-empirical rate equation is obtained to describe the leaching process and the reaction orders with respect to concentration of ammonia and ammonium sulphate are 2.983 0 and 0.941 1, respectively.
文摘The acute toxic effects of ammonium sulphate to fresh-water catfish, Heteropneustes fossilis (H.fossilis) have been studied by determining LC50 values with 95% confidence limits, by the graphic method, the logistic method, the Spearman and Karber method and the trimmed Spearman-Karber method. The trimmed Spearman-Karber method was found the most ideal for ammonium salt toxicity test. The flaws in the trimmed Spearman-Karber method are also discussed.
基金Supported by Construction Project of Maize Industry Technology System of Modern Agriculture in Yunnan Province(Yunnong(ke)2009-53Yunnongcai(2009-171))~~
文摘[Objective] To understand the application effects of urea ammonium chloride fertilizer on maize production. [Methods] A field plot experiment was conducted to study the effects of urea ammonium chloride of different fertilization patterns on summer maize yield and yield components. [Results] Urea ammonium chloride had a long fertilizer effect and the same yield-increasing effect with urea, which could im- prove the agronomic traits and economic traits of maize apparently and the applica- tion of urea ammonium chloride with nutrient reduction of 40% （namely just use urea ammonium chloride equaled 60% pure nitrogen）, had the same yield-increasing effect with urea of traditional fertilization patterns, and input-output ratio was high and the economic benefit was remarkable. [Conclusion] To provide scientific theoretical direc- tion for large area popularization and application of urea ammonium chloride.
基金the Department of Science and Technology,DST,New Delhi,India,for fnancial assistance received through a SERC fast track project(No.SR/FTP/CS-100/2007)
文摘In this study, a new method of synthesis of polyethylene glycol supported potassium tribromide （PEG KBr3） and its application in acylation and bromination reactions are reported. Ammonium persulphate oxidizes I（Br to the corresponding tribromide which is entrapped by polyethylene glycol leading to stable PEG KBr3. The reagent is proved to be highly efficient for the acylation of variety of alcohols and bromination of activated aromatic substrates. The method is a mild, one pot reaction and involves no use of toxic reagents.
