POSSIBILITIES AND PERSPECTIVES FOR DEVELOPMENT OF METALLURGY IN THE REPUBLIC
OF MACEDONIA
MOŽNOSTI IN PERSPEKTIVE ZA RAZVOJ METALURGIJE V REPUBLIKI MAKEDONIJI
JOVAN K. MICKOVSKI1, N. NACEVSKI1, B. NIKOV2, S. MILOSEVSKI3
'Faculty of Technolo|>y and Metallurgy, University 'St. Cyril and Metodius', R. Boškovic b.b., 91000 Skopje, Macedonia -Department of Science 'Zletovo' - Metallurgical and Chemical Company, Veles 'Administration for International Scientific and Technical Cooperation, Ministry of Science
Prejem rokopisa - received: 1997-10-01; sprejem za objavo - accepted for publication: 1997-10-21
Installed metallurgical capacities in the Republic of Macedonia exceed the local market and a significant share of products is exported. These exports represent a very significant share of foreign currency inflovv. The production of steel is based on scrop import. Ferroalloys industry shows improving performances because of transformation of ownership and restructuring. The increasing of production capacities is expected and especially it is planned to build facilities for exploitation of ali lead in zine concentrates produced in Macedonia.
Key words: Macedonia, metallurgical industry, production of steel, ferroalloys, lead, zine, cadmium, silver
Instalirane metalurške kapacitete v Republiki Makedoniji presegajo absorbcijo domačega trga in precejšnja količina proizvodov se izvaža. Ta izvoz predstavlja pomemben deleže dotoka deviz. Proizvodnja jekla bazira na uvozu starega železa. Proizvodnja ferolegur kaže naraščujoče dosežke zaradi olastninjenja in restrukturiranja. Pričakuje se povečanje kapacitet, predvsem pa se načrtuje povečanje exploatacije koncentratov svinca in cinka.
Ključne besede: Makedonija, metalurška industrija, proizvodnja jekla, ferozlitine, svinec, cinka, kadmij, srebro
1 INTRODUCTION
The capacities of ferrous and non ferrous metallurgy are overextended considering the market requirements in the Republic of Macedonia. In accordance vvith the fifty years period of development of the Republic of Macedonia, vvithin the former Yugoslav Federation, and the natural resources, the strategic development of ferrous metallurgy of the Republic of Macedonia vvas projeeted in accordance vvith the capacities in Slovenia and the previously started construction of the Steel Complex in Zenica, Bosnia and Herzegovina (BH). The strategy of the Yugoslav industrial development vvas strongly ori-ented tovvards the West European market and the regions more closer to Europe vvere developed as final exporters for vvestern markets. Other regions should have sup-ported the technological and the industrial development of northern regions through ravv materials, and have pro-vided food and other less finalized products for local markets.
The production of steel in Macedonia, the primary processing of steel sheets and the production of ferro-chrome and ferrosilicon, combined vvith Slovenian production should have supplied the Yugoslav market vvith beaded profiles. Profiled steel should have been provided by the Republic of BH vvhile the production of tubes vvas given to the Steel Complex in Sisak, Republic of Croatia.
In the former SFRY, the planed roles did not change, not even after the year 1970 and in Macedonia, tvvo large extractive metallurgical capacities, one for ferroalloys
(FeNi) and the second for lead and zine, have been built. Processing plants for these ravv materials have not been foreseen in Macedonia.
Considering the industrial structure in Macedonia vvith the processing of steel and other metals vvas far be-lovv the installed capacities for steel constructions and seam tubes, as vvell as the disproportion betvveen extrac-tive and processing units in steel industry, the Mace-donian ferrous industry vvas forced tovvards foreign markets. The foreseen supply vvith semi finished products for the Steel Complex Skopje from the Steel Complex in Smederevo has never been accomplished since, and be-side the blast furnaces and the steel plant, rolling mills for profiles almost identical to the assortment of the Steel Complex in Skopje vvere built in Serbia. The steel processing capacities in Macedonia, vvere left vvithout ravv materials, and faced vvith the local market competi-tion. The solution vvas found in the import of semi-fin-ished products, mainly from the former USSR and other foreign markets.
