Most processes of steel manufacture necessarily generate a substantial proportion of slag. Often much of this is landfilled, and at many plants it will be the main item (by tonnage) that is dumped. This rock-like material can be used as an aggregate, but the main obstacle to widespread use is concern over the volume stability. The main cause of volume instability is hydration of free lime, although hydration of free magnesia may also contribute in some cases. There are three key steps to effective use of this abundant secondary aggregate. First, some pretreatment of the slag is usually necessary (such as weathering). Second, a test is necessary that reliably predicts the behaviour in use, within a reasonable time. This is commonly an expansion test. Third, calibration of the test is necessary so that test results can provide a useful distinction between material which is suitable and that which is not; this is normally achieved by linking laboratory tests to road trials. Subject to these three steps, steelmaking slag can make a valuable contribution to the need for secondary aggregates.
ROBINSONH. L.: ‘The utilization of blastfurnace and steel making slags as aggregates for construction’, 327–330; 2002, (eds. ScottP. W. and BristowC. M.), Industrial minerals and extractive industry geology, London, The Geological Society.
5.
HOLLIDAYK. A.: ‘Steel slag: the high performance industrial aggregate’, Steel World, 1997, 2, 11–14.
6.
EGGLESTONH. K.: ‘Use of blast furnace and steel slags as a rail ballast material in U.S.A.’, Proc. Utilisation of Steelplant Slags Symp., Illawarra, February 1979, 75-80; Parkville, Australasian Institute of Mining and Metallurgy
7.
MERKELT.: ‘Successful utilisation of steel slags in Germany’, 87–99; 2001, (eds. GeiselerJ. and MotzH.), Proc. 2nd Eur. Slag Conference, Düsseldorf, 9-11 October 2000, Duisburg, Euroslag.
8.
ALEXANDREJ.: ‘Utilization of BOF slag in Europe meets high standards’, 168-171; 1993, Proc. 1st Eur. Oxygen Steelmaking Congress, DüsseldorfNeuss, 21-23 June 1993, Düsseldorf, Verein Deutscher Eisenhüttenleute,
9.
GEISELERJ.: ‘Use of steelworks slag in Europe’. Waste Management, 1996, 16, 59–63.
10.
GEISELERJ.: ‘Steel slag — generation, processing and utilization’, 87-97; 1994, (eds.MahantP., PicklesC. and LuW-K.), Proc. Int. Symp. on Resource Conservation and Environmental Technologies in Metallurgical Industries, Toronto, 20-25 Aug. 1994, Montreal, Canadian Institute of Mining, Metallurgy and Petroleum.
11.
DEPARTMENT OF THE ENVIRONMENT: ‘Hardcore’, Building Research Establishment Digest276, 1983, London, HMSO.
12.
CRAWFORDC. B. and BURNK. N: ‘Building damage from expansive steel slag backfill’, Proceedings of the American Society of Civil Engineers, J Soil Mechanics Foundations Division, 1969, 95, 1325–1334.
13.
GNAEDINGERJ. P: ‘Open hearth slag — a problem waiting to happen’, J Performance Constructed Facilities, 1987, 1, 78–83.
14.
DEOB. and BOOMR.: ‘Fundamentals of steelmaking metallurgy’, 146–160; 1993, New York, Prentice Hall International.
15.
MIKLOSP: ‘The utilization of electric arc furnace slags in Denmark’, 101–110; 2001, (eds. GeiselerJ. and MotzH.), Proc. 2nd Eur. Slag Conference, Düsseldorf, 9-11 October 2000, Duisburg, Euroslag.
16.
JONESN. C.: ‘The successful use of electric arc furnace slag in asphalt’, 111–121; 2001, (eds. GeiselerJ. and MotzH.), Proc. 2nd Eur. Slag Conference, Diisseldorf, 9-11 October 2000, Duisburg, Euroslag.
17.
LEEA. R.: ‘Blastfurnace and steel slag: production, properties and uses’, 23; 1974, London, Edward Arnold.
