scholarly journals Efficiency of Chemical and Biological Leaching of Copper Slag for the Recovery of Metals and Valorisation of the Leach Residue as Raw Material in Cement Production

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 654 ◽  
Author(s):  
Päivi Kinnunen ◽  
Jarno Mäkinen ◽  
Marja Salo ◽  
Ratana Soth ◽  
Konstantinos Komnitsas

Copper slags produced in vast quantities in smelting operations could be considered as secondary material sources instead of stockpiling them in landfills. This study investigates the recovery of valuable metals from copper slag and the valorisation of the leach residue as construction material in line with the principles of a circular economy. By taking into account that the environmental characterization of the as-received copper slag did not allow its disposal in landfills without prior treatment, chemical and biological leaching were tested for the recovery of metals. Pre-treatment with acids, namely HNO3 and H2SO4, resulted in the extraction of several target metals and the production of an almost inert waste. Despite the clearly better oxidative conditions prevailing in the bioleaching reactors, chemical leaching resulted in the higher dissolution of Cu (71% vs. 51%), Co (70% vs. 36%), and Zn (65% vs. 44%). The acid consumption was much lower during the bioleaching experiments compared to the chemical leaching. The bioleach residue was suitable for its use as supplementary cementitious material, showing a better performance than the reference sample without causing any detrimental effects to the calcium aluminate cement (CAC) quality. The complete valorisation of copper slags is expected to improve the economics of the process, by avoiding landfill costs and producing saleable products with high added value.

2015 ◽  
Vol 1130 ◽  
pp. 296-299
Author(s):  
René Kermer ◽  
Sabrina Hedrich ◽  
Beate Brett ◽  
Daniel Schrader ◽  
Konstantin Räuchle ◽  
...  

Ashes from lignite combustion for power generation contain strategic metals, metalloids and rare earth elements and may thus be a potential source of industrially demanded metals. The presented project focuses on the assessment and exploitation of this potential raw material. Lignite ash assessment showed that largest ash amounts for potential exploitation are available in the Lusatia district, Saxony. Mechanical ash pre-treatment in principle provided enriched fractions by different methods but still suffered from low yields of enriched fractions. Thermal ash processing showed multiple significant phase changes compared to original ash. Subsequent chemical leaching using HClaq resulted in high metal extraction. Alternatively, bioleaching was applied using acidophilic Fe (II) and S-oxidizing or Fe (III)-reducing microorganisms (MO) as well as heterotrophic MO. The results indicated likewise high and partly specific metal mobilizations. Industrial ash exploitation was accomplished by direct reaction with acids resulting in Al-Fe-solutions which potentially can be applied in water treatment.


2021 ◽  
Vol 12 (3) ◽  
pp. 168-174
Author(s):  
N. V. Sych ◽  
◽  
L. I. Kotyns'ka ◽  
M. M. Tsyba ◽  
V. M. Vikarchuk ◽  
...  

As an alternative to means for lowering total cholesterol and low-density lipoprotein (LDL) cholesterol, the paper considers the possibility of using carbon adsorbents. From a medical point of view, the removal of cholesterol with enterosorbents is extremely effective. By binding cholesterol, sorbents reduce the risk of cardiovascular disease. The paper searches for new raw material sources and attempts to create enterosorbents with a high capability to adsorb cholesterol. The aim of the work was to develop adsorbents from spent coffee residue with a large proportion of mesopores, to determine the parameters of the porous structure and to study their adsorption capacity against cholesterol. Samples of activated carbon with a large proportion of mesopores (399 and 465 m2/g) were obtained by the traditional method of carbonization-activation of spent coffee grounds and pre-treated hexane to remove fatty acids. The sorption of cholesterol from alcohol solutions has been studied by spectrophotometric method and its effectiveness for the prevention and treatment of atherosclerosis was proved. It has been shown that a sample of activated carbon from spent coffee residue pre-treated with hexane (maximum value reaches 7.5 mg/g) has the best sorption capacity. The intermediate position is occupied by the sample obtained without pre-treatment with solvent (maximum value reaches 6.3 mg/g). Natural Brand carbon has the weakest sorption characteristics (maximum capacity reaches 5.3 mg/g). It can be stated that the adsorption of cholesterol increases with the growth of the specific surface area of mesopores. The parameters of adsorption processes were calculated using the obtained sorption isotherms. Adsorption isotherms were calculated using the Langmuir and Freundlich equations. It is shown that the values of the maximum adsorption calculated by the Langmuir equation have a good agreement with the experimental data.


