Key Engineering Materials Vol. 682

Abstract: Method of scrap recovery by hot extrusion in a contrast to traditional aluminum recycling process distinguishes itself with a low energy consumption and high recovery efficiency. Additionally, this type of recycling allows to recover materials even from highly fragmented forms of metal like chips, foils or filings by omitting melting procedure. In the present study results of 413.0 aluminum chips plastic consolidation will be presented. Chips after machining process were used as a charge material for the entire recycling process. In order to determined the best emulsion elimination method, three separate processes such as centrifugation, annealing and pressing were carried out. In result dry, wet and cleaned chips in a form of cylindrical billets were hot extruded into longitudinal square cross-section profiles. Mechanical properties were examined by uniaxial tensile tests while microstructure observations were performed by means of scanning electron microscopy. It has been showed that emulsion elimination by annealing gives the best results while at the same time all extruded materials revealed no significant differences in mechanical properties.

Abstract: Hydrometallurgical routes of copper recovery from smelted low-grade e-waste are presented. Electronic scrap was smelted to produce Cu–Zn–Ag-Sn alloys of various phase compositions. The alloys were then treated in the following ways: (a) anodic dissolution with simultaneous metal electrodeposition using ammoniacal solutions with various ammonium salts (chloride, carbonate, sulfate). This resulted in the separation of metals, where lead, silver and tin accumulated mainly in the slimes, while copper was transferred to the slime, electrolyte and then recovered on the cathode. (b) leaching in ammoniacal solutions of various compositions and then copper electrowinning. Alloy was leached in chloride, carbonate, sulfate and thiosulfate baths. This resulted in the separation of the metals, wherein copper and zinc were transferred to the electrolyte, while metallic tin and silver as well as lead remained in the slimes. Copper was selectively recovered from the ammoniacal solutions by the electrolysis, leaving zinc ions in the electrolyte. The best conditions of the alloy treatment were obtained, where the final product was copper of high purity (99.9%) at the current efficiency of 60%. Thiosulfate solution was not applicable for the leaching of the copper alloy due to secondary reactions of the formation of copper(I) thiosulfate complexes and precipitation of copper(I) sulfide.

Abstract: Metallurgy of KGHM Polska Miedź S.A. is one of the world leaders in the production of copper. It is the result of high volume and quality production of copper and silver, as well as the use of modern technology direct to copper process in flash smelting furnace in HMG II. Soon this will be also the case for HMG I. The intention is to modernise, and upgrade technological processes within all the smelters to increase effectiveness, also to decrease production costs, and improve contamination of environment. In the year 2014 production of electrolytic copper increased about 2% in respect to 2013, and reached the record value 577 thousands ton. Production of silver increased 8% attaining value of 1256 ton. These perfect results were obtained through optimisation of smelting processes from one side, and rising the content of own concentrates, and foreign batches with higher content of precious metals. Production of metallic gold in 2014 was equal to 2,5t. Moreover KGHM is the third world producer of rhenium. They produce also lead technical and refined, as well as selenium, nickel sulphate, and platinum-palladium concentrate. The KGHM is also substantial producer of sulphuric acid, what is the direct effect of very efficient technology of desulphurisation of exhausts in the used metallurgical processes. The challenge for future is to increase retrieving of elements associated with copper production on every phase of the production. Due to the use of new technologies one expects also to achieve improved retrieving of other metals. Since 20% of KGHM revenue comes from silver, this is an important position in the overall balance of corporation focused mainly on copper exploitation. This is also why KGHM develops co-operations with scientific centres on the level bigger than laboratory (i.e. demo and/or pilot scales). The corporation is directly involved in research and development (subsidised national and international projects), while the value of these projects exceeds 200 mln PLN. There were created several collaborations with academic institutions targeting improvement of retrieval of energy from exploration processes, increase automation, remote control mining, and others. All of them are state of the art, and very modern technologies. KGHM must stay innovative, to preserve its market advantage. Metallurgy itself using own implemented technologies, resumes extended efforts to explore fully the richness of elements associated with the main metals.

