scholarly journals Methodologies for the Possible Integral Generation of Geopolymers Based on Copper Tailings

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1367
Author(s):  
Hengels Castillo ◽  
Humberto Collado ◽  
Thomas Droguett ◽  
Sebastián Sánchez ◽  
Mario Vesely ◽  
...  

It is of interest to study the use of copper tailings as a raw material to generate geopolymers due to the exorbitant amounts of existing tailings deposits, which also produce different risks to nearby communities. Therefore, using this industrial waste as construction material would result in several environmental and economic benefits. Due to the above, it is necessary to perform laboratory tests that account for the relevant variables to obtain fresh geopolymer pastes with good consistency, and to obtain hardened geopolymers with good mechanical strength. This report gives an account of the experimental work carried out in the laboratory of the CIMS Sustainable Mining Research Center of the Engineering Consulting Company JRI, exposing the preliminary results observed in the generation of geopolymers by means of seven different methods using copper tailings and NaOH. Of the seven methods evaluated in the laboratory, it was observed that two of them deliver better results from a qualitative point of view, where the influence of the curing stage stands out, reflecting that temperature is one of the critical variables for the formation of geopolymers based on copper tailings and NaOH. The best means to work the mixtures should be studied to optimize the solubility of the NaOH and, therefore, the dissolution of the aluminosilicates in the tailings.

Proceedings ◽  
2018 ◽  
Vol 2 (20) ◽  
pp. 1313
Author(s):  
Angélica Lozano-Lunar ◽  
Auxi Barbudo ◽  
José María Fernández ◽  
José Ramón Jiménez

Among the actions proposed by the European Union for the implementation of Circular Economy is the use of waste as a secondary raw material (SRM). During the fusion of the scrap, a steel dust is generated, named Electric Arc Furnace Dust (EAFD). The EAFD is composed mainly of potentially leachable heavy metals, so is classified as “hazardous” waste. Around the world, approximately 70% of this waste is deposited in landfills, with a previous treatment through cement-based materials to prevent the metals’ mobility. However, this action is not in accordance with the Circular Economy concept due to the greater use of resources and the loss of deposited metals. The present investigation analyses the use of EAFD as SRM in conventional mortar production for its use as a construction material. Different substitution percentages (25%, 50% and 100%) were used replacing siliceous filler by EAFD. The investigation analysed the behaviour of conventional mortars by tests of workability, compressive strength, water absorption by capillarity and leaching behaviour in granular and monolithic state. The results obtained indicate a slight improvement in mechanical behaviour with the incorporation of EAFD, the reason why its use as SRM in conventional mortars would benefit the construction industry and would encourage the Circular Economy. From an environmental point of view, the mechanisms of Pb fixation should be improved in granular state.


2019 ◽  
Vol 35 (5) ◽  
pp. 579-593
Author(s):  
Diego Andrés Rueda-Ordóñez ◽  
Manoel Regis L.V. Leal ◽  
Antonio Bonomi ◽  
Luís Augusto Barbosa Cortez ◽  
Otávio Cavalett ◽  
...  

AbstractThe Colombian industrial sector is moving toward alternative forms of treatment of industrial waste, considering that the waste can be a source of raw material in the production chain. Thus, aiming at the decrease in mineral fertilizer use, and maintaining or even raising the crop yield, the sugarcane industry has recently advanced in the composting of the industrial waste and application in the field, both of them being potentially sustainable practices. This manuscript reports the economic benefits and the greenhouse gas (GHG) emissions related to the sugarcane production system in Colombia that has been simulated in this study to evaluate the beneficial effects of reusing industrial waste from ethanol production. This study was performed using the Virtual Sugarcane Biorefinery (VSB) modeling software for the simulation of agricultural and industrial parameters on integrated alternatives for the sugarcane industry. Colombian sugarcane sector was modeled using three scenarios representing agricultural systems that do not use composted industrial waste vs a paired scenario for each condition where composted waste is utilized. Regarding compost and vinasse use as fertilizer and soil conditioner, GHG emissions from the biogenic origin are not included as a reported item in the matrix of GHG emissions of the sugarcane sector. Inputs for the economic and environmental assessment models are based on actual operational data from two mill sites, one located in the traditional sugarcane production region of Cauca River Valley and the other one, on the agricultural expansion region of Llanos Orientales. Here, we have found that the reuse of composted industrial waste is beneficial and provides an economic cost savings of 2–6% per year. However, it also results in an annual increase of 10–20% in the GHG emissions.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Guojin Tan ◽  
Zhiqing Zhu ◽  
Yafeng Gong ◽  
Chenglin Shi ◽  
Ziyu Liu

