Papers by Keyword: Deoxidization

Abstract: In Atmospheric Plasma Spraying (APS), it is important to understand the controlling factors dominating molten metal droplets’ reaction dynamics to control final coating compositions and properties. The present paper focuses on a novel Computational Fluid Dynamics (CFD) modeling of mass transfer mechanisms of an inflight molten metal droplet leading to droplet oxidation control during APS. The onset conditions of droplet internal circulation and its effect on the deoxidizer oxidation behavior during APS are theoretically examined. Moreover, rapidly supplying these elements from the inside to the droplet surface requires the rapid switching of the mass transfer mechanism to rapid convective flow due to a very limited in-flight time of less than 1ms. The temperature and velocity variations within the droplet would influence the thermo-physical properties of the droplet and the plasma gas and it controls the onset of the internal circulations within the droplets. A novel User Defined Function (UDF) is developed to capture the onset of Hill’s vortex formation and its effect on the rapid-rate convective mass transfer mechanism during APS. Further, a detailed analysis of particle size effect on in-flight in-situ deoxidation during APS of NiAlC droplets was performed. It is observed that the smaller size droplets will undergo more severe oxidation during a flight than larger size droplets due to more molecules of O2 available for reaction in the smaller droplet.

Abstract: A method to fabricate a new kind rare earth salt refiner for purifying impure red copper was introduced in present paper, and the application of which on deoxidization, conductivity and mechanical properties of impure red copper were also inspected by composition analysis, Scanning Electron Microscope (SEM) and mechanical properties test technologies. The effect mechanism of the rare earth salt refiner on the performance of red copper was discussed in detail in this paper.

Abstract: Three oxidant decontaminants, including NaClO, H₂O₂ and an organic peroxyl acid, were introduced to destroy the cyanide ion. The residual cyanide ion concentrations in different decontamination water were detected by a cyanide ion selective meter. Before the detection process, the oxidants left in the cyanide decontamination water were pretreated by adding a certain amount of Na₂SO₃. Results showed that starch-iodide solution indicator method presented a perfect function on determining the dosage of Na₂SO₃. Values of the relative mean deviations on residual cyanide detection were below 5%. After the decontamination water was deoxidized by Na₂SO₃, whether the sample distillated or not could not affect the value of CN^- quite much. Non-distillation was confirmed alternative in the detection of cyanide ion decontamination water. Too much standing time would lead to a relatively lower CN^- concentration, especially in that of non-distillation.

Abstract: The deoxidization of coal-bed methane is carried out under low temperature which ranges from 150°C to 200°C. In the three deoxidizers, the deoxidization characteristic of BJ-1 is mainly studied. With the function of BJ-1, oxygen content can be reduced to 1% or less. Moreover, the CBM whose CH₄ content is below 30%, can be deoxygenated safely. When the space velocity exceeds 25000h^-1, the oxygen content of outlet gas begin to great than 1%. In addition, through the experiment, the initial deoxidization temperature is determined as 160°C.

Abstract: In order to reduce the production cost, In one factory product the SPHC steel of general requirements using slag washing process （BOF→Slag washing oxygen alloying→Ladle argon-blown→CC）, the system study was analyzed about deoxidization and desulphurization behavior of slag washing process. The results of the study show that, when the content of Als 300~500ppm, dissolved oxygen 3~6ppm, the steel desulfurization rate remains stable at 35% to 48%, the average desulfurization rate is 42%. The process of the [N] content, increasing [S] are lower than the LF refining, the operation is simple and can meet the metallurgical requirements.