Use Of Industrial By-products Research Articles

Strength and Abrasion Characteristics of ISF Slag Concrete

Use of industrial by-products as raw materials in concrete is becoming necessary to address the sustainability of both the concrete and the industrial growth. The present study assesses the potential of imperial smelting furnace (ISF) slag as in concrete, considering the presence of toxic elements (lead and zinc) and their detrimental effects on the early hydration of cement. Equivalent volume of sand was replaced by ISF slag in different percentages. Concrete specimens were prepared at different water-to-cement ratios. Compressive, flexural, and pull-off strength, along with abrasion resistance, were examined. Leaching potentials of toxic lead, zinc, and cadmium from ISF slag concrete mixtures were also analyzed to evaluate environmental viability. Results are encouraging because sign of delay in setting was not observed. Improvement in compressive and pull-off strength, comparable flexural strength and abrasion resistance, and leaching of toxic elements within safe limits assures the potential of future use of ISF slag as sand in concrete.

Case Study to Promote the Use of Industrial Byproducts: The Relevance of Performance Tests

Abstract Currently, there is strong pressure to use industrial byproducts and recycled materials in the construction of transportation infrastructure and geotechnical works. The reuse of these materials positively affects the environment by reducing deposits and preserving raw materials. The related geotechnical, geoenvironmental, economical, and social issues should be addressed so that these materials can be used in construction to provide sustainable development. This paper presents a study of all of these aspects and focuses on Portuguese electrical arc furnace steel slag. A huge laboratory research program was carried out that addressed four elements of geotechnical and geoenvironmental behavior: ultimate strength under monotonic loading, resilient behavior (stiffness), susceptibility to permanent deformation due to repeated loading, and leachability. These test results were compared with those from the empirical tests used in the national specifications for embankments and structural layers of transportation infrastructures. It was concluded that performance-based laboratory test results show much better material performance than the results based on empirical tests (Los Angeles and micro-Deval). Furthermore, this material shows better mechanical performance than in the mechanical tests of natural unbound granular materials used in road construction. Additionally, leaching test results show that this byproduct is inert, which caused it to become known as “inert steel aggregates for construction” (ISAC). These laboratory conclusions were validated in a full-scale field trial by end performance testing (using devices that measure in situ stiffness through spot tests and continuous monitoring, as well as lysimeters to measure leaching values). This field trial involved raw materials and ISAC. A final remark is made about some socioeconomic aspects that should be taken into account in decision making regarding the use of ISAC in public works.

Use of industrial by-products in earthworks in the Czech Republic

Abstract The use of industrial by-products as a construction fill is set to increase in order to minimize the environmental impact of large infrastructure construction schemes. The Czech Republic is one of a number of countries where these products are now used. This paper gives a brief background to the use of colliery spoil, fly ash, blast furnace slag and PRESTAB, with particular reference to the construction of the D47 motorway and R48 expressway near Ostrava.

Hydration of mineral shrinkage-compensating admixture for concrete: An experimental and numerical study

The use of shrinkage-compensating admixture in concrete has been proven to be an effective way to mitigate the shrinkage of concrete. The hydration of a shrinkage-compensating admixture in cement paste and concrete is investigated in this paper with numerical simulation and experimental study. An ettringite-based mineral shrinkage-compensating admixture (MSA) is developed taking use of industrial by-products. The MSA is designed with special considerations to the stoichiometry of ettringite formation, i.e. it should provide stable sources of sulfate and alumina which are necessary for the ettringite formation. Experimental results prove that the new MSA can successfully compensate the autogenous shrinkage of concrete.

Use of Industrial Byproducts to Filter Phosphorus and Pesticides in Golf Green Drainage Water

