钢铁渣的农业资源化利用

钢铁渣是钢铁冶金生产的主要固体废弃物,开发冶金炉渣的综合利用技术对于防止环境污染和促进冶金工业的长期可持续发展有十分重要的意义.钢铁渣的理化特性进行了简要的介绍,详细论述了其在农业生产上的资源化再利用技术以及施用钢铁渣肥料后的土壤环境效应.钢铁渣应用于农业生产可以使其含有的有益元素得到充分利用,不会对农产品及土壤环境造成危害,而且通过在钢铁渣中加入添加剂合成新型农业肥料可以有效地提高钢铁渣肥料的附加值,更好地满足农业生产的高产和优质的需求.     

Influence of Cr2O3 on the Viscous Flow Behavior and Structure of Cr-Containing Molten Titanium Slag

Herein, the influence of Cr₂O₃ on the viscous flow behavior and structure of Cr-containing molten titanium slag is investigated in this work. The melting and viscosity properties are studied by hemisphere method and rotating cylinder method, respectively. In addition, the structure of Cr-containing molten titanium slag is investigated by Raman spectroscopy. It is shown in the results that the melting temperature and viscosity both increase with the increase of Cr₂O₃ content. The activation energy for viscous flow increases with increasing Cr₂O₃ content, which is in the same trend as viscosity. When the Cr₂O₃ content increases from 0% to 3%, the simpler 6-coordinated Ti⁴⁺ and TiO₄⁴⁻ monomer unit transformed into more complex O–Ti–O deformation and Ti₂O₆⁴⁻ chain unit. Furthermore, the fraction of relatively complex silicate structural units shows an increasing trend. Cr₂O₃ behaves as a network former and enhances the degree of polymerization of network structure, and the variation of Cr-containing molten titanium slag structure is consistent with the increasing trend of viscosity.     

A modified method for calculating the viscosity of multicomponent slags based on Kriging interpolation

Model prediction is an effective method to obtain the physicochemical properties data of molten slags, which is difficult to test experimentally due to their high melting points. Empirical models are prevalent at present; however, it needs large amount of experimental data to fit the empirical parameters with narrow application scope. In this paper, the Kriging interpolation method modified with oxide property weights, is firstly introduced into the viscosity prediction of multicomponent slags. The prediction results of CaO–Al₂O₃–SiO₂, CaO–Al₂O₃–CaF₂, CaO–Al₂O₃–SiO₂–MgO and CaO–Al₂O₃–SiO₂–MgO–CaF₂ systems showed that the predicted errors by the Modified Kriging Interpolation (MKI) method are smaller than those by various empirical models. It is anticipated that the MKI method can be extended to predicting the continuous physicochemical properties of multicomponent slags.     

配加钢渣对包钢烧结矿指标的影响

文章介绍了包钢一烧车间配用钢渣后对烧结矿指标的影响,结果表明,配用钢渣后,利用系数没有明显变化,烧结矿w(TFe)、w(SiO2)和w(P)均有一定程度的提高,转鼓强度得到提高。     

Production of mortars using novel glass-ceramic porous spherical particles with chemical composition into SiO2-CaO-Al2O3-MgO quaternary system as replacement of sand aggregates

A novel production of new aggregate for mortars based on glass-ceramic porous spherical particles into SiO₂-CaO-Al₂O₃-MgO quaternary system is reported. Crystalline blast furnace slags (c-BFS) are transformed into new glass-ceramic porous spherical materials with lower density than their precursor. The conversion occurs by c-BFS projection into an oxygen/Liquefied Petroleum Gas (LPG) plume-flame. The aim of the present work is to evaluate these new materials as aggregates to replace the sand in conventional mortars formulations in order to indicate a potential way to reduce the use of this mineral resource and also how industrial wastes can be transformed in useful materials with direct application into the construction materials field. The characterization of the precursor and products were carried out by optical microscopy; scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) and their densities were measured by Helium pycnometry. Additionally, the compressive strengths at different aging times (7, 14 and 28 days), from a control sample and diverse mortars based on glass-ceramic porous spherical particles were evaluated. Finally, thermal conductivities from all the specimens cured at 28 days were also measured.     

Study on electrical conductivity of FexO–CaO–SiO2–Al2O3 slags

The composition dependences of electrical conductivity of Fe_xO–CaO–SiO₂–Al₂O₃ slags at different oxygen potentials and temperatures have been studied experimentally in the present work. From the experimental results, the total electrical conductivity and electronic conductivity for all the slags monotonously decrease as increasing CO/CO₂ ratio from about 0 to 1. With the increase of Fe_xO content, the total electrical conductivity and electronic conductivity increase at a fixed CO/CO₂ ratio. It is also found that the ionic conductivity of all the studied slags increases as increasing the CO/CO₂ ratio, which is resulted from the increase of Fe²⁺ ion concentration. In addition, the temperature dependences of ionic, electronic and total conductivity for different compositions obey the Arrhenius law. The electronic transference number exhibits a strong relationship with oxygen potential, but is independent of temperature.     

Studies of the Crystallization of Antimony-Containing Slag Glass-Ceramic

The paper explains the necessity and basic principles of fabricating slag glass-ceramic based on special local antimony-containing slag. A CaO-Al₂O₃-SiO₂ three-component phase diagram was used to plan a base glass composition, to which four selected nucleating agents, Cr₂O₃, ZrO₂, P₂O₅, and TiO₂, were added separately. Studies focused on their roles in the crystallization of the present slag glass system with the aid of differential thermal analysis, X-ray diffractometery, and scanning electron microscopy. Comparisons showed that the four nucleating agents behaved differently and therefore exerted different influences on crystallization. TiO₂ proved to be the best one, and its optimal concentration was 10 wt%.     

顶渣碱度对轴承钢质量的影响

分析了轴承钢冶炼过程中顶渣碱度对钢中氧含量和脱硫率的影响。通过试验证明增加石灰用量，控制顶渣三度在２．５９左右，能够降低钢中氧含量和提高脱硫率，对电炉冶炼操作及主要技术经济指标无良影响，可在大生产条件下推广应用。     

Transformation of stainless steel slag toward a reactive cementitious binder

Argon oxygen decarburization (AOD) slag represents more than 50 wt% of the slag from stainless steel production. Although some applications are available, e.g., as aggregates for road constructions or fertilizers, they are characterized by low economic value and limited applicability. In order to increase the economic value of AOD slag, alternative applications have been proposed, e.g., as partial or full replacement for Ordinary Portland Cement (OPC). The work presented here investigates whether the adaptation of the AOD slag chemistry within a high temperature process leads to an improvement of its hydraulic properties and thereby can demonstrate its potential to be converted into a hydraulic binder suitable for OPC replacement. For this purpose, three synthetic AOD slags with basicities (CaO/SiO₂) of 2.0, 2.2, and 2.4 were synthesized, and the effect of the CaO/SiO₂ ratio on the material stability, the amount of tricalcium silicate formed, and their hydraulic properties investigated. X‐ray diffraction, scanning electron microscope (SEM), and isothermal calorimetry analysis were used to characterize the microstructure and the hydraulic activity. The results show that the proposed method is indeed a promising way to stabilize a stainless steel AOD slag and convert it into a hydraulic binder.