2 FERROUS METALLURGY
At present, in the Republic of Macedonia, the follovv-ing metallurgic capacities for production and processing of steel and ferroalloys are in operation: - Electric Steel Processing Plant and Rolling Mili in Skopje "Rudnici i Zelezarnica Skopje"
-	Chemical Electric-Metallurgical Complex "Jugo-hrom", in Jegunovce (in the vicinity of Tetovo)
-	Company with mixed ownership for production of ferronickel "Fenimak" in Kavadarci
-	Factory for welded tubes "11 Oktomvri" in Kuma-novo
2.1 Steel complex 'Skopje'
The Steel Complex in Skopje was built in accordance to the silicate ores reserves on the territory of Mace-donia. Due to the lack of cocking coal, and considering the large reserves of lignite in Serbia, electrometallurgy procedure vvith lovv combustion electro reduction furnaces and prereduction in rotation furnaces vvith lignite, vvas selected. For the beneficiation of the charge up to 42% Fe, a peletisation unit for the magnetic iron ore from the Damjan Mine, in the vicinity of Radovis, vvas built vvith magnetic separation, and use of imported fer-rous concentrates. The 5 electroreduction lovv combustion furnaces vvith the installed povver of 195 MW and five 90 m long rotation furnaces, vvere projected to pro-duce about 600.000 t/years of pig iron. Hovvever, due to unsolved technological problems, the production of pig was obtained mainly by reduction of the cold charge in the electric furnaces, vvhich, besides the unfavorable chemical content - high concentration of silicium vvith-out manganese - significantly increased the priče of pig iron. Within a period of 25 years of production, the projected capacity vvas not achieved because of back of re-ducing agents and of electric power. Because of these limiting factors and technological problems in the pre-re-duction process, for vvhich numerous pilot and semi-in-dustrial researches have been carried out, the maximum production ever reached vvas 280.000 t/year'.
The processing of pig iron vvith high content of silicon vvas achieved in tvvo LDAC converters, 130 t each. Because of the small individual capacity of the electric furnaces for homogenization of the chemical content and maintenance of temperature tvvo reservoirs for liquid iron vvere provided. Pig iron from the electric furnaces vvith more than 2% Si, vvas processed in the unit for desiliconition in pig iron ladle. The steel obtained from the converters vvas čast in slab ingots up to 1981, later a continuous caster for slabs vvas built.
In order to provide the ovvn steel required by the roll-mg mili capacity, an electric are furnace of 100 t vvas build and additional 200.000 t of pig steel provided. In 1988, the capacity of the electric are furnace vvas increased to 350.000 t/year, vvhile in the second phase, by melting of serap iron steel production vvas planned to reach 500.000 t/year. Hovvever, due to technological problems in the computerized electric are furnace and difficulties in the supply of appropriate and sorted serap iron, the nevv furnace did reach only a yearly production of 250.000 t/year steel.
The basic product are lovv carbon and carbon manganese structural as vvell as ship plates and boiler plates. 558
Later also the production of microalloyed steels vvith niobium, vanadium, titan and zirconium vvas developed. The converters vvere also suitable for the production of deep dravving steels.
The Steel Complex 'Skopje' includes the follovving three rolling mills:
-	Hot rolling mili for 3.000 mm heavy plates vvith the capacity of 500.000 t/year, on a reversible four-high rolling stand, vvith a vertical duo-stand on line
-	Hot rolling mili for 1.600 mm rolled strips vvith the capacity of 850.000 t/year, vvith a four-high rolling pre-stand and a final six stands train vvith four-high rolling stands; and
-	Rolling mili for cold rolled strips vvith tvvo lines: (a) a five stands train vvith the capacity of 500.000 t/year and (b) a four-high reversible stand of 300.000 t/year.