2015 ◽  
Vol 4 (2) ◽  
Author(s):  
Lucília S. Ribeiro ◽  
José J.M. Órfão ◽  
Manuel Fernando R. Pereira

AbstractThe catalytic conversion of lignocellulosic biomass to obtain high added value compounds and fuels is a rapidly developing field. Given the abundance of this renewable raw material and its reduced impact on the food chain, it is an attractive source for obtaining chemicals or fuels in the context of a sustainable economy. In this work, bi-functional catalysts were developed that were capable of performing in a single step the hydrolysis and hydrogenation of cellulose to produce compounds that may be used in the production of fine chemicals or easily converted into fuels (e.g., sorbitol). Different activated carbon (AC) supported metal catalysts were examined for the one-pot hydrolytic hydrogenation of cellulose. Among the prepared catalysts, 0.4% Ru/AC was shown to be the most active and selective for the conversion of cellulose into sorbitol. When microcrystalline cellulose was used, a conversion of 32% was reached after 5 h of reaction, with a selectivity to sorbitol of 30%. Moreover, ball-milled cellulose allowed attaining conversions over 50%, with selectivities to sorbitol of 45%. The results obtained showed that Ru/AC is effective for the hydrolytic hydrogenation of cellulose to sugar alcohols and that the conversion can be greatly improved by using the substrate after pre-treatment by ball-milling.


2015 ◽  
Vol 770 ◽  
pp. 3-7
Author(s):  
V.F. Torosyan ◽  
D.S. Gorlov

The principal directions in the development of construction material industry include expansion of raw material sources, quality improvement of raw materials subjected to preliminary treatment, application of modifying components, constructive and technological modernization of manufacturing process. Manufacturing of ceramic bricks is one that dominates this industry. We know that there isn’t enough conditional clay suitable for ceramics production in most East regions of Russia and West Siberia. However, in many regions there are powerful heat power plants and highly-developed metallurgical enterprises, which produce sideline products alongside with basic output. The issue of complex utilization of wastes produced by power engineering and metallurgy has not been successfully resolved yet. Slag and other silica-containing sideline products of main production have not practically been used to the full. Nevertheless, it’s necessary to note, that disperse condition of silica-containing wastes as well as their physical and chemical characteristics predetermine prospective application of silica-containing materials in ceramics.


Author(s):  
Rubens Maciel Filho ◽  
Laura Plazas Tovar ◽  
Yurany Camacho Ardila ◽  
Jaiver Efrén Jaimes Figueroa ◽  
Maria Regina Wolf Maciel

In this chapter sugarcane bagasse may be submitted to a biological route in which the technologies used to obtain lignocellulosic ethanol (2nd generation ethanol) from lignocellulosic materials involve pre-treatment and the hydrolysis of the polysaccharides in the biomass into fermentable sugars for subsequent fermentation. Taking into consideration the use of sugarcane bagasse as a raw material for 2nd generation ethanol, the acid hydrolysis / pretreatment of sugarcane bagasse could be more feasible that others, and must be evaluated in this context. On the other hand, from biomass is possible to obtain products with high added value and energy, mainly by the use of thermochemical processes (e.g. pyrolysis and gasification) and biochemical processes (e.g., fermentation and anaerobic digestion). However, the products obtained from the thermochemical processes can be used as raw material for biochemical processes which multiplies the quantity of products to be obtained from biomass.


