磷肥工业含氟废液钾盐转化法生产氢氟酸的研究

用氨中和磷肥工业产生的氟硅酸溶液得到氟化铵溶液 ,再将氟化铵溶液与氟化钾在一定的条件下反应得到氟化氢钾并挥发出氨 ,氟化氢钾的分解温度为 40 0℃ ,将其加热分解得氟化氢气体和氟化钾 ,氟化氢气体可生产氢氟酸 ,氟化钾和氨循环使用 ,同时副产二氧化硅 ,钾盐及产物闭路循环 ,整个处理过程无废物排放 ,处理成本低。

Structures and Thermodynamic Properties of HCOCl-HOCl Complexes

B3LYP/6-311＋＋G level were employed to obtain the optimized geometries and calculated frequency of HCOCl and HOCl complexes.Five stable isomers were obtained,and the one with ClO-H…O=C hydrogen bond was the most stable among five stable isomers,the BSSE and ZPE corrected interaction energy were of-11.92 kJ/mol.The formation of hydrogen bonds made the H―O stretching modes of complexes red-shifted relative to that of the monomer.At 298.15 K and standard state,the formations of stable complexes were an exothermic and non-spontaneous process.

Simultaneous Determination of Clonidine Hydrochloride,Hydrochlorothiazide, and Rutin in Zhenju Jiangya Tablet by Capillary Electrophoresis

Aim To develop a method for the determination of three drug components： clonidine hydrochloride, hydrochlorothiazide and rutin in Zhenju Jiangya tablet. Methods An uncoated capillary tube was used to analyze under 20 kV voltage at 20 ℃. The samples were introduced into the capillary tube by hydrodynamic mode applying 50 kPa for 5 s and detected at 210 nm. Results The linear ranges of clonidine hydrochlofide, hydrochlorothiazide, and rutin were 10 μg· mL^-1 - 100μg· mL^-1, 30μg· mL^-1 - 300 μg· mL^- 1, and 30μg · mL^-1 - 300μg · mL^-1, respectively. Inter-day and intra-day RSD were all below 10.5%. The recoveries were 94.96% for clonidine hydrochloride, 84.45% for hydroehlorothiazide, and 89.88 % for rutin. Conclusion Clonidine hydrochloride, hydrochlorothiazide, and rutin are baseline separated. The method is simple and rapid for simultaneous determination of the three drug components in Zhenju Jiangya tablet.

Potassium Fractions in Soils as Affected by Monocalcium Phosphate,Ammonium Sulfate,and Potassium Chloride Application

Soil potassium （K） deficiency has been increasing over recent decades as a result of higher inputs of N and P fertilizers concomitant with lower inputs of K fertilizers in China; however, the effects of interactions between N, P, and K of fertilizers on K status in soils have not been thoroughly investigated for optimizing N, P, and K fertilizer use efficiency. The influence of ammonium sulfate （AS）, monocMcium phosphate （MCP）, and potassium chloride application on K fractions in three typical soils of China was evaluated during 90-d laboratory soil incubation. The presence of AS significantly altered the distribution of native and added K in soils, while addition of MCP did not significantly affected K equilibrium in most cases. Addition of AS significantly increased water-soluble K （WSK）, decreased exchangeable K （EK） in almost all the soils except the paddy soil that contained considerable amounts of 2：1 type clay minerals with K added, retarded the formation of fixed K in the soils with K added, and suppressed the release of fixed K in the three soils without K added. These interactions might be expected to influence the K availability to plants when the soil was fertilized with AS. To improve K fertilizer use efficiency, whether combined application of AS and K was to be recommended or avoided should depend on K status of the soil, soil properties, and cropping systems.

Molybdenum removal from copper ore concentrate by sodium hypochlorite leaching

The removal of molybdenum from a copper ore concentrate by sodium hypochlorite leaching was investigated. The results show that leaching time,liquid to solid ratio,leaching temperature,agitation speed,and sodium hypochlorite and sodium hydroxide concentrations all have a significant effect on the removal of molybdenum.The optimum process operating parameters were found to be：time,4 h;sodium hydroxide concentration,10%;sodium hypochlorite concentration,8%;liquid to solid ratio,10：1;temperature,50℃;and, agitation speed,500 r/min.Under these conditions the extraction of molybdenum is greater than 99,9%and the extraction of copper is less than 0.01%.A shrinking particle model could be used to describe the leaching process.The apparent activation energy of the dissolution reaction was found to be approximately 8.8 kJ/mol.

