136 Livarski vestnik, letnik 70, št. 3/2023 
Določanje razmerja kovinskih komponent šarže v kupolki
Determining the Ratio of the Metal Components of the 
Charge at the Cupola Furnace
Povzetek
Talilna peč je najpomembnejša oprema v livarni. Za taljenje litega železa se uporabljajo 
različne vrste peči. Pri pripravi taline za visoko stopnjo proizvodnje se v obratih za litje 
železa uporabljajo predvsem kupolke ali električne talilne peči. Glavne prednosti kupolk v 
primerjavi z električnimi so: enostavna in gospodarna naprava, manj škodljiva za okolje, 
manjša občutljivost na nizkokakovostne materiale šarže in onesnaževalce, oksidacijske 
in redukcijske reakcije med taljenjem v kupolki potekajo znotraj talilne cone in nad njo, 
kar omogoča uporabo visoko oksidiranega in nizkokakovostnega odpadnega materiala, 
cenejših zlitin in nekovinskih dodatkov. Ena osnovnih tehnoloških težav pri delovanju 
kupolke je določitev razmerij med komponentami šarže, ki jo sestavljajo koks, topilo in 
kovinska šarža, da bi ustvarili talino z želeno kemijsko sestavo. V praksi je masno razmerje 
kovinske šarže in koksa v določenih vrednostih, prav tako tudi skupna masa topila glede na 
maso koksa. Izkazalo se je, da je glavna težava določitev sestavin kovinskega dela šarže, ki 
je običajno sestavljena iz odpadkov iz lastne proizvodnje, jeklenega odpada, kupljene sive 
litine, nodularne litine, silicijevega mangana, ferosilicija itd. V tem prispevku smo z metodo 
izbire iz razpoložljivega razpona izračunali deleže kovinskih komponent kovinskega dela 
šarže za izdelavo taline iz sive litine, standardizirane pod oznako EN-GJL-250: 
Ključne besede: kupolka, šarža, kovina, komponente
Summary
The most important equipment in a foundry is the melting furnace. Various types of furnaces 
have been used for cast iron melting. In cases of melt preparation for production at high 
capacities, the primary melting methods used in iron casting plants are cupola furnaces 
or electric melt furnaces. The main advantages of cupola furnaces compared to electric 
ones are: simple and economical device, less harmful to the environment, less sensitive 
to low-quality charge materials and contaminants, oxidation and reduction reactions take 
place within and above the melt zone during cupola melting, which allows the use of highly 
oxidized and low-quality scrap material, lower prices of alloys and non-metallic additions. 
One of the basic technological problems in the work of the cupola furnace is to determine 
the relationships between the charge components consisting of coke, flux, and metal charge 
to obtain a melt of a given chemical composition. In practice, the mass ratio of metal charge 
and coke is in certain mass relations as well as the total mass of flux in relation to the mass 
of coke. It turns out that the main problem is to determine the components of the metal part 
of the charge, which usually consists of waste of own production, steel scrap, purchased 
cast iron, nodular cast iron, silicon manganese, ferrosilicon, etc. In this paper, using the 
method of selection from the available range, the proportions of metal components of the 
L. Lazić
1
, M. Lovrenić-Jugović
1
, M. Borošić
2
1
Univerza v Zagrebu, Fakulteta za metalurgijo / University of Zagreb, Faculty of Metallurgy (CRO), 
2
ABS Sisak d.o.o. (CRO) / 

 Livarski vestnik, letnik 70, št. 3/2023 137
1 Uvod
Kupolka je visoka jaškasta peč z jeklenim 
obodom, obloženim z ognjevzdržnim 
materialom, uporablja pa se predvsem za 
proizvodnjo različnih vrst litega železa in 
brona za livne postopke. Nadaljuje se proces 
taljenja v peči, ki je primerna za predelavo 
grodlja, odpadkov lastne proizvodnje 
(odrezani konci, zavrnjeni izdelki), 
dodajajo se železove zlitine za zagotovitev 
kemijske sestave v primeru primanjkljajev v 
postopku taljenja [1]. Glavni vir energije za 
postopek taljenja je metalurški koks. Zaradi 
enostavnih delovnih postopkov ta vrsta peči 
pri optimalnih tehnoloških parametrih porabi 
majhno količino goriva [2]. Razdelki so 
razporejeni vertikalno, zato so primerni za 
tri ali štiri stojala [3]. V primerjavi s šaržnimi 
talilnimi napravami ima ta peč z navpičnim 
jaškom s protitokom veliko verjetnost 
dobrega talilnega učinka [4]. Sodobne 
kupolke so običajno opremljene z gorilniki 
za obogatitev s kisikom ali s plazemskimi 
gorilniki. S povečanjem stopnje segrevanja 
lahko kupolko upravljamo bolj fleksibilno, 
kar je pogosto potrebno pri proizvodnji 
ulitkov [5].
