Zhang Min

Bio: Zhang Min is an academic researcher. The author has contributed to research in topics: Continuous casting & Steelmaking. The author has an hindex of 1, co-authored 5 publications receiving 3 citations.

Continuous casting mold powder for high-aluminum steel and preparation method thereof

Abstract: The invention belongs to the technical field of molten steel continuous casting, and specifically relates to continuous casting mold powder for high-aluminum steel and a preparation method thereof. The technical problem to be solved by the invention is to provide the continuous casting mold powder which can ensure the smooth casting of the high-aluminum steel and realize multi-furnace continuous casting, and can be used for obtaining good casting blank quality. The mold powder comprises the following components by weight percentage: 15-30% of CaO, 11-20% of SiO2, 10-20% of Al2O3, less than orequal to 1% of MgO, 7-13% of F-, 5-10% of C, 10-30% of BaO+SrO, 1-6% of B2O3, less than or equal to 12% of total amount of Na2O+Fe2O3+Li2O, and inevitable impurities. The lubricity of the mold powderto a casting blank is ensured; the occurrence of breakout is avoided; the surface defects of the casting blank can be reduced or prevented; and the quality of the casting blank is ensured.

Continuous casting powder for low-carbon high-aluminum steel and preparation method thereof

Abstract: The invention belongs to the technical field of molten steel continuous casting, and particularly relates to continuous casting powder for low-carbon high-aluminum steel and a preparation method thereof. The technical problem to be solved by the continuous casting powder for low-carbon high-aluminum steel is to provide the continuous casting powder which can ensure smooth casting of the low-carbonhigh-aluminum steel, realize multi-furnace continuous casting and obtain good casting blank quality. The casting powder is prepared from the following components of, in percentage by weight, 15%-30 %of CaO, 11%-26% of SiO2, 10%-20% of Al2O3, 7%-13% of F , 5%-10% of C, 12%-25% of BaO, at least one Na2O of B2O3 or Li2O, more than or equal to 5% and less than or equal to 14% of Na2O + B2O3 + Li2O in total, and unavoidable impurities. According to the continuous casting powder for the low-carbon high-aluminum steel and the preparation method thereof, the lubricating property of the casting powder to a casting blank is guaranteed, the steel leakage condition is avoided, in addition, surface defects of the casting blank can be reduced or prevented, and the quality of the casting blank is guaranteed.

Effect of Dispersant on the Dispersibility of CaO–Al2O3-Based Mold Powder Slurry

Abstract: The fast hydration rate of aluminate makes the slurry of CaO–Al2O3-based mold flux coagulates fast, which hinders the production and large-scale application in steel plants. This study selected four dispersants and investigated their mechanism and influence on the dispersibility of CaO–Al2O3-based mold powder slurry. Main results showed that the stability of CaO–Al2O3-based mold powder slurry was poorer than CaO–SiO2-based mold powder slurry. The addition of non-ionic dispersant, OP-10 or glycerol, could make the viscosity of the CaO–Al2O3-based slurry become larger, and the macromolecule dispersant, Poly Vinyl Pyrrolidone, resulted in unstable variation of the viscosity of the mold powder slurry. The anionic dispersant, tannic acid, performed well, as it was able to release negative charges covering the powder particles, and the electrostatic repulsion made the aggregation among particles difficult to occur. The 5 wt% addition of tannic acid was found to effectively improve the dispersion of the CaO–Al2O3-based slurry.

Tundish covering agent for titanium-containing steel and preparation method and application of tundish covering agent

Abstract: The invention provides a tundish covering agent for titanium-containing steel and a preparation method and application of the tundish covering agent. The tundish covering agent for the titanium-containing steel comprises the following components of, in percentage by mass, 25 %-50 % of alkaline earth metal oxide, 10 %-25 % of Al2O3, 20 %-50 % of TiO2, 5 %-15 % of Na2O and 2 %-10 % of CaF2, whereinthe alkaline earth metal oxide is selected from one or more of CaO, BaO, MgO and SrO. According to the tundish covering agent for the high-titanium steel (the titanium content is larger than or equalto 0.1 %), the inclusion adsorption capacity is high and the performance is stable after inclusion adsorption, the heat preservation performance is good, molten steel is purified, and the secondary pollution to the molten steel is reduced; and according to experimental results, after the agent is applied to a slab continuous casting machine for 50 minutes, a slag surface is not crusted, and the temperature drop of the molten steel is small and is 3-5 DEG C; and the molten steel is not polluted or slightly polluted, and the burning loss of Ti is 0-0.012 %.

Theoretical analysis and experimental study of the application of CO2 in the smelting of 410S stainless steel

Abstract: The use of CO2 as a blown gas in the smelting process of 410S stainless steel is investigated and compared with the use of N2. The experimental smelting of a Fe–C–Cr melt with CO2 replacing N2 in different proportions shows the effect of CO2 on decarburization and chromium oxidation. The results show that the decarburization rate increases with increasing CO2 proportion. When the replacement ratio was less than 75%, the oxidation loss rate of Cr decreased with increasing replacement ratio. When CO2 completely replaces N2, the C content in the liquid melt is relatively low, causing an increase in CO partial pressure from the blown CO2, resulting in increased oxidation loss of Cr. An industrial test using a 70-t stainless steel smelting furnace verifies that when [%C]> 0.1, the use of CO2 as a blown gas results in excellent decarburization and chromium retention performance, and the Fe-Si reductant consumption decreases with reduction in chromium oxidation loss in molten steel. Blown CO2 induces a temperature drop in the molten steel that cannot be ignored for stainless steel smelting. This study provides a reliable foundation for the application of CO2 in stainless steel smelting.

Oxidation Mechanism During Pyrometallurgical Vanadium Extraction Process Using CO2-Containing Gas

Abstract: In the present work, the oxidation characterization and mechanism of vanadium extraction by bottom injection of CO2 were investigated based on laboratory experiments and pilot tests. In addition, variations of the compositions of all stable phases including gas, hot metal, slag, and spinel during the vanadium extraction process through injecting pure O2, 15 vol.% CO2-85 vol.% O2, and 30 vol.% CO2-70 vol.% O2 gases were simulated based on the recently optimized vanadium-containing oxides database stored in FactSage software. As a consequence, oxidation of vanadium by CO2 was an apparent second-order reaction. Transformation of dissolved vanadium to vanadium-containing spinel can be enhanced with bottom injection of 15 vol.% CO2–85 vol.% O2 into the hot metal. With the increase of bottom injected CO2 from 15 vol.% to 30 vol.%, the oxidation of dissolved vanadium could be restrained due to the reduction of oxygen potential originating from partial replacement of O2 by CO2.