scholarly journals Applied WEEE pre-treatment methods: Opportunities to maximizing the recovery of critical metals

2018 ◽  
Vol 20 (4) ◽  
pp. 706-711 ◽  
Keyword(s):  
Raw Materials ◽  
Hazardous Substances ◽  
Critical Metals ◽  
Treatment Methods ◽  
Treatment Processes ◽  
Ferrous Metals ◽  
General Recommendation ◽  
Recovery Treatment ◽  
Non Ferrous Metals ◽  
Pre Treatment

<p>WEEE is a fast-growing waste stream that includes potentially hazardous substances, but also valuable secondary raw materials, which can be recovered by adequate recycling and recovery treatment. In the last years, the research interest has moved from the conventional recycling (recovery of ferrous and non-ferrous metals, plastic, glass and other “mass relevant” fractions presented in WEEE), to the innovational recycling, aimed to recover trace elements, such as critical metals (CMs) and rare earth elements (REEs). Currently, the majority of CMs and REEs are lost during the pre-treatment processes. In this paper, an overview of the most relevant e-waste categories and products in terms of CMs and REEs presence, a description of currently applied pre-treatment methods and fate of the observed group of metals during pre-processing phase, as well as general recommendation in order to avoid losses of CMs and REEs within the WEEE treatment chain, are elaborated.</p>

scholarly journals The periclase-chromite refractory decomposition by the action of the pulverized coal and gas medium in course of copper-sulfide raw materials processing

2018 ◽  
pp. 31-36
Author(s):  
A. M. Klyushnikov ◽  
E. N. Selivanov ◽  
K. V. Pikulin ◽  
V. V. Belyaev ◽  
A. B. Lebed' ◽  
...  
Keyword(s):  
Surface Layer ◽  
Raw Materials ◽  
Weight Percent ◽  
Pulverized Coal ◽  
Refractory Powder ◽  
Ferrous Metals ◽  
Composition And Structure ◽  
Non Ferrous Metals ◽  
Refractory Surface ◽  
Gas Medium

The investigating results are given for the periclase-chromite refractories' composition and structure which are in contact with the pulverized coal and gas medium in the coppersulfide smelting furnaces. The high-temperature burnt copper concentrate and the sulfur dioxide gas suspensions combined action changes the surface and deep refractories layers chemical composition, with that the impurities content reach the value in weight percent: Fe 54,0, Cu 7,2, Zn 6,4, S 1,8. The refractory's surface layer saturation with the iron and non-ferrous metals oxides decreases the porosity and gives rise to low-melting compositions and eutectics. The refractory decomposition is induced by the shelling of the refractory surface layers with the filled porous taking place in course of the heating-cooling cycling because of the phase's thermal linear expansion coefficients. When the spent refractory disposal, it is feasible to separate mechanically the surface layer for the non-ferrous metals extracting, the rest part can be used for obtaining the refractory powder of various purpose.

scholarly journals The Results of Studying the Technique of Making Golden Horde Products Made of Non-Ferrous Metals (from the Collection of the Volgograd Regional Museum of Local Lore)

2019 ◽  
pp. 61-74
Author(s):  
Kseniya Kovaleva
Keyword(s):  
Raw Materials ◽  
Secondary Raw Materials ◽  
Ferrous Metals ◽  
Subsequent Processing ◽  
Wide Range ◽  
Digital Microscope ◽  
Non Ferrous Metals ◽  
Group 2 ◽  
Large Groups ◽  
Cast Products