Procesni prostor kupolke je sestavljen 
iz naslednjih con, ki so razporejene 
navpično: zbiralnik, območje zgorevanja, 
območje redukcije, območje taljenja in 
območje predgretja (Slika 1). Staljeni 
material se zbira v zbiralniku. V zgorevalni 
ali oksidacijski coni poteka hitro zgorevanje 
koksa, pri čemer nastajata toplota in 
CO
2
. Temperatura se giblje med 1550 in 
1850 °C. Oksidacija silicija in mangana 
ustvarja dodatno toploto. Redukcija iz CO
2
 
v CO poteka v redukcijski coni. Zaradi te 
1 Introduction
The cupola furnace is a vertical shaft furnace 
with a steel shell, lined with refractory 
material, which is mainly used for the 
production of various types of cast iron and 
bronze in casting processes. The melting 
processes in the furnace continue which is 
capable of processing pig iron, waste of own 
production (crop ends, foundry returns), 
and the addition of ferroalloys to make the 
chemical compositions in a case where 
there is a shortfall in the melting processes 
[1]. Metallurgical coke is the principal energy 
source for the melting process. Due to the 
simple operational processes, this type of 
furnace consumes a low amount of fuel at 
optimal technological parameters [2]. The 
sections are arranged in a vertical position 
to withstand the three or four stands [3]. 
Compared to batch-type melters, this 
counterflow vertical shaft furnace has a 
high likelihood of good melting performance 
[4]. Modern cupola installations are usually 
equipped with either oxygen enrichment or 
plasma torches. By increasing the heating 
rate, the cupola can be operated more 
flexibly, which is often necessary in casting 
production [5].
The process space of the cupola 
furnace consists of the following zones 
arranged in a vertical position: well zone, 
combustion zone, reducing zone, melting 
zone, and preheating zone (Figure 1). The 
molten material is collected in the well zone. 
In the combustion or oxidizing zone, rapid 
combustion of coke takes place generating 
heat and CO
2
. The temperature varies 
from 1550 to 1850°C. Oxidation of silicon 
and manganese generates additional heat. 
metal part of the charge were calculated to produce a gray cast iron melt standardized with 
the code EN-GJL-250. 
Key-words: cupola furnace, charge, metal, components

138 Livarski vestnik, letnik 70, št. 3/2023 
endotermne reakcije se temperatura v tej 
coni zniža na približno 1200 °C. Posebnost 
te cone je, da ustvarjena redukcijska 
atmosfera šaržo varuje pred oksidacijo. V 
talilni coni se kovinska šarža začne topiti in 
še naprej uhaja proti zbiralniku. Pri prehodu 
skozi redukcijsko cono staljeno železo 
pobere ogljik, ki tvori Fe
3
C. V zbiralniku se 
topilo prav tako tali in reagira z nečistočami 
v staljeni kovini; posledično nastaja žlindra, 
ki plava na površini staljene kovine in jo 
varuje pred oksidacijo.
Ta prispevek obravnava težavo 
določanja razmerja med komponentami 
šarže, da bi ustvarili talino z želeno kemijsko 
sestavo. V praksi je masno razmerje med 
šaržo kovin in koksom od 1:10 do 1:8. 
