Usage Of Slag Research Articles

Improvement of Geotechnical Properties of Clayey Soil Using Biopolymer and Ferrochromium Slag Additives.

The geotechnical properties of clay soil and its mixtures with different proportions (0.75%, 0.85%, 1%, and 1.15%) of Agar Gum biopolymer and Ferrochromium Slag (0.25%, 0.50%, 0.75%, and 1%), having various curing times and freeze-thaw cycles, were studied through a series of soil mechanical tests to investigate possibilities to improve its undesired/problematic plasticity, compaction, and shear strength characteristics. The results revealed that treatment with an optimal ratio of 1% Agar Gum and 1% Ferrochromium Slag alone, as well as together with, improved the geotechnical properties of the clay soil considerably. Both the unconfined and shear strength properties, along with the cohesion and internal friction angle, increased as much as 47 to 173%, depending on the curing time. The higher the curing time, the higher the shear strength, cohesion, and internal friction angle are up to 21 days. Deteriorating the soil structure and/or fabric, freeze-thaw cycles, however, seem to have an adverse effect on the strength. The higher the freeze-thaw cycle, the lower the shear strength, cohesion, and internal friction angle. Also, some improvements in the plasticity and compaction properties were determined, and environmental concerns regarding Ferrochromium Slag usage have been addressed.

Effect of curing conditions on the alkali-activated blends: Microstructure, performance and economic assessment

To enhance the application of alkali-activated materials in engineering, this study investigates the influence of cast-in-place and prefabrication by steam curing and autoclaved curing on alkali-activated materials with different slag-fly ash mass ratios. The selection of the three curing methods is based on current construction techniques: onsite construction (ambient curing), production of prefabricated cement-based components (steam curing), and production of aerated concrete blocks (autoclaved curing). In this paper, the dissolution ability of CaO, SiO2 and Al2O3 in fly ash and slag was first evaluated. Subsequently, the hydration products of the samples were analyzed using X-ray diffraction, thermogravimetric analysis, and a scanning electron microscope. Additionally, the degree of hydration of the samples was quantitatively analyzed using the selective dissolution method combined with 29Si NMR. The results showed that compared to ambient curing, autoclaved curing, which provides a high-temperature and high-pressure environment, enhances the reactivity of slag and fly ash. This enhancement is reflected in the increase in their solubility and the degree of reaction from 28.3% to 14.6%–69.9% and 63.7% respectively. The pore structure, compressive strength, and shrinkage of the samples were also evaluated. The results demonstrate that autoclaved curing enhances the formation of hydration products, reduces porosity, and increases compressive strength. Compared to ambient curing, steam curing can reduce the shrinkage rate from 64.8% to 68.4%, while autoclaved curing can decrease it from 87.9% to 95.1%. Based on the economic analysis, autoclaved curing can offset the total costs by reducing the usage of slag and lowering raw material expenses, demonstrating its cost-effectiveness. The obtained results can provide a theoretical foundation for the large-scale application of alkali-activated slag-fly ash materials in civil engineering construction.

Ladle Furnace Slag: Synthesis, Properties, and Applications

AbstractLadle slag is a byproduct formed during the ladle refining stage of steel making. It is a dusty material that has been considered industrial waste. Technical advancements towards a sustainable industry led to the development of different applications for ladle slag. Depending on the processing methods during the steel slag production and the weathering of the slag post‐production, the elemental composition of the steel slag largely varies. Owing to this, its characteristics cannot be generalized and specific applications depending on the sources are developed. It is generally used in construction materials, soil rejuvenation, and CO2 capture. This paper reviews the production process, the mineralogical and morphological properties, stabilization techniques, and the applications of ladle furnace (LF) slag. One of the prime focuses of waste remediation and sustainable industry is to find meaningful ways to turn waste into products. In this respect, a comprehensive review of the properties of LF slag and its current application will help provide a framework for the development of future sustainability goals. With increased slag usage, the ladle refining process of steelmaking can be turned into a more carbon‐neutral process.