The cold rolling mili includes also a department zine coating vvith the capacity of 100.000 t/year as vvell as a line for plastification of plates vvith the capacity of 25.000 t/year.
The rolling mili capacities vvere built for about 2.000.000 t/year of final products, vvhile the maximal production obtained by the Steel Complex 'Skopje' vvas 1.250.000 t/year because of the lack of steel of ovvn production. Considering the discrepancies in the primary metallurgical and processing production the Steel Com-plex vvas forced to import semi products or to undertake loan arrangements.
The Macedonian market could absorb maximally 100.000 t/year cold roll and plates, vvhile the possibilities for absorption of hot mili strips are greater since the Fac-tory for vvelded tubes vvith the capacity of about 600.000 t/year is located at a distance of about 35 km from the Steel Complex. The Steel Complex disposed of the ma-jority of production on the markets of the former Yugo-slav republics and to export markets.
After 1991 a significant decrease in production oc-curred due to the economic and political erisis in the former USSR, the main foreign partner and in the former SFRY. Consequently, in the follovving 4 years the production of the Steel Complex vvas significantly decreased and than even discontinued.
The cost of production of pig iron in electroreduction lovv combustion furnaces and steel in converters vvas too high and in 1988 it vvas stopped.
Also the costs analyses of steel production from local ores led to its stopping. Lately tvvo electric reduction furnaces vvere restruetured and the production of ferroman-ganese and siliconmanganese vvas started on the base on imported ravv materials. The actual production amounts to 36.000 t/year of ferromanganese and 44.000 t/year siliconmanganese. Other units vvere preserved and the converter unit vvas dismantled.
2.2 Production of 'Jugohrom' Jegunovce
The enterprise 'Jugohrom' is the producer of mass ferroalloys as FeSi, FeCr, silicon metal and silicon-chrome primarily for the requirements of the ferrous metallurgy and casting industry of the former SFRY. The products are lately totally exported.
The capacity of 'Jugohrom' vvas rebuilt for a modern production of ferroalloys, vvith melting aggregates vvith medium and large installed povver; permanently moder-nized in terms of technique and technology, providing:
-	Increased production compared to the originally pro-jected;
-	Alternative production and quick adjustment to the market conditions, necessary for a competitive mar-ket oriented production;
-	Improvement of operating conditions;
-	Environment protection etc.
The production of ferroalloys in 'Jugohrom' in ac-cordance vvith its assortment can be performed in nine electric furnaces vvith the total installed capacity of 140.2 MVA, in accordance vvith the schedule presented in Table 1.
The intensive development of processes of ladle processing for acquiring ferroalloys vvith improved physical-mechanical properties, as vvell as technological and exploitation characteristics required the application of a broad scale of complex alloys - modifficators for čast iron. Based on these trends of development in met-allurgy, in the current phase of modernization, 'Jugohrom' has developed the technology for production of complex alloys-modificators based on ferrosilicon used as inoculant and nodulators.
The production of these alloys is based on FeSi, vvith addition of Mn, Ba, Ca, Al, Mg, Ce, MM, and C. By ap-plying the direct procedure, a further alloy-up of melted FeSi or its alloys into a melting pot vvith spilling, sinking and mixing homogenous complex alloys - modificators of a broad assortment like FeSi, FeSiAl, FeSiMn,
FeSiBa, FeSiBaMn, FeSiMgCeMM and composite mix-tures FeSiC and FeSiBaC are obtained.
The production capacity and assortment depend of the demand on local as vvell as on export markets.