Apnenec je pogosto topilo. Skupna masa 
apnenca je običajno enaka 20 % mase 
koksa [6]. Zato je glavna težava določitev 
komponent kovinskega dela šarže. Za 
določanje sestavin kovinskega dela šarže 
Reduction of CO
2
 to CO occurs in the 
reduction zone. Due to this endothermic 
reaction, the temperature in this zone 
decreases to approximately 1200°C. A 
special feature of this zone is that the 
created reducing atmosphere protects 
the charge from oxidation. In the melting 
zone, the metal charge starts melting and 
continues to leak toward the well zone. 
Passing down through the reduction zone 
the molten iron picks up carbon forming 
Fe
3
C. In the well zone, the flux also melts 
and reacts with the impurities of the molten 
metal forming a slag, which floats on the 
surface of the molten metal protecting it 
from oxidation.
This article discusses the problem 
of determining the relationship between 
the components of the charge to obtain a 
melt of a given chemical composition. In 
practice, the mass ratio of metal charge 
and coke is in the range of 1:10 to 1:8. 
Limestone is a common flux. The total mass 
of limestone is usually 20% of the mass of 
coke [6]. For that reason, the main problem 
is to determine the components of the metal 
part of the charge. When determining the 
components of the metal part of the charge, 
three methods are usually used: The 
analytical method, the graphic method, the 
so-called Triangle method, and the method 
of selection from the available range [7]. 
In this paper, using the latter method, the 
proportions of metal components of the 
metal part of the charge were calculated to 
produce a gray cast iron melt standardized 
with the code EN-GJL-250.
Slika 1. Shematski prerez kupolke
Figure 1. Schematic cross-sectional view of the 
cupola furnace

 Livarski vestnik, letnik 70, št. 3/2023 139
se običajno uporabljajo tri metode: analitična 
metoda, grafična metoda, t. i. metoda 
trikotnika ena metoda preveč in metoda 
izbire iz razpoložljivega območja [7]. V tem 
prispevku smo z uporabo slednje metode 
izračunali deleže kovinskih komponent 
kovinskega dela šarže za izdelavo taline iz 
sive litine, standardizirane pod oznako EN-
GJL-250.
2 Izračun kovinskih komponent šarže  
 na 100 kg taline
Kemijska sestava sive litine (EN-GJL-250) 
je podana v Preglednici 1, vrstica 1, 
komponente kovinske šarže pa v isti 
preglednici v naslednjem vrstnem redu: 
odpadki iz lastne proizvodnje (vrstica 4), 
kupljena siva litina (vrstica 5), odpadno 
jeklo (vrstica 6), nodularna litina (vrstica 9), 
beli grodelj (vrstica 10), silicijev mangan 
(vrstica 13), ferosilicij (vrstica 14).
Med prehajanjem skozi redukcijsko 
cono staljeno železo pobere ogljik z 
naslednjo reakcijo:
3Fe + 2CO → Fe
3
C + CO
2
Po drugi strani pa potekajo reakcije 
oksidacije mangana in silicija v območju 
zgorevanja z reakcijami:
2Mn + O
2
 → 2MnO + toplota
Si + O
2
 → SiO
2
 + toplota
Iz tega razloga se glede na dejanske 
proizvodne podatke [7] ogljik poveča za 
12,5 %, silicij zmanjša za 22,5 % in mangan 
za 27,5 % v primerjavi z začetnim stanjem 
šarže. Med postopkom taljenja se količina 
žvepla poveča za 62,5 %, količina fosforja pa 
se bistveno ne spremeni, zato sprememba 
količine fosforja med postopkom taljenja ni 
upoštevana (Preglednica 2, vrstica 2).
Zahtevana povprečna vsebnost 
elementa E
ch
 v šarži ob upoštevanju njegove 
2. Calculation of Charge Metal  
 Components Per 100 kg of the Melt
The chemical composition of the gray cast 
iron (EN-GJL-250) is given in Table 1, row 
1, and the metal charge components in the 
same table in the following order: Waste of 
own production (row 4), Purchased gray 
cast iron scrap (row 5), Steel scrap (row 
6), Nodular cast iron (row 9), White pig iron 
(row 10), Silicomanganese (row 13), and 
Ferrosilicon (row 14).