Introduction. The article is devoted to the results of tracing research of things made of non-ferrous metals from the collections of Tsarevskoe, Vodyanskoe, and Mechetnoe settlements, stored in the funds of the Volgograd regional museum of local lore. Method. The author used the method of tracing. The digital microscope DigiMicro 2.0. was used to record the results of observation. Analysis. The author studied 63 products and allocated two large groups: 1) cast products and 2) forged products. The study fixed the following operations for cast products: the use of open and closed molds, casting in composite forms, casting by the smelted model, by the impression, liner casting. In group 2, the following methods of forging were singled out: forming forging, punching, drawing and forging of wire, bending, drawing, twisting, hacking, cutting. Soldering was used to connect the elements. After forming, most of the products passed the subsequent processing associated with the removal of defects (primarily post-casting) and the application of decor (hammering, engraving, stamping, polishing). In addition, the decor could be formed during the creation of the mold (cast decor). Results. As a result of the study, it was noted the use of a wide range of techniques and operations with a comparative technological simplicity for most products. It was also noticed that a few things have been specially prepared for the processing, and it demonstrates the use of secondary raw materials.

scholarly journals Assessing possibility of technogenic raw material processing using ultra-low concentrations of sodium cyanide

2020 ◽  
Vol 24 (5) ◽  
pp. 1105-1112
Author(s):  
Anastasia Vasilkova ◽  
◽  
Alexander Byvaltsev ◽  
Olga Khmelnitskaya ◽  
Grigory Voiloshnikov ◽  
...  
Keyword(s):  
Raw Materials ◽  
Sodium Cyanide ◽  
Gold Recovery ◽  
Raw Material ◽  
Ferrous Metals ◽  
Low Concentrations ◽  
Reagent Consumption ◽  
Copper Zinc ◽  
Non Ferrous Metals ◽  
Technogenic Raw Materials

The purpose of the study is to conduct experiments in order to determine the possibility of technogenic gold-bearing raw material cyanidation using ultra-low concentrations of NaCN. Experiments are carried out on the cyanidation of three samples of technogenic raw materials of different composition. The first sample consists of pyrite cinders (Au - 1.8-2.3 g/t, Ag - 13-22 g/t, Fe - 48.52%, Cu - 0.15-0.30%, Zn - 0.3-0.6%). The second sample is represented by the aged tailings of copper-zinc flotation (sample I) with the content of Au - 0.8 g/t, Ag - 7.0 g/t, Fe - 17.2%, Cu - 0.212%, Zn - 0.207%. The next object is the copper-zinc flotation tailings of a concentration plant (sample II), with the following content of Au - 1.22 g/t, Ag - 15.2 g/t, Cu - 0.13%, Zn - 0.23%. It is recommended to use an aqueous wash from non-ferrous metals with subsequent lime treatment as a preliminary processing of pyrite cinders. Cyanidation is carried out at different consumptions of reagent: from 0.075 to 3 kg/t. The experiments have shown that gold recovery in this range of NaCN consumption varies from 42.9 to 44.2%; moreover, a decrease in the reagent consumption allows to reduce the concentration of non-ferrous metal ions in cyanidation solutions. Before cyanidation sample I has also been subjected to aqueous wash to remove acid and non-ferrous metals. NaCN consumption varies from 0.25 to 2.2 kg/t. In this case the extraction of gold amounts to 36.6-46.4%. Cyanidation of tailings (sample II) is carried out in the range of 0.15-1.2 kg/t of NaCN. Gold recovery varies from 24.1 to 30.9%. The cyanidation technology of technogenic raw materials in the field of ultra-low concentrations of sodium cyanide is promising, since it provides acceptable gold recovery under low reagent consumption. For further research in the field of development of an extraction technology of valuable components, the flotation tailings of copper-zinc production (sample II) are chosen as a promising object. It is planned to carry out semi-industrial tests, calculate technical and economic indicators and develop process regulations.

scholarly journals Components’ Characterization of End-of-Life Dishwashers

2021 ◽  
Vol 5 (1) ◽  
pp. 84
Author(s):  
Eirini Evangelou ◽  
Georgios N. Anastassakis ◽  
Spyridon Dionysios Karamoutsos ◽  
Athanasios Stergiou
Keyword(s):  
Stainless Steel ◽  
Eddy Current ◽  
Raw Materials ◽  
Electronic Equipment ◽  
Current Sensor ◽  
Magnetic Separator ◽  
Ferrous Metals ◽  
Non Ferrous Metals ◽  
Hand Sorting