High strength fiber reinforced concrete with steel slag as partial replacement of coarse aggregate: Overview on mechanical and microstructure analysis

The growth in construction development and an increase in the number of predisposed waste products has instigated vendors and investigators in studying the use of substitute resources that valor preserve usual resources and defend ecology, helping the reduction of aggregate occupying 70% volume in concrete. Steel slag, a byproduct of steel industry can be used to substitute aggregates in standard concrete mixtures. Steel slag has essentially identical properties to ordinary aggregates and is easily obtained as a byproduct of the steel industry. Steel slag usage conserves natural resources and cleans the environment. This work primarily intends to study the mechanical behaviour of high strength fiber reinforced concrete (HSFRC) of M70 grade such in compression and tension tests, by replacing coarse aggregate by 40 %, 45 % and 50% with steel slag and pondering 1 % of steel fibers. The microstructure of concrete mixes is analysed, results indicated that 50% replacement has better performance in the strength and microstructural aspects.

Preparation and validation of sustainable metakaolin based geopolymer concrete for structural application

Geopolymer is one of the trending research areas in composite materials; there are many areas in geopolymer that unexplored still need to be explored. In this paper, an attempt is made to explore such an area and develop high-performance concrete. The optimal percentage of slag and activators, such as potassium and calcium hydroxide ratio, were investigated in metakaolin-based geopolymer. At ambient conditions, alkaline to binder (A/B) ratios of 0.25, 0.35, and 0.45 were used to cast the different proportions of geopolymer concrete at ambient conditions when tested at 7, 28, and 90 days. The fresh, mechanical properties, probability, matrix andsmoothening plot for modulus of elasticity of geopolymer were investigated. Ishikawa diagram,which signifies cause-and-effect factors of geopolymer concrete is discussed. Geopolymer was observed to have medium workability and mechanical properties and showed excellent results compared with traditional concrete at 30 % slag usage at a 0.35 ratio of A/B. At 30 % of GGBS, geopolymer concrete optimum mix maximum strength was observed.trix Matrix, and smoothening analysis show that linear relationships vary among the parameters used for analyses.

Waste incorporation in paver block production

Now-a-days a lot of open areas are being laden with non-traditional types of pavement material known as paver blocks. Paver blocks are different from typical concrete or asphalt-based pavements. It is built by accumulating individual blocks on an even surface forming a level surface layer to bear traffic/non-traffic loads. With the expansion in the construction development sector, there has been an increase in the consumption of natural resources for producing cement which contributes to the greenhouse gas effect. There has also been a sharp rise in industrialization, which is responsible for producing a huge amount of waste materials. Considering the popularity of paver blocks and the increase in their growth of demand, there is a scope to incorporate various waste materials as ingredients. This paper summarizes some of the various experimental works reported on paver blocks where there has been waste incorporation achieved for the manufacturing of paver blocks. Fly ash has been established as a good cement replacement material. Successful cement replacement of up to 40% was achieved by the usage of slag with satisfactory results where strength increased by more than 3% in comparison to normal. Geo-polymer reaction based precast blocks are easy alternatives but fly ash alone does not perform good in ambient conditions and hence it is required to be accompanied with slags in geo-polymer matrix formation. Based on the reported experimental data, it is observed that the water absorption remains less than 30% of the allowable limit. The abrasion resistance of the geopolymer paver block was 15% lesser than the cement paver block. For geo-polymer centered blocks strength advancements may be achieved with an increased concentration of alkali as well as alkali silica ratio in the matrix.

Effect of recycled flux over mechanical properties of A36 steel in submerged arc welding

ABSTRACT The objective of the current research is to analyse the feasibility of utilising welding slag as flux material in Submerged Arc Welding (SAW) of A36 steel. The amount of welding slag incorporated with virgin flux is varied from 20 to 50 percent in weight at an equal interval of 10%. The material welded with virgin flux and slag mixture of different proportion is tested for hardness, tensile and impact properties along with its soundness through radiography and ultrasonic testing. Hardness, tensile, yield and impact strength of the weld decreases with incremental inclusion of slag in SAW flux. Up to 30% slag additions provide optimum results where as 40 and 50% slag addition causes detrimental weld quality. Radiography and ultrasonic testing confirms the defect free weld samples welded with less slag addition, whereas welds performed with higher slag addition possess internal defects. Based on the weld quality and cost of weld materials, it is suggested to use waste slag up to 20–30 wt % with SAW flux wherein any deviation from this level will deteriorate either quality or profitability. The study favours usage of slag in the flux and contributes for reduction in the overall slag generation.