The metallurgical production in 'Jugohrom' vvas con-ditioned by the development of nevv technologies of steel production and casting of gray and nodular iron, primar-ily by the ladle processing by modification, alloying and microalloying, providing a high yield of metal and ferro alloys. From this point of vievv, the long-standing experi-ence of 'Jugohrom' vvill be directed in future tovvards:
-	quality improvement of the present assortment of ferroalloys and modificators;
-	production of special, fine ferroalloys, especially of fine FeSi, by application of nevv technologies;
-	extension of the production of complex alloys -modificators vvith nevv more efficient types and assortment of inoculators and nodulators;
-	introduction of quality FeSi vvith lovv content of Si: FeSi 15 (14-16 Si) for production of resolvable an-odes for cathodic protection, FeSi 15 povvder for separation of ore minerais in heavy liquids;
-	development of auxiliary devices for casting indus-try and metallurgy;
Development of dust collecting and utilization of vvaste gases heat and its conversion into electric povver, ali contributing to the environment protection and improvement of the overall operation of the enterprise.
2.3 Production of ferronickel
The Ferronickel producer 'Feninmak' in Kavadarci is organized as a share holding company and exploits local ravv materials of laterite type.
The technological process includes are beneficiation and preparation for metallurgical processing based on differences in density and magnetic properties of minerais in the ore and the distribution of the nickel. The process is performed in the plant for ore pulverizing, pneu-matic, dry and vvet magnetic separation, as vvell as for
Table 1: Characteristics of the melting units in 'Jugohrom'
Furnace	TVpe of the furnace	Install. capacity MVA	Type of electrodes	Production of ferroalloys		
				Basic		Alternative
				Type	Production technical capacities t/year	
I	Electric-arc reduction	6.5	A	Si-metal	3.400	FeSi45/75/90
11	"	10.0	A	"	4.000	"
III	"	6.5	A		3.00	FeSi45/75/90 SiCr
IV	"	16.0	A	"	5.200	FeSi45/75/90 Cr
V	Electric-arc rafin.	3.5	G	LC FeCr	4.500	"
VI	Electric-arc slake	4.4	So	FeSi 75	13.300	FeSi 45/CaC2
VII	Electric-arc reduction	21.3	So	FeSi 75	13.300	FeSi 45/CaC2
VIII	„	48.0	So		34.000	FeSi 45
IX	"	24.0	So	"	14.000	FeSi 45HCFeCr
Total	9	140.2			77.300	
pelletisation of nickel concentrate. It has been foreseen that the magnetic fraction in the ore should be about 30%, representing the ferrous concentrate, vvith a Iower content of nickel and the difference with higher nickel content.
Besides preparation and pelletisation, the technologi-cal process includes roasting of the pellets, their pre-re-duction in rotation furnaces by addition of lignite and melting of the pre-reduced material into 16% FeNi, vvhich is further refined up to 45% FeNi into oxidind converters. Two pyrometallurgical lines with separate ro-tating and rectangular electric furnaces with six Sode-berg electrodes set in line are in operation. The projected total capacity of the plant vvas 21.000 t/year nickel in FeNi by average ore content of 1.03% Ni. So far only one technological line vvas used:.
Changes in mining technology and unprecise previ-ous geological investigations lead to a very small magnetic fraction vvith higher percentage of nickel during ex-ploitation and affected the production costs. Consequently, magnetic concentration is being avoided and the overall ore supply is ground and pelletized.
Nickel is a stock exchange product vvhich priče in the last 10 years changed significantly. In 1984 and 1985 it vvas very lovv and the production of FeNi vvas interrupted only one and a half year follovving the start of production. As a result of changes in nickel prices on vvorld market and after investments of several companies the production of one technological line re-started at the end of 1991. During recent years the production increased permanently, hovvever the projected values, vvill not be obtained due to the decrease average content of nickel in the ore. Table 2 indicates the trend of production in the restart period.
Table 2: Production of Ni as FeNi in 'Fenimak'
Year	1992	1993	1994	1995
Produced in t	4.220	4.493	3.981	4.960
Due to the second decrease of the nickel priče in the period of 1993 to 1995, the society in the period of 1993/94 operated vvith loss and profit vvas obtained later because of the light increase of nickel priče.
