APPLICATION OF STAINLESS STEEL SLAG WASTE AS A PARTIAL REPLACEMENT TO MANUFACTURE CEMENT MORTARS

Transcription

1 International Conference Industrial Waste & Wastewater Treatment & Valorisation APPLICATION OF STAINLESS STEEL SLAG WASTE AS A PARTIAL REPLACEMENT TO MANUFACTURE CEMENT MORTARS Julia Rosales, University of Córdoba, Spain Construction Engineering- University of Cordoba (Spain)

2 STAINLESS STEEL PRODUCTION INTRODUCTION 40 Million metric tonne (Mt) % st ASIA (71%) 2 nd EUROPE (21%) 3 rd AMERICA (8%) Italy (25%) Germany (19%) Spain (15%) France (8%) Poland (6%) Belgium (4%) Finlande (4%) Luxembourg (3%) Spain 3 rd European producer UK (3%) International Stainless Steel Forum, 2014 Others (13%) World Steel Asociation, 2013

3 STAINLESS STEEL MANUFACTURING PROCESS INTRODUCTION Raw materials Melting Refining AOD Refining VOD Ladle Refining LF Continuous casting Surface grinding Grinded slab 20% Raw Materials WASTE 85% Waste LANDFILL AGGREGATES SLAG VALORISATION

4 VALORIZATION STAINLESS STEEL WASTE INTRODUCTION AGGREGATES SLAG AGRICULTURE Soil improvement CONSTRUCTION Road base Concrete Addition to Clinker AGRICULTURE Soil improvement TREATING WASTEWATER CONSTRUCTION Soil-cement Concrete CEMENT MORTAR WASTE UTILIZATION LESS USE OF NATURAL RESOURCES SUSTAINABILITY

5 STAINLESS STEEL SLAG WASTE (SW) AS CEMENT REPLACEMENT IN MORTAR OBJETIVES Few research related to stainless steel slag waste for use as a substitute for cement Principal objetive: study of cement replacement by different percentages of stainless steel slags crushed and without crushed for making mortars to determine the optimal replacement rate to increase the economic value of stainless steel slag waste and decrease the cement content TREATMENT AND PROCESSING OF SW Study the cementitious properties Analysis of environmental effects through leaching test Study the effect on the compressive strength, flexural and shrinkage Application of multivariate analysis methods

6 STAINLESS STEEL SLAG WASTE AS CEMENT REPLACEMENT IN MORTAR RESEARCH DESIGN SW Steel Stainless Steel PROCESSING SW Unprocessed SW-C STAINLESS STEEL FACTORY ACERINOX 10%CEM 20%CEM 30%CEM REPLACEMENT MANUFACTURE OF MORTAR Crushed - Sieved OXIDE COMPOSITION LEACHING COMPRESSIVE STRENGTH FLEXURAL STRENGTH SHRINKAGE MULTIVARIATE ANALYSIS

7 STAINLESS STEEL SLAG WASTE AS CEMENT REPLACEMENT IN MORTAR MATERIALS AND EXPERIMENTAL METHODS CHEMICAL ANALYSIS X-ray fluorescence (XRF) (UNE-EN 196-2) Leaching test (UNE- EN ) MECHANICAL ANALYSIS SW SW-C SW REPLACEMENT 10% 20% 30% SW-C REPLACEMENT 10% 20% 30% Compressive Strength DAYS (UNE-EN 196-1) Fexural Strength DAYS (UNE-EN 196-1) Shrinkage DAYS (UNE-83831) CEM Standardized Sand + Water CONTROL

8 X-RAY FLUORESCENCE (XRF) CEMENTITIOUS PROPERTIES SW AND SW-C CHEMICAL PROPERTIES RESULTS SiO 2 (%) Al 2 O 3 (%) Fe 2 O 3 (%) CaO (%) MgO (%) SO 3 (%) K 2 O (%) SW 31,34 5,18 1,25 46,26 10,90 0,37 0,00 SW-C 30,31 5,01 0,93 46,45 11,51 0,36 0, SW SW-C LIMITS Percentage (%) CHEMICAL COMPOSITION SIMILAR CLINKER CONVENTIONAL FLY ASH SiO2 (%) Al2O3 (%) Fe2O3 (%) CaO (%) MgO (%) SO3 (%) K2O (%) POZZOLANIC REACTION CHARACTERISTICS Chemical composition limits pozzolanic materials (Calleja, J. 1985)

9 LEACHING TEST HEAVY METALS LEACHATE BY SW AND SW-C CHEMICAL PROPERTIES RESULTS Concentrations in the leachate (mg/kg) ,1 0,01 Stainless steel slag L/S = 2 l/kg 0,001 Ni Cu Cr Zn As Se Mo Cd Sb Ba Hg Pb ,1 0,01 Stainless steel slag L/S = 10 l/kg 0,001 Ni Cu Cr Zn As Se Mo Cd Sb Ba Hg Pb HAZARDOUS NON-HAZARDOUS INERT L/S=2 SW SW-C L/S=10 SW SW-C CHROMIUM MOLYBDENUM Classification Non hazardous Non hazardous Non hazardous Non hazardous NON HAZARDOUS Sw Sw-C