Golf courses are vulnerable to phosphate (PO) and pesticide loss by infiltration of the sandy, porous grass rooting media used and through subsurface tile drainage. In this study, an effort was made to remove PO, chlorothalonil, mefenoxam, and propiconazole in a golf green's drainage water with a filter blend comprised of industrial byproducts, including granulated blast furnace slag, cement kiln dust, silica sand, coconut shell-activated carbon, and zeolite. To test this filter media, two 6-h storm events were simulated by repeat irrigation of the golf green after PO and pesticide application. Drainage flows ranged from 0.0034 to 0.6433 L s throughout the course of the simulations. A significant decrease in the chlorothalonil load for the experimental run (with filter media) was observed compared with the control (without filter media) ( < 0.05). In general, percent reductions in chlorothalonil were very high (>80%) near peak flows. In contrast, filter media was not effective in removing PO, mefenoxam, or propiconazole ( > 0.05). Instead, it appears that the filter blend added PO to the effluent above flow rates of 0.037 L s. Overall, flow rate, the amount of filter media used, and contaminant properties may have influenced the filter media's ability to remove contaminants. More research is needed to determine the optimal blend and configuration for the filter media to remove significant amounts of all contaminants investigated.

Use of Industrial Byproducts as Alumina Sources for the Synthesis of Calcium Sulfoaluminate Cements

Calcium sulfoaluminate (CSA) cements show some desirable environmentally friendly features that include the possibility of using several industrial byproducts as raw materials in their manufacturing process. Alumina powder, from the secondary aluminum manufacture, and anodization mud, from the production process of anodized aluminum, have proved to be suitable as partial or total substitutes for an expensive natural material like bauxite. CSA clinker generating raw mixtures, containing limestone, natural gypsum, bauxite, and/or one of the alumina-rich byproducts, were heated 2 h in a laboratory electric oven at temperatures ranging from 1150 to 1300 °C. Conversion of reactants into 4CaO·3Al(2)O(3)·SO(3) (the key component of CSA cements), evaluated using X-ray diffraction (XRD) analysis, increased with an increase of both burning temperature and byproduct concentration. When examined through differential thermogravimetric and XRD analyses, a synthetic CSA clinker (made from the raw mixture incorporating alumina powder as a total replacement of bauxite) mixed with 20% gypsum showed a hydration behavior almost similar to that of an industrial CSA cement containing the same amount of gypsum.

Use of Industrial By-products to Sorb and Retain Phosphorus

The potential of six industrial by-products for use as phosphorus-sorbing materials (PSMs) in solutions was evaluated. These included two different acid mine drainage treatment residuals (AMDR1 and AMDR2), water treatment residual (WTR), fly ash, bauxite mining residual, and flue gas desulfurization product (FGD). Characterization of the by-products and their mechanisms for sorption and retention of inorganic phosphorus (P) from solution identified those PSMs that sorbed primarily by an iron and aluminum (Fe/Al) mechanism, those that sorbed primarily by a calcium and magnesium (Ca/Mg) mechanism, and those that sorbed by both mechanisms. Degree of P sorption and associated mechanisms were strongly influenced by the pH, buffer capacity, ionic strength, and common ion effects.

Stabilisation of clayey soils with industrial by-products: part B

The use of industrial by-products in the stabilisation of problematic soils presents economic, environmental and social benefits. The geotechnical and physico-chemical behaviour of some Australian clayey soils of contrasting mineralogy stabilised with commonly employed industrial by-products has been investigated in the laboratory for developments in pH, plasticity, and undrained shear strength at curing periods of up to 1 year. Stabilising agents including hydrated lime, fly ash and ground granulated blastfurnace slag (‘slag') were utilised. The results of this study showed that soils mixed to moisture contents well above their respective liquid limits developed substantial undrained shear strength directly upon exposure to cementitious stabilisers and continued to gain significant strength thereafter. It is noteworthy that samples treated with slag activated with hydrated lime gained more strength at shorter periods of curing than comparable samples of activated fly ash and samples simply treated with equivalent proportions of hydrated lime. The pH measurements gave an indication of cementitious activity that was closely aligned to the development of undrained shear strength, where a reducing pH was observed to consistently coincide with gains in strength. Plasticity tests indicated that smectite-dominant soils have a reduction in plasticity index, while kaolinite-dominant soils have an increase in plasticity index as strong inter-particle bonds are formed. This study also found that organic matter obstructed cementitious activity. The underlying micromechanical aspects related to geotechnical response have been detailed in an accompanying paper by the authors (part A).

