Study of CO2injection on the desulfurization of low-titanium slag

2019 ◽  
Vol 116 (4) ◽  
pp. 417
Author(s):  
Baohua Wang ◽  
Mingbo Zhang ◽  
Rong Zhu ◽  
Shengtao Qiu
Keyword(s):  
Air Cooling ◽  
Water Cooling ◽  
Steelmaking Process ◽  
Titanium Slag ◽  
Desulfurization Rate ◽  
Sulfate Ions ◽  
Injection Process ◽  
Desulfurization Process ◽  
Low Sulfur ◽  
Cooling Air

A new idea that the low-titanium slag (LTS) used in the steelmaking process after CO2injection desulfurization is proposed in this paper. The CO2injection process mainly involves the grinding of low-titanium slag, mixing of slag and water, CO2injection, filtration, and then obtains the low sulfur and low titanium slag. The effects of cooling rates (water cooling, air cooling, crucible cooling, and furnace cooling) and CO2injection on the desulfurization of LTS were studied by both experimental and thermodynamic calculations. The results showed that sulfite and sulfate ions couldn’t be removed from LTS using this method, and the main removal substance in slag was sulfide ion S2−. The desulfurization mechanism with CO2injection was that the CO2injection reacted with H2O to form H2CO3, and then the H+disrupted from H2CO3reacted with the S2−in the slag to achieve desulfurization. During the desulfurization process, the desulfurization reaction was mainly determined by S2− + CO2(aq) + H2O (l) = CO32− + H2S(g) within the first 5 min, and then the main desulfurization reaction was S2− + 2CO2(aq) + 2H2O(l) = 2HCO3− + H2S(g). As the cooling rate decreasing, the desulfurization rate of LTS increased. The desulfurization effect of furnace-cooled slag is the highest in four kinds of slag. The desulfurization rate of furnace-cooled slag reaches 72.28%, which is 4.34, 1.75 and 1.15 times than that of water-cooled slag, air-cooled slag and crucible-cooled slag, respectively. The optimal rate of desulfurization is 80.0%.

Effects of cooling methods on the occurrence of sulfur in the low-titanium slag

2018 ◽  
Vol 115 (2) ◽  
pp. 208 ◽  
Author(s):  
Baohua Wang ◽  
Mingbo Zhang ◽  
Yongyu Gong ◽  
Shiping Huang ◽  
Shengtao Qiu ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Air Cooling ◽  
Water Cooling ◽  
Mineral Phase ◽  
Titanium Slag ◽  
Rate Decrease ◽  
Mineral Phases ◽  
Cooling Air ◽  
Large Sheet ◽  
Cooling Methods

The distribution of sulfur existence in the mineral phase and occurrence in the low-titanium slag with different cooling methods (water cooling, air cooling, crucible cooling, and furnace cooling) were studied by XRD, EPMA and XPS. The results show that with the cooling rate decrease, the distribution of S changes from clustering dots to large sheet or surface, and the occurrence of S in the mineral phase transfers gradually from the vitreous, perovskite, merwinite and the intertwined phase of some mineral phases to the gehlenite. During the transfer, the velocity decreases with the increasing of the cooling rate. The S in the water cooling slag only exists in the form of SO32−and SO42−, while the occurrences of S in the air cooling slag, crucible cooling slag, and furnace cooling slag are S2−, SO32−and SO42−.

scholarly journals Effects of deformation on the microstructure of a Ti-V microalloyed steel in the phase transition region

2004 ◽  
Vol 57 (4) ◽  
pp. 303-311
Author(s):  
Wiliam Regone ◽  
Sérgio Tonini Button
Keyword(s):  
Phase Transition ◽  
Phase Transformation ◽  
Transition Region ◽  
Microstructural Evolution ◽  
Microalloyed Steel ◽  
Hot Forging ◽  
Microalloyed Steels ◽  
Air Cooling ◽  
Water Cooling ◽  
Phase Transition Region

Microalloyed steels are used in the forging of many automotive parts like crankshafts and connecting rods. They are hot worked in a sequence of stages that includes the heating to the soaking temperature, followed by forging steps, and finally the controlled cooling to define the microstructure and mechanical properties. In this work it was investigated the thermomechanical behavior and the microstructural evolution of a Ti-V microalloyed steel in the phase transition region. Torsion tests were done with multiple steps with true strain equal to 0.26 in each step. After each torsion step the samples were continuous cooled for 15 seconds to simulate hot forging conditions. These tests provided results for the temperature at the beginning of the phase transformation, and allowed to analyze the microstructural changes. Also, workability tests were held to analyze the microstructural evolution by optical and scanning electron microscopy. Results from the torsion tests showed that the temperature for the beginning of phase transformation is about 700 ºC. Workability tests held at 700 ºC followed by water-cooling presented microstructures with different regions: strain hardened, and static and dynamic recrystallized. Workability tests at 700 ºC followed by air-cooling showed a complex microstructure with ferrite, bainite and martensite, while tests at 650 and 600 ºC followed by water-cooling showed a microstructure with allotriomorphic ferrite present in the grain boundaries of the previous austenite.