While passing down through the 
reduction zone the molten iron picks up 
carbon by reaction:
3Fe + 2CO → Fe
3
C + CO
2
On the other side, the reactions of 
oxidation of manganese and silicon take 
place in the combustion zone by reactions:
2Mn + O
2
 → 2MnO + heat
Si + O
2
 → SiO
2
 + heat
For this reason, according to actual 
production data [7], carbon has an increase 
of 12.5%, silicon has a decrease of 22.5%, 
and manganese of 27.5% compared to the 
initial state of the charge. During the melting 
process, the amount of sulfur has an 
increase of 62.5%, and phosphorus does 
not change significantly, so the change 
in the amount of phosphorus during the 
melting process is not taken into account 
(Table 2, row 2).
The required mean content of the 
element E
ch
 in the charge, taking into 
account its change in the melting process, 
is calculated according to the expression:
E
ch
 = E
m
 · (100 – X) / 100, %    (1),
where E
m
 is the content of the element in 
the molten metal, and X is the amount of 
increase or decrease of the element during 
the melting process (in the expression sign 
- in case of an increase, i.e., sign + in case 

140 Livarski vestnik, letnik 70, št. 3/2023 
Preglednica 1. Kemijska sestava sive litine (EN-GJL-250) in sestavine kovinske šarže
Table 1. The chemical composition of the gray cast iron (EN-GJL-250) and the components of metal 
charge
Materiali šarže /  
Charge materials
Masni delež /
Mass fraction
% (kg)
Kemijska sestava / Chemical composition
C Si Mn P S 
% kg % kg % kg % kg % kg
1.
Zahtevana sestava taline / 
Required melt composition
100 3 3 1,8 1,8 0,7 0,7 0,15 0,15 0,1 0,1
2.
Povečanje/zmanjšanje mase 
elementov /  
Increase / Decrease of the 
mass of the elements
12,5 0,43 -22,5 -0,41 -27,5 -0,23 0 0 62,5 0,062
3.
Potrebna povprečna 
vsebinska sestava šarže /  
Required mean content 
composition of the charge
2,63 2,63 2,21 2,21 0,9 0,9 0,15 0,15 0,04 0,038
4.
Odpadki iz lastne 
proizvodnje /  
Waste of own production
20 3 0,6 1,8 0,36 0,7 0,14 0,15 0,03 0,1 0,02
5.
Kupljena odpadna siva litina 
/ Purchased cast iron scrap
15 3,2 0,48 2 0,3 0,7 0,105 0,2 0,03 0,1 0,02
6.
Odpadno jeklo (v skladu z 
izračunom) /  
Steel scrap (according to the 
calculation)
14 0,3 0,042 0,4 0,056 0,7 0,098 0,05 0,01 0,05 0,007
7. Skupni vnos / Total entered 49 1,122 0,716 0,336 0,04 0,047
8.
Potreba po vnosu /  
Need to enter
51 1,503 1,489 0,556 0,11 0,009
9.
Nodularna litina, (A) / 
Nodular cast iron, (A)
21 3,4 0,714 2,2 0,462 0,4 0,084 0,12 0,03 0,02 0,0042
10.
Beli grodelj, (B) /  
White pig iron, (B)
30 3,6 1,08 1 0,3 0,3 0,09 0,08 0,03 0,02 0,006
11. Skupaj / Total 100 2,916 1,478 0,51 0,16 0,058
12.
Primanjkljaj/presežek po 
elementih /  
Deficit/surplus by elements
0,286 -0,732 -0,379 0,01 0,02
13.
Silicijev mangan MnSi
20
 / 
Silicomanganese MnSi
20
0,748 1,5 0,01 20 0,150 65 0,486 0,1 0,0007 0,02 0,0001
14.
Ferosilicij FeSi
20
 / 
Ferrosilicon FeSi
20
3 1 0,03 20 0,6 1 0,03 0,2 0,006 0,02 0,0006
15. Skupaj / Total 103,748 2,956 2,228 1,026 0,17 0,058
16.