Properties of controlled low-strength materials incorporating cement kiln dust and slag

This research evaluated the potential use of cement kiln dust (CKD) together with slag to replace the use of cement in the production of controlled low-strength material (CLSM). The low strength requirements of CLSM compared to conventional concrete enable the use of industrial by-products for the production of CLSM. In this study, the workability-related fresh properties of CLSM mixtures were observed through slump flow diameter, V-funnel flow time and filling capacity. Setting times, temperature rise, air content and unit weight of CLSM mixtures were also determined as part of fresh properties. The hardened properties that were monitored for 28 days included the unconfined compressive strength. The test results presented herein show that a combination of less than 50 kg/m3 slag and up to 300 kg/m3 CKD provides a good mix that satisfies the requirements of a CLSM with similar or better properties to that of CKD-based CLSM mix containing Portland cement. Suitable CLSM mixtures with reasonable fresh and hardened properties could also be developed by using CKD alone. However, reduced strength in such CLSM mixtures may limit their field application. The slag significantly assisted in increasing compressive strength of CKD-based CLSM mixtures. A CLSM mix containing a combination of slag and CKD was shown to have excellent characteristics for flowable backfill and excavatable base material. Therefore, producing CKD/slag based CLSM through the use of co-generated products from the cement and iron manufacturing processes can provide leadership for the construction industry in the transition for sustainable development.

Characterization of the EAF Steel Slag as Aggregate for Use in Road Construction

The use of industrial by-products requires knowledge of the characteristics of the materials. This paper presents characterization data on slag generated in the melting of steel scrap by electric arc furnace (EAF). Characterization of EAF slag, as one of the most significant types of non-hazardous metallurgical waste, was carried out through an examination of its physical and chemical properties with special emphasis on chemical and structural characteristics and potential use in road construction. Croatian EAF black steel slag, generated from carbon steel production process in CMC Sisak d.o.o., is the most interesting from the asphalt technology point of view, but in order to assess the suitability and reusing potential of EAF slag in asphalt mixture production, it is necessary to know its chemical, radiochemical, physical, morphological, mineralogical, and textural characteristics, as well as how it interacts with individual segments of the environmental system. For this purpose, the study was carried out using several different analytical methods and this paper aims to explore the feasibility of utilizing steel slag as aggregates in asphalt mixtures. Optical Microscopy (OM), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectrometry (EDS) and -spectrometric analysis were employed to study the texture, morphology and composition of steel slag. Tests on the soundness of the slag for use as aggregate in road construction were carried out in accordance with European standards.

Properties of concrete using metallurgical industrial by-products as aggregates

The use of industrial by-products and waste materials in concrete opens a whole new range of possibilities in the reuse of materials in the building industry. In this research study, concretes were made with chemical foundry sand (QFS) and green foundry sand (GFS) as substitution for raw sand. Also Electric arc furnace slag (EAFS) and blast furnace slag (BSF) were used as substitution for coarse raw aggregates in 25%, 50% and 100% of concrete production. Two concrete production stages were carried out. In stages 1 and 2, slump test and compressive and tensile splitting strengths and modulus of elasticity were determined. Due to adequate properties of all concretes found in stage 2, length change (during 56 weeks), sorptivity and high temperature exposure evaluation were also determined. The tests results obtained from concretes produced in stages 1 and 2 were compared with those of conventional concrete (CC) and the adequate use of the by-products for concrete production was verified.

Sustainable binders for soil stabilisation

Portland cement is the most commonly and widely used binder in ground improvement soil stabilisation applications. However, many changes are now affecting the selection and application of stabilisation additives. These include the significant environmental impacts of Portland cement, increased use of industrial by-products and their variability, increased range of application of binders and the development of alternative cements and novel additives with enhanced environmental and technical performance. This paper presents results from a number of research projects on the application of a number of Portland cement-blended binders, which offer sustainability advantages over Portland cement alone, in soil stabilisation. The blend materials included ground granulated blastfurnace slag, pulverised fuel ash, cement kiln dust, zeolite and reactive magnesia and stabilised soils, ranging from sand and gravel to clay, and were assessed based on their mechanical performance and durability. The results are presented in terms of strength and durability enhancements offered by those blended binders.