Oil shale semicoke is a hazardous byproduct in oil shale retorting process. In Jilin province, China, abundant oil shale resources are mainly used for retorting shale oil accompanying with a large number of oil shale semicoke slags, which will generally cause environmental pollution and disposal problems. If oil shale semicoke can be utilized as a road base or subbase course construction material, it will be a great help to the disposal of a long-term accumulated oil shale semicoke in landfill sites. Moreover, the resource treatment of oil shale semicoke in road project construction could obtain positive social and economic benefits. Subsequently, we conducted a series of laboratory tests to study the practicability of cement-stabilized oil shale semicoke as a road base or subbase course construction material, including the raw material test, modified compaction test, unconfined compressive strength (UCS) test, splitting tensile strength (STS) test, compressive resilient modulus (CRM) test, and freezing-thawing test. In this paper, test results were compared with the technical requirements of Chinese road base construction specification, preliminarily confirming that cement-stabilized oil shale semicoke can be used as a subbase course material of a highway or a base course material of a low-grade highway.


1969 ◽  
Vol 62 (4_Suppla) ◽  
pp. S23-S35
Author(s):  
B.-A. Lamberg ◽  
O. P. Heinonen ◽  
K. Liewendahl ◽  
G. Kvist ◽  
M. Viherkoski ◽  
...  

ABSTRACT The distributions of 13 variables based on 10 laboratory tests measuring thyroid function were studied in euthyroid controls and in patients with toxic diffuse or toxic multinodular goitre. Density functions were fitted to the empirical data and the goodness of fit was evaluated by the use of the χ2-test. In a few instances there was a significant difference but the material available was in some respects too small to allow a very accurate estimation. The normal limits for each variable was defined by the 2.5 and 97.5 percentiles. It appears that in some instances these limits are too rigorous from the practical point of view. It is emphasized that the crossing point of the functions for euthyroid controls and hyperthyroid patients may be a better limit to use. In a preliminary analysis of the diagnostic efficiency the variables of total or free hormone concentration in the blood proved clearily superior to all other variables.


2008 ◽  
Vol 59 (2) ◽  
pp. 129-134
Author(s):  
Ion Teoreanu ◽  
Roxana Lucia Dumitrache ◽  
Stefania Stoleriu

Any change of the raw material sources for glazes, economically, ecologically motivated, and also from the glaze quality point of view, is conditioned by the molecular formula rationalization and by the variation limits of the molecular formula, respectively. The proper glaze compositions are placed within their limit variation intervals with optimized processing and utilization properties. For this purpose, the rationalization criteria and procedures of molecular formulas are summarized in the present paper, as well as the results referring to their rationalization obtained in the authors� previous work. Thus, one starts from a base of raw materials that are selected, usable and also accessible for the design and producing of the glazes. On these bases the groundwork and the design equation for the glaze recipes are developed, exemplified for a single glaze. For an easy access to results, computer programs are used for an easy access to results.


Author(s):  
Olga Leptiukhova ◽  
Marija Utkina

For more than half a century bicycle transport demonstrates its effectiveness as one of the elements of the transport network of the city. Currently, vehicles with low-power motors such as electric bicycle, electric scooter, gyrometer, segway, wheelbarrow, scooter motor and others are gaining people's attention. These vehicles can be combined into a group of low-speed individual vehicles (hereinafter - NITS) with similar re-quirements for the operational parameters of urban infrastructure. From the urban point of view, the interest in NITC is that the number of its users has increased significantly in recent years. The article presents the results of a sociological survey of residents of Serpukhov, allowing to assess the current and potential readi-ness of the population to use NITC. The growing popularity of NITC has led to an increase in the environmen-tal and economic effect, which is manifested at a particular level of development of the movement on NITC. The ecological and economic effect of the use of NITC has an extremely positive impact on the improvement of the urban environment. This article provides a list of indicators that reflect the growth in the standards of living of society from movement by the NITC, and the calculation of one of them - the increase in entrepre-neurial activity on the streets with increased traffic to the NITC. Indicators are necessary for calculation of complex criterion of efficiency and safety of street network due to development of the movement by NITC. The result will allow public authorities authorized to make decisions on the strategy of transport policy of cities to quantify the ratio of economic benefits from the development of infrastructure of the NITC with the cost of its construction and operation.


Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 792
Author(s):  
Kati Väkeväinen ◽  
Noora Rinkinen ◽  
Roosa-Maria Willman ◽  
Jenni Lappi ◽  
Kaisa Raninen ◽  
...  

