Metallurgical By-Products in Earthworks, Hazards of their Utilization

2014 ◽  
Vol 1020 ◽  
pp. 98-109 ◽  
Author(s):  
František Kresta
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Nonferrous Metal ◽  
Steel Slag ◽  
Mineralogical Composition ◽  
Volume Changes ◽  
Volume Stability ◽  
Alternative Sources ◽  
Furnace Slag ◽  
By Products

Metallurgical by-products, primarily blast furnace and steel slag, have ranked among important alternative sources of fill as well as of material for the structural layers in highways. The properties of aggregates based on blast furnace or steel slag are determined to a decisive degree by the process employed by the specific ironmaker or steelmaker in question, or as the case may be, the specific producer of a nonferrous metal. Main hazards of metallurgical by-products are closely connected to their chemical and mineralogical composition and they are resulted in volume changes. Pavement deformation of the D47 motorway does not constitute Czech Republic’s first example of damage to an engineering structure due to volume changes of metallurgical by-products, but since this problem became widely known it drew greater attention to the problems of volume stability of the metallurgical by-products. Comparison of blast furnace slag, steel slag and other metallurgical by products parameters allow us to define the most hazardous material as steelworks waste. It is surprising that such material obtained a certificate based on which it was used as fill.

scholarly journals Concrete Properties Comparison When Substituting a 25% Cement with Slag from Different Provenances

2018 ◽  
Author(s):  
María Eugenia Parrón-Rubio ◽  
María Dolores Rubio-Cintas ◽  
Francisca Pérez-García ◽  
Antonio Gonzalez-Herrera
Keyword(s):  
Blast Furnace ◽  
Environmental Sustainability ◽  
Blast Furnace Slag ◽  
Construction Material ◽  
Steel Slag ◽  
High Energy ◽  
Stainless Steel Slag ◽  
Concrete Properties ◽  
Furnace Slag ◽  
By Products

Concrete consumption greatly exceeds the use of any other material in engineering. This is due to its good properties as construction material and the availability of its components. Nevertheless, the present worldwide construction increase and the high-energy consumption for cement production means a high environmental impact. On the other hand, one of the main problem in iron and steel industry is waste generation and by-products that must be properly processed or reused to promote the environmental sustainability. One of these by-products are blast furnace slag. Cement substitution by slag strategy achieves two goals, raw materials consumption reduction and waste management. In the present work, four different concrete mixtures are evaluated. 25% cement is substituted by different blast furnace slag. Tests are made to evaluate the advantages and drawbacks of each mixture. Depending on the origin, characteristics and treatment of the slag, concrete properties change. Certain mixtures provide proper concrete properties. Stainless steel slag produces a fluent mortar that reduces the water consumption whit a slight mechanical strength loss. Mixture with electric arc slag furnace properties are better to the reference concrete (without slag) when slag is treated similarly to the cement.

Effect of Phosphogypsum on the Properties of Over-Sulfur Phosphogypsum–Ground Granulate Blast-Furnace Slag Cement

2014 ◽  
Vol 638-640 ◽  
pp. 1453-1459
Author(s):  
Zhi Jiang Lv ◽  
Zong Shou Lin ◽  
Hao Jie Wang
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Setting Time ◽  
Steel Slag ◽  
Cement Clinker ◽  
Strength Deterioration ◽  
Volume Stability ◽  
Granulate Blast Furnace Slag ◽  
Mechanical Performances ◽  
Furnace Slag

Over-sulfur phosphogypsum(PG)–ground granulate blast-furnace slag(GGBFS) cement paste is utilized by GGBFS, Portland cement clinker(PCC), additive, water and modificated phosphogypsum paste(MPG), produced by milling PG mixed with a certain proportion of steel slag(SS), GGBFS and water. The effect of PG on the properties of over-sulfur PG– GGBFS cement was investigated. The mechanical performances and hydration mechanism of the cement with different kinds, proportions and particle size of PG were analyzed based on setting time, volume stability, strength test, XRD and SEM analyses. The experimental results show that,the optimum mixture of PG amount in the binder was 45%. Overdose of PG may caused strength deterioration. The optimum grinding time of MPG in the binder was 20min. The soluble phosphorus content of PG in the binder was under 0.05%.

Researcher Progress of Steel Slag Cascade Utilization in Building Materials

2014 ◽  
Vol 629-630 ◽  
pp. 293-298 ◽  
Author(s):  
Gang Meng ◽  
Kai Feng Zhang ◽  
Shi Ran Zhao ◽  
Meng Xue Ouyang ◽  
Xiang Li
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Building Materials ◽  
Steel Slag ◽  
Test Methods ◽  
Fine Aggregate ◽  
Volume Stability ◽  
Slag Powder ◽  
Steel Slag Powder ◽  
Furnace Slag

This paper studied the cascade use of industrial waste slag as the cementitious material, the fine aggregate and the coarse aggregate, assisted by XRD, SEM and other microscopic test methods. The results that the system had the best volume stability when the steel slag addition of 40%. When the cement mortar prepared by 10% steel slag fine aggregate, and mixed with 20% steel slag powder and 20% blast furnace slag powder, the mortar construction performance and shrink resistant performance is excellent. On the basis of concrete double mixing 25% steel slag aggregate and 30% steel slag powder, compound mixing 20% blast furnace slag powder, the durable properties of concrete are also excellent.

