The Laboratory Study of Metallurgical Slags and the Reality

Abstract

The development of new materials and their production processes along with the environmental constraints demand new data of high quality, especially thermodynamic and physical property data. As slags play a crucial role in metallurgical processes and recycling, the need of better understanding of the reaction mechanisms between slag and metal is also increasingly felt. High precision data and better understanding of the reaction mechanism require efficient collaboration between the researchers in the laboratory and in the industries. Unfortunately, in some cases, the reported data are not obtained in well-controlled experimental conditions. Without the knowledge of the experimental conditions, the use of the data in industrial practice would possibly lead to unintended results. In other cases, the measurements themselves, even their principles, are questionable. This review article addresses how to make the laboratory investigation more relevant to the industrial reality. Some existing uncertainties in the laboratory studies are also discussed. To help a sensible discussion, some specially designed experiments are conducted to support the argument. The review is focused on slag properties (namely, sulfide capacity, phosphate capacity, apparent viscosity, and apparent interfacial tension) and studies of interfacial slag phenomena.

The Melting Mechanism of Hydrogen Direct Reduced Iron in Liquid Slag

“…While a nonarbitrary determination of the interfacial tensions can be made, in theory, the necessary condition for carrying out the measurements is the equilibrium state as any chemical reaction will influence the energy balance. [ 21 ] However, in this study, the effect of ongoing reactions is significant as the penetration is influenced by the amount of residual oxides, i.e., the reduction degree. Specifically, with ongoing reactions, it means the dissolution of the residual oxides by the penetrating slag.…”

Svjetska proizvodnja čelika u razdoblju od 2000. do 2020. godine

“…Uloga troske je višestruka, a najvažnija je da asimilira neželjene primjese. 17 Tijekom oksidacije željeza i primjesa nastali oksidi prelaze u trosku koja može biti i koristan sporedni proizvod. [18][19][20][21][22][23] Troska nastaje i od drugih dodataka uloženih u proizvodne agregate (npr.…”

Viscosity experiments of slag-spinel suspensions: The effect of volume fraction, particle size, and shear rate

“…In contrast, recent reviews on high-temperature slag viscosity studies concluded that these rheology parameters are often not reported 9 and thereby the reported values do not accurately represent the viscosity of this high-temperature suspension. 10 There are two main causes for the lack of reporting and controlling: first, there is a lack of emphasis on the complexity and the wide-variety of parameters which control the rheology of high-temperature suspensions. 10 Second, the crystals inside a slag are non-inert and precipitate, grow or dissolve depending on the temperature or composition.…”

“…10 There are two main causes for the lack of reporting and controlling: first, there is a lack of emphasis on the complexity and the wide-variety of parameters which control the rheology of high-temperature suspensions. 10 Second, the crystals inside a slag are non-inert and precipitate, grow or dissolve depending on the temperature or composition. Therefore, the shape, size and volume fraction of the crystals within a slag can vary with the thermal history of the slag or changes in composition, however, hightemperature viscosity measurements devices are commonly not equipped with the possibility to measure the particle morphology at the temperature of interest.…”