scholarly journals Analysis of the Possibility of Using Slags from the Thermal Treatment of Municipal Waste as Potential Component of Cement—Case Study

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6491
Author(s):  
Monika Czop ◽  
Beata Łaźniewska-Piekarczyk ◽  
Małgorzata Kajda-Szcześniak

In Europe there are nearly 500 incinerators. There are over 2000 of them in the world. It is estimated that the combustion of 1 ton (Mg) of waste produces about 250–300 kg of slag. Due to the large amounts of this waste, the construction industry’s demand for raw materials and the reduction of CO2 emissions, research was undertaken to use slags as a cement component. The problem was complex because slags generated in the thermal treatment of municipal waste have different chemical compositions and physical properties and contain variable amounts of impurities. The choice of chemical analyses of slag was dictated by the potential influence on the properties of cement mortars. The total moisture of raw slag (4–10%), the bulk density (600–1267 kg/m3) and the specific surface after grinding (over 3000 cm2/g) were determined. The pH (11.9) and the content of sulphates (3.5% by weight), chlorides (0.3% by weight) and selected heavy metals (Cd, Cu, Fe, Mn, Zn, Pb) were measured in the aqueous extract. The obtained results of the washing test were compared with the values resulting from the currently binding legal regulations. In the next step, cement mortars with 30% addition of tested slags were designed and made. The article presents the results of compressive strength tests, which were compared with the results of samples without the addition of slag. The addition of slag to the cement mortar decreased S_MSWI 1 by 64% and S_MSWI 2 by 31%. The high loss of strength and the swelling of the S_MSWI 1 test led to the activation of the NaOH slag. In the endurance test, an increase from 16 to 32 MPa was recorded. Preliminary studies show that the addition of slag in the cement mortar allows obtaining the strength at the level of 30–32 MPa.

2019 ◽  
Vol 828 ◽  
pp. 14-17
Author(s):  
Malgorzata Ulewicz ◽  
Jakub Jura

The preliminary results of utilization of fly and bottom ash from combustion of biomass for the produce of cement mortars has been presented. Currently, this waste are deposited in industrial waste landfills. The chemical composition of waste materials was determined using X-ray fluorescence (spectrometer ARL Advant 'XP). ). In the studies sand was replaced by mix of fly and bottom ash from the combustion of biomass in an amount of 10-30% by weight of cement CEM I 42.5 R (Cemex). The obtained cement mortar concrete were subjected to microscopic examination (LEO Electron Microscopy Ltd.) and their compressive strength (PN-EN-196-1), frost resistance (PN-EN 1015-11 and PN-B -04500 ) and absorbability (PN-85/B-04500) were identified. The obtained results showed, the replacement of the cement by mix ashes from combustion of biomass reduce consumption of raw materials and will have a good influence on the environment.


Resources ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 83
Author(s):  
Jolanta Latosińska ◽  
Dorota Miłek ◽  
Angelika Komór ◽  
Robert Kowalik

Social and economic changes make it necessary to put in a great deal of conscious effort to shift towards a closed-loop economy, where waste provides a source of raw materials. The low level of selective collection of municipal waste poses a challenge in many countries, including Poland. One of the major causes of the problems in Poland lies in the fact that waste collection points (WCPs) do not have adequate waste containers. The paper aims to put forward a proposal to improve the operation of WCPs. Seeking for new solutions, it is necessary to account for the conditions under which the bodies responsible for waste management take their decisions. They have to comply with the legislation in force, and at the same time, choose the options that generate the lowest costs. The study concerned a typical residential district with housing in multi-family buildings. For two fill rate variants and four emptying schedules, the number of above-ground containers was calculated. Two variants: for above-ground containers (variant I) and for semi-underground containers (variant II), were compared in terms of operating costs and investment outlays. The proposed increase in the number of above-ground containers, and additionally providing semi-underground containers, will contribute to increased engagement of the local community in the selective collection of waste.