Process Development and Design of Chlorine Dioxide Production Based on Hydrogen Peroxide

This paper presents a process development and design of chlorine dioxide production based on hydrogen peroxide. The process is characterized by cleaner production, high efficiency, and waste minimization. Optimization of process conditions, selection of equipment, and experiment of recycle of waste acid are carried out. The process design is realized in consideration of several aspects such as operation, material, equipment design and safety. An industrialized process flowsheet is developed according to experiment. A pilot testing is carried out to confirm the lab results. Process design of chlorine dioxide production based on hydrogen peroxide is realized.

Acid Release from an Acid Sulfate Soil Sample Under Successive Extractions with Different Extractants

An acid sulfate soil sample was successively extracted with deionized water, 1 mol L-1 KCl and 0.000 5 mol L-l Ca(OH)2 solutions. The results showed that only very small amounts of acidity were extracted by deionized water, possibly through slow jarosite hydrolysis. Acid release through jarosite hydrolysis was greatly enhanced by Ca(OH)2 extraction at the expense of the added OH- being neutralized by the acid released. Successive extraction of the sample with KCl removed the largest amounts of acidity from the sample. However, it is likely that the major form of acidity released by KCl extraction was exchangeable acidity. The results also show the occurrence of low or non charged Al and Fe species in water and Ca(OH)2 extracts after first a few extractions. It appears that such a phenomenon was related to a decreasing EC value with increasing number of extractions.

Kinetics of 2,4-dichlorophenol dechlorination by Pd-Fe bimetallic nanoparticles in the presence of humic acid

The remediation of groundwater which contains chlorinated organic compounds (COCs) by nanoscale bimetallic catalysts has received increasing interest in recent years. This report presents the dechlorination of 2,4-dichlorophenol (2,4-DCP) by Pd-Fe bimetallic nanoparticles in the presence of humic acid (HA) to investigate the feasibility of using Pd-Fe for the in situ remediation of contaminated groundwater. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Pd-Fe nanoparticles. The rate constant k values of 2,4-DCP dechlorination were 0.017, 0.013, 0.009, 0.006 and 0.004 min?1 for HA concentrations of 0, 5, 10, 15 and 20 mg/L, respectively. The relationship between HA dosage and k values can be described as a linear model.

Functional Polyethylene Glycol with Carboxyl-supported Platinum as an Efficient Catalysis System for the Hydrosilylation of Alkenes

A series of carboxylated long chain polyethylene glycols(abbreviated as PEGCOOH) has been synthesized and used to support chloroplatinic acid.These supported catalysts were then tested for their efficiency in the hydrosilylation of alkenes.The factors affecting their catalytic properties,e.g.relative molecular mass of polyethylene glycol,reaction temperature,platinum content,and type of alkenes,have been studied.It was found that the activity of the platinum catalyst decreased with increasing length of the polyethylene glycol chain,and increased with reaction temperature.Moreover,these catalysts could be reused several times without a noticeable decrease in activity or selectivity.The reaction pathway leading to excellent selectivity for the β-adduct of hydrosilylation of alkenes with triethoxysilane catalyzed by this catalysis system was discussed.

Closed Loop Recycling of Chlorine for Sustainable Development of Polyurethane Industry

Increasing demand is fueling the booming polyurethane industry worldwide. An impeding issue for poly- urethane industry is how to handle the large quantity of hydrogen chloride byproduct generated from the synthesis of intermediates, i.e., isocyanates. In the meantime, the traditional chloro-alkaline process sufibrs both from the high en- ergy intensity of electrolysis method and the disparity in the chlorine and caustic soda market. To solve these prob- lems, the state-of-the-art chlorine recycling technologies are reviewed and compared. Approaches for cost-effective utilization of chlorine in polyurethane industry are investigated. Chinese academies and enterprises＇ on-going effort on the development of a novel hydrogen chloride oxidation process for the synthesis of chlorine is presented. With this process, the closed loop recycling of chlorine can be realized. Tremendous economic, environmental and social bene- fits can be expected. A wide adoption of this technology will significantly advance the sustainable development of polyurethane industry.

Centrifugation-assisted preparation and thermostability of Form I clopidogrel hydrogen sulfate

Of all reported polymorphs of clopidogrel hydrogen sulfate, Form Ⅰ is difficult to produce and store owing to its poor thermostability. It is reported that Form Ⅰ can spontaneously transform into Form Ⅱ at high temperature and humidity. In this study, high purity Form I of clopidogrel hydrogen sulfate with good thermodynamic stability was prepared by a centrifugation-assisted recrystallization technology. The resultant product was characterized by powder X-ray diffraction （PXRD）, differential scanning calorimetry （DSC） and scanning electron microscope （SEM）. The results showed that the crystallinity and crystallite size of the Form Ⅰ prepared by the centrifugation-assisted recrystallization method were larger than those obtained by conventional anti-solvent recrystallization methods. Long-term thermostability testing demonstrated that the improved product can keep stable crystal structure even at high temperature and humidity.