2012 ◽  
Vol 19 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Dorota Walkowiak-Tomczak

Determination of Chemical Composition of Plums During Pre-Treatment and DryingThanks to drying, fruits are available on the market throughout the year. Parameters of drying conditions affect eg the content of bioactive compounds in the product. The aim of the study was to investigate the effect of pretreatment conditions and the applied drying method on changes in the chemical composition of plums. Analyses were conducted on plums cv. 'Valor', which were subjected to pre-treatment including blanching, drilling and osmotic dehydration. Next they were dried by the convection method at air temperature of 60°C and flow rate of 1.5 m/s. Dehydration was run in a 61.5% sucrose solution at a temperature of 50°C for 1 or 2 h. Convection-dried plums, with no osmotic dehydration applied, constituted the reference sample. In fresh, dehydrated and dried fruits determinations included dry matter, polyphenols by colorimetry with the Folin reagent and contents of sugars by colorimetry using 3,5-DNS acid. As a result of blanching and dehydration the content of dry matter increased. Water loss after dehydration amounted to as much as 1.45 g H2O/g d.m.0after 2 h in comparison with blanched plums. As a result of dehydration total contents of sugars and polyphenols in plums decreased (mg/100 g d.m.). In convection-dried prunes the content of polyphenols was by 30÷50% higher than in the raw material, but lower than in the reference sample.


Author(s):  
Muntasir Muntasir ◽  
Pius Weraman

Community Partnership Program in small home industry of making fish floss brand "Savitri" and "Tiaras" inKupang city in the form of application of electric centrifugation filter model has been implemented. One of the problemsin the production of Savitri and Tiaras fish floss is that there is still a lot of oil in the frying product which is only drainedon a simple sieve and then placed for some time on traditional tools of filter and paper that can cause low quality and lowquality, so it is necessary to reduce the oil yield frying fish floss product. In order to increase the added value and sellingvalue of the products, it is necessary synergy between Universities and Partners in the form of application of the results ofscience and technology to the public. The main components of the composer of the versatile filter are the cylindrical plateas the bucket of the filter, the cylinder filter, the electric dynamo as the centrifuge system rotator and the load-bearingconstruction. The method of this program is the provision of materials, design and manufacture of tools, demonstrationtools and the provision of a versatile filter cylinder system centrifuge model by the team, simulation tools, specialcounseling at the location of partners and suggestions as a follow-up in the endurance of production. The output of thisprogram can provide added value in the form of the use of this tool can improve labor efficiency, increase productivitypartners by producing 40 kg to 50 kg raw material, raw fish marlin, fish meat after cleaning, processed, fried, in andpacked into 80-100 packs of fish floss with the price of Rp. 40,000.00 per package weighing 250 grams. With estimatedpartners will earn a profit of Rp 3,200,000 - 4,000,000.00 per production or 12,800,000.00 - 16,000,000.00 per month incash and consumptions, as well as the abundance of non-greasy, clean and hybrid fish products


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.


Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 122
Author(s):  
Karina J. Lagos ◽  
Bojan A. Marinkovic ◽  
Alexis Debut ◽  
Karla Vizuete ◽  
Víctor H. Guerrero ◽  
...  

Ecuadorian black mineral sands were used as starting material for the production of iron-titanium oxide nanostructures. For this purpose, two types of mineral processing were carried out, one incorporating a pre-treatment before conducting an alkaline hydrothermal synthesis (NaOH 10 M at 180 °C for 72 h), and the other prescinding this first step. Nanosheet-assembled flowers and nanoparticle agglomerates were obtained from the procedure including the pre-treatment. Conversely, nanobelts and plate-like particles were prepared by the single hydrothermal route. The nanoscale features of the product morphologies were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The ilmenite and hematite molar fractions, within the ilmenite-hematite solid solution, in the as-synthetized samples were estimated by Brown’s approach using the computed values of unit-cell volumes from Le Bail adjustments of X-ray powder diffraction (XRPD) patterns. The resulting materials were mainly composed of Fe-rich ilmenite-hematite solid solutions (hematite molar contents ≥0.6). Secondary phases, which possibly belong to lepidocrocite-like or corrugated titanate structures, were also identified. The current study demonstrated the feasibility of employing Ecuadorian mineral resources as low-cost precursors to synthesize high-added-value nanostructures with promising applications in several fields.


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.


Sign in / Sign up

Export Citation Format

Share Document