18.
MILLMANM. S.: ‘Secondary steelmaking developments in British Steel’, Ironmaking Steelmaking, 1999, 26, 169–175.
19.
POSCHW., PRESSLINGERH. and HIEBLERH.: ‘Mineralogical evaluation of ladle slags at Voestalpine Stahl GmbH’, Ironmaking Steelmaking, 2002, 29, 308–312.
20.
EMERYJ. J.: ‘Slags as industrial minerals’, 127–141, 1978, (ed. CoopeB. M.), Proc. 3rd Industrial Minerals Int. Conf, Paris, 13-15 Mar. 1978, London, Metal Bulletin Ltd.
21.
SAHAYJ. S., NAGPALO. P. and PRAsADS.: ‘Waste management of steel slag’, Steel Times Int, 2000, 24, 38-40; 43.
22.
BANNENBERGN. and ARLTK. J.: ‘Utilisation of used refractory material and slag as secondary raw materials’, Veitsch-Radex Rundschau, 1997, no. 1, 3-10.
23.
THORNTONG. and ANDERSOND.: ‘Low phosphorus basic oxygen steelmaking practices in British Steel’, Ironmaking Steelmaking, 1994, 21, 247–251.
24.
JuacEsL. M.: Investigaticn of the connection between test results found in the laboratory on volume stability and the values found in practice for LD slags’, ECSC Final Report EUR 13430 EN, Commission of the European Communities Luxembourg, 1991.
25.
PRESSLINGERH., MAYRM. and APFOLTERERR.: ‘Quantitative phase evaluation of converter slags’, Steel Res., 1999, 70, 209–214.
26.
PROCTORD. M.: ‘Physical and chemical characteristics of blast furnace, basic oxygen furnace, and electric arc furnace steel industry slags’, Environ. Sci. Technol., 2000, 34, 1576–1582.
27.
INOUER. and SUITOH.: ‘Hydration of crystallized lime in BOF slags’, ISIJ Int, 1995, 35, 272–279.
28.
MOTZH.: The European standardisationof slags’, 151-162; 2001, (eds J. Geiseler and H. Motz), Proc. 2nd Eur. Slag Conference, Düsseldorf, 9-11 October 2000, Duisburg, Euro slag.
29.
GOLDRINGD. C. and JucREsL. M.: ‘Petrology and stability of steel slags’, Ironmaking Steelmaking, 1997, 24, 447–456.
30.
GUTTW. and NIXONP. J.: Steel-making slag as a skid resistant roadstone’, Chem. Ind., 17 June 1972, 503–504.
31.
HEATONB. S.: ‘Steel furnace slag as an aggregate in asphaltic concrete’, 81–85; 1979, Proc. Utilisation of Steelplant Slags Symp., Illawarra, February 1979, Parkville, Australasian Institute of Mining and Metallurgy
32.
VERHASSELTA. and CHOQUETE: Stabilire dimensionelle des scories LD’, La Technique Routière, 1985, 4, 4–23.
33.
JUCKESL. M.: ‘Dicalcium silicate in blast-furnace slag: a critical review of the implications for aggregate stability’, Min. Process. Extract. Metall (Trans. Inst. Min. Metall C), 2002, 111, C120–C128.
34.
BRITISH STANDARDS INSTITUTION: ‘Tests for chemical properties of aggregates - Part 1. Chemical analysis’, BS EN1744-1:1998, London, British Standards Institution.
35.
SCHUURH. M. L. and BROADBENTC P.. ‘Slag utilisation in The Netherlands’, 231–239; 1991, (ed. CribbS. J.), Conf. on The Economic Treatment of Mineral Wastes, Bath, 21-22 June 1990, Lichfield, MIRO.
36.
TAYLORR. K. and CRIPPSJ. C.: ‘Mineralogical controls on volume change’, 268–302: 1984, (eds AttewellP. B. and TaylorR. K.), Ground movements and their effects on structures Glasgow and London, Surrey University Press
37.
