scholarly journals Characterization of dusts from secondary copper production

2020 ◽  
Vol 56 (2) ◽  
pp. 221-228
Author(s):  
D. Orac ◽  
M. Laubertova ◽  
J. Piroskova ◽  
D. Klein ◽  
R. Bures ◽  
...  

Various types of waste, including dusts, are produced in the pyrometallurgical production of copper from secondary raw materials. According to the European Waste Catalogue and Hazardous Waste List, dusts from secondary copper production are classified as hazardous waste. In secondary copper production 3.87 million tons of copper were produced worldwide in 2017. The dusts are produced in the following thermal operations: reduction of the melt in the shaft furnace (shaft furnace dust), converting (converter dust), and pyrometallurgical refining (refining dust). These dusts contain significant amounts of heavy metals (Zn, Pb, and Sn) in oxidic forms. The dusts are regarded as secondary raw materials, and it is necessary to look for ways of extracting these heavy metals. The aim of this work was to characterize the individual types of dust and determine their quantitative and qualitative composition. The content of heavy metals in copper shaft furnace dust is (52.16% Zn, 19.33% Pb), in copper converter dust (32.40% Zn, 14.46% Pb), and in refining dust (32.99% Zn).

2020 ◽  
Vol 12 (9) ◽  
pp. 3780
Author(s):  
Karmen Pažek ◽  
Jernej Prišenk ◽  
Simon Bukovski ◽  
Boris Prevolšek ◽  
Črtomir Rozman

In this paper, the quality of the municipal waste sorting process in seven waste management centers in Slovenia was assessed using the qualitative multicriteria analysis (MCA) method DEX (Decision EXpert) implemented in DEXi software, which is based on multicriteria decomposition of the problem and utility functions in the form of “if–then” decision rules. The study was based on eight types of secondary raw materials. The quality of the secondary raw materials, the regularity of the delivery of secondary raw materials to recycling units based on the sorting efficiency, and the loading weight of the individual baled fractions in the transport of secondary raw materials for recycling were the main parameters used in the model. The final assessment shows “good” waste management service in centers A and D. Centers B, C, and F were rated “average”. The “bad” rating was assigned to centers E and G.


2019 ◽  
Vol 8 (4) ◽  
pp. 10686-10692

Polyhydroxyalkanoate (Pha) Is A Family Of Naturally Occurring Polymers Which Is Reportedly Produced By More Than 75 Genera Of Gram-Positive And Gram-Negative Bacteria. Although The Industrial Production Of This Bioplastic Commenced Decades Ago, Its Large Scale Production Is Still Debilitated By Factors Such As Rate Of Production By The Bacteria And The Raw Materials For Its Production, Which Finally Elevates The Production Cost. The Present Thrust In This Area Is To Isolate Bacterial Species Which Have A High Turnover Of Pha With Minor Expenditure. Sewage And Sewage Sludge Samples Are Rich Sources Of Microflora Which Offer A Nutrient Limited Habitat To The Individual Organisms. Under These Conditions Of Stress, Native Organisms Develop A Metabolomics Which Efficiently Convert Vital Nutrients Into Essential Macromolecules, And In This Case A Storage Polymer Of Industrial Significance I.E. Pha. In This Pilot Study An Attempt Was Made To Isolate Indigenous Bacterial With Ability To Produce The Polymer.


Author(s):  
Araylym Nalibaeva ◽  
Gauhar Bishimbaeva ◽  
Nina Gusarova ◽  
Svetlana Verhoturova ◽  
Boris Trofimov ◽  
...  

The possibility and prospects of using tertiary phosphine sulfides synthesized on the basis of on affordable and secondary raw materials as effective extractants of heavy metals have been investigated


Author(s):  
Md. Shazzad Hossain ◽  
Farzana Khan Rony ◽  
Sazia Sultana ◽  
Md.Humayun Kabir ◽  
Sumaya F. Kabir ◽  
...  

Over the past few years, activated carbon (AC) has attained significant attention as an efficient adsorbent for heavy metal (lead, cadmium, chromium etc.) removal. In Bangladesh, bagasse and jute fibre are the two most potential raw materials for producing activated carbon due to their high availability and low cost. The activated carbon was produced by thermal treatment method. The produced AC were characterized using FTIR, XRD, SEM etc. Batch experiments under agitation was also carried out for adsorption of heavy metals and then characterized using AAS (Atomic Adsorption Spectroscopy). Adsorption with commercially available activated carbon was also done to use as standard. Among all ACs produced in this study, the highest percentage removal of heavy metals which were Cr3+ and Cd2+ was at 57.06% and 43.01% respectively for J-400 ( AC produced from jute fibre at 4000C). This obtained value was 16.6% and 12.9% higher in comparison to Commercially available Activated carbon for Cr3+ and Cd2+ respectively.


1981 ◽  
Vol 64 (4) ◽  
pp. 875-883
Author(s):  
Shiv K Soni ◽  
Daniel Van Gelder

Abstract Due to the existence of 2 asymmetric carbon atoms in: the propoxyphene molecule, there are 4 diastereomers: alpha dextro, alpha levo, beta dextro, and beta levo. Only α-d-propoxyphene is included under the federal Controlled Substances Act. Baseline separations of propoxyphene from various incipients (aspirin, caffeine, phenacetin, and acetaminophen) present in pharmaceutical and illicit preparations, and between the alpha and beta diastereomers, were achieved by high pressure liquid chromatography. The column eluant was collected and propoxyphene was extracted. The optical isomers were differentiated and characterized by melting points and by chemical microcrystalline tests. Using hot stage thermomicroscopy, the eutectic melting points of binary isomeric mixtures of propoxyphene bases and salts were found to be depressed about 10° and 15-30°C, respectively, below the individual isomer melting points. The characteristic microcrystals formed with the alpha racemic mixtures by using a glycerin-aqueous gold chloride reagent were not produced by the beta racemic mixtures.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3564
Author(s):  
Arnas Majumder ◽  
Laura Canale ◽  
Costantino Carlo Mastino ◽  
Antonio Pacitto ◽  
Andrea Frattolillo ◽  
...  

The building sector is known to have a significant environmental impact, considering that it is the largest contributor to global greenhouse gas emissions of around 36% and is also responsible for about 40% of global energy consumption. Of this, about 50% takes place during the building operational phase, while around 10–20% is consumed in materials manufacturing, transport and building construction, maintenance, and demolition. Increasing the necessity of reducing the environmental impact of buildings has led to enhancing not only the thermal performances of building materials, but also the environmental sustainability of their production chains and waste prevention. As a consequence, novel thermo-insulating building materials or products have been developed by using both locally produced natural and waste/recycled materials that are able to provide good thermal performances while also having a lower environmental impact. In this context, the aim of this work is to provide a detailed analysis for the thermal characterization of recycled materials for building insulation. To this end, the thermal behavior of different materials representing industrial residual or wastes collected or recycled using Sardinian zero-km locally available raw materials was investigated, namely: (1) plasters with recycled materials; (2) plasters with natural fibers; and (3) building insulation materials with natural fibers. Results indicate that the investigated materials were able to improve not only the energy performances but also the environmental comfort in both new and in existing buildings. In particular, plasters and mortars with recycled materials and with natural fibers showed, respectively, values of thermal conductivity (at 20 °C) lower than 0.475 and 0.272 W/(m⋅K), while that of building materials with natural fibers was always lower than 0.162 W/(m⋅K) with lower values for compounds with recycled materials (0.107 W/(m⋅K)). Further developments are underway to analyze the mechanical properties of these materials.


Sign in / Sign up

Export Citation Format

Share Document