INFLUENCE OF INCORPORATION OF JUTE FIBRE AND FERROCHROME SLAG ON PROPERTIES OF CONCRETE

ABSTRACT The present experimental study tries to examine the impact of ferrochrome slag usage as a substitution of coarse aggregates and jute fibre (JF) on different characteristics of concrete. For this, 12 numbers of concrete mixes have been fabricated by introducing 0%, 50% and 100% ferrochrome slag aggregates (FSA) in place of natural coarse aggregates (NCA) and adding 0%, 0.1%, 0.2% and 0.3% JF in concrete. The workability, 7, 28, and 90 days compressive strength (CS), flexural strength (FS), split tensile strength (STS), ultrasonic pulse velocity (UPV), rebound number (RN), water absorption (WA), volume of voids (VV), density of designated mixes, have been studied to access the effect of incorporation of FSA and JF in concrete. The experimental outcome analysis depicts the concrete mix having 50%–100% FSA and 0.1% JF has strength, physical and non-destructive parameters similar to those of normal concrete. Furthermore, 50%–100% FSA usage has been recommended as a substitution of coarse aggregates because the incorporation of FSA has no substantial impact on various concrete properties. It is also detected that 0.1% JF could be introduced in concrete without significant degradation of concrete behaviour since, beyond this level, the properties of concrete are adversely affected.

Використання ґрунтів і вторинних продуктів промисловості, оброблених розчином селікату натрія в шарах основи дорожнього одягу

Introduction. Growing volumes of road construction increase the need to expand and rationally use of raw materials. The need for stone materials can be solved through the wide spread using of local materials, recycled products of industry in the pavement base courses and decreasing the use of natural construction materials by replacing them with alternatives, including soils, slag materials that are metallurgical industry wastes. Experience of ferrous metallurgy slag usage has been accumulated in the road industry of Ukraine. Their usage makes it possible to extend the construction season, increases the strength and reliability of road structures due to their physical and mechanical properties, significantly reduces the road pavement energy consumption, simplifying the technology of works and the estimated cost of road construction. It was determined that the layers of pavement made from blast furnace slag have a high bearing capacity. Slag structures in 5–10 years of hardening are not inferior to, and in 10–20 years surpass cement structures on durability and deformation resistance. However, there is an urgent need to provide strength and open road traffic on the already built road section in a shortest possible term, so there is a need to accelerate the activation of the slow-setting binder. Therefore water glass (water solution of sodium silicate) is used.Purpose. The purpose of the work is to study the feasibility of using the soils and recycled industry products treated with water glass in the road pavement base courses.Materials and methods. Experimental tests of soils and blast furnace slags treated with water glass with different content of water solution of sodium silicate were performed.Results. The feasibility of using the asphalt concrete mixtures on the basis of soils and recycled products of industry treated with water glass in the pavement base courses is determined. Recommendations regarding technological parameters of preparation, transportation, laying and compaction of such mixes are given.Conclusions. Performed studies have shown that the physical and mechanical parameters of soils and blast furnace slags treated with water glass meet the requirements of current regulations of Ukraine. The advantages of use are noted, namely: the possibility of replacement of traditional stone materials by the local materials and recycled products of industry, reducing the transport component in the cost of construction. The obtained results indicate the feasibility of using the soils and recycled products of industry treated with water glass in the road construction.Keywords: soils, recycled products of industry, graded blast furnace slag, water solution of sodium silicate, water glass

Comparison of The Effect of Steel Slag Usage As a Fine Aggregate Against Compressive Strength And Flexture on Reinforced Concrete With Normal Concrete (Experimental Study)