SEKIA.et al: ‘Development of dusting prevention stabilizer for stainless steel slag’, Kawasaki Steel Technical Report, October 1986, no. 15, 16–21.
38.
REXM.: ‘Blastfurnace and steel slags as liming materials for sustainable agricultural production’, 137-149; 2001, (eds J. Geiseler and H. Motz), Proc. 2nd Eur. Slag Conference, Düsseldorf, 9-11 October 2000, Duisburg, Euro slag.
39.
GNAEDINGERJ. P and GNAEDINGERR. J.: Discussion on ref 12, Nov. 1970, 2131-213 2.
40.
MONACOA. and LuVi-R.: ‘The effect of cooling conditions on the mineralogical characterizaticn of steel slag’, 107–116; 1994, (eds MahantP., PicklesC. and LuW-K.), Proc. Int. Symp. on Resource Conservation and Environ-mental Technologies in Metallurgical Industries Toronto, 20-25 Aug. 1994, Montreal, Canadian Institute of Mining, Metallurgy and Petroleum.
41.
CRAWFORDC. B. and BURNK. N: Reply to discussions on ref 12, July1971, 1026-102 9.
42.
CLARKL.(Chairman): ‘The thaumasite form of sulfate attack. Risks, diagnosis remedial works and guidance on new construction’, Report of the Thaumasite Expert Group, Department of the Environment, Transport and the Regions, London, 1999.
43.
GEISELERJ. and SCHLOSSERR.: ‘Investigations concerning the structure and properties of steel slags’, 40–42; 1989, Proc. 3rd Int. Conf. on Molten Slags and Fluxes, Glasgow, 1988, London, The Institute of Metals.
44.
WACHSMUTHE.: ‘Contribution to the structure of BOF-slags and its influence on their volume stability’, Can. Metall Q., 1981, 20, 279–284.
45.
RUSSELLR. O.: ‘Everlasting BOF linings at LTV Steel?’, 220-225; 1993, Proc. 1st Eur. Oxygen Steelmaking Congress, DüsseldorfNeuss, 21-23 June 1993, Düsseldorf, Verein Deutscher Eisenhüttenleute,
46.
GEISELERJ.: ‘Untersuchungen zum Hydratation-sverhalten von synthetischen Magnesiowilstiten’, Steel Res., 1987, 58, 210–214.
47.
RAMACHANDRANV. S., SERADP. J. and FELDMANR. E: ‘Mechanism of hydration of calcium hydroxide’, Nature, 1964, 201, 288–289.
48.
THOMASG. H.: ‘Investigations on LD slag with particular reference to its use for road construction’, ECSC Final Report EUR 8622 EN, Commission of the European Communities Luxembourg, 1983.
49.
SPANOVICHM. and FEWELLR.: Discussion on ref 12, Sept. 1970, 1808–1810.
50.
JucxEsL. M.: ‘Improved utilisation of blast furnace and steel works slags’, ECSC Final Report EUR 11681 EN, Commission of the European Communities, Luxembourg, 1988.
51.
SUZUKIA., HARUNAJ. and ARAIK.: ‘Hardening of BOF slag by carbon dioxide processing’, Abstracts from Presentations to 98th ISIJ Meeting, Nagoya, 16-18 October 1979, Trans. Iron Steel Inst Jpn., 1980, 20, 310.
52.
BRITISH STANDARDS INSTITUTION: ‘Tests for thermal and weathering properties of aggregates - Part 2: Magnesium sulfate test’, BS EN1367-2:1998, London, British Standards Institution.
53.
VERHASSELTA. and CHOQUETE: ‘Steel slags as unbound aggregate in road construction: problems and recommendations’, 204-211; 1989, (eds R. H. Jones and A. R. Dawson), Proc. Int. Symp. on Unbound Aggregates in Roads (UNBAR 3), Nottingham, 11-13 April 1989, London, Butterworth&
54.
