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Number of results: 10
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Abstract

An innovative method for determining the structural zones in the large static steel ingots has been described. It is based on the

mathematical interpretation of some functions obtained due to simulation of temperature field and thermal gradient field for solidifying

massive ingot. The method is associated with the extrema of an analyzed function and with its points of inflection. Particularly, the CET

transformation is predicted as a time-consuming transition from the columnar- into equiaxed structure. The equations dealing with heat

transfer balance for the continuous casting are presented and used for the simulation of temperature field in the solidifying virtual static

brass ingot. The developed method for the prediction of structural zones formation is applied to determine these zones in the solidifying

brass static ingot. Some differences / similarities between structure formation during solidification of the steel static ingot and virtual brass

static ingot are studied. The developed method allows to predict the following structural zones: fine columnar grains zone, (FC), columnar

grains zone, (C), equiaxed grains zone, (E). The FCCT-transformation and CET-transformation are forecast as sharp transitions of the

analyzed structures. Similarities between steel static ingot morphology and that predicted for the virtual brass static ingot are described.

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Authors and Affiliations

A.A. Ivanova
B. Kania
P. Kwapisiński
W. Wołczyński
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Abstract

The Structural Peclet Number has been estimated experimentally by analyzing the morphology of the continuously cast brass ingots. It

allowed to adapt a proper development of the Ivantsov’s series in order to formulate the Growth Law for the columnar structure formation

in the brass ingots solidified in stationary condition. Simultaneously, the Thermal Peclet Number together with the Biot, Stefan, and

Fourier Numbers is used in the model describing the heat transfer connected with the so-called contact layer (air gap between an ingot and

crystallizer). It lead to define the shape and position of the s/l interface in the brass ingot subjected to the vertical continuous displacement

within the crystallizer (in gravity). Particularly, a comparison of the shape of the simulated s/l interface at the axis of the continuously cast

brass ingot with the real shape revealed at the ingot axis is delivered. Structural zones in the continuously cast brass ingot are revealed: FC

– fine columnar grains, C – columnar grains, E – equiaxed grains, SC – single crystal situated axially.

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Authors and Affiliations

A.A. Ivanova
Z. Lipnicki
P. Kwapisiński
W. Wołczyński
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Abstract

A vertical cut at the mid-depth of the 15-ton forging steel ingot has been performed by curtesy of the CELSA – Huta Ostrowiec plant.

Some metallographic studies were able to reveal not only the chilled undersized grains under the ingot surface but columnar grains and

large equiaxed grains as well. Additionally, the structural zone within which the competition between columnar and equiaxed structure

formation was confirmed by metallography study, was also revealed. Therefore, it seemed justified to reproduce some of the observed

structural zones by means of numerical calculation of the temperature field. The formation of the chilled grains zone is the result of

unconstrained rapid solidification and was not subject of simulation. Contrary to the equiaxed structure formation, the columnar structure

or columnar branched structure formation occurs under steep thermal gradient. Thus, the performed simulation is able to separate both

discussed structural zones and indicate their localization along the ingot radius as well as their appearance in term of solidification time.

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Authors and Affiliations

W. Skuza
B. Kania
P. Kwapisiński
W. Wołczyński
A.W. Bydałek
W. Wajda
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Abstract

There are presents the internal recycling in anode furnace, in addition to mainly blister copper and converter copper. During the process

there arise the two types of semi-finished products intended for further pyro metallurgical processing: anode copper and anode slag. The

stream of liquid blister copper enters into the anode furnace treatment, in which the losses are recovered, e.g. copper, resulting from

oxidation and reduction of sulfides, oxides and the oxidation of metallic compounds of lead, zinc and iron. In the liquid phase there are

still gaseous states, which gives the inverse relationship relating to the solid phase, wherein the gases found an outlet in waste gas or

steam. The results of chemical analysis apparently differ from each other, because crystallite placement, the matrix structure and the

presence of other phases and earth elements are not compared, which can be regained in the process of electrorefining. One should not

interpret negatively smaller proportion of copper in the alloy, since during the later part of the production more elements can be obtained,

for example from sludge, such as platinum group metals and lanthanides. According to the research the quality of blister copper, to a large

extent, present in the alloy phase to many other elements, which can be recovered.

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Authors and Affiliations

A.W. Bydałek
P. Schlafka
K. Grządko
W. Wołczyński
P. Kwapisiński
M. Wędrychowicz
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Abstract

The scope of work included the launch of the process of refining slag suspension in a gas oven using a variety of technological additives.