If the present trend of increase of nickel priče vvill continue, the production could increase to 5.500 t/year vvith only one technological line and be profitable. Follovving the re-start, rigorous economic measures have been undertaken related vvith the restructuring of the production, to the decrease of the number of employees, to the improvement of the technology vvithin given conditions related to the supply of ravv materials and direct marketing. Fenimak' is forced to import lignite from SR Yugoslavia. The enterprise undertakes serious and de-tailed investigations of the mineralogy of the mine de-posit, as well as for possible alternatives for economic beneficiation of the nickel ore. The production could increase only if the nickel content in the charge of furnaces
is increased. This can be obtained through the supply of rich ravv materials and requires additional vvorking capi-tal. Domestic investments are almost impossible because of the present economic situation, since Macedonia is exhausted by the political and economic changes im-posed by the disintegration process and the vvar on the territory of the former SFRY as vvell as the economic and transport blockades of some neighbours of the Republic of Macedonia. Nevv investments in the present production of Fenimak' and its increase vvith the re-start of the second technological line vvill be vvelcome and of benefit for the investors since the enterprise employs qualified managerial staff and disposes of modern technological devices vvith capacity non exploited.
Ferro-nickel is sold on foreign markets and only a very small quantity vvas sold on the local market, because of the crisis in steel metallurgy during the last years.
3 CAPACITIES OF NONFERROUS METALLURGY IN MACEDONIA
Moderate quantities of nonferrous metals are pro-duced in the MHK 'Zletovo'. Smelter 'Zletovo' is using Imperial smelting process for exstraction of zine, lead, cadmium and silver.
3.1 Lead and zine
Lead and zine ores have been exploited for centuries in the Kratovo-Zletovo ore deposit. Traces such as tools, slag, pots etc. indicate that lead has been smelted in the region during the Roman period.
'Zletovo' Metallurgical and Chemical Company in Titov Veles is the only producer of lead and zine in the Republic of Macedonia. It is based mainly on the ore de-posits and capacities of the three surrounding lead and zine mineš: Zletovo, Saša and Toranica.
The Imperial Smelting process route vvas the most convenient for treating lead and zine concentrates simul-taneously. Moreover, it offered an opportunity to pro-duce bulk concentrates, thus increasing the overall metal recovery. Therefore, an agreement vvas signed, the site preparation began, and the first quantities of slab zine and lead bullion vvere produced in November 1972.
'Zletovo' Smelter vvas designed for a maximum production of 65,000 tpa of slab zine and 35,000 tpa of lead bullion. Figure 1 shovvs the annual production rates m the period from 1973 to 1995. Numerous prerequisites are required to reach the designed capacity of the ISF.
The break of the continuous grovvth of metal production from 1986 to 1991 vvas due to series of problems arising from the disintegration of former Yugoslavia, in-ternational sanetions against the Federal Republic of Yu-goslavia, and Greek embargo against the Republic of Macedonia. These events created enormous difficulties in transporting both ravv materials and products and led to higher production costs.
Production rate[1000 tpa]
60 50 40 30 20 10
1973
1978
1983 Vear
1988
1993
Figure 1: Annual production of slab zine, lead bullion and secondary lead from plant start-up to 1995
Slika 1: Letna proizvodnja slabov cinka, primarnega in sekundarnega cinka od zagona podjetja do 1995.
Most of the refined lead produced at 'Zletovo' smelter is consumed within the country, mainly in the lead bat-teries plant having a capacity of 24000 tpa. Hovvever, due to the same reasons as above, especially the disinte-gration of SFR Yugoslavia, the market the battery plant was designed for, the production rate has been reduced dovvn to 30%.
Lead and zine production rates are inereased since the Dayton and New York agreements vvere signed last year, but a period of several years is necessary for a fuli recovery.
3.2 Cadmium
Most of the cadmium fed onto the sinter machine is eliminated during the sintering process. The degree of elimination depends mainly on sulfur and cadmium con-tents of the ravv mix, but the usual level is as high as 65 to 80%. With the construction of the cadmium plant based on the Ion Exchange Process the recovery of cad-
New cadmium input 300
Cd plant residue 361
JL
Sinter plant
Dross and blue powder 71
HGP dust 571
Sinter 143
IS - Furnace
Cadmium plant
228
Slab zine 72
Caustic Cadmium 210
Zn Refinery
mium is accomplished vvith high efficiency (over 92% as shovvn in figure 2).