FULLALOVEL.: ‘Damage scares fail to halt steel slag use’, New Civil Engineer, 12 April 1984, 4–5.
55.
BAILEYJ. J. and REITZH. M.: Discussion of ref. 12, Sept. 1970, 1810–1813.
56.
VERHASSELTA. and CHOQUETE: Reply to discussion on ref. 53, 235-256; 1989, (eds.JonesR. H. and DawsonA. R.), Proc. Int. Symp. on Unbound Aggregates in Roads (UNBAR 3), Nottingham, 11-13 April 1989, London, Butterworth&
57.
ANON. Steelphalt: the alternative solution for the roads of tomorrow’, Steel World, 1999, 4, 60–61.
58.
GEISELERJ. and moTzH.: ‘Untersuchung iiber den Zusammenhang zwischen im Laboratorium ermittelten Versuchsergebnimn zur Raumbeständigkeit und dem Praxisverhalten von LD-Schlacken’, ECSC Final Report EUR 13966 DE, Commission of the European Communities Luxembourg, 1992.
59.
AMERICAN SOCIETY FOR TESTING AND MATERIALS: ‘Standard test method for potential expansion of aggregates from hydration reactions’, ASTM D 4792-95, Philadelphia, American Society for Testing and Materials
60.
KOLLERH.: ‘Practical experience in road construction using LD slag’, Information Day on Utilization of Blast Furnace and Steelmaking Slags, Liége, 27 January 1988, Brussel Commission of the European Communities (D.G. XII), Paper 111.5.
61.
BRITISH STANDARDS INSTITUTION: ‘Methods of testing cement - Part 2: Chemical analysis of cement’, BS EN 196-2: 1995, London, British Standards Institution.
62.
CATOULP.: ‘Dosage conductimétrique rapide de la chaux libre dans les scones Thomas et LD-AC’, Centre Nation. Rech. Métallurg., Oct. 1964, no. 1, 75-79.
63.
AMERICAN SOCIETY FOR TESTING AND MATERIALS: ‘Standard test methods for chemical analysis of hydraulic cement’, ASTM C114-99, Philadelphia, American Society for Testing and Materials
64.
BRITISH STANDARDS INSTITUTION: ‘Quicklime, hydrated lime and natural calcium carbonate - Part 2. Methods of chemical analysis’, B56463: Part 2: 1984, London, British Standards Institution.
65.
PRESSLERE. E., BRUNAUERS. and KANTROD. L.: ‘Investigation of the Franke method of determining free calcium hydroxide and free calcium oxide’, Anal. Chem., 1956, 28, 896–902.
66.
MULLERC. M. and FIXW.: ‘Bestimmung von Freikalk in Stahlwerksschlacken - Auswahl eines Lösungsmittels’, Arch. Eisenhfittenwes., 1974, 45, 685–691.
67.
WITTERH. and FIXW: ‘Bestimmung von Freikalk in Stahlwerksschlacken - Schnellverfahren mittels Leitfähig-keitmessung’, Arch. Eisenhiittenwes., 1974, 45, 791–794.
68.
BARTLM. and PEKAREKD.: The quantitative determination of uncombined calcium hydroxide and oxide in clinker and cement by X-ray diffraction’, Analyst, 1972, 97, 848–853.
69.
VANLERBERGHEL., DUMAREYR. and VAN BLAEREL.: ‘Problems in the determination of free CaO in BOF slag’, Proc. 46th Chemists’ Conference, Scarborough, 10-12 May 1994, 75-81, Grangetown, British Steel Technical.
70.
LEAE. M.: The chemistry of cement and concrete’, 3rd edn, 111-112; 1970, London, Edward Arnold.
71.
PIRETJ.et al: ‘Recherche pour une meilleure valorisation du laitier de haut fourneau et de la scone LD’, ECSC Final Report EUR 11750 FR, Commission of the European Communities, Luxembourg, 1988.
72.