Abstract: A hydrogen-based treatment, including Hydrogen Decrepitation (HD) and Hydrogen Disproportionation-Desorption-Recombination (HDDR), was used as part of a recycling procedure for scrap neodymium-iron-boron magnets. Chemical methods of removing nickel coating out of magnets were tested, however ineffectively. Powders were obtained from magnets after the HD and were further processed by the HDDR. Finally, material with maximum energy product (BH)_max of 74 kJ/m³ was produced. Chemical composition of magnets (MS, EDS), magnetic properties (VSM) and microstructure observations (SEM) were carried out.

Abstract: Aeration step, one of the major stages in the Becher process was carried out on reduced Hatinh (Vietnam) ilmenite in NH₄Cl solution and the effect of several processing parameters were thoroughly investigated including the temperature, time, liquid/solid weight ratio (L/S), air flow rate and concentration of NH₄Cl solution. The obtained results showed that longer rinsing time, higher liquid/solid ratio and air flow rate facilitated metallic iron rusting. The rusted iron amount increased when the temperature increased and reached the highest value at 70°C. Variation of NH₄Cl concentration showed similar impact as that of temperature. The highest amount of rusted iron achieved at 0.5% NH₄Cl. Chemical analysis and XRD results indicated that 98% of metallic iron in reduced ilmenite has been transformed to iron oxides at an aeration condition (70°C, 8 h, L/S=7/1, air flow rate = 4 l/min and 0.5% NH₄Cl). Consequently, TiO₂ content from approximately 60% in the reduced ilmenite increased up to approximately 80% in the aerated rutile.

Abstract: Electrical conductivity is one of the most important physico-chemical parameters in chemical engineering as well as in the technology of many industrial process. Especially in the metals production by the electrolysis from molten salts or metals recovery from slags in the electric furnaces, where the great energy is needed.In this work the continuously varying cell constant (CVCC) technique for measuring conductivity of non-ferrous slags and molten salts was used. This is high-accuracy technique, which requires no calibration. The technique was verified by measuring conductivity of standard KCl solution and molten KCl. A good agreement was obtained between measured and commonly accepted literature values. The results of measured conductivity of KF-AlF₃ melts were compared with data obtained by other authors. It was proved that CVCC technique can measure accurately the electrical conductivity of high-temperature molten salts and metallurgical slags.

Abstract: The aim of the study is the functional analysis of management system for laboratory tests in control of the manufacturing process, based on standard functionality of the SAP R/3 as an example of ERP systems.

Abstract: This paper focuses on the factors that influence the changes in copper prices. A brief review of the literature showed several areas of interests of researchers, such as global economic situation and development of Asian countries. This paper draws attention to concurrent price trends, some pairs of raw materials (e.g. copper – aluminum, copper – silver, even copper – palladium). This paper uses multiple regression model containing monthly data spanning from January 2012 to June 2015, which consist of 42 observations for metals: copper, zinc, aluminum, silver, gold, platinum and palladium. And it shows a strong relationship between the prices of copper and other metals.

Abstract: The article presents the methodology of World Class Manufacturing (WCM) used in one of the factory the mechanical engineering industry. The company has factories all over the world, while in Poland produces on average 800 ready-made machines by a year. The article presents the following pillars WCM: S (Safety) CD (Cost Deployment), Fl (Focused Improvement), AA (Autonomous Activity), PM (Professional Maintenance), QC (Quality Control), L & CS (Logistics & Customer Service), EEM (Early Equipment Management), EPM (Early Product Management), PD (People Development), E (Environment). Each pillar uses methods and tools. By using the methodology of WCM in the factory has reduced losses and improved the quality of the products.

Abstract: Development of the multiscale numerical model of innovative incremental forming process, dedicated for manufacturing complex components for the aerospace industry is the main aim of the work. Description of the incremental forming concept based on division of large die into a series of small anvils subsequently pressed into the material is presented within the paper. Particular attention is put on material behavior at both, macro and micro scale levels, respectively. A Finite Element Method (FEM) supported by Digital Material Representation (DMR) concept was used during the investigation. Results in the form of strain distributions and shapes of grains obtained from different sample areas after incremental forming process are presented within the paper.