Bulgaria is a major producer of zinc in the Balkans (about 100,000 tons per year). The two zinc plants (KCM S.A., Plovdiv, and LZC S.A., Kardzhali) deliver the necessary raw materials from Bulgaria and abroad. But the zinc production at LZC Kardzhali for nearly a year has stopped. Turkey is a main producer of zinc sulfide concentrates from the Balkan countries. In this connection, an analysis of the delivered Turkish sulfide zinc concentrates is made through statistical processing of data about their chemical content. For the aim of processing them according to the classic hydrometallurgical scheme, studies are carried out using X-ray phase analysis as well as DTA and TGA. Providing optimal charge for roasting in fluid bed furnace (FBF) can be successfully done by using the WEB-based information system we have written, which calculates mixtures of different raw materials. The program system developed is illustrated by calculations of charges of 5 zinc concentrates from Turkey. The accomplishment of optimal mixing of concentrates and providing a stable mix composition for a long period of time is a task of primary importance in the technological process control in zinc hydrometallurgy. 1. Introduction The world production of zinc during the last years experiences a shortage of enough quantity of quality zinc raw materials. Regardless of the fact that during the years 2006–2012 the production of primary zinc raw materials increased from 8 839？K？tons to 13 604？K？tons (increase percentage of 18.9%) and forecast to increase to about 14 000？kt in 2013, the demand usually exceeds the supply on the world markets [1–4]. Despite the expected considerable increase of the global production of concentrates in 2013, it is anticipated that the world supply of primary zinc raw materials will remain insufficient. This is due to the continuing position of China as the chief importer of concentrates and to the expected increase in the global production of refined zinc. This follows as a consequence of the ever-increasing consumption of metal zinc, mainly in China, India, and Brazil [3, 5, 6]. A major producer of zinc on the Balkans is Bulgaria (about 100 000？tons per year) [2, 7]. Bulgarian zinc plants deliver a part of the necessary zinc sulfide concentrates from Bulgaria and the Balkan countries—Turkey, Romania, Greece, Serbia, and Macedonia (Figure 1). A part of primary raw materials is imported from Poland, Morocco, Peru, Canada, and others. Figure 1: Processed zinc concentrates in Bulgaria in kt (a) and % (b). Turkey is a main producer of sulfide zinc concentrates
References
[1]
S. Wilkinson, “The zinc industry: challenges and opportunities,” in Proceedings of the 4th International Conference ZINC, Plovdiv, Bulgaria, September 2006.
[2]
N. Dobrev, “Zinc production in Bulgaria. State and perspectives,” in Proceedings of the 4th International Conference ZINC, Plovdiv, Bulgaria, September 2006.
[3]
Metalls Despatch, “Newsletter of the International Metals Study Groups,” Issue No. 10, November 2010, http://www.insg.org/%5Cdocs%5CMD10.pdf.
[4]
International Lead and Zinc Study Group, http://www.ilzsg.org/static/statistics.aspx.
[5]
P. White, “ZINC: funds, fundamentals of China,” in Proceedings of the 4th International Conference ZINC, pp. 1135–1247, Plovdiv, Bulgaria, September 2006.
[6]
P. R. Chandna, “Zinc metal industry in India,” in Proceedings of the 4th International Conference ZINC, p. 49, Plovdiv, Bulgaria, September 2006.
[7]
N. Dobrev and A. Shukerov, “The outlook for the Bulgarian lead and zinc sector,” in Proceedings of the 55th Annual Session of ILZSG, Lisbon, Portugal, October 2010, http://www.ilzsg.org/generic/pages/list.aspx?table=document&ff_aa_document_type=P&from=1.
[8]
B. S. Boyanov, M. P. Sandalski, and K. I. Ivanov, “Zinc sulfide concentrates and optimization of their roasting in fluidezed bed reactor,” World Academy of Science, Engineering and Technology, vol. 73, pp. 326–332, 2011.
[9]
M. P. Sandalski, B. S. Boyanov, P. G. Georgiev, and A. K. Sotirov, “Web based expert system optimization for processes in chemical technology,” in Proceedings of 42nd International October Conference of Mining and Metallurgy, pp. 569–572, Kladovo, Serbia, October 2010.
[10]
F. Habashi, “Recent trends in extractive metallurgy,” Journal of Mining and Metallurgy, Section B, vol. 45, no. 1, pp. 1–13, 2009.
[11]
Y. Umetsu, “Advances and challenges in zinc production,” in International Symposium on Lead & Zinc Production, pp. 89–101, Kyioto, Japan, October 2005.
[12]
P. Lessidrenski, I. Gruev, A. Apostolov, S. Stoyanova, and E. Bekrieva, “Jarosite technology for zinc production at the lead and zinc complex and optimization of the reagent mode,” in Proceedings of the 4th International Conference ZINC, pp. 213–216, Plovdiv, Bulgaria, September 2006.
[13]
S. Kharbish, “A Raman spectroscopic investigation of Fe-rich sphalerite: effect of fe-substitution,” Physics and Chemistry of Minerals, vol. 34, no. 8, pp. 551–558, 2007.
[14]
B. S. Boyanov, R. I. Dimitrov, and ？. D. ？ivkovíc, “Thermal behaviour of low-quality zinc sulphide concentrate,” Thermochimica Acta, vol. 296, no. 1-2, pp. 123–128, 1997.
[15]
J. C. Balarini, L. D. O. Polli, T. L. S. Miranda, R. M. Z. D. Castro, and A. Salum, “Importance of roasted sulphide concentrates characterization in the hydrometallurgical extraction of zinc,” Minerals Engineering, vol. 21, no. 1, pp. 100–110, 2008.
[16]
B. S. Boyanov and N. K. Kolev, “Characteristics and roasting of sulphide zinc concentrates in fluid bed roaster,” in Proceedings of the 4th International Conference ZINC, pp. 275–288, Plovdiv, Bulgaria, September 2006.
[17]
？. D. ？ivkovi？, N. Mitevska, and V. Savovi？, “Kinetics and mechanism of the chalcopyrite—pyrite concentrate oxidation process,” Thermochimica Acta, vol. 282-283, pp. 121–130, 1996.
[18]
？. D. ？ivkovi？, N. Milosavljevi？, and J. ？esták, “Kinetics and mechanism of pyrite oxidation,” Thermochimica Acta, vol. 157, no. 2, pp. 215–219, 1990.
[19]
J. G. Dunn, “The oxidation of sulphide minerals,” Thermochimica Acta, vol. 300, no. 1-2, pp. 127–139, 1997.
[20]
N. Strabac, D. Zivkovic, ？. D. ？ivkovi？, and I. Mihajlovic, Sulfidi—termijska, termodinamicka i kineticka analiza, Technical Faculty of Bor, University of Belgrade, 2005.
[21]
B. Boyanov, M. Sandalski, and R. Dimitrov, “Software for optimising the mixing proportions of polycomponent raw materials,” Bulgarian Chemistry and Industry, vol. 71, no. 1, pp. 10–13, 2000.