Blackcurrant is a healthy, affordable, and traditionally gardened berry that, thus far, has been underused in food applications. From the consumers’ point of view, the acidic taste of blackcurrants is a challenge; therefore, these berries have mainly been utilized for sugary juice production. This research study aimed to develop a frozen vegan blackcurrant product with pleasant sensory properties and potential probiotic function. A candidate probiotic, Lactoplantibacillus plantarum Q823, was used in the manufacturing process. The physicochemical properties, nutritional composition, and consumer preference for the developed product were assessed, as was the viability of L. plantarum Q823 during storage time and in an in vitro gastrointestinal model. Consumers (n = 71) perceived the developed product to be pleasant. L. plantarum Q823 had high viability counts (log colony forming units (cfu) g−1 7.0 ± 0.38) in the final product, although the viability of L. plantarum Q823 during storage time needs to be enhanced to obtain a probiotic product. Thus, within an optimized formulation, blackcurrant berries represent a potential raw material for functional frozen food products.


Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2012
Author(s):  
Samantha Jo Grimes ◽  
Filippo Capezzone ◽  
Peteh Mehdi Nkebiwe ◽  
Simone Graeff-Hönninger

Rising consumer attraction towards superfoods and the steadily increasing demand for healthy, environmentally sustainable, and regionally produced food products has sharpened the demand for chia. Over the course of 4 years, two early flowering chia varieties belonging to Salvia hispanica L., and Salvia columbariae Benth. Species were identified to complete their phenological development and, therefore, able to reach maturity under a photoperiod >12 h, thus enabling the cultivation of chia in central Europe—more specifically, in southwestern Germany—consistently for the first time. Results obtained by the conducted field trial in 2018 showed that chia seed yields and thousand-seed mass ranged from 284.13 to 643.99 kg ha−1 and 0.92 to 1.36 g, respectively. Further, the statistical analyses showed that the protein content of the cultivated chia varieties ranged from 22.14 to 27.78%, the mucilage content varied from 10.35 to 20.66%, and the crude oil content amounted up to 28.00 and 31.73%. Fatty acid profiles were similar to previously reported data with α-Linolenic acid being the most prominent one, ranging from 60.40 to 65.87%, and we obtained ω6:ω3 ratios between 0.2 and 0.3. In conclusion, chia could represent a promising raw material from a nutritional point of view, while being able to diversify the local food basis of southwestern Germany.


2021 ◽  
Vol 13 (14) ◽  
pp. 7572
Author(s):  
Gigliola D’Angelo ◽  
Marina Fumo ◽  
Mercedes del Rio Merino ◽  
Ilaria Capasso ◽  
Assunta Campanile ◽  
...  

Demolition activity plays an important role in the total energy consumption of the construction industry in the European Union. The indiscriminate use of non-renewable raw materials, energy consumption, and unsustainable design has led to a redefinition of the criteria to ensure environmental protection. This article introduces an experimental plan that determines the viability of a new type of construction material, obtained from crushed brick waste, to be introduced into the construction market. The potential of crushed brick waste as a raw material in the production of building precast products, obtained by curing a geopolymeric blend at 60 °C for 3 days, has been exploited. Geopolymers represent an important alternative in reducing emissions and energy consumption, whilst, at the same time, achieving a considerable mechanical performance. The results obtained from this study show that the geopolymers produced from crushed brick were characterized by good properties in terms of open porosity, water absorption, mechanical strength, and surface resistance values when compared to building materials produced using traditional technologies.


2018 ◽  
Vol 174 ◽  
pp. 01006 ◽  
Author(s):  
Břetislav Teplý ◽  
Tomáš Vymazal ◽  
Pavla Rovnaníková

Efficient sustainability management requires the use of tools which allow material, technological and construction variants to be quantified, measured or compared. These tools can be used as a powerful marketing aid and as support for the transition to “circular economy”. Life Cycle Assessment (LCA) procedures are also used, aside from other approaches. LCA is a method that evaluates the life cycle of a structure from the point of view of its impact on the environment. Consideration is given also to energy and raw material costs, as well as to environmental impact throughout the life cycle - e.g. due to emissions. The paper focuses on the quantification of sustainability connected with the use of various types of concrete with regard to their resistance to degradation. Sustainability coefficients are determined using information regarding service life and "eco-costs". The aim is to propose a suitable methodology which can simplify decision-making in the design and choice of concrete mixes from a wider perspective, i.e. not only with regard to load-bearing capacity or durability.


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