JAPANESE STANDARDS ASSOCIATION: ‘Iron and steel slag for road construction (English translation)’, JIS A 5015, 1992, Tokyo, Japanese Standards Association.
73.
FARRANDB. L. and EMERYJ. J.: ‘Recent improvements in the quality of steel slag aggregate’, 99–106; 1994, (eds. MahantP., PicklesC. and LuW-K.) Proc. Int. Symp. on Resource Conservation and Environmental Technologies in Metallurgical Industries, Toronto, 20-25 Aug. 1994, Montreal, Canadian Institute of Mining, Metallurgy and Petroleum.
74.
OKAMOTOA., FUTAMURAE. and KAWAMURAK: ‘Hydration behaviour of LD slag at autoclave test’, Trans. Iron Steel Inst. Jpn., 1981, 21, 16–24.
75.
AMERICAN SOCIETY FOR TESTING AND MATERIALS: ‘Standard method for autoclave expansion of Portland cement’, ASTM C151-98a, Philadelphia, American Society for Testing and Materials
76.
EMERYJ. J.: ‘A simple test procedure for evaluating the potential expansion of steel slag’, 90–103; 1974, Selected workshop papers, Ottawa, Roads and Transportation Association of Canada.
77.
BRITISH STANDARDS INSTITUTION: ‘Methods of test for soils for civil engineering purposes’, BS 1377: 1975, London, British Standards Institution.
78.
AMERICAN SOCIETY FOR TESTING AND MATERIALS: ‘Tentative method of test for bearing ratio of laboratory-compacted soils’, ASTM D 1883-61T, Philadelphia, American Society for Testing and Materials
79.
BRITISH STANDARDS INSTITUTION:Armourstone — Part 1: Specification, BS EN 13383-1: 2002, London, British Standards Institution.
80.
BRITISH STANDARDS INSTITUTION: Armourstone — Part 2: Test methods’, BS EN 13383-2: 2002, London, British Standards Institution
81.
BRITISH STANDARDS INSTITUTION: ‘Tests for thermal and weathering properties of aggregates- Part 3: Boiling test for Sonnenbrand’ basalt’, BS EN 1367-3: 2001, London, British Standards Institution
82.
BRITISH STANDARDS INSTITUTION: ‘British Standard Guide to use of industrial by-products and waste materials in building and civil engineering’, B56543: 1985, London, British Standards Institution.
83.
BRITISH STANDARDS INSTITUTION: ‘Hot rolled asphalt for roads and other paved areas - Part 1. Specification for constituent materials and asphalt mixtures’, B5594: 1992, London, British Standards Institution.
84.
BRITISH STANDARDS INSTITUTION: ‘Coated macadam for roads and other paved areas - Part 1. Specification for constituent materials and for mixtures’, B54987: Part 1: 1993, London, British Standards Institution.
85.
GEISELERJ.: ‘Ab senkung der Freikalkgehalt von LD-Schlacken im flässigen Zustand’, Stahl Eisen, 1987, 107, 39-45 (403–9).
86.
GEISELERJ.: ‘Reduction of the free lime content of BOF slags in liquid state’, Stahl Eisen, 1987, 107, 107.
87.
KOHNM.: ‘A new BOF slag treatment technology’, 445-453; 1997, Proc. 2nd Eur. Oxygen Steelmaking Congress, Taranto, 13-15 October 1997, Milan, Associazione Italiana di Metallurgia.
88.
KOHNM., DRISSENP. and SCHREYH.: ‘Treatment of liquid steel slags’. 123–135; 2001, (eds. GeiselerJ. and MotzH.), Proc. 2nd Eur. Slag Conference, Düsseldorf, 9-11 October 2000, Duisburg, Euroslag.
89.
SCHEELR. and PETERSENH.: ‘Zur Aussortierung von LD-Schlacken mit geringem Freikalkgehalf, Stahl Eisen, 1977, 97, 555–557.
90.
YONGQUANC. and QIZHONGC.: ‘Experiment on crushing EAF slag’, SEAISI Q., 1993, 22, 81–85.