Cadmium is leached from the hot gas dust precipita-tor by means of vveak sulfuric acid. Depending on the chemical compounds in vvhich cadmium is present in the dust, leaching efficiencies from 30 to 60% are obtained. The resulting leach liquor is countercurrently vvashed in a system of three decanters, filtered through a pair of sand ftlters and subjeeted to ion exchange on IR 120 cat-ion exchange resin. Stripping is performed by means of 10% brine solution. Cadmium sponge produced by ce-mentation on zine rods in suitable trammel tanks is melted in a caustic furnace and combined vvith the zine refinery to a cadmium alloy for further refining.
Despite the high stage efficiencies, the magnitude of losses is high and disturbing. As shovvn in figure 2, cadmium recirculating load is very high relative to the nevv input and this feature must contribute considerably to the losses.
Cadmium production rate in a zine and lead smelter depends primarily on the quantities of nevv cadmium fed vvith the ravv materials. Since significant quantities of zine concentrates have been purchased from various pro-ducers around the vvorld, it is obvious that the Zn/Cd ra-tio is rather a varying parameter. Hovvever, there are tvvo objeetives that a zine smelter must achieve:
-	High cadmium elimination to provide good zine quality
-	High cadmium recovery to avoid environmental problems
The annual production of cadmium from the 'Zletovo' Smelter from its start up to 1994 is shovvn in figure 3.
3.3 Silver
Unlike cadmium, most of the silver fed vvith concentrates reports in the lead bullion. Desilvering of the later is performed by adding metallic zine and removing the resulting solid intermetallic compounds (mainly Ag2Zns) together vvith a substantial amount of mechanically en-trained lead as a silver erust. Further treatment of the erust includes evaporating of zine, oxidizing of lead and electrolytic refining of silver.
Production rate [tpa]
Figure 2: Overall cadmium balance Slika 2: Celovita bilanca kadmija.
Figure 3: Annual cadmium production from plant start-up to 1995 Slika 3: Letna proizvodnja kadmijev od zagona podjetja do leta 1995.
Production rate [tpaj
Year
Figure 4: Annual silver production from plant start-up to 1995 Slika 4: Letna proizvodnja srebra od zagona podjetja do 1995.
The electrolytic silver refinery vvas introduced in 1982. Its total capacity amounts 30 tpa electrolytic silver, but the highest production achieved so far vvas 24.35 t in 1986.
4 CONCLUSIONS
-	The installed metallurgical capacities of iron, its al-loys and nonferrous metals in the Republic of Mace-donia encompasses the requirements of the local market and is directed tovvards the foreign market;
-	The participation of steel, ferro alloys and nonferrous metals alloys in the nationai foreign currency inflovv is very significant;
-	due to the discrepancies betvveen the primary steel production and the installed melting capacities, as vvell as the limited possibilities for supply of ravv materials, the metallurgy in Macedonia is forced to import steel in a slabs and serap;
-	considering the 30 years of experience in the steel industry and in the production of ferro alloys, follovving the carried out transformation of ovvnership and completion of the restrueturing processes, more profitable operating and its further development may be expected;
-	increasing the production capacities regarding various metals could also be expected, but it is intended to provide facilities for treating ali the lead and zine concentrates produced in the Republic of Macedonia. With respect to this, installing a nevv lead smelter plant has been considered.
5 REFERENCES
' Program of the restrueturing for Iron and steel work 'Skopje' during the period 1991-1995, vvith vision to 2000, Iron and steel work 'Skopje', Department for development, Skopje, 1990 2 Analysis of production posibilities, markets condition and financial effects of project FEN1- Kavadarci. RTB Bor, Institut za bakar. Bor, 1983