Papers by Keyword: Flux

Abstract: Mg especially in the molten state is well known for its high affinity to O₂. When O₂ content of the atmosphere is larger than 4%, molten Mg will burn! To avoid this, melt protection is necessary. At present mostly SF₆ is used during primary production and processing of Mg and its alloys. Unfortunately SF₆ is a very potent greenhouse gas that is > 23,000 times more effective than CO₂. This also affects life cycle considerations e.g. for the use of Mg alloys in transportation. However, other protective gases like SO₂ or fluorinated hydrocarbons like HFC134a, Novec 612, or AMCover (=HFC134a) have been suggested to replace SF₆. Additionally fluxes mixed from different salts may be used again as well to protect molten Mg. But fluxes and feasible replacements of SF₆ have also disadvantages. Moreover SF₆ and other fluorinated hydrocarbons are under discussion especially in Europe. There is an existing EU legislation that will ban SF₆ from 2018 and there are similar discussions regarding all other fluorinated hydrocarbons. Due to this, new innovative ways have to be found or old methods have to be renewed to allow Mg industries further safe processing of molten magnesium. This contribution will report the state of the art in protecting molten Mg and alternatives to the use of SF₆.

Abstract: This study used coagulation - ultrafiltration technology for domestic sewage treatment, which was used widely in water supply and secondary treatment with sewage, in order to achieve high efficiency, low-cost, integrated treatment of domestic sewage treatment. This article chooses fly ash coagulant is not only simple preparation process, low cost, and with the traditional aluminum chloride and ferric chloride coagulation effect. The research results show that the coagulation can make the organic particles size distribution to move to larger particles area and significantly reduce colloidal substance. Ultrafiltration membrane system can further remove the coagulation treatment failed to completely remove polymer and part in the process of low molecular substances, to achieve high organic matter removal efficiency. The backwash of ultrafiltration membrane can make membrane flux recovery by about 80%. This system of SS can remove more than 95%, COD removal rate can reach 60% ~ 70%.

Abstract: The main objective of this study was to investigate membrane fouling caused by natural organic matter (NOM). Flux measurement, fourier transform spectroscopy (FTIR), scanning electron microscopy (SEM) were employed to compare the surface morphology of fouled membrane and chemically cleaned membrane. Sodium hypochlorite (NaClO), sodium hydroxide (NaOH), hydrochloric acid (HCl) were used as chemical cleaning agents respectively. Flux analysis demonstrated that chemical cleaning have little effect on flux recovery. FTIR spectrometry revealed that polysaccharide and protein took the major responsibility for membrane fouling. SEM showed that foulants filled the pores and blocked the membrane surface which led to the flux decline.

Abstract: A different production method including a formulated flux has been devised to hot-dip Q235 Galfan alloy coating on structural steel. The microstructure and composition of the Galfan coatings, applied by the hot dip process, was performed using SEM and EDS technology to evaluate the coating thickness and its relationship with technological parameters. The experimental results showed that the coating of specimen has eutectic crystal shape and its thickness is thinner than Zinc coatings’ scale. Moreover, the Galfan plating does not grow with the extension of time for immersion. The temperature of immersion and the extraction speed will affect the coating thickness too.

Abstract: Use calcium carbonate, sodium carbonate and barium carbonate as blowing agent, polyethylene glycol as binder,Cr₂O₃ as nucleating agent,TiO₂ as nucleating agent,CaF₂ as a flux in glass powder, we can produce porous glass-ceramics, and after above research, the apparent density, powder density, porosity, the main phase, microscopic characteristics and thermal performance of the samples would be test. The results show that: considering the physical and mechanical performance of porous glass-ceramics, the froth effect of sodium carbonate is most ideal. When the dosage is 6%, the apparent density is minimum, the porosity is maximum and the thermal conductivity is maximum and the main phase is wollastonite.

Abstract: Based on meteorological field output by MM5 mesoscale meteorological model and concentration field output by CALPUFF air quality model, “flux method” was applied to study effects of long-range transport of air pollutants on the atmospheric environment, in which micro-element method was used to solve the process of air pollutants transport in long-range of three-dimensional space. This method was first applied in studying a construction project’s impact on air quality in Guanzhong region of Shanxi Province. The results shows that the deviation of flux method is less which the value is 16 percent, and among all year around, the pollutants transport the more flux to the ENE and WSW directions of the project compared to other directions. Additional, the flux of fall and winter is more than it of spring and summer, and the project has a more severe influence of atmospheric environment in Xi’an city than it of Weinan city.

Abstract: To treat coking wastewater with A²O-MBR hybrid process, membrane pollution control has become an important factor affecting the long-term stable operation of the system. The experiment reported in this paper focused on the membrane fouling of this hybrid system and try to evaluate the effects of aeration intensity and flux on the membrane fouling. The results show that the optimal parameters of membrane module operation are: aeration 0.2 m3/h, membrane flux 11.5 L/(m²·h), and with the maintenance of cleaning measures the membrane module can be kept under long-term stable operation.

Abstract: Our objective was to make transparent glaze using oak ash which has a high content of CaO and contains P₂O₅. However, the melting point of oak ash is above 1340^°C, making it difficult to make transparent glaze using only oak ash. In order to lower the melting point of oak ash, flux materials were mixed to oak ash and melting characterization was carried out. Feldspar, which is largely composed of Na₂O and K₂O andlimestone largely composed of CaO were used as the flux materials. The materials were added 10, 20 and 30wt%, respectively, in order to produce the glaze. Depending on the type and amount of flux materials added, the samples were fired at temperatures between 1280~1320^°C in the reducing atmosphere. As the amount of feldspar added was increased, the melting point decreased substantially. Samples with limestone added did not melt completely even at temperatures 1300^°C and wollastonite phase was observed in the glaze layer.

Abstract: For lack of existing low temperature solder paste , developed a low-temperature Sn-Bi solder paste, focused on finding the optimal formula , at the same time on the flux of the solder paste, is printing performance and wettability can be tested through performance test to find the optimal flux formula.

Abstract: Forward osmosis is an emerging membrane technology with potential applications in desalination and wastewater reclamation, osmotic pressure gradient cross the FO membrane is used to generate water flux. In contrast with conventional pressure-driving membrane process, the advantage of FO is significant: energy saving, high solute rejection and low fouling propensity. In this study, alginic acid (AA), boving serum albumin (BSA), humic acid (HA) and tannic acid (TA) were used to investigate the influence of organic fouling. The flux changed obviously, the rejection was approving and the absorption of organics was observed in the study. Ultrasonic oscillation was employed to wipe the organics off the fouling membranes, which was intend to study the quality of absorption of organic matters.