The treatment of Wastes of Electrical and Electronic Equipment (WEEE) is a significant source of secondary raw materials. Ferrous and non-ferrous metals, electronic equipment, and plastics are among these materials. One of the most common metals sourced out of WEEE is stainless steel. Dishwashers are common sources of stainless steel, so large amounts of stainless steel can be recovered from them. In this project, dishwashers were submitted to size reduction via shredding, and the shredded products went through a magnetic separator (which separates all the magnetic ferrous components), an eddy current sensor (which separates all the non-ferrous components) and an induction sorting sensor (which removed all the metallic fractions). This procedure led to the following two streams: one with stainless steel, boards, and cables and another stream mainly including plastic. In the next stage, the stainless-steel stream passed through a high-intensity magnetic separator, leading to a magnetic and a non-magnetic stream. Thereafter, hand sorting was applied to both streams which aimed to increase the recovery from each stream.

scholarly journals A Review of Seaweed Pre-Treatment Methods for Enhanced Biofuel Production by Anaerobic Digestion or Fermentation

Fermentation ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 100 ◽  
Author(s):  
Supattra Maneein ◽  
John J. Milledge ◽  
Birthe V. Nielsen ◽  
Patricia J. Harvey
Keyword(s):  
Heavy Metals ◽  
Anaerobic Digestion ◽  
Relative Content ◽  
Biofuel Production ◽  
Treatment Methods ◽  
Treatment Processes ◽  
Polysaccharide Composition ◽  
Pre Treatment

Macroalgae represent a potential biomass source for the production of bioethanol or biogas. Their use, however, is limited by several factors including, but not restricted to, their continuous supply for processing, and low biofuel yields. This review examines recent pre-treatment processes that have been used to improve the yields of either biogas or bioethanol from macroalgae. Factors that can influence hydrolysis efficiency and, consequently, biofuel yields, are highly affected by macroalgal composition, including content of salts, heavy metals, and polyphenols, structural make-up, as well as polysaccharide composition and relative content of carbohydrates. Other factors that can influence biofuel yield include the method of storage and preservation.

scholarly journals Sludge Thermal Utilization, and the Circular Economy

2019 ◽  
Vol 29 (4) ◽  
pp. 157-175 ◽  
Author(s):  
Jurand D. Bień ◽  
Beata Bień
Keyword(s):  
Circular Economy ◽  
Raw Materials ◽  
Action Plan ◽  
High Water ◽  
Hazardous Substances ◽  
High Water Content ◽  
Pre Treatment ◽  
Potential Methods ◽  
By Products ◽  
Consumption Waste

Abstract In 2015, the European Commission has adopted an ambitious Circular Economy Action Plan (CEAP), which includes measures that would help stimulate Europe’s transition towards a circular economy. In general four key action areas have been defined: production, consumption, waste management and secondary raw materials. Actions will lead to the resource-efficient and environmentally friendly outcomes. Biological materials should be returned to the natural metabolic cycles after necessary pre-treatment while waste that can not be prevented or recycled is to be used for the energy recovery. Sewage sludge is a large-tonnage waste produced at wastewater treatments plants (WWTPs). Its utilization causes some problems. High water content in sludge, hazardous substances as heavy metals, organic toxins and pathogens limit some potential methods of sludge utilization. Thermal treatment methods offer a solution, some hazardous substances can be destroyed or removed, energy can be recovered and some nutrients can be obtained from ash or other by-products.