Use of Industrial By‐Products in Urban Roadway Infrastructure

SummaryIncorporating the beneficial use of industrial by‐products into the industrial ecology of an urban region as a substitute or supplement for natural aggregate can potentially reduce life cycle impacts. This article specifically looks at the utilization of industrial by‐products (IBPs) (coal ash, foundry sand, and foundry slag) as aggregate for roadway sub‐base construction for the Pittsburgh, Pennsylvania, urban region. The scenarios compare the use of virgin aggregate with the use of a combination of both virgin and IBP aggregate, where the aggregate material is selected based on proximity to the construction site and allows for minimization of transportation impacts. The results indicate that the use of IBPs to supplement virgin aggregate on a regional level has the potential of reducing impacts related to energy use, global warming potential, and emissions of nitrogen oxides (NOx), sulfur dioxide (SO2), carbon monoxide (CO), PM10 (particulate matter—10 microns), mercury (Hg), and lead (Pb). Regional management of industrial by‐products would allow for the incorporation of these materials into the industrial ecology of a region and reduce impacts from the disposal of the IBP materials and the extraction of virgin materials and minimize the impacts from transportation. The combination of reduced economic and environmental costs provides a strong argument for state transportation agencies to develop symbiotic relationships with large IBP producers in their regions to minimize impacts associated with roadway construction and maintenance—with the additional benefit of improved management of these materials.

Assessment of the use of industrial by-products for induced reduction of As, and Se potential leachability in an acid soil

Four industrial by-products (phosphogypsum, PG; red gypsum, RG; sugar foam, SF and ashes from the combustion of biomass, ACB) were evaluated as possible amendments for reducing the leachability and bioavailability of As and Se in a metalloid-spiked acidic soil. The treatments were applied as single, double and triple amendments and at two different rates. The effectiveness of the treatments was evaluated after a series of leaching experiments using a chelating agent (DTPA solution) or a weak acidification (acetic acid at pH 4.93). The most effective treatments (ACB and RG, both applied at high rate) were identified by means of Cluster Analysis using the leachability indexes. Different sorption mechanisms involved in the overall reduction of metalloid leachability were identified using scanning electron microscopy (SEM-BSE and SEM-EDS). In the ACB-treated samples, Se was found associated to organic matter aggregates and to Fe compounds. In the RG-treated samples, EDS analyses showed that As and Se were associated to Fe/Ti (hydr)oxides phases which are present not only in the by-product as maghemite and rutile, but also in the soil as hematite and goethite. In addition, the application of RG induced the formation of non-crystalline Al-hydroxy polymers with As and Se in their composition.

Production of MgO-type expansive agent in dam concrete by use of industrial by-products

A novel MgO-type expansive agent in a designed formula has been prepared with industrial by-products—magnesite, serpentine and dolomite calcined at 1150 °C for 1 h. The compositions of expansive agent were studied by X-ray diffractometry (XRD), DSC and scanning electron microscopy (SEM), and the results showed that the main phases were MgO, CaO and C 2S. The hydration of CaO to Ca(OH) 2 is quick and can be completed in 3 days in water at 20 °C, and MgO to Mg(OH) 2 is slow and about 57% MgO hydrates into Mg(OH) 2 in 180 days under the same condition, which is quicker than in water. The hydrations of CaO and MgO generate expansions in early and later age, respectively. The shrinkage of roller compacted concrete will be compensated by adding the expansive agent. The utilization of these industrial by-products in the construction of hydraulic dams not only compensates the shrinkage of dam, but also reduces the environmental pollution.