A COMPARATIVE STUDY OF LARGE HYDRAULIC GENERATORS WITH AIR-COOLING AND WATER-COOLING

1993 ◽  
Vol 21 (5) ◽  
pp. 605-613
Author(s):  
LIN XIANSHU ◽  
GAO JINLING ◽  
YU GUOQIN
Keyword(s):  
Comparative Study ◽  
Air Cooling ◽  
Water Cooling

scholarly journals Experimental Investigation on the Energy Properties and Failure Process of Thermal Shock Treated Sandstone Subjected to Coupled Dynamic and Static Loads

Minerals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 25
Author(s):  
Xiang Li ◽  
Si Huang ◽  
Tubing Yin ◽  
Xibing Li ◽  
Kang Peng ◽  
...  
Keyword(s):  
Thermal Shock ◽  
Split Hopkinson Pressure Bar ◽  
Failure Process ◽  
Air Cooling ◽  
Hopkinson Pressure Bar ◽  
Loading Test ◽  
Rock Engineering ◽  
Deep Rock ◽  
Pressure Bar ◽  
Cooling Air

Thermal shock (TS) is known as the process where fractures are generated when rocks go through sudden temperature changes. In the field of deep rock engineering, the rock mass can be subjected to the TS process in various circumstances. To study the influence of TS on the mechanical behaviors of rock, sandstone specimens are heated at different high temperatures and three cooling methods (stove cooling, air cooling, and freezer cooling) are adopted to provide different cooling rates. The coupled dynamic and static loading tests are performed on the heated sandstone through a modified split Hopkinson pressure bar (SHPB) system. The influence of heating level and cooling rate on the dynamic compressive strength, energy dissipations, and fracturing characteristics is investigated based on the experimental data. The development of the microcracks of the sandstone specimens after the experiment is analyzed utilizing a scanning electron microscope (SEM). The extent of the development of the microcracks serves to explain the variation pattern of the mechanical responses and energy dissipations of the specimens obtained from the loading test. The findings of this study are valuable for practices in rock engineering involving high temperature and fast cooling.

Residual Stress Analysis Considering Phase Transformation and Transformation Plasticity for Heat-Treated Large Size Shaft

2016 ◽  
Vol 725 ◽  
pp. 647-652 ◽  
Author(s):  
Yusuke Yanagisawa ◽  
Yasuhiro Kishi ◽  
Katsuhiko Sasaki
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Phase Transformation ◽  
Air Cooling ◽  
Water Cooling ◽  
Stress Distributions ◽  
Transformation Plasticity ◽  
Large Size ◽  
Heat Treated ◽  
Good Agreement

The residual stress distributions of the forgings after both water-cooling and air-cooling were measured experimentally. The residual stress occurring during the heat-treatment was also simulated considering the phase transformation and the transformation plasticity. A comparison of the experiments with the simulations showed a good agreement. These results shows that the transformation plastic strain plays an important role in the heat treatment of large forged shafts.

New Results of the Heat-Treated CuZn39Pb3 Brass Behavior and Resistance to Cavitation Erosion

2021 ◽  
Vol 890 ◽  
pp. 173-180
Author(s):  
Ilare Bordeaşu ◽  
Nicușor Alin Sîrbu ◽  
Iosif Lazăr ◽  
Ion Mitelea ◽  
Cristian Ghera ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cavitation Erosion ◽  
Stress Relief ◽  
Air Cooling ◽  
Water Cooling ◽  
Characteristic Parameters ◽  
Volume Heat ◽  
Heat Treated ◽  
Hardness Increase

The paper presents the results of the behavior and resistance to the erosion by vibrating cavitation of the CuZn39Pb3 brass, obtained by quenching the volume heat treatment from 800°C with water cooling, followed by the stress-relief to 250°C, with air cooling. Comparison with both the delivery status and the naval brass (used for ship propellers), based on the characteristic parameters values, recommended by the ASTM G32 standards and used in the Cavitation Laboratory of the Polytechnic University of Timisoara, shows that the hardness increase resulted from the heat treatment led to a significant increase of resistance to vibrating cavitation.