One key element in that development is concrete. The basic ingredients of concrete is a mixture of cement, water, fine aggregate and coarse aggregate, while the concrete using steel reinforcement called reinforced concrete. The times in the era of rapid globalization have resulted in increasing number of second-hand goods / waste can be a problem for the existence of life, one of which is the existence of waste steel slag. To that end, much has been done in order to recycle in order to overcome the problem of the existence of this waste. One way is to capitalize upon such waste for purposes that could be used. In this study, the steel slag is used as a substitute or substitutes in normal concrete mix. Variations addition of steel slag at normal concrete to determine the compressive strength and flexural strength better and is expected to improve the quality of the concrete form of the compressive strength and strong bending. The variation of the addition of steel slag used was 0%, 15%, 25%, and the testing was done by the compressive strength and flexural strength. From the test results obtained by the resulting increase in the value of the slump, the increase in the compressive strength and increased compressive strength lentur. The increase in the capacity of steel slag respectively 11.91% and 20.35%, of normal concrete. Whereas the increase in the flexural strength of steel slag substitution respectively 16.62% and 31.18% of normal concrete. Therefore, if conducted further research it is better grades of steel slag enlarged variation of more than 25% in order to be used as a substitute. Continued research for high quality concrete can be done by mixing a solution that can increase the holding capacity of steel slag with other concrete constituent materials.

Nutrient Supply to Seawater from Steelmaking Slag: The Coupled Effect of Gluconic Acid Usage and Slag Carbonation

Vanishing of seaweeds in coastal areas has become a serious environmental problem. Part of the reason is nutrient deficiency in seawater, especially iron. Steelmaking slag is probably one of the best nutrient suppliers in terms of cost and quantity. Utilizing steelmaking slag to fertilize coastal seaweeds may simultaneously address the two challenges of seaweed restoration and byproduct treatment. However, direct usage of slag from a basic oxygen furnace is not practical because of negative effects such as a sharp pH increase and magnesium loss. To address the disadvantages, this work investigated the leaching behavior of a practical steelmaking slag in an artificial seawater and clarified the coupled effect of gluconic acid usage and slag carbonation on aiding the nutrient supply. Slag carbonation prevents a drastic pH increase and Mg loss, while gluconic acid induces formation of stable chelated complexes. The combination of slag carbonation and gluconic acid usage results in significant improvements in the nutrient supply. By leaching the slag, the maximum concentration of Fe in seawater increases to 0.29 mg L−1, 193 times larger than the value in the initial seawater (1.5 μg L−1).

Strategies for Promoting Steelmaking Slag Resourcezation in Taiwan

Because of the world ever-growing pursuit of economic growth, natural resources have been overly exploited and squandered. Such actions have created a negative effect on the environment and led to resource depletion. These problems subsequently garnered the government attention for waste reuse, in which they began to promote sustainable circulation and reuse of resources to lower natural resource consumptions. Accordingly, the concept of the "3 R's," namely, reduce, recycle, and reuse was introduced. However, the said concept merely adopts a unidirectional, cradle-to-grave-based treatment and fails to consider the effects of waste on the economy and society. Taiwan produces approximately 20 million tonne s of waste annually, roughly 40% of which are slags. The illegal dumping and burying of slags have negatively influenced Taiwan's environment, economy, and society. Thus, the present study revolutionized the 3R concept by introducing the cradle to cradle concept. Producers are recommended to consider product features and slag usage options during the steelmaking process. Transparent productions, effective management, scientific treatments, and systematic inspections are employed to bring slags into industrial circulations, facilitating the recycling and reuse of resources.

A review of steel slag usage in construction industry for sustainable development

Use of by-products from the steelmaking process can play an important role in achieving sustainable development. The available literature suggests that the use of iron and steel industry slags as mineral admixture or partial replacement of cement improves the microstructure of the concrete as well as its mechanical and durability characteristics. This paper reviews utilization of steel slag (SS) in the construction industry by considering current and possible future utilization fields, advantages of SS usage, and problems associated with its use. Strength and durability evolution of concretes or mortars containing SS in different ratios as aggregate or cement replacement material, combined use of ground granulated blast furnace slag with SS, and some relatively new fields of utilization of SS are also addressed. Improvements in and results of SS utilization in cement and concrete are discussed by addressing its beneficial effects. This article could help researchers to understand the recent developments in evaluation of SS in the construction industry.