10 COMPRESSIVE STRENGTH STAINLESS STEEL SLAG WASTE AS CEMENT REPLACEMENT IN MORTAR MECHANICAL BEHAVIOR RESULTS Compressive strength (Mpa) S1 10% REPLACEMENT S2 20% REPLACEMENT Compressive strength (Mpa) a a a LOSS OF COMPRESSIVE STRENGTH LOWER 25% b b d 28 DAYS c S3 30% REPLACEMENT Time (d) CR Sw Sw-C REPLACEMENT 10% Sw AND Sw-C COMPRESSIVE STRENGTH INCREASES SW-C BETTER RESULTS

11 FLEXURAL STRENGTH STAINLESS STEEL SLAG WASTE AS CEMENT REPLACEMENT IN MORTAR Flexural strength (Mpa) b a a b b c 28 DAYS c MECHANICAL BEHAVIOR RESULTS LOSS OF FLEXURAL STRENGTH LOWER 15% REPLACEMENT 10% Sw AND Sw-C FLEXURAL STRENGTH INCREASES Flexural strength (Mpa) 12, , ,5 10 9,5 9 y = 0,1391x + 3,9232 R² = 0, Compressive strength (Mpa) FLEXURAL STRENGTH VS COMPRESIVE STRENGTH HIGH POSITIVE CORRELATION AMONG THE COMPRESSIVE STRENGTH AND FLEXURAL STRENGTH

12 SHRINKAGE STAINLESS STEEL SLAG WASTE AS CEMENT REPLACEMENT IN MORTAR 1,400 MECHANICAL BEHAVIOR RESULTS shrinkage (μm/m) 1,200 1,000 0,800 0,600 0,400 0,200 0, Age (days) Control S1-Sw S1-Sw-C S2-Sw S2-Sw-C S3-Sw S3-Sw-C REPLACEMENT 10% Sw AND Sw-C PRESENT VALUES OF RETRACTION SIMILAR THAT THE CONTROL THE MORTARS WITH A REPLACEMENT OF 20% AND 30% Sw AND Sw-C HAVE HIGH SHRINKAGE VALUES

13 MULTIVARIATE ANALYSIS MATERIALS AND EXPERIMENTAL METHODS The mechanical behavior of mortars must be analyzed as a whole (Compressive Strength, Flexural Strength and Shrinkage) Multivariate analysis: a useful tool to evaluate the influence of addition of slag waste in the mechanical behavior MULTIVARIATE ANALYSIS METHODS Ordination Analysis. Principal Components Analysis (PCA) Multivariate Analysis of Variance (MANOVAs) SAS 9.4

14 MULTIVARIATE ANALYSIS RESULTS MANOVAs Pillai approx F Pr(>F) Mechanical behavior vs All treatment 1,86 9,53 < 0,0001 *** DIFFERENT Control vs Replacement Series Pillai approx F Pr(>F) Control vs S1 0, ,11 < 0,0001 *** Control vs S2 0, ,56 < 0,0001 *** Control vs S3 0, ,75 < 0,0001 *** Unprocessed vs Crushed Pillai approx F Pr(>F) DIFFERENTS SW vs SW-C 0, ,12 < 0,0001 *** S2SW vs S2SW-C 0,1827 2,46 0,08

15 STAINLESS STEEL SLAG WASTE AS CEMENT REPLACEMENT IN MORTAR CONCLUSIONS The replacement cement by stainless steel slag waste for the manufacture of mortar improves the mechanical behavior, valorizing this waste and reducing The cement the consumption replacement of raw by materials, stainlessobtaining steel as slaga result wastea product provides thatan notincreased cause environmentally in compressive effects according and flexural to thestrength leachates analysis. for 10% substitution respect to the control. For stainless steel slag waste crushed we are observed better results. For The mortars stainless manufactured steel slags have with presented this percentage, high values metal the oxides retractions similar to are those similar present to the in conventional control mortar. fly ash. These values result in positivity cementitious capacity in the stainless steel slag waste. The use of multivariate analysis can be a useful tools to evaluate the effect of this waste as a replacement of cement.

16 International Conference Industrial Waste & Wastewater Treatment & Valorisation APPLICATION OF STAINLESS STEEL SLAG WASTE AS A PARTIAL REPLACEMENT TO MANUFACTURE CEMENT MORTARS Julia Rosales, University of Córdoba, Spain juliarosalesgarcia@gmail.com THANKS FOR YOUR ATTENTION J. Rosales F. Agrela M. Cabrera M.G. Beltrán J.Ayuso