Razlika glede na sestavo 
taline /  
Difference in relation to the 
given melt composition
3,748 +0,04 +0,018 +0,126 +0,02 +0,02
spremembe v postopku taljenja se izračuna 
s formulo:
E
ch
 = E
m
 · (100 – X) / 100, %   (1)
kjer je E
m
 vsebnost elementa v staljeni kovini, 
X pa je količina povečanja ali zmanjšanja 
elementa med postopkom taljenja (v 
of a decrease). Example of calculating the 
required carbon content in the charge:
C
ch
 =3 · (100 – 12,5) / 100 = 2,625 %.
The calculation for Si, Mn and S is 
performed in an analogous way. The results 
are shown in Table 1, row 3.

 Livarski vestnik, letnik 70, št. 3/2023 141
formuli znak – v primeru povečanja in znak 
+ v primeru zmanjšanja). Primer izračuna 
zahtevane vsebnosti ogljika v šarži:
C
ch
 =3 · (100 – 12,5) / 100 = 2,625 %.
Izračun za Si, Mn in S se izvede na enak 
način. Rezultati so prikazani v Preglednici 
1, vrstica 3.
Da bi zagotovili želeno sestavo taline, 
je treba zmanjšati vsebnost ogljika. To je 
mogoče doseči z zahtevanim deležem 
jeklenih odpadkov v šarži. To količino je 
mogoče določiti na podlagi ravnotežne 
enačbe ogljika v šarži:
C
ch.st
 · m
st
 + (100 – m
st
) · C
ch.m
 = C
ch
 · 100 (2)
kjer so C
ch.st
 vsebnost ogljika v jeklenih 
odpadkih (%), m
st
 masa jeklenih odpadkov 
(kg), C
ch.m
 želena vsebnost ogljika v talini 
(%), C
ch
 predizračun vsebnosti ogljika v 
šarži (%).
Z vnosom podatkov v enačbo (2) 
dobimo:
0,3
t
 · m
st
 + (100 – m
st
)
t
 · 3,0 = 2,625
t
 · 100
     = 13,88 kg
Za nadaljnji izračun se privzame 
vrednost 14 kg jeklenega odpadka na 100 
kg šarže. Masa ogljika, vnesenega v šaržo 
z jeklenimi odpadki, se izračuna, kot sledi: 
C
st
 = 0,3 · 14/100 = 0,042 kg. Izračun za Si, 
Mn in S se izvede na enak način. Rezultati 
so prikazani v Preglednici 2, vrstica 6.
Običajno se v sestavo kovinske 
šarže doda 15 % lastnih odpadkov in 15 
% kupljene sive litine. Sestava in deleži 
posameznih komponent so prikazani v 
Preglednici 1, vrstici 4 in 5. Vsota vseh 
komponent je prikazana v 7. vrstici. Na 
podlagi razlike med 3. in 7. vrstico (vrstica 
8) dobimo mase posameznih elementov, ki 
jih dodamo šarži.
Za primer vzemimo livarno, ki ima na 
razpolago nodularno litino (vrstica 9) in belo 
litino (vrstica 10). Za določitev njihovega 
deleža v kovinski šarži glede na zahtevano 
In order to obtain the desired melt 
composition, it is necessary to lower the 
carbon content. This can be achieved by 
the required proportion of steel scrap in the 
charge. This amount can be determined 
from the carbon balance equation in the 
charge:
C
ch.st
 · m
st
 + (100 – m
st
) · C
ch.m
 = C
ch
 · 100  (2)
where are C
ch.st
 the content of the carbon in 
steel scrap (%), m
st
 the mass of steel scrap 
(kg), C
ch.m
 the desired content of carbon in 
the melt (%), C
ch
 pre-calculate the carbon 
content in the charge (%).
Entering data into the equation (2) is 
obtained:
0,3
t
 · m
st
 + (100 – m
st
)
t
 · 3,0 = 2,625
t
 · 100
     = 13,88 kg
For further calculation, a value of 14 
kg of steel scrap per 100 kg of charge is 
adopted. The mass of carbon introduced 
into the charge with steel scrap is calculated 
as follows: C
st
 = 0.3 · 14/100 = 0.042 kg. The 
calculation for Si, Mn, and S is performed 
analogously. The results are shown in Table 
2, row 6.
