Kaiping Du

Characterization of Sintering Dust, Blast Furnace Dust and Carbon Steel Electric Arc Furnace Dust

In order to make a complete understanding of steel plant metallurgical dusts and to realize the goal of zero-waste, a study of their properties was undertaken. For these purposes, samples of two sintering dusts (SD), two blast furnace dusts (BFD), and one electric arc furnace dust (EAFD) taken from the regular production process were subjected to a series of tests. The tests were carried out by using granulometry analysis, chemical analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy via SEM (EDS), and Fourier transform infrared spectroscopy (FTIR). The dominant elements having an advantage of reuse are Fe, K, Cl, Zn, C. The dominant mineralogical phases identified in sintering dust are KCl, Fe2O3, CaCO3, CaMg(CO3)2, NaCl, SiO2. Mineralogical phases exist in blast furnace dust are Fe2O3, Fe3O4, with small amount of KCl and kaolinite coexist. While in electric arc furnace dust, Fe3O4, ZnFe2O4, CaCO3, CaO, Ca(OH)2 are detected.

Effect of MgO on Emergence of Blast Furnace Primary Slag with Comprehensive Furnace Burden

Based on the furnace burden of high content of Al2O3, the process of softening and melting and the characteristic of primary slag were studied with the increase of MgO content in the sinter and adding some MgO into the pellet. The results showed that the content of MgO in the primary slag increased with the increase of MgO in the sinter and pellet. Meanwhile, the permeability of the furnace burden was improved because of low viscosity of high MgO primary slag. Compared with the increase of MgO content in the sinter, the increase of MgO content in the pellet can improved the softening and melting characteristic of the comprehensive furnace burden more effectively. More Mg-bearing pellet should be chosen in the comprehensive furnace burden for the purpose of improvement the fluidity of primary slag and the permeability of the furnace burden in the burden of high Al2O3 content.

Characteristics and analyses of COG injection from tuyere in COREX melter gasifier

ABSTRACT Coke oven gas (COG), as an environment-friendly source, is projected to be introduced into the COREX process to reduce solid fuel consumption. In this paper, a static model has been developed based on mass and heat balance, which can calculate characteristics of melter gasifier, such as the raceway adiabatic flame temperature (RAFT), volume and component of bosh gas. The results showed that compared with N2, the COG injection from tuyere is more effective on reducing the RAFT and improving the bosh gas volume. The quantity of COG injected is limited for the RAFT, and without other thermal compensation, the largest injection quantity is about 150 Nm3 t−1. The quantity of COG injection can be increased by preheating tuyere oxygen, adjustment of fuel structure and addition of tuyere oxygen. COG injection can promote the reduction and hearth permeability, decrease the RAFT and protect the tuyere, which is beneficial to COREX operation.

Numerical Simulation of the Erosion in the Hearth of Corex Melter Gasifier under the Condition of Different Drainage Type

The campaign life of COREX melter gasifier mainly depends on the hearth refractory erosion which is strongly affected by the liquid iron flow and heat transfer. In this work, a three-dimensional mathematical model at steady state, which takes fluid buoyancy force and turbulence model into consideration, is introduced to describe the flow, temperature and wall shear stress distribution in the hearth under the condition of continuous tapping and intermittent tapping respectively in detail. The accuracy of model is evaluated using plant operational data. The results show that a ring shaped channel flow with a high flow rate around fine coke region is formed. Meanwhile, a larger scale of recirculation loop can be observed in the coke free region. Severe mechanical erosion could occur at the sidewall under the condition of continuous tapping, while that shifts to the bottom of hearth pool under the condition of intermittent tapping.

Three-Dimensional Numerical Simulation of the Thermal Damaged Mechanism of Baosteel Blast-Furnace Tuyere

Due to the hostile working environment, blast furnace tuyere was easily damaged, which increase the blast furnace blown down percentage. In this paper, tuyere damage statistic is made to improve the understanding that the main thermal damage form of blast furnace tuyere is melting loss. A 3D computational fluid dynamic (CFD) model has been developed to simulate the temperature and the velocity of cooling water, together with the temperature field of the tuyere body. Through the simulation, the position where cooling blind position occurs easily is found. The results show that the temperature distribution of tuyere body and the cooling water play an important role for the understanding of the tuyere’s working condition and the highest temperature position is at the bottom of the front tuyere, which have an intimate relationship with the thermal damaged of tuyere.