Identification of Asbestos Content in Bulk Materials Imported in Nepal

2020 ◽  
Vol 13 (13) ◽  
pp. 5-7
Author(s):  
Arvind Pathak ◽  
Manbir Giri ◽  
Bishnu Pokhrel ◽  
Manoj Nidhi Wagle

The bulk materials include the construction materials such as plaster sand gravel and cement as well as raw materials. Asbestos is the naturally occurring magnesium silicate mineral fibers which has high tensile strength, flexibility and resistance to chemicals, high temperature and stress; this is why it has been considered and used in bulk materials. These mineral fibers are needle shaped and can stick to lung tissue when inhaled and cause inflammation and serious health problems such as asbestosis, mesothelioma and lung cancer or internal fibrosis. It can be detected by simple microscopic method using mineral acid and heat treatment. The method would help in quality analysis of asbestos fiber and save from asbestos induced disease and to develop alternative materials of asbestos fiber material.

2020 ◽  
Vol 4 (1) ◽  
pp. 41-48
Author(s):  
Teodoro Astorga Amatosa ◽  
Michael E. Loretero

Bamboo is a lightweight and high-strength raw materials that encouraged researchers to investigate and explore, especially in the field of biocomposite and declared as one of the green-technology on the environment as fully accountable as eco-products. This research was to assess the technical feasibility of making single-layer experimental Medium-Density Particleboard panels from the bamboo waste of a three-year-old (Dendrocalamus asper). Waste materials were performed to produce composite materials using epoxy resin (C21H25C105) from a natural treatment by soaking with an average of pH 7.6 level of sea-water. Three different types of MDP produced, i.e., bamboo waste strip MDP (SMDP), bamboo waste chips MDP (CMDP) and bamboo waste mixed strip-chips MDP (MMDP) by following the same process. The experimental panels tested for their physical-mechanical properties according to the procedures defined by ASTM D1037-12. Conclusively, even the present study shows properties of MDP with higher and comparable to other composite materials; further research must be given better attention as potential substitute to be used as hardwood materials, especially in the production, design, and construction usage.


2021 ◽  
Vol 11 (10) ◽  
pp. 4392
Author(s):  
Apolka Ujj ◽  
Kinga Percsi ◽  
Andras Beres ◽  
Laszlo Aleksza ◽  
Fernanda Ramos Diaz ◽  
...  

The use and quality analysis of household compost have become very important issues in recent years due to the increasing interest in local food production and safe, self-produced food. The phenomenon was further exacerbated by the COVID-19 pandemic quarantine period, which gave new impetus to the growth of small home gardens. However, the knowledge associated with making high-quality compost is often lacking in home gardeners. Therefore, the objective of this research was to find answers to the following questions: can the quality of backyard compost be considered safe in terms of toxicity and nutrient content? Can weed seed dispersion affect the usability of backyard compost? In general, can the circulation of organic matter be increased with the spread of home composting? In this study, 16 different house composts were analysed for stability, weed seed contamination, toxic elements, and nutrient content using analysis of variance. The results of the research showed that the quality properties of the composts (including their weed seed dispersion effect) were greatly influenced by the different techniques and raw materials used. The toxicity levels, as well as the content of macro and microelements, were within the parameters of safe-quality compost. The specific macronutrient (Ca, Mg) and micronutrient (Fe, Mn) contents of the tested composts have a similar and, in some cases, more favorable nutrient supply capacity in crop production than the frequently-used cow manure-based composts. With a plan of basic education on composting, there is potential to encourage farmyard composting.


2021 ◽  
Vol 11 (8) ◽  
pp. 3545
Author(s):  
Fernanda Andreola ◽  
Isabella Lancellotti ◽  
Paolo Pozzi ◽  
Luisa Barbieri

This research reports results of eco-compatible building material obtained without natural raw materials. A mixture of sludge from a ceramic wastewater treatment plant and glass cullet from the urban collection was used to obtain high sintered products suitable to be used as covering floor/wall tiles in buildings. The fired samples were tested by water absorption, linear shrinkage, apparent density, and mechanical and chemical properties. Satisfactory results were achieved from densification properties and SEM/XRD analyses showed a compact polycrystalline microstructure with albite and wollastonite embedded in the glassy phase, similar to other commercial glass-ceramics. Besides, the products were obtained with a reduction of 200 °C with respect to the firing temperatures of commercial ones. Additionally, the realized materials were undergone to leaching test following Italian regulation to evaluate the mobility of hazardous ions present into the sludge. The data obtained verified that after thermal treatment the heavy metals were immobilized into the ceramic matrix without further environmental impact for the product use. The results of the research confirm that this valorization of matter using only residues produces glass ceramics high sintered suitable to be used as tile with technological properties similar or higher than commercial ones.