Usually, 15% of own waste and 15% 
of purchased gray cast iron are added to 
the composition of the metal charge. The 
composition and proportions of individual 
components are shown in Table 1, rows 4 
and 5. The sum of all components is shown 
in row 7. The masses of the individual 
elements to be added to the charge were 
obtained on the difference between the 3rd 
and 7th rows (row 8).
Take, for example, the foundry has 
at its disposal Nodular Cast Iron (row 9) 
and White Cast Iron (row 10). In order to 
determine their share in the metal charge 
concerning the required melt composition, it 
is necessary to set up a balance equation in 
which the letter A denotes Nodular Cast Iron 
and B White Cast Iron. The calculation is 

142 Livarski vestnik, letnik 70, št. 3/2023 
sestavo taline je treba sestaviti ravnotežno 
enačbo, v kateri je s črko A označena 
nodularna litina, z B pa bela litina. Izračun 
se glede na vsebnost silicija izvede, kot 
sledi:
A + B + 49 = 100
2,2 · A + 1,0 · B = (A + B) · 1,489
A = 20 %  B = 31 %
V 9. in 10. vrstico je treba vnesti 
izračunane deleže in izračunati masne 
deleže posameznih elementov z naslednjo 
formulo:
E
i
 = E
i
’ · A / 100     (3)
kjer so A masa komponente šarže (kg), E
i
’ 
delež elementa i v komponenti šarže.
Potrebno je primerjati povprečno 
sestavo začetne sestave šarže po elementih 
(vrstica 3) z izračunanimi vrednostmi (vrstica 
11) in rezultate vpisati v vrstico 12. Znak 
(+) označuje presežek, (-) pa primanjkljaj 
posameznega elementa. Izkazalo se je, 
da je treba dodati 0,732 kg silicija in 0,379 
kg mangana. Ta primanjkljaj je mogoče 
nadomestiti s silicijevim manganom 
MnSi20 (65 % Mn, 20 % Si) in ferosilicijem 
FeSi20 (20 % Si, 1,0 % Mn) (vrstici 13 in 
14). Izračun potrebne mase silicijevega 
mangana za nadomestitev primanjkljaja 
mangana s stopnjo uporabnosti 0,95:
m
MnSi
 = 0,462 · 100 / (65 · 0,95) = 0,748 kg
Masa silicija, dodanega s silicijevim 
manganom, je:
m
MnSi
 = X
Si
 · 100 / (20 · 0,95) 
X
Si
 = m
MnS
 · 20 · 0.95 / 100 = 0.142 kg
Primanjkljaj silicija (0,732 - 0,142) = 
0,59 kg je mogoče nadomestiti z dodatkom 
ferosilicija:
m
FeSi
 = 0,59 · 100 / (20 · 0,95) = 3,1 kg 
(zaokroženo na vrednost 3,0)
performed according to the silicon content, 
in the following way:
A + B + 49 = 100
2,2 · A + 1,0 · B = (A + B) · 1,489
A = 20 %  B = 31 %
It is necessary to enter the calculated 
proportions in rows 9 and 10 and to calculate 
the mass fractions of individual elements 
using the expression:
E
i
 = E
i
’ · A / 100     (3)
where are A mass of charge component 
(kg), E
i
’ the proportion of the i-th element in 
the charge component.
It is necessary to compare the mean 
composition of the initial composition of 
the charge by elements (row 3) with the 
calculated values (row 11), and enter the 
results in row 12. The sign (+) indicates 
the surplus, and (-) the deficit of an 
individual element. It turns out that it is 
necessary to add 0.732 kg of silicon and 
0.379 kg of manganese. This deficit can 
be compensated by silicon manganese 
MnSi
20
 (65%Mn, 20% Si) and ferrosilicon 
FeSi
20
 (20% Si, 1.0%Mn) (rows 13 and 
14). Calculation of the required mass of 
silicon manganese to compensate for the 
manganese deficit with a degree of usability 
of 0.95:
m
MnSi
 = 0,462 · 100 / (65 · 0,95) = 0,748 kg
The mass of silicon introduced with 
silicon manganese is:
m
MnSi
 = X
Si
 · 100 / (20 · 0,95) 
X
Si
 = m
MnS
 · 20 · 0.95 / 100 = 0.142 kg
Silicon deficit of (0.732 - 0.142) = 
0.59 kg can be compensated by adding 
ferrosilicon:
𝑚 FeSi
 = 0,59 · 100 / (20 · 0,95) = 3,1 
kg (Rounded to the value of 3.0)

 Livarski vestnik, letnik 70, št. 3/2023 143
Vrstica 16 prikazuje razliko med 
izračunano sestavo šarže glede na 
zahtevano sestavo taline. Razlike so 
praktično zanemarljive. V praksi se v 
primeru majhnih razlik v količinah C, P in 
C korekcija sestave komponent šarže ne 
izvaja.