91.
MONTGOMERYD. G. and WANGG.: ‘Instant-chilled steel slag aggregate in concrete - strength related properties’, Cement Concrete Res., 1991, 21, 1083–1091.
92.
MOUSELR.: Steelplant slag granulation system’, 172-175; 1993, Proc. 1st Eur. Oxygen Steelmaking Congress, DiisseldorfNeuss, 21-23 June 1993, Diisseldorf, Verein Deutscher Eisenhättenleute,
93.
FEATHERSTONEW. B. and HOLLIDAYK. A.: ‘Slag treatment improvement by dry granulation’, Iron Steel Eng., 1998, 75, 42–46.
94.
ANON.: ‘Blast granulation system of BOF slag’, Trans. Iron Steel Inst. Jpn., 1986, 26, 840.
95.
KANAMORIK.: ‘Safe disposal of molten LD converter slag using rapidly rotating roller’, Trans. Iron Steel Inst. Jpn., 1973, 13, 255–264.
96.
THOMASG. H.: ‘Progress in the utilisation of steel slags in the UK’, 77–86; 2001, (eds. GeiselerJ. and MotzH.), Proc. 2nd European Slag Conference, Düsseldorf, 9-11 October 2000, Duisburg, Euroslag.
97.
ANDRIEUXP.: Planches experimentales a base de scones LD’, Information Day on Utilization of Blast Furnace and Steelmaking Slags, Liége, 27 January 1988, Brussels, Commission of the European Communities (D.G. XII), Paper 111.6.1.
98.
HILTUNENA., PUTROJ. and POYLIOE.: ‘Manufacture, use and improved utilization of by-products of blast furnace steel works in Finland’, Paper presented at Seminar on the Steel Industry and Recycling, Diisseldorf, 24-27 April 1995, Geneva, United Nations Economic Commission for Europe (Working Party on Steel).
99.
COLLINSR. J. and SHERWOODP. T.: ‘Use of waste and recycled materials as aggregates: standards and specifications’, Report prepared by the Building Research Establishment (BRE) for the Department of the Environment, 7-8, HMSO, London, 1995.
100.
JUCKESL. M.: Discussion on Ref. 53. In Proc. Int. Symp. on Unbound Aggregates in Roads (UNBAR 3), Nottingham, 11-13 April 1989, 235; (eds.JonesR. H. and DawsonA. R.) London, Butterworths.
101.
BONNOTJ.et al: ‘Etudes pratiques sur les scones LD utilisées en technique routiére’, ECSC Final Report EUR 7909 FR, Commission of the European Communities, Luxembourg, 1982.
102.
MORISHITAS., KIODEH. and KOMAIK.: The development of the new aging process of steel-making slag’, SEAISI Q., 1997, 26, 37–48.
103.
TANIGAWAK., OKUDAK. and KUMAMOTOT.: ‘Recent technology and developments for efficient slag processing and utilization’, SEAISI Q., 1993, 22, 49–59.
104.
AMERICAN SOCIETY FOR TESTING AND MATERIALS: ‘Standard specification for steel slag aggregates for bituminous paving mixtures’, ASTM D 5106-91, Philadelphia, American Society for Testing and Materials
105.
PRUNEVIEILLEJ. M.: ‘Slag bound mixtures in French road construction — history and developments’, 63-75; 2001, (eds.GeiselerJ. and MotzH.), Proc. 2nd Eur. Slag Conference, Düsseldorf, 9-11 October 2000, Duisburg, Euroslag.
106.
BESTN. E: ‘Volumetric stability of weathered LD slags containing both free lime and periclase’, ECSC Final Report EUR 10753 EN, Commission of the European Communities, Luxembourg, 1987.
107.
PIRETJ., LESGARDEURA. and DELMARCELLEA.: ‘Utilisation de la scone LD en construction routiére’, ECSC Final Report EUR 7631 FR, Commission of the European Communities, Luxembourg, 1982.