Analysis of the Optimum Usage of Slag for the Compressive Strength of Concrete.

Ground granulated blast furnace slag is widely used as a mineral admixture to replace partial Portland cement in the concrete industry. As the amount of slag increases, the late-age compressive strength of concrete mixtures increases. However, after an optimum point, any further increase in slag does not improve the late-age compressive strength. This optimum replacement ratio of slag is a crucial factor for its efficient use in the concrete industry. This paper proposes a numerical procedure to analyze the optimum usage of slag for the compressive strength of concrete. This numerical procedure starts with a blended hydration model that simulates cement hydration, slag reaction, and interactions between cement hydration and slag reaction. The amount of calcium silicate hydrate (CSH) is calculated considering the contributions from cement hydration and slag reaction. Then, by using the CSH contents, the compressive strength of the slag-blended concrete is evaluated. Finally, based on the parameter analysis of the compressive strength development of concrete with different slag inclusions, the optimum usage of slag in concrete mixtures is determined to be approximately 40% of the total binder content. The proposed model is verified through experimental results of the compressive strength of slag-blended concrete with different water-to-binder ratios and different slag inclusions.

非鉄金属製錬の現状と課題

Present status and issues of non-ferrous extractive metallurgy were described in this short review from resource and environmental points of view. Recent trend of shortage of non-ferrous ores and severe regulations gave several impacts to non-ferrous extractive metallurgical industry, although significant innovations of non-ferrous extractive metallurgical processes have not been done in this decade.There are three big issues in the society. The first one is how to control iron, sulfur and minor impurities like arsenic. Sulfur is over supplied in the world, then more than 10 millions tons sulfur are stored near oil and natural gas refineries. Therefore, a development of new application of sulfur is still essential. Usage of slag is also big problem. Since regulations on the usage of slag became severe, we have to change a mind that slag is not a sink of minor impurities but an important by-product containing iron which is major impurity in non-ferrous ores.Good collaboration of each non-ferrous smelter and refinery will be required to keep them in Japan to treat not major non-ferrous metals but harmful minor elements like arsenic and cadmium. Keeping non-ferrous industry is one of keys to achieve the sustainable development in Japan.

Use of granular slag columns for lead removal

The use of granular blast furnace slag (GBFS)-packed columns to treat lead-containing solutions has been investigated. The results obtained indicated that the slag usage rate decreased with increasing flow velocity, particle size, initial lead concentration and decreasing with bed height. Lead removed selectively in the presence of other heavy metal ions. High concentrations of sodium and especially calcium in the solutions impeded the uptake of lead. For 20 mg l −1 lead concentration an empty bed contact time greater of 4 min provided to efficient use of the slag bed. Column pH was an important parameter to lead removal under dynamic conditions and reflected the influence of the investigated factors. During all runs lead breakthrough coincided with an abrupt drop in effluent pH. The apparent mechanisms of lead removal in GBFS column are sorption (ion exchange and adsorption) on the slag surface and precipitation.

銅製錬スラグの高温酸化による改質

Slags produced from iron and steel making industry or non-ferrous smelting plants are now considered one of the important domestic resources in various fields. Although the most copper smelting slags have been used in cement plant as a component of iron oxide in clinker, the market is not big enough to consume the amount of slag available, and furthermore, advanced usage of slag with higher value will be expected.In this study, the copper slags are oxidized in air at 1, 000°C for 1-20 hours. After oxidation the X-ray diffraction pattern, infra-red absorption spectra, and EPMA images showed an existence of iron oxide (Fe203, Fe2O4), CaO-Al2O3-Si02 system, and discrete Si02 in different phases. The dissolution test with HCl, H2SO4 and NaOH solution was carried out for Fe and SiO2 in the samples. The results indicate that the oxidized slags exhibit high resistance against the dissolution of both Fe and SiO2. According to the Seger cone test, the oxidized slags were stable at higher temperature than that for non-oxidized slags. As a result of slag lining tests on a steel plate, the strong anchoring effect was observed at the interface probably due to the reaction between iron plate and Fe ions in slag. The alkali-aggregate reaction of slags in concrete was examined by the ASTM chemical method, resulting in finding all spots inside the safe range of figure.