After the refining process (in the context of copper recovery), an assessment of the effect of selected reagents at the level of the slag

refining suspension (in terms of copper recovery). Method sieve separated from the slag waste fraction of metallic, iron - silicate and

powdery waste. Comparison of these photographs macroscopic allowed us to evaluate the most advantageous method of separating

metallic fraction from the slag. After applying the sample A (with KF2 + NaCl) we note that in some parts of the slag are still large

amounts of metallic fraction. The fraction of slag in a large majority of the elements has the same size of 1 mm, and a larger portion of the

slag, the size of which is from 2 to 6 mm. Definitely the best way is to remove the copper by means of the component B (with NaCl ) and

D (with KF2

). However, as a result of removing the copper by means of component C (with CaO) were also obtained a relatively large

number of tiny droplets of copper, which was problematic during segregation. In both cases we were able to separate the two fractions in a

fast and simple manner.

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Authors and Affiliations

P. Migas
S. Biernat
P. Kwapisiński
W. Wołczyński
A.W. Bydałek
A. Bydałek
K. Jasińska
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Abstract

The copper droplets contained in the post-processing liquid slag are subjected to the treatment by the complex reagent. The complex reagent has been recently elaborated and patented in frame of the Grant No. PBS3/A5/45/2015. In particular, the complex reagent is dedicated to the post-processing slags coming from the Smelter and Refinery Plant, Głogów, as a product of the direct-to-blister technology performed in the flash furnace. The recently patented complex reagent effectively assists not only in agglomeration, and coagulation but also in the deposition of the copper droplets at the bottom of crucible / furnace as well. The treatment of the postprocessing slags by the complex reagent was performed in the BOLMET S.A. Company as in the industrial conditions which were similar to those usually applied in the KGHM – Polish Copper (Smelter and Refinery Plant, Głogów). The competition between buoyancy force and gravity is studied from the viewpoint of the required deposition of coagulated copper droplets. The applied complex reagent improves sufficiently the surface free energy of the copper droplets. In the result, the mechanical equilibrium between coagulated copper droplets and surrounding liquid slag is properly modified. Finally, sufficiently large copper droplets are subjected to a settlement on the crucible / furnace bottom according to the requirements.
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Authors and Affiliations

C. Senderowski
W. Wołczyński
A.W. Bydałek
P. Migas
K. Najman
P. Kwapisiński
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Abstract

A brief description of the innovative mathematical method for the prediction of CET – localization in solidifying copper and copper alloys’ ingots is presented. The method is to be preceded by the numerical simulation of both temperature field and thermal gradient filed. All typical structural zones were revealed within the copper and copper alloys’ massive ingots or rods manufactured by continuous casting. The role of thermal gradient direction for the single crystal core formation has been enlightened. The definition for the index describing proportion between volume fraction of the columnar structure and volume fraction of the equiaxed structure has been formulated by means of the interpretation of some features of the liquidus isotherm velocity course. An attempt has been undertaken to apply the developed mathematical method for the structural zones prediction in the rods solidifying under industrial conditions. An industrial application has been shown, that is, it was explained why the innovative rods should be assigned to the overhead conductors in the electric tractions.
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Authors and Affiliations

P. Kwapisiński
1
ORCID: ORCID
W. Wołczyński
2
ORCID: ORCID

  1. KGHM Polska Miedź S.A., M. Skłodowskiej-Curie 48, 59-301 Lubin, Poland
  2. Institute of Metallurgy and Materials Science, W. Reymonta 25, 30-059 Kraków, Poland
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Abstract

The copper and copper alloys’ ingots have been subjected to structural observation in order to estimate the Peclet Number at which these ingots were solidifying. It was stated that the formation of columnar structure within the ingots occurred at a high Peclet Number, higher than the threshold value of this parameter, Pe = 500. The formulated relationships of the Growth Law correspond to a high Peclet Number due to application of the adequate development in series of the Ivantsov’s function. The Growth Law has been developed on the basis of the definition of the wavelength of perturbation which leads to the dispersion of the planar s/l interface. New definition of the index of stability connected with the behavior of solute concentration at the s/l interface has been delivered. The current definition is related to non-equilibrium solidification. The index can be easily calculated using some parameters delivered by a given Cu-X phase diagram. Physical meaning of the formulated Growth Law has also been presented.
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Authors and Affiliations

P. Kwapisiński
1
ORCID: ORCID
W. Wołczyński
2
ORCID: ORCID

  1. KGHM Polska Miedź S.A., ul. M. Skłodowskiej-Curie 48, 59-301 Lubin, Polska
  2. Institute of Metallurgy and Materials Sciences PAS, Reymonta St. 25, 30-059 Kraków, Poland

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