Papers by Keyword: Sinter

Abstract: A large amount of finely dispersed manganese ore left after benefication operations or blown out from the furnaces is unsuitable for direct use in electric furnaces and blast furnaces, therefore it is necessary to granulate it in order to have the efficient use of its fine ore particles in metallurgy. To make our research more of practical use, we found it is reasonable not only work over manganese fines sintering but also to attempt mitigating the negative effect on the environment produced by the further sintering and apply the biofuel within the total fuel mass. Under laboratory conditions, the studies have been carried out with the objective to obtain manganese sinter, in which wood biomass is applied, namely initial and pre-pyrolyzed, at temperatures of 673, 873, 1073 and 1273 K. The amount of biofuel in the sinter blend was 25 wt.%. It has been established that the biomass use causes the decrease in the specific capacity of the sintering plant. However, for the efficient manganese ores sintering process, the biofuel of high pyrolysis temperature of 1273 K is required. To achieve the specific capacity and the yield to be as high as those when coke breeze is only used, the amount of the biofuel for manganese ore sintering should be less than 25 wt.% of the solid fuel. Additionally, it has been revealed that the further increase in the biofuel ratio in the total fuel amount is possible on condition that its reactivity is decreased, or larger particles of the biofuel are used.

Abstract: The influence of the light burning temperature on the sintering property of nature dolomite has been investigated by two-step sintering process in the temperature range 1500 °C to 1600 °C. The resulting bulk densities and apparent porosities of the sintered dolomite samples were examined, and analyzing the sintered dolomite by scanning electron microscopy and X-ray diffraction were performed. The results showed light burned at 850 °C for 3 h, the main phases of the dolomite with 3-5 grain size were MgO, CaO and little CaCO₃, and then fired at 1600 °C,the density of sintering dolomite reached to 3.38 g/cm³, the apparent property was 1.2 %, the size of MgO grain up to 3.75 μm . However when dolomite light burned at 1050 °C for 3 h, the main phases were MgO and CaO, and then fired at 1600 °C,the density of sintering dolomite only was 3.30 g/cm³, the apparent property was 2.3 %, the size of MgO only was 3.05 μm .

Abstract: Cheap alloying elements and creative processing techniques are a way forward to open up more industrial opportunities for Ti in sectors where it is not extensively applied yet, rather than in aerospace and biomedical applications. This study focuses on understanding the joint effect of using a commercial steel powder to add Fe to pure Ti and its processing by press-and-sinter on the behaviour of low-cost PM Ti alloys. It is found that the calibrated addition of steel permits to develop new low-cost Fe-bearing Ti alloys that can satisfactorily be produced using the blending elemental PM approach. Densification of the samples and homogenization of the chemical composition are enhanced by the high diffusivity of Fe. The low-cost α+β alloys reach comparable physical and mechanical properties to those of wrought-equivalent PM Ti alloys, such as Ti-6Al-4V, and are therefore promising candidates for load-bearing lightweight products.

Abstract: The questions of oxidizing roasting of iron ore raw materials with production sinter and pellets are considered. The question of reduction roasting of iron ore raw materials is studied. Phase transformations of oxidizing and regenerative roasting are considered. Features of phase transformations of iron ore raw materials containing titanium are discussed. The reducibility, durability and temperatures of softening and melting of metallurgical iron ore raw materials are studied In Vitro. The effect of the durability of burned iron ore pellets on compression is also defined.

Abstract: The chemical composition of pellets of various basicity from pig iron ore materials is described. The metallurgical characteristics (reducibility, strength, softening and melting temperatures) is analyzed. The micro X-ray diffraction phase analysis is made. Also the sinter of various basicity from titaniferous raw materials is investigated.

Abstract: Generated during the combustion of coal for electricity production, fly ash is a solid waste and causes great ecomomic burden and serious environmental pollution. On the other hand, it is a good resource for the preparation of industrial products. Especially, alumina rich fly ash from Inner-Mongolia Guohua Junggar Power Plant typically contains 45-55% alumina, 30-40% silica, and 5-10% other metallic oxides, it is a perfect resource for alumina extraction. In order to improve the utilization value of alumina rich fly ash and lessen environmental strain, a novel approach for alumina extraction from alumina rich fly ash was proposed. The proposed process includes a pre-desilication process, soda lime sintering process, dissolving process, carbonation process and calcination process. The technological conditions for alumina extraction from Junggar alumina rich fly ash were optimized by means of orthogonal experment design. The extraction rate of alumina was 96%. Value-added products, such as electrolytic grade alumina and white carbon black, were produced at the same time.

Abstract: In order to improve the qualities of sinter of Ansteel, the sinter’s metallurgical property was examined and analyzed that from the second workshop and the fourth workshop of ironmaking plant. And mineralogical composition and microstructure in high basicities sinter were investigated and analyzed by the X-ray diffraction, the optical microscope and the scanning electron microscope in laboratory. It was found that the differences between in sinter’s mineralogical composition and microstructures are according with the differences in chemical composition and the metallurgical indexes. Both the sinter’s minerals are mainly composed of hematite, magnetite or maghemite, calcium ferrite, dicalcium silicate, silicate glass phase. The content of the carbon in the fourth workshop is higher. So, it should decrease the content of the carbon that makes the microstructure of the sinter more rational.

Abstract: High temperature self-compensation lubricating composite materials were fabricated by vacuum sintering method in this work. The FeCrWMoV alloy powder was used as the basic material, the TiC and Co ceramic powder was used as reinforcing material and TiH₂ and CaCO₃ was used as pore-forming material. The changes of the crushing strength, micro-hardness and porosity were analyzed with the temperature. The pore structure and surface morphology of the preforms were analyzed using scanning electron microscope (SEM). The conclusion is that the most appropriate sintering temperature is 1250^oC in the process of sintering, and the formation of secondary organization has significant influence on the properties of composite materials.

Abstract: Microhardness of various minerals in sinter was tested in order to better production of sinter with high microhardness minerals in WISCO. The results showed that the hematite microhardness was highest and the glass phase microhardness was lowest, the various minerals microhardness from highest to lowest was: hematitecalcium ferritemagnetiteglass phase. So the hematite and calcium ferrite should be development, and the glass phase should be inhabited in sinter on production. Minerals microhardness was connected with component elements and crystalline structure of the minerals besides ferrous content of sinter.

Abstract: The content and stability of FeO in sinter are the important comprehensive indicators to assessing the sintering production. They not only reflect the quality and energy consumption of agglomerates, but also influence the smelting results of blast furnace. The effects of the FeO content of original ores on the FeO content in sinter and the creating ability of calcium ferrite are discussed in this paper. The results show that the content of FeO in sinter of hematite is much lower than magnetite. With the increasing of the FeO content of original ore, the FeO content in sinter increases but the content of calcium ferrite gets low, and the quantity of bonding phase hasn't apparently change.