Corrosion Resistance of Industrial Pure Titanium and its Alloys under High Temperature and Different Cooling Methods

2021 ◽  
Vol 891 ◽  
pp. 3-9
Author(s):  
Cang Tian Wang ◽  
Qing Long Meng ◽  
Fang Hao Chen ◽  
Jing Hong Wang ◽  
You Ran Zhi ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Acid Corrosion ◽  
Pure Titanium ◽  
Corrosion Current ◽  
Chemical Equipment ◽  
Air Cooling ◽  
Water Cooling ◽  
Corrosion Condition ◽  
Impedance Technique ◽  
Cooling Methods

Industrial pure titanium (TA2) and Ti-6Al-4V (TC4) have been widely available for chemical equipment. However, the corrosion resistance changes during their post-fire performance. In this research, the electrochemical properties of industrial pure titanium and Ti-6Al-4V after heat treatment and different cooling methods were analyzed by AC impedance technique and dynamic polarization method. The results support two conclusions. Firstly, when the temperature is approximate to the phase transition point, for pure titanium and its alloys, water-cooling can obtain better corrosion resistance than air-cooling. With regard to pure titanium, its best corrosion resistance can be obtained at 800°C under water-cooling. For Ti-6Al-4V, its best corrosion resistance can be obtained when the temperature reached 910 °C under water cooling condition. Secondly, the corrosion current density under acid corrosion condition has risen compared with neutral corrosion condition. These results can provide some experimental data and theoretical basis for post-fire anticorrosion performance of titanium materials, and also support the safety, risk evaluation of titanium equipment.

Study on Metallography Test of the Steel SPV490 for Atmospheric Storage Tank After Fire

2016 ◽  
Author(s):  
Zhou Fang ◽  
Weiwei Hu ◽  
Deyu Liu ◽  
Guanghai Li ◽  
Zhe Wang
Keyword(s):  
Mechanical Properties ◽  
Working Conditions ◽  
Storage Tank ◽  
High Strength ◽  
Air Cooling ◽  
Microscopic Structure ◽  
Water Cooling ◽  
Storage Tanks ◽  
Fire Temperature ◽  
Optical Microstructure

The fire process was simulated by the heat treatment to the Steel SPV490 of atmospheric storage tank, thereby obtaining the metal specimens in different fire temperature, holding time, and cooling modes. And as the temperature increases, the microscopic structure of Steel SPV490 changes under different working conditions, which could be shown in optical microstructure pictures after doing the interception, inlay, polishing, finishing to the specimens. The result shows that, the mechanical properties of the Steel SPV490 for storage tank changes as the temperature rising from the microscopic view. Nodulizing of the cementite in pearlite occurs, and the strength decreases when the high strength steel SPV490 of large atmospheric storage tanks under air cooling condition below 700 °C, however, it equivalents to the normalizing process, as the sorbite occurs in the steel, and the strength increases a bit when the temperature is above 900 °C. The water-cooling of steel SPV490 above 900 °C equivalents to the process of quenching. The occurrence of martensitic substantially increases the strength and the brittleness, and the elongation decreases rapidly.

Part II. Research on the Performance of a Type of Internally Air-cooled Turbine Blade

1953 ◽  
Vol 167 (1) ◽  
pp. 351-370 ◽  
Author(s):  
D. G. Ainley
Keyword(s):  
Gas Flow ◽  
Thermal Stresses ◽  
Turbine Blades ◽  
Small Diameter ◽  
Rotor Blades ◽  
Air Cooling ◽  
Gas Temperature ◽  
Flow Through ◽  
Cooling Air ◽  
Practical Feasibility

A comprehensive series of tests have been made on an experimental single-stage turbine to determine the cooling characteristics and the overall stage performance of a set of air-cooled turbine blades. These blades, which are described fully in Part I of this paper had, internally, a multiplicity of passages of small diameter along which cool air was passed through the whole length of the blade. Analysis of the, test data indicated that, when a quantity of cooling air amounting to 2 per cent, by weight, of the total gas-flow through the turbine is fed to the row of rotor blades, an increase in gas temperature of about 270 deg. C. (518 deg. F.) should be permissible above the maximum allowable value for a row of uncooled blades made from the same material. The degree of cooling achieved throughout each blade was far from uniform and large thermal stresses must result. It appears, however, that the consequences of this are not highly detrimental to the performance of the present type of blading, it being demonstrated that the main effect of the induced thermal stress is apparently to transfer the major tensile stresses to the cooler (and hence stronger) regions of the blade. The results obtained from the present investigations do not represent a limit to the potentialities of internal air-cooling, but form merely a first exploratory step. At the same time the practical feasibility of air cooling is made apparent, and advances up to the present are undoubtedly encouraging.

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