2020 ◽  
Vol 38 (10A) ◽  
pp. 1522-1530
Author(s):  
Rawnaq S. Mahdi ◽  
Aseel B. AL-Zubidi ◽  
Hassan N. Hashim

This work reports on the incorporation of Flint and Kaolin rocks powders in the cement mortar in an attempt to improve its mechanical properties and produce an eco-friendly mortar. Flint and Kaolin powders are prepared by dry mechanical milling. The two powders are added separately to the mortars substituting cement partially. The two powders are found to improve the mechanical properties of the mortars. Hardness and compressive strength are found to increase with the increase of powders constituents in the cement mortars. In addition, the two powders affect water absorption and thermal conductivity of the mortar specimens which are desirable for construction applications. Kaolin is found to have a greater effect on the mechanical properties, water absorption, and thermal conductivity of the mortars than Flint. This behavior is discussed and analyzed based on the compositional and structural properties of the rocks powders.


2019 ◽  
Author(s):  
Onsardi Onsardi

The title of this study is the Strategy of Increasing Consumer Food Loyalty in CurupCity, Rejang Lebong Regency (Case Study in "Henvian" Typical Food Industry). Thisresearch is based on the importance of strategies in increasing business and consumerloyalty to products sold.Strategies to increase business and consumer loyalty can bedone with a SWOT analysis. Place of this research is the "Henvian" shop that sellstypical Rejang lebong food. The method used in this study is descriptive qualitative.Informants in this study were people who were considered to know for certain about theHENVIAN Specialty Food Store in Curup City, Rejang Lebong Regency. The dataanalysis technique used in this study is a SWOT analysis to determine the strengths,weaknesses, opportunities and threats in a typical Rejang Lebong food business.By using SWOT analysis techniques that consist of strengths (weakness), weaknesses(weakness), opportunities (opportnity) and threats (threath). The results of this studycan be concluded that the internal factors that are the strength of the marketing strategyare the quality of the product that is good at a price affordable to the public andtourists, service that is friendly and responsive to consumer needs, as well astechnological advancements that facilitate the promotion of business. Internal factorsthat are a weakness are often lack of stock, there are some products that do not meet thestandard packaging, the product shelf life is short, employees do not use uniforms.External factors that become opportunities are a fairly high economic community,abundant raw materials while external factors that are a threat are the manycompetitors, an unstable economy, the price of basic needs increases. Based on theresults of the SWOT analysis of internal and external factors, the strategy used is toimprove product quality by improving the appearance of packaging and quality ofcontent and quality of service by providing uniforms to employees and providingstandards of service to consumers. .Keywords: Strategy, Consumer Loyalty, SWOT


2018 ◽  
Vol 69 (8) ◽  
pp. 2040-2044
Author(s):  
Georgeta Velciu ◽  
Virgil Marinescu ◽  
Adriana Moanta ◽  
Ladislau Radermacher ◽  
Adriana Mariana Bors

The influence of fly ash adittion (90 % fraction [ 100 mm) on the cement mortar characteristics was studied. The XRD, XRF, SEM and FTIR determinations indicated that fly ash used has a hollow microstructure of microsphere and cenosphere whose total content in SiO2, Al2O3 and Fe2O3 is 88.63 % and that of CaO and MgO of 8.55 %. The mechanical, thermal and dielectric determinations made on mortar samples with content of fly ash in the 0-40 % range have highlighted fact that the mechanical strength of cement mortars is maximal at 20 %, the increase in fly ash content leads to a decrease in relative density and thermal conductivity as well as and to increased dielectric losses tgd.


Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 194
Author(s):  
Joanna Pawłat ◽  
Piotr Terebun ◽  
Michał Kwiatkowski ◽  
Katarzyna Wolny-Koładka

Sterilization of municipal waste for a raw material for the production of refuse-derived fuel and to protect surface and ground waters against biological contamination during transfer and storage creates a lot of problems. This paper evaluates the antimicrobial potential of non-equilibrium plasma in relation to the selected groups of microorganisms found in humid waste. The proposed research is to determine whether mixed municipal waste used for the production of alternative fuels can be sterilized effectively using low-temperature plasma generated in a gliding arc discharge reactor in order to prevent water contamination and health risk for working staff. This work assesses whether plasma treatment of raw materials in several process variants effectively eliminates or reduces the number of selected groups of microorganisms living in mixed municipal waste. The presence of vegetative bacteria and endospores, mold fungi, actinobacteria Escherichia coli, and facultative pathogens, i.e., Staphylococcus spp., Salmonella spp., Shigella spp., Enterococcus faecalis and Clostridium perfringens in the tested material was microbiologically analyzed. It was found that the plasma treatment differently contributes to the elimination of various kinds of microorganisms in the analyzed raw materials. The effectiveness of sterilization depended mainly on the time of raw materials contact with low-temperature plasma. The results are very promising and require further research to optimize the proposed hygienization process.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2136
Author(s):  
Shaokang Zhang ◽  
Ru Wang ◽  
Linglin Xu ◽  
Andreas Hecker ◽  
Horst-Michael Ludwig ◽  
...  

