Oulu, 15.05.2014

1. Iwona JONCZY, PhDEng.SilesianUniversity of TechnologyFaculty of Mining and GeologyInstitute of Applied GeologyGliwice, Poland Mineral and chemical composition of metallurgical slags Oulu, 15.05.2014

2. Upper Silesia is one of the best developed regions in Poland. Rich deposits of metal ores and hard coal have contributed to the extensive development of metallurgy and coal mine industry which started as early as in the Middle Ages.

3. The extensive mining and metallurgical activity carried out over years has brought about changes of the environment. Metallurgybecame especially problematic, mainly because of considerable amounts of wastes coming into being during production.

4. For many years metallurgical slags were collected on the dumps.

5. There are propositions: • to apply slag for the production of road aggregate, aggregate for the production of concrete mixtures, as raw material for the production of mineral wool, • to return slags to metallurgical processes, • to liquidate waste dumpsto reclaim the land used for the dumps and to effect their subsequent revitalization.

6. That is why it is important to carry out research on their mineral and chemical composition, which may deliver some information during an economic exploitation of slags, e.g.: • connected with new phases forming in metallurgical processes, • forms of metal occurrence in slag components, • possibilities of metals release from slag components and their migration to the environment.

7. Each type of the slag should be taken individually, we can not make too many generalizations of mineral and chemical composition of the slag. • Due to the phase composition, metallurgical slags are one of the most diverse groups of waste materials. • Phases, which crystallized in a furnace can be identified with the minerals forming as a result of geological processes. • However, their chemical compositions usually are much richer than their natural counterparts.

8. SLAGS AFTERZINC AND LEADPRODUCTION

9. SLAGS AFTER STEEL PRODUCTION

10. Researchmethods • Chemical analysis • Electron probe microanalysis • Microscopic analysis in transmitted and reflected light • Scanning microscopy • X-ray analysis

11. CHEMICAL COMPOSITION OF SLAGS AFTERZINC AND LEADPRODUCTION Concentration of the elements [Mass%] Ranges and meanvaluesare shown for 20 samples of the wastes

12. CHEMICAL COMPOSITION OF SLAGS AFTERZINC AND LEADPRODUCTION Concentration of the elements [ppm] Meanvaluesare shown for 20 samples of the wastes

13. CHEMICAL COMPOSITION OF SLAGS AFTER IRON AND STEEL PRODUCTION

14. Mineral composition of metallurgical slag Components formed during the metallurgical processes: glaze, metallic aggregates, oxides and silicates. Secondary phases, which are connected with the crystallization on the dump: calcite, gypsum.

16. Electron probe microanalysis It is a kind of spectroscopy methods. That method permits to observe a small area of the sample and shows a qualitative and quantitativecomposition of a sample. Thatanalysisshowsalsodistribution of theelements.

19. Drop of iron surrounded by glaze

20. Metallurgical slag isa byproduct of the smelting process, whichcould be compared to magmaticprocesses. Under high temperaturemineralscrystallizeinthe correct order. The same order isin magma and inthemetallurgicalalloy. Itshould be noted, however, that the minerals in the earth were formed over thousands and millions of years, mineralsfrommetallurgicalalloyhadshort time to formedtheirstructure.

21. Process of theircrystallization is often interrupted by the rapid cooling of the slag melt. Therefore, the composition of the slag is dominated by small crystals surrounded by glaze. Well formed crystals, whichidentification by microscopic examinationispossible, are present in small amounts. The chemical composition of phase crystallizing fromtheslag is often richer than the chemical composition of their natural counterparts.

22. Mineralcomposition of slags in transmitted and reflected light during microscopic analysis