2014 ◽  
Vol 78 (6) ◽  
pp. 1405-1416 ◽  
Author(s):  
U.-N. Berninger ◽  
G. Jordan ◽  
J. Schott ◽  
E. H. Oelkers

Natural hydromagnesite (Mg5(CO3)4(OH)2·4H2O) dissolution and precipitation experiments were performed in closed-system reactors as a function of temperature from 22.5 to 75ºC and at 8.6 < pH < 10.7. The equilibrium constants for the reaction Mg5(CO3)4(OH)2·4H2O + 6H+ = 5Mg2+ + 4HCO3– + 6H2O were determined by bracketing the final fluid compositions obtained from the dissolution and precipitation experiments. The resulting constants were found to be 1033.7±0.9, 1030.5±0.5 and 1026.5±0.5 at 22.5, 50 and 75ºC, respectively. Whereas dissolution rates were too fast to be determined from the experiments, precipitation rates were slower and quantified. The resulting BET surface areanormalized hydromagnesite precipitation rates increase by a factor of ~2 with pH decreasing from 10.7 to 8.6. Measured rates are approximately two orders of magnitude faster than corresponding forsterite dissolution rates, suggesting that the overall rates of the low-temperature carbonation of olivine are controlled by the relatively sluggish dissolution of the magnesium silicate mineral.


2014 ◽  
Vol 1000 ◽  
pp. 12-15
Author(s):  
Jiří Švec ◽  
Tomáš Opravil ◽  
Jiří Másilko

Reusing and recycling of secondary raw materials from high-volume industrial productions (especially form construction materials and binders fabrications) is very important way of conserving environment and it is also interesting from the economical point of view. The production of common hydraulic binders, especially Portland cement, burdens the environment with considerable amount of combustion gases and consumes energy in massive scale. Alternative (low – energy) binder can be used as Portland cement substitution in applications with lower mechanical properties requirements. Mined limestone wash sediments contain large amount of clay components, but there is also indispensable share of fine calcite. This composition makes these sediments a promising material for the preparation of hydraulic binders as Roman cement or hydraulic lime.


2008 ◽  
Vol 26 (5) ◽  
pp. 293-309 ◽  
Author(s):  
K. Baris ◽  
A. Ozarslan ◽  
N. Sahin

This paper examines the CO2 sequestration potential of magnesium silicate minerals in Turkey for two example cases, the Orhaneli-Bursa and Divrigi-Sivas regions. The distribution and properties of the silicate mineral deposits are provided and the quantities of CO2 that can be sequestered in these deposits is estimated. The silicate minerals in the Orhaneli and Divrigi deposits provide significant CO2 sequestration capacity. Assuming 100% mineral carbonation efficiency, approximately 2.4 million tons/year of olivine and 6.5 million tons/year of serpentine would be required to sequester the CO2 released by the power plants investigated in this study. Although more detailed studies are needed, it is concluded that this approach has potential given Turkey's large dunite (olivine) and serpentine reserves. Furthermore, the proximity of these deposits and active open-pit mines to thermal power plants emitting CO2 facilitate the utilization of mineral carbonation.