This paper studies the influence of hydroxyethyl methyl cellulose (HEMC) on the properties of calcium sulfoaluminate (CSA) cement mortar. In order to explore the applicability of different HEMCs in CSA cement mortars, HEMCs with higher and lower molar substitution (MS)/degree of substitution (DS) and polyacrylamide (PAAm) modification were used. At the same time, two kinds of CSA cements with different contents of ye’elimite were selected. Properties of cement mortar in fresh and hardened states were investigated, including the fluidity, consistency and water-retention rate of fresh mortar and the compressive strength, flexural strength, tensile bond strength and dry shrinkage rate of hardened mortar. The porosity and pore size distribution were also analyzed by mercury intrusion porosimetry (MIP). Results show that HEMCs improve the fresh state properties and tensile bond strength of both types of CSA cement mortars. However, the compressive strength of CSA cement mortars is greatly decreased by the addition of HEMCs, and the flexural strength is decreased slightly. The MIP measurement shows that HEMCs increase the amount of micron-level pores and the porosity. The HEMCs with different MS/DS have different effects on the improvement of tensile bond strength in different CSA cement mortars. PAAm modification can improve the tensile bond strength of HEMC-modified CSA cement mortar.


2021 ◽  
Vol 13 (9) ◽  
pp. 4851
Author(s):  
Ming-Hui Liao ◽  
Chi-Tai Wang

The chemical industry has sustained the development of global economies by providing an astonishing variety of products and services, while also consuming massive amounts of raw materials and energy. Chemical firms are currently under tremendous pressure to become lean enterprises capable of executing not only traditional lean manufacturing practices but also emerging competing strategies of digitalization and sustainability. All of these are core competencies required for chemical firms to compete and thrive in future markets. Unfortunately, reports of successful transformation are so rare among chemical firms that acquiring the details of these cases would seem an almost impossible mission. The severe lack of knowledge about these business transformations thus provided a strong motivation for this research. Using The Open Group Architecture Framework, we performed an in-depth study on a real business transformation occurring at a major international chemical corporation, extracting the architecture framework possibly adopted by this firm to become a lean enterprise. This comprehensive case study resulted in two major contributions to the field of sustainable business transformation: (1) a custom lean enterprise architecture framework applicable to common chemical firms making a similar transformation, and (2) a lean enterprise model developed to assist chemical firms in comprehending the intricate and complicated dynamics between lean manufacturing, digitalization, and sustainability.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3079
Author(s):  
Beata Jaworska ◽  
Dominika Stańczak ◽  
Joanna Tarańska ◽  
Jerzy Jaworski

The generation of energy for the needs of the population is currently a problem. In consideration of that, the biomass combustion process has started to be implemented as a new source of energy. The dynamic increase in the use of biomass for energy generation also resulted in the formation of waste in the form of fly ash. This paper presents an efficient way to manage this troublesome material in the polymer–cement composites (PCC), which have investigated to a lesser extent. The research outlined in this article consists of the characterization of biomass fly ash (BFA) as well as PCC containing this waste. The characteristics of PCC with BFA after 3, 7, 14, and 28 days of curing were analyzed. Our main findings are that biomass fly ash is suitable as a mineral additive in polymer–cement composites. The most interesting result is that the addition of biomass fly ash did not affect the rheological properties of the polymer–cement mortars, but it especially influenced its compressive strength. Most importantly, our findings can help prevent this byproduct from being placed in landfills, prevent the mining of new raw materials, and promote the manufacture of durable building materials.


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