Flotation and magnetic methods to recover non-ferrous metals from low grade technogenic raw materials

2019 ◽  
pp. 11-16
Author(s):  
E. V. Chernousenko ◽  
◽  
G. V. Mitrofanova ◽  
I. N. Vishnyakova ◽  
Yu. S. Kameneva ◽  
...  
Keyword(s):  
Raw Materials ◽  
Low Grade ◽  
Magnetic Methods ◽  
Ferrous Metals ◽  
Non Ferrous Metals ◽  
Technogenic Raw Materials

scholarly journals ECOLOGICAL ASPECTS OF THE TECHNOGENIC DEPOSITS PRESERVATION OF NON-FERROUS METALS IN THE NORTH CAUCASUS

2021 ◽  
Vol 13 (2) ◽  
pp. 265-272
Author(s):  
Ivan ALBOROV ◽  
◽  
Fatima TEDEEVA ◽  
Olga BURDZIEVA ◽  
◽  
...  
Keyword(s):  
Negative Impact ◽  
Raw Materials ◽  
Ferrous Metal ◽  
Industrial Building ◽  
North Caucasus ◽  
Mountain Rivers ◽  
The North ◽  
Ferrous Metals ◽  
Non Ferrous Metals ◽  
Waste Deposits

The article presents the results of research on a comprehensive assessment of techno genic waste deposits located in the North Caucasus region, gives a brief description of the material composition of techno genic raw materials, element-by-element quantitative reserves that are part of the accumulated secondary georesources for their possible utilization, production of non-ferrous metals and raw materials for the manufacture of industrial building materials. The article considers the sanitary and ecological parameters of the functioning of man-made raw materials in complex orographic, meteorological and geographical conditions. The critical aspects of the preservation of techno genic waste deposits in the current anthropogenic conditions are identified. The risk factors for the removal of toxic and harmful geomaterials into the water area with significant harm to the flora and ichthyofaunal are identified. For a deeper assessment of the minerals contained in the extracted ore, a unified state register of techno genic waste deposits should be created, Taking into account the high fragmentation of all the above – mentioned process links at the present time , the owners, taking into account the current sanitary and regulatory requirements, must take adequate measures to ensure the regulatory and environmental requirements in accordance with the current Federal Law “On Production and Consumption Waste”. The need for complex processing of waste from mining and processing industries in the North Caucasus is also dictated by environmental aspects due to the high risk of the occupied territories (they are located in floodplain terraced areas of mountain rivers) due to the flooding of mountain rivers, including the high vulnerability of resort and recreational and balneological complexes due to the negative impact of these negative sources. The assessment of the useful components contained in the extracted ore is currently not carried out in full, and the accumulated waste from processing non-ferrous metal ores is used in small volumes.

Improving the sludge disintegration efficiency of sonication by combining with alkalization and thermal pre-treatment methods

2012 ◽  
Vol 65 (10) ◽  
pp. 1809-1816 ◽  
Author(s):  
S. Şahinkaya ◽  
M. F. Sevimli ◽  
A. Aygün
Keyword(s):  
Oxygen Demand ◽  
Treatment Method ◽  
Waste Activated Sludge ◽  
Treatment Methods ◽  
Treatment Processes ◽  
Lack Of Information ◽  
Proposed Model ◽  
Soluble Chemical Oxygen Demand ◽  
Pre Treatment ◽  
Sludge Settleability

One of the most serious problems encountered in biological wastewater treatment processes is the production of waste activated sludge (WAS). Sonication, which is an energy-intensive process, is the most powerful sludge pre-treatment method. Due to lack of information about the combined pre-treatment methods of sonication, the combined pre-treatment methods were investigated and it was aimed to improve the disintegration efficiency of sonication by combining sonication with alkalization and thermal pre-treatment methods in this study. The process performances were evaluated based on the quantities of increases in soluble chemical oxygen demand (COD), protein and carbohydrate. The releases of soluble COD, carbohydrate and protein by the combined methods were higher than those by sonication, alkalization and thermal pre-treatment alone. Degrees of sludge disintegration in various options of sonication were in the following descending order: sono-alkalization &gt; sono-thermal pre-treatment &gt; sonication. Therefore, it was determined that combining sonication with alkalization significantly improved the sludge disintegration and decreased the required energy to reach the same yield by sonication. In addition, effects on sludge settleability and dewaterability and kinetic mathematical modelling of pre-treatment performances of these methods were investigated. It was proven that the proposed model accurately predicted the efficiencies of ultrasonic pre-treatment methods.

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