Analysis Of Separation Mechanism Of The Metallic Phase Of Slag In The Direct-To-Blister Process

Abstract

The article discusses the structure of the slag in the liquid state, the properties and interactions within the slag. The analysis of structures occurring in slag suspension were presented with regard to differences in chemical composition in micro-areas. Two different mechanisms for formation of precipitates in Cu-Fe-Pb alloys during extraction were showed.Keywords: decopperised, crystallisation, slag, structure.W artykule omówiono strukturę żużli w stanie ciekłym, oraz właściwości i oddziaływania wewnątrz żużli. Przedstawiono wyniki analiz występujących struktur w żużlu zawiesinowym, w odniesieniu do różnic w składzie chemicznym w mikroobszarach. Wskazano na dwa różne mechanizmy tworzenia wydzieleń stopu Cu-Fe-Pb podczas ekstrakcji. Analysis of the problems IntroductionIncreasing metallurgical yields and improving quality of the metals/alloys requires introducing numerous processes and techniques during designing of solidification, melting and casting. These are, reported in literature, reducing metals oxides present within slags [1][2][3], melt protecting with fluxes [4], melt modification before casting into foundry molds [5,6], riser protecting with insulating sleeves against surplus heat loses [7] as well as considering back-diffusion phenomena in solidifying metals and alloys [8]. The present paper deals with suspension slags of Cu production, their structure, composition, and mechanisms of extraction processes which proceed inside the slags.Suspension slag is formed during the extraction process of copper production in the melting flash. Then-formed suspension slag is directed to the electric furnace-arc where it is decopperisied. Decopperisation causes the reduction of oxides forms of primarily copper, lead and iron and then segregation of a Cu-Fe-Pb alloy. The moment of slag contacting the layer of coke reduction (phase 1), the majority of Cu 2 O is removed and the total copper content of the slag decreases to approx. 2,0%.Over the next 4-5 hours (phase 2) of the process, the content decreases to approx. 0.8%. Following the tapping process (phase 3), the content keeps decreasing and reaches a minimum of approx. 0.5%. The changes of concentration in the slag (particularly in phase 2 and 3) affect the structure and properties what have the decisive impact on the slag suspension decopperisation. The structure of slag in the liquid stateThe properties of the slag are determined by its structure. Slag structure can be described either by the molecular theory [1] or can be analyzed as electrolytes [2]. A. Bydałek and M. Brzózka [3] assumed that the slags in the liquid state were the boundary type of strong electrolyte solutions. In that case slag has ordered construction of the ion and tend to surround cations with oxygen ions. Small ions with high charge (Si 4+ , B 3+ ) strongly attract oxygen and produce a significant density of their immediate environment. Large ions with low charges (Ca 2+ , Na 1+ ) weakly attract oxygen. Tiemkina [9,14] however, pointed that, the creation of a multi-component systems ...

Reagents Activity in a Copper Droplets / Post-Processing Slag Suspension

“…The mechanism of coagulation is well illustrated in Fig. 1, where the small spherical droplets or rod-like droplets tend to be swallowed by the dominant droplet which is growing due to the smaller droplets feeding, [1]. Fig.…”

“…1. Coagulation and sedimentation, both are strongly influenced by the extraction technology, [1], and [2]. Usually, the copper droplets contain lead and iron, [3].…”

Method and Apparatus for Assessing the Properties of Slags

“…The Slag-Prop Cu database [6,7] was prepared based of their physical, mechanical and technological properties, collected from their own research and literature. The database combines the information collected over the years of laboratory and industrial research.…”

Copper droplets agglomeration/coagulation in the conditions similar to industrial ones

“…So, it is obvious that the extraction technology plays an essential role in the subsequent process of * INSTITUTE OF METALLURGY AND MATERIALS SCIENCE, 25 REYMONTA STR., 30 059 KRAKÓW, POLAND ** UNIVERSITY OF ZIELONA GÓRA, 50 PODGÓRNA STR., 65-516 ZIELONA GÓRA, POLAND # Corresponding author: w.wolczynski@imim.pl. droplets coagulation, [1]. The coagulation (preceded by the copper droplets agglomeration) is carried out during the second step of the slag treatment performed with the use of some reagents, [2].…”