Stabilization of As, Cr, Cu, Pb and Zn in soil using amendments – A review

The spread of contaminants in soil can be hindered by the soil stabilization technique. Contaminant immobilizing amendments decrease trace element leaching and their bioavailability by inducing various sorption processes: adsorption to mineral surfaces, formation of stable complexes with organic ligands, surface precipitation and ion exchange. Precipitation as salts and co-precipitation can also contribute to reducing contaminant mobility. The technique can be used in in situ and ex situ applications to reclaim and re-vegetate industrially devastated areas and mine-spoils, improve soil quality and reduce contaminant mobility by stabilizing agents and a beneficial use of industrial by-products. This study is an overview of data published during the last five years on the immobilization of one metalloid, As, and four heavy metals, Cr, Cu, Pb and Zn, in soils. The most extensively studied amendments for As immobilization are Fe containing materials. The immobilization of As occurs through adsorption on Fe oxides by replacing the surface hydroxyl groups with the As ions, as well as by the formation of amorphous Fe(III) arsenates and/or insoluble secondary oxidation minerals. Cr stabilization mainly deals with Cr reduction from its toxic and mobile hexavalent form Cr(VI) to stable in natural environments Cr(III). The reduction is accelerated in soil by the presence of organic matter and divalent iron. Clays, carbonates, phosphates and Fe oxides were the common amendments tested for Cu immobilization. The suggested mechanisms of Cu retention were precipitation of Cu carbonates and oxy-hydroxides, ion exchange and formation of ternary cation–anion complexes on the surface of Fe and Al oxy-hydroxides. Most of the studies on Pb stabilization were performed using various phosphorus-containing amendments, which reduce the Pb mobility by ionic exchange and precipitation of pyromorphite-type minerals. Zn can be successfully immobilized in soil by phosphorus amendments and clays.

Produção biotecnológica de poli-hidroxialcanoatos para a geração de polímeros biodegradáveis no Brasil

In recent years, several studies have been developed in Brazil to produce biodegradable materials. A particular family of bacterial polymers, the polyhydroxyalkanoates (PHA), has received special attention. PHAs are thermoplastic, biodegradable, biocompatible, are synthesised from renewable resources and can substitute petrochemical plastics in some applications. Different aspects have been focused to increase productivity and to reduce the cost of PHA production: bacterial improvement, use of industrial by-products as raw material, bioreactor design, process operation strategies, downstream process, mathematical modelling, polymer characterisation, application and biodegradability of blends. A production process was transferred to industry and studies to produce new PHA by controlling monomer composition are in progress. All these aspects are presented in this review.

Simulating operational alternatives for future cement production

To support decisions on product and process development options and strategic planning, information on the consequences of planned changes are needed. For this purpose a flexible model for cement manufacturing has been developed. The model predicts the environmental, product and economic performance in a life cycle perspective, simulating different operational alternatives. Interesting future operational alternatives, such as an increase in the use of industrial by-products and wastes as raw materials and fuels have been explored. The results, i.e. the consequences from a life cycle perspective of potential development options, are discussed. The nine simulations show that the use of recovered material and alternative fuel (defined waste) can be increased while maintaining the current requirements on clinker performance. An increase in the use of recovered material and alternative fuel replaces the use of resources. The simulations also show that the emissions of CO 2, NO X , SO 2, CO, VOC, CH 4 and dust can be reduced between 30 and 80% depending on the use of recovered material and alternative fuel. The transport of recovered material and alternative fuel increases with increased use. However, the environmental benefits of the increase in use of recovered material and alternative fuel are by far greater than the resource use and emissions to air associated with the increase in transport.

Production of high strength concrete by use of industrial by-products

Blast furnace slag aggregates (BFSA) were used to produce high-strength concretes (HSC). These concretes were made with total cementitious material content of 460–610 kg/m 3. Different water/cement ratios (0.30, 0.35, 0.40, 0.45 and 0.50) were used to carry out 7- and 28-day compressive strength and other properties. Silica fume and a superplasticizer were used to improve BFSA concretes. Slump was kept constant throughout this study. Ten percent silica fume was added as a replacement for ordinary portland cement (OPC) in order to obtain HSC. The silica fume was used as highly effective micro-filler and pozzolanic admixture. Superplasticizer at dosages of 2%, 1.5%, 1%, 0.5% and 0% by OPC weight for 0.30, 0.35, 0.40, 0.45 and 0.50 w/c ratios, respectively, were adopted. Results showed that compressive strength of BFSA concretes were approximately 60–80% higher than traditional (control) concretes for different w/c ratios. These concretes also had low absorption and high splitting tensile strength values. It is concluded that BFSA, in combination with other supplementary cementitious materials, can be utilized in making high strength concretes.

Alkali-activated binders by use of industrial by-products

Cement kiln dust (CKD) materials are used as alkaline accelerators for latent hydraulic substances and as alkali activators for different alumosilicate materials, including ground-granulated blast furnace slag, low-calcium fly ash and metakaolin. The dusts differ in their phase composition, especially in the amount of reactive phases and the kind and amount of alkali salts. The quantitative phase composition, pore solution composition and strength behavior of the activated blends is reported.