3 Sklepi
Za izdelavo taline sive litine, standardizirane 
pod kodo EN-GJL-250, v kupolki, naj bi na 
podlagi rezultatov izračuna 100 kg kovinske 
šarže sestavljalo naslednje: odpadki iz 
lastne proizvodnje 20 kg, kupljena siva litina 
15 kg, odpadno jeklo 14 kg, nodularna litina 
21 kg, beli grodelj 30 kg, silicijev mangan 
0,748 kg, ferosilicij 3 kg. Razlika dodanih 
3,748 kg kovinskega dela šarže ne vpliva 
bistveno na zahtevano sestavo taline.
Predstavljeni primer izračuna sestave 
kovinskega dela šarže pri taljenju v 
kupolki se je v praksi izkazal za izredno 
učinkovitega. Vendar pa je enak način 
izbire iz razpoložljivega obsega mogoče 
uporabiti tudi v primeru drugih vrst talilnih 
peči za proizvodnjo ulitkov ob upoštevanju 
posebnosti dela vsake od teh peči.
Kot primer izračuna sestave kovinskega 
dela šarže smo zaradi zahtevnejših 
procesnih reakcij v primerjavi z drugimi, na 
primer električnimi pečmi, izbrali kupolko. 
Očitno je, da je pri ostalih naštetih pečeh 
izračun šarže manj zahteven.
Row 16 shows the difference between 
the calculated charge composition with 
respect to the required melt composition. 
The differences are practically negligible. In 
practice, in the case of small differences in 
the amounts of C, P and C, the correction of 
the composition of the charge components 
is not performed.
3 Conclusion
In order to produce the cast iron melt 
standardized with the code EN-GJL-250 in 
the cupola furnace, according to the results 
of the calculation, 100 kg of metal charge 
should consist of: Waste of own production 
20 kg, purchased gray cast iron 15 kg, Steel 
scrap 14 kg, Nodular cast iron 21 kg, White 
pig iron 30 kg, Silicomanganese 0.748 kg, 
Ferrosilicon 3 kg. The difference of the 
added 3.748 kg of metal part of the charge 
does not significantly affect the required 
melt composition.
The presented example of the 
calculation of the composition of the metal 
part of the charge for the case of melting in 
a cupola furnace, proves to be very effective 
in practice. However, the same method of 
selection from the available range can be 
applied in the case of other types of melting 
furnaces in casting production, taking into 
account the specifics of the work of each 
of them.
As an example of the calculation of the 
composition of the metal part of the charge, 
the cupola furnace was chosen because of 
more complex process reactions compared 
to others, for example, electric furnaces. 
Clearly, in the other listed furnaces, the 
charge calculation is less demanding.

144 Livarski vestnik, letnik 70, št. 3/2023 
Viri / References
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of Foundry Cupolas”. Philadelphia, PA: Baird, 2008, str. 95–250
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10.51542/ijscia.v2i2.3
[3] Larsen, E.D., Clark, D.E., Smartt, H.B., and Kevin L. M. Intelligent Control of Cupola 
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215–219.
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- and Fuel, Alloy Costs, Foundry Management & Technology; Nashville Vol. 144, Iss. 1, 
2016, str. 18
[6] Matyuhin, V.I., Matyuhin, A.V. Calculation and design of a cupola complex for iron 
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5-9904848-2-5.