Search Results (4)

This work presents the results of paper laser processing. It begins with the selection and examination of the processing parameters, then an examination of the properties of the modified papers and examples of applications of the developed modification method. The properties of laser-modified paper were studied using reflectance spectrophotometry to examine the colour aspects of the modified papers, scanning electron microscopy (SEM) and confocal microscopy for a morphological analysis, and Raman spectroscopy to analyse the papers under the influence of laser light. The influence of laser processing on the wettability of paper and the evenness of unprinted and printed paper was also investigated. The knowledge gained on paper surface modification with laser light was used to propose several applications, such as methods of marking, tactile detection, the controlled removal of optical brightener, ink, and metallised coatings from paper packaging, highlighting the design and aesthetics of paper. The developed laser-assisted method shows a promising, ecological approach to the design of many value-added paper products. Full article

The purpose of this study was to conduct experiments comprising the high-temperature reduction treatment of commercially produced iron ore fines and lumps aimed at increasing the use value of the ore. The analysed ore was Ukrainian iron ore sold under the Rudomain commercial name, mined from a bed located in the southern part of the Saksagan region (Kryvyi Rih, Ukraine). The study describes in detail the basic physical, chemical, and physico-chemical properties of the analysed ore, and it comprised a thermodynamic analysis, which is typically used as the basis for defining reduction conditions. The Ukrainian ore—Rudomain—exhibited a lower total Fe content (58.20 wt%) and, by contrast, the highest SiO₂ content (13.40 wt%), whereas SiO₂ is present in this type of ore not only in form of silica (SiO₂) but also in form of hydrated iron silicate (Fe₃Si₂O₅(OH)₄), i.e., the form of iron that is the most difficult to reduce. In the study, tests of thermal stability and thermal shock stability were carried out in various conditions, while the hardened pellets were thermally stable up to temperatures of 950 °C. The results of the performed experiments in high-temperature reduction of Rudomain iron ore were then compared with the results obtained with two other types of iron ores, in particular Krivbas and Carajas. Krivbas and Carajas ores show higher degrees of reduction and degrees of metallization than Rudomain ore. High-temperature experiments in thermal stability and carbothermic reduction have brought favourable information that is useful for the treatment of lower-grade ores with higher contents of SiO₂, while Rudomain iron ore exhibited a rather good potential for effective metallisation. Full article

Material Flow Cost Accounting (MFCA) is an environmental management accounting method that allocates costs to material and energy flows through a process, thereby enabling a simultaneous reduction in environmental impacts alongside an improvement in business and economic efficiency. This study illustrates the versatility of MFCA beyond its usual application to existing production and manufacturing processes. In this paper, MFCA is used to assess the financial viability of two emerging recycling technologies, IRETA2 (Development and Evaluation of Recycling Routes to Recover Tantalum from Electronic Waste) and ReComp (Development of an Innovative, Economically and Ecologically Sensible Recycling Method for Metallised ABS and PC/ABS Composite Waste). These two projects differ in their process structure. Whilst IRETA2 is a strictly linear recycling process, ReComp consists of two process streams, split according to the treatment of its two material fractions. For both projects, the lab-scale experimental results were used to develop an MFCA model of the recycling process scaled at each project partner’s facilities. MFCA was utilised to calculate the projects’ overall profit or loss, the impact of the final products’ market conditions and processing rate (in the case of IRETA2), or machinery capacity (for ReComp) on the overall results. The results show that neither IRETA2 nor ReComp are financially viable based on the current output products’ market value and quantity produced. However, through a sensitivity analysis, it is demonstrated that IRETA2 could become financially viable if the processing rate or market conditions were to improve. Additionally, ReComp could become financially viable if there was an increase in machine capacity. Finally, this paper also explores possible implications of MFCA when applied to emerging recycling technologies on EU policy and strategy, particularly those related to the EU Green Deal, such as extended producer responsibility and supply chain acts. Full article

We present our own Interdigitated Back Contact (IBC) technology, which was developed at ISC Konstanz and implemented in mass production with and at SPIC Solar in Xining, China, with production efficiencies of over 24%. To our knowledge, this is the highest efficiency achieved in the mass production of crystalline silicon solar cells without the use of charge-carrier-selective contacts. With an adapted screen-printing sequence, it is possible to achieve open-circuit voltages of over 700 mV. Advanced module technology has been developed for the IBC interconnection, which is ultimately simpler than for conventional double-sided contacted solar cells. In the next step, we will realize low-cost charge-carrier-selective contacts for both polarities in a simple sequence using processes developed and patented at ISC Konstanz. With the industrialisation of this process, it will be possible to achieve efficiencies well above 25% at low cost. We will show that with the replacement of silver screen-printed contacts by copper or aluminium metallisation, future IBC technology will be the end product for the PV market, as it is the best performing c-Si technology, leading to the lowest cost of electricity, even in utility-scale applications. Full article