FERROCHROME SLAG AS SUPPLEMENTARY CEMENTITIOUS MATERIAL

1. FERROCHROME SLAG AS SUPPLEMENTARY CEMENTITIOUS MATERIAL Ahmad BADNJKI 99559477500

2. What is Ferrochrome (FeCr) Slag • Ferrochromium (FeCr) slag is a by-product from the production of ferrochromium, which is an essential component in the stainless steel industry. • The FeCr slag samples used in this study were provided by the Antalya Ferrochrome Plant, one of the largest producers of FeCr in Eurasia. The bulk density of the slag is around 1.8 t/m3 and the volume generated is about 81000 m3 /year.

3. What is Ferrochrome (FeCr) Slag • Ferrochrome (FeCr) slag is by product from the production of Ferrochrome, an essential component in stainless steel industry. • FeCr metal is produced in electric-arc furnaces by a physical –chemical process. • Granulated slag samples were collected when the industry adopted water cooled slag granulation process. • Lumped slag samples were collected from the air cooled slag after material recovery. Pictures of the slag samples are shown in Fig.3.1. and 3.2.

4. Physical properties  -Shape and Appearance    Water cooled ferrochrome slag is appeared to be dark in color and is said to have granulated and crystalline texture. Whereas air cooled slag is grey in color and is said to have a lumpy texture.  Air cooled lumpy slag as available was found to have the desirable size range of 8 to 20 mm -Comparison Between FCS & LSA the specific gravity of the FeCr slag ranges between 2.84 and 3.15 g/m3 compared with 2.65 g/m3 for limestone aggregate. While it has water absorption values between 0.25% and 2.3% in comparison with 0.38% for limestone aggregate. The Los Angeles Abrasion and CBR values of FeCr slag are between 14- 18% and 107-140% compared with 21% and 103% for limestone aggregate, respectively. -The Conclusion Analysis of Physical Properties  From the physical properties test results it can be revealed that there are several potential uses of FeCr slag: 1) it can be used as an aggregate in concrete and hot mix asphalt and concrete pavements, 2) as a base or sub-base material, and 3) as an embankment and landfill material. 

5. Chemical Properties of Ferrochrome (FeCr) Slag  The chemical composition of FeCr slag includes three major elements: Silicon (Si), Aluminium (Al), and Manganese (Mg). Together with their oxides, these components make up 83% of the slag.

6. Effect of Ferrochrome (FeCr) Slag in concrete Setting  Time The existence of MgO in large quantities can retard the initial hydration of cement and increase its setting  time  as  well  as  causing  large  changes  of volume of about 10% in concrete and asphalt mixes .However,  this  adverse  effect  can  be  eliminated  by  slag weathering in atmospheric conditions  Workability  the workability of the mixture decreases because of the fineness 

7. Effect of Ferrochrome (FeCr) Slag in concrete  Compresion strength    -In a recent study, Acharya and Patro* investigated the effect of using ferrochrome ash (Water cooled FCA) and lime dust in concrete properties. Up to 40% of FCA was used as cement substitution in concrete mixtures, The results from Acharya and Patro study indicated that replacement of OPC up to 47% by FCA (40%) and lime dust (7%) has comparable positive impact on the 28 days strength and appreciable impact on long term strength properties.    - Number of researchers* studied the properties of normal and high strength concrete made with FeCr slag as an aggregate. The results indicated that replacement up to 75% of FeCr slag in lieu of fine aggregates improved the strength of concrete compared with conventional concrete. The drying shrinkage generally decreased with increasing replacements of sand by FeCrSlag. FeCr-slag acts to increase both the thermal conductivity and specific heat effectively. FeCr-slag led to noticeable modifications in the microstructure characteristics of the hardened blends.  *https://www.researchgate.net/publication/323169407_Research_on_the_use_of_Ferro-Chrome_slag_in_civil_engineering_applications

8. Application of Ferrochrome (FeCr) Slag in Road Construction • The  use  of  FeCr  slag  as  an  aggregate  in  road  construction  is  practiced  in  many  countries  such  as Finland, Sweden,  South  Africa and  India .  Due  to its superior physical properties over the natural  aggregates beside it is cheaper than natural  aggregates, roads can  be built  with thinner  bases and sub-bases than  when  using  natural aggregates. • A research by Altan YILMAZ* showes the effect of the compresion strength when we totally replacenatural  aggregates by FCA. It approves that FCA usable in road construction according to Turkish Standards. http://journals.tubitak.gov.tr/engineering/issues/muh-13-37-3/muh-37-3-3-1204-10.pdf

9. Application of Ferrochrome (FeCr) Slag inRip rap Application  • Due to availability of large boulder size slag material and due to its high compressive strength in soaked condition, the ferro chrome slag is suitable for rip rap applications to stabilize slopes of earthen embankments, particularly reservoir bunds and canal embankments. The water absorption value is also very low (about 0.3%). The ferrochrome slag boulders have more weight compared to natural rock boulders and hence it is beneficial in slope stability aspect also.  

10. Application of Ferrochrome (FeCr) Slag inRip rap Application  • Ferrochrome slag particles have more strength, toughness and are less abrasive. The slag is available with sizes ranging from 6.3mm to 70mm. The shear Parameters of Slag determined using large shear Box is 520 and hence, it has good frictional characteristics. So, the ferro chrome slag can be advantageously used as construction material for stone columns used to support structures such as embankments and oil storage tanks in soft clays.   https://www.youtube.com/watch?v=PUvnO4M1NzA

11. References • Altan Yilmaz and Mustafa Karasahin (2010), Mechanical properties of ferrochromium slag in granular layers of flexible pavements, Material and Structures, Vol. 43, pp.309-317.  • N. Su, Z. Chen, H. Fang, Cem. Concr. Comp. 23  • (2001)  • B.B. Lind, A.M. Fallman, L.B. Larsson, Waste Manage. 21 (2001)  • P. Niemelä, M. Kauppi, INFACON XI (2007)  • A. Das, M. Lobo, AL TAMMAN INDSIL FERRO CHROME LLC (unpublished presentation) (2017)  • P.H. Kumar, A. Srivastava, V. Kumar, M.R. Majhi, V.K. Singh, J. Asian Ceram. Soc. 2 (2014)