Analysis of Abandoned Mine Wastes Disposal Techniques in Malawi: A Concept of Circular Economy

Non-operational mines mostly constitute of significant quantities of valuable mineral resources within tailings and waste rock that can be disposed properly using innovative techniques. Proper waste disposal techniques do not only reduce the need for new mines to be developed but also have broad beneficial results on mining environmental impact. This paper presents a solution on abandoned mine wastes in Malawi. Malawi government wants to embrace techniques on former mine waste recycling operations that incentivize investment. Thus, this analysis proposes abandoned mine waste recycling technique for Malawi government to adopt. Recycling technique, as one of the current direction methods, is determined for adoption. The powerful impacts of recycling principles in turning Malawi’s abandoned mine wastes into beneficial products that can support and sustain its economy are given. The concept of circular economy is prominently in the picture, so the wastes can be changed into wealth and other created benefits.

Development of Warm In-Place Recycling Technique as an Eco-Friendly Asphalt Rehabilitation Method

Cold In-place Recycling (CIR) has been widely used in the world since it is easy to apply it in the field at a low cost. However, it is not normally used as a surface layer as a result of its inconsistent quality due to an excessive amount of fine aggregates pulverized during the milling process. Hot In-place Recycling (HIR) can retain the original shape of the aggregates, but it often produces a large amount of Volatile Organic Compounds (VOCs). Therefore, a third in-place recycling technique is introduced in this paper: Warm In-place Recycling (WIR). The WIR technique overcomes the limitations of both CIR and HIR techniques by lowering a heating temperature while adding a Tetraethylenepentamine (TEPA)/Soybean/SBS additive. To identify the effect of the additive on the RTFO-aged binder, viscosity and dynamic modulus values were measured at different temperatures. Based on Hamburg Wheel Tracking (HWT) and Disc-Shaped Compact Tension (DCT) tests, the additive improved the moisture susceptibility and low temperature cracking resistance. The indirect infrared heating equipment reduced the emission by lowering the pavement surface heating temperature by 20 °C from 140 to 120 °C. Compared with the heating at 140 °C, the LPG usage for heating at 140 °C was lowered by 21%. The proposed WIR equipment with an additive would revolutionize the in-place recycling practices.

Exuberant as Trend Forecast Method for Kertabumi Klinik Sampah Community Plastic Recycling

Recycling movement is such a never- ending campaign. This movement are grown larger in the society whether in individual or group activities. Any of the groups with the same spirit and vision are blurred in the community to achieve wider impact of recycling plastic. One of the active campaigner is Kertabumi Klinik Sampah which well-known in tinkering any of the recycling technique within the communities around Jakarta. Communities under Kertabumi facilitation are encouraged to turned plastic waste into unique and valuable products. Fostering creativity is the idea of this research aiming to observe the possibility of trend design implementation on the plastic recycle product. Exuberant trend forecasting is used as an approach to designing functional and aesthetical aspect on the product. Moreover, the styling result is offered as a design recommendation for the community to develop their product in the future.

The Influence of Initial Purity Level on the Refining Efficiency of Aluminum via Zone Refining

Zone refining is a well-known technique, usually using pure initial materials to produce high purity metals. However, the effectiveness of zone refining in the purification of different purity levels of metals as well as its feasibility for use as a recycling technique for low quality metals are rarely investigated. In this work, conducted at IME/RWTH Aachen University, three kinds of Al with different purities, i.e., three-layer electrolysis (4N), commercial pure (2N8) and recycled Al (1N7), were put on focus to address the above-mentioned issue. The experiments were conducted with an optimized zone length combination at the moving rate of 1.2 mm/min for five zone passes. The results showed that the 4N pure initial Al was improved to 5N5 after five passes, much higher than the results for commercial pure- or recycled Al, where less than 50% reduction of total impurities was achieved.

Analisis Efisiensi Penggunaan Teknologi Aspal Daur Ulang Pada Jalan Tol Elevated Ir. Wiyoto Wiyono

The use of recycling technologies to the principles of green roads should get priority. Reclaimed Asphalt Pavement (RAP) has not been used properly is a problem in this study. Hotmix Recycling is a recycling technique that can be applied to road pavement rehabilitation and maintenance. The research was conducted to determine the cost-efficiency of recycled asphalt. The method used in this research is to analyze the unit price of conventional asphalt maintenance and to analyze the unit price of recycled asphalt in order to find out how much efficiency is obtained of asphalt pavement recycled. The results showed that the cost of conventional asphalt is Rp.1,160,000 per ton and the price of recycled asphalt is Rp.915,000 per ton, there is a savings of Rp. 245,000 per ton, The use of recycled asphalt technology in the periodic asphalt of the Ir. Wiyoto Wiyono toll roads can save operational and maintenance costs of Rp. 3,013,500,000.00

Assessment of Curing Exposures Effect on the Long-term Engineering Properties of Novel Lightweight Aggregate Concrete

At present, most of the generated waste expanded polystyrene (EPS) in developed countries are transported to landfill and in some developing and/or less-developed countries such as Iraq are sent to open landscapes; consequently, this inadequate waste disposal can be very dangerous to our health and environment. This study describes engineering properties of sustainable lightweight aggregate concrete (LWAC) incorporating novel aggregates of waste EPS produced by a unique recycling technique of densifying. The new recycling technique significantly improved the segregation resistance of EPS beads in concrete as these beads are ultra-light material. The novel LWA of densified EPS (DEPS) was used as partial natural aggregate replacement in the mixes. Three water/cement (W/C) ratios were used. Three different types of curing conditions of indoor full water curing, outdoor weathering exposure, and heating exposure were employed during this study to represent different conditions which concrete may be subject to. The engineering properties of concrete investigated were consistency, dry density, compressive strength, and ultrasonic pulse velocity (UPV) for long-term performance of more than one-year age. It was indicated that the properties of concrete were not only primarily influenced by the employed curing conditions but the content of DEPS in the mixtures and additionally the W/C ratio had effect on the properties of concrete. However, adequate engineering properties can be achieved using an appropriate amount of DEPS with proper W/C and curing conditions.

Microstructure, mechanical properties, and electrical conductivity of the solid-state recycled pure copper machining chips

The demand for new methods to reduce CO2 emission by reusing metal scrap has increased recently. This study deals with a new recycling technique utilizing a friction stir consolidation process. In this work, copper was directly recycled from machining chips in the solid-state form without any remelting to reduce environmental pollution and to increase the economic value of the waste material. During the process, copper chips were loaded into the chamber; then, a rotating tool was plunged into the chips at a specified rotational speed and feed rate. Due to the huge amount of heat generated, the softened material was compressed and synthesized to form a consolidated part. Microstructure, mechanical properties, and electrical conductivity of the finished samples were evaluated and compared with as-received material. Also, a numerical model was implemented to predict the evolution of the main field variables, including temperature, density, and strain.