Phosphorus adsorption and desorption characteristics of constructed wetland gravels and steelworks by-products

Soil Research ◽  
1997 ◽  
Vol 35 (2) ◽  
pp. 375 ◽  
Author(s):  
R. A. Mann
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Constructed Wetlands ◽  
Blast Furnace Slag ◽  
Steel Slag ◽  
P Adsorption ◽  
Granulated Blast Furnace Slag ◽  
Adsorption Capacities ◽  
Furnace Slag ◽  
By Products

Laboratory phosphorus (P) adsorption and desorption experiments were conducted on 9 substrata to evaluate their potential to remove P from sewage effluent. The substrata comprised 2 gravels used in constructed wetlands, Hawkesbury sandstone, and 6 steelworks by-products: granulated blast furnace slag, blast furnace slag, steel slag, fly ash, bottom ash, and coal wash. The studies involved ion-exchange experiments and calculation of Langmuir and Freundlich adsorption isotherms and column adsorption/desorption trials. The ability to adsorb P was then correlated to the physico-chemical attributes including X-ray fluorescence analyses of each substratum. High P adsorption capacities (>380 mg/kg) were shown for granulated blast furnace slag, blast furnace slag, and steel slag, as well as fly ash. All steelworks by-products had adsorption capacities greater than the constructed wetland gravels and Hawkesbury sandstone. The P adsorption capacities of the substrata were significantly correlated with Ca (r2 = 0 · 9206), Mg (r2 = 0 · 8681), pH (r2 = 0 · 7009), S (r2 = 0 · 6696), and Si (r2 = 0 · 6438) when fly ash was omitted from the analyses. Further research is recommended to evaluate the sustainability of using slags for P removal (as well as other contaminants present in wastewater), using full-scale constructed wetlands. Research should include an evaluation of any likely environmental impacts using leachability and toxicity studies.

scholarly journals Synergistic Excitation Mechanism of CaO-SiO2-Al2O3-SO3 Quaternary Active Cementitious System

2021 ◽  
Vol 8 ◽  
Author(s):  
Fusheng Niu ◽  
Yukun An ◽  
Jinxia Zhang ◽  
Wen Chen ◽  
Shengtao He
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Steel Slag ◽  
Cementitious Materials ◽  
Test Block ◽  
Hydration Reaction ◽  
Alkaline Environment ◽  
Granulated Blast Furnace Slag ◽  
Cementitious System ◽  
Furnace Slag

In this study, the influence of steel slag (SS) content on the strength of the cementitious materials was investigated. The quaternary active cementitious material (CaO-SiO2-Al2O3-SO3) was prepared using various proportions of steel slag (SS), granulated blast furnace slag (BFS), and desulfurized gypsum (DG). The mechanism of synergistic excitation hydration of the cementitious materials was examined using various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FTIR). The strength of the mortar test block was initially increased and decreased later with the increase of the SS content. Mortar test block with 20% steel slag, 65% granulated blast furnace slag, and 15% desulfurized gypsum with 0.35 water-binder ratio showed the highest compressive strength of 57.3 MPa on 28 days. The free calcium oxide (f-CaO) in the SS reacted with water and produced calcium hydroxide (Ca(OH)2) which created an alkaline environment. Under the alkaline environment, the alkali-activated reaction occurred with BFS. In the early stage of hydration reaction, calcium silicate hydrate (C-S-H) gel and fibrous hydration product ettringite (AFt) crystals were formed, which provided early strength to the cementitious materials. As the hydration reaction progressed, the interlocked growth of C-S-H gel and AFt crystals continued and promoted the increase of the strength of the cementitious system.

scholarly journals Arsenic Removal from Water Using Industrial By-Products

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Branislava M. Lekić ◽  
Dana D. Marković ◽  
Vladana N. Rajaković-Ognjanović ◽  
Aleksandar R. Đukić ◽  
Ljubinka V. Rajaković
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Arsenic Removal ◽  
Fixed Bed ◽  
Steel Production ◽  
Groundwater Treatment ◽  
Maximum Sorption Capacity ◽  
Column Adsorption ◽  
Furnace Slag ◽  
By Products

In this study, removal of arsenic ions using two industrial by-products as adsorbents is represented. Removal of As(III) and As(V) from water was carried out with industrial by-products: residual from the groundwater treatment process, iron-manganese oxide coated sand (IMOCS), and blast furnace slag from steel production (BFS), both inexpensive and locally available. In addition, the BFS was modified in order to minimise its deteriorating impact on the initial water quality. Kinetic and equilibrium studies were carried out using batch and fixed-bed column adsorption techniques under the conditions that are likely to occur in real water treatment systems. To evaluate the application for real groundwater treatment, the capacities of the selected materials were further compared to those exhibited by commercial sorbents, which were examined under the same experimental conditions. IMOCS was found to be a good and inexpensive sorbent for arsenic, while BFS and modified slag showed the highest affinity towards arsenic. All examined waste materials exhibited better sorption performances for As(V). The maximum sorption capacity in the batch reactor was obtained for blast furnace slag, 4040 μgAs(V)/g.

Study on Sulfate Resistance of Concrete with Compound Mineral Admixture

2011 ◽  
Vol 99-100 ◽  
pp. 420-425 ◽  
Author(s):  
Qian Rong Yang ◽  
Xiao Qian Wang ◽  
Hui Ji
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Steel Slag ◽  
Sulfate Attack ◽  
Mineral Admixture ◽  
Sulfate Resistance ◽  
Chemical Attack ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

The strength, expansion and amount of scaling of concrete with compound mineral admixture (CMA) from steel slag, granulated blast furnace slag and fly ash were studied. The result shows that damage by crystallization press from sulfate attack when concrete was exposed to sulfate environments under wetting–drying alternation is much larger than that from sulfate chemical attack. Adding CMA to concrete could reduce the damage from expansion of concrete caused by sulfate chemical attack, but the resistance of concrete to damage by crystallization press from sulfate attack was remarkably reduced.

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