2020 ◽  
Author(s):  
Carlos Galhano ◽  
Pedro Lamas ◽  
Diogo Seixas

The massive growth of the ceramic industry and the consequent demand for construction materials worldwide has motivated the search for alternative solutions aimed at reducing the use of mineral / natural resources as the main source of raw materials. One of the strategies frequently adopted by the scientific community is the reuse of industrial waste. It is beneficial not only to reduce the overexploitation of mineral resources but also to reduce the environmental, economic and social impacts resulting from their incorrect disposal/treatment and consequent deposition on land unsuitable or that purpose. Duetoconsiderationssuchasphysico-mechanical characteristics and the high production rate, two different types of industrial waste were selected for this work, ashes resulting from the burning of coal in thermoelectric power plant, commonly known as bottom ash (B), and the Marble Powder (MP). It was intended to test the technological feasibility of the manufacture of ceramic materials produced from clay mixtures containing these two residues. For this purpose, the fine fraction(<63μm)obtained from the sieving of the marbleresidue(MR)and slag(Bf)was used,aswellasacoarsergrainslagfractionrangingfrom63-125μm(Bg). The resulting test samples were subjected to a firing of 950 °C under an oxidizing atmosphere, following a primary drying process. Faced with the standard values, the new ceramic materials obtained from MP have seen their mechanical and porous characteristics decrease and increase, respectively. Atthesametime,althoughtheadditionofBinno way influenced the mechanical characteristics,a significant improvement the porous characteristic was observed. The incorporation of these residues produced a color very close to the original sample material. Keywords: industrial waste, ceramic, construction materials, bottom ash, Marble Powder


Author(s):  
Rijk Block ◽  
Barbara Kuit ◽  
Torsten Schröder ◽  
Patrick Teuffel

<p>The structural engineering community has a strong responsibility to contribute to a more efficient use of natural resources. Nowadays the construction industry is by far the most resource intense industry sector, approximately 40-50% of all primary raw materials are used, which raises the question about the architects and engineer’s accountability. In this context and as a result of the Paris Climate agreement the Dutch government defined the program “Nederland Circulair in 2050”, which states the ambition to use 50% less primary materials in 2030 and to have a full circular economy in 2050.</p><p>One possible approach to achieve these ambitious goals is the application of renewable, bio-based materials in the built environment and to replace traditional, typically cement-based, materials. Already in the past natural building materials, such as timber and bamboo have been used widely, but in recent years new materials came up and provide new opportunities to be used in the construction industry. The authors explored various alternatives, such as hemp and flax fibres, mycelium and lignin-based fibres for composite materials, which will be described with various experimental and realised case studies.</p>


2019 ◽  
pp. 658-687 ◽  
Author(s):  
R. V. Ralegaonkar ◽  
M. V. Madurwar ◽  
V. V. Sakhare

Due to ever increasing demand for the conventional construction materials as well as an increase in agro-industrial by-products it is essential to reuse these materials. As a smart city solution this chapter briefs an overview for the application of alternate raw materials as a principal source for the development of sustainable construction materials. The potential application of the discussed raw materials is elaborated as cementitious material, the aggregates as well as alternative reinforcement material. To understand the process of application, sustainable masonry product development is discussed in detail. In order to evaluate the feasibility of the raw material, the necessary physico-chemical test evaluation methods are also briefed. The developed end product performance evaluation is also discussed by desired tests as recommended by standards. The chapter concludes with a positive note that reuse of agro-industrial by-products is a feasible solution for the smart city development.


2021 ◽  
Vol 1017 ◽  
pp. 91-100
Author(s):  
Ekaterina V. Fomina ◽  
Natalia I. Kozhukhova ◽  
Evgeny A. Belovodsky ◽  
V.A. Klimenko ◽  
Marina I. Kozhukhova

The influence of the genesis of quartz-containing rocks on the strength of particles and changes in morphology during destruction from the standpoint of the mineralogical approach in the development of the scientific direction "geonics" ("geomimetics") has been investigated. The kinetics of dry grinding of raw materials in a laboratory ball roller mill was carried out. The features of the formation and development of cracks, particle size distribution, changes in the morphology and microstructure of fragments have been studied. It was found that in natural quartz cracks develop along the surface, where the highest concentration of impurities creates a defect structure with destruction into small particles. The purest structure of hydrothermal quartz is susceptible to brittle fracture into fragments similar in morphology to the base particle. Reducing the defectiveness of the structure increases the strength of the crystals. The internal energy potential of techno genic raw materials is determined by its defective structure, which undergoes the greatest deformations during grinding, allowing obtaining the maximum values of the specific surface area and reduce the grinding time. A difference in the degree of crystallinity of quartz, which composes the polymineral techno genic raw materials, makes it possible to obtain the optimal granulometry of fine particles. The conducted research is aimed at identifying the mechanisms of destruction of quartz rocks and can be used in solving engineering problems not only in construction materials science, but also in geotechnics.


Sign in / Sign up

Export Citation Format

Share Document