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Sulfidic mining wastes generated from mining processing such as mineral beneficiations and ore excavation possibly pose potential threats in environment and human activities due to the acid mine drainage and heavy metal leaching. It is essential to seek out alternative solutions to reprocess and repurpose those wastes rather than accumulating them in stockpiles or tailing impoundments. Alkali-activated materials, sometimes equal to geopolymer (low calcium content), are threedimensional frameworks by reacting aqueous alkali metal solutions with solid aluminosilicate powders. It facilitates the valorisation of potential secondary raw materials including mining waste rocks. Therefore, it is worthy to investigate the mining waste rock based geopolymer, thereby reducing the environmental impact and producing high value-added materials. Mining waste rocks are received from Neves Corvo mine, Portugal, as raw materials for geopolymer preparation. Waste rock is not suitable for geopolymer production due to its chemically inert properties. However, mechanochemical activation using rod ball mill, was carried out to enhance the chemical reactivity in this study. Next, corresponding geopolymers were produced with different milling durations, that is 6 h, 12 h and 24 h. Different curing temperature were also investigated. Finally, 7-day compressive strength was measured to assess the mechanical performance of geopolymers. The tackiness properties of the waste rock-based geopolymer were evaluated. And tack test was performed with and without a Pentaethylenehexamine (PEHA) additive. The results indicates that a longer milling duration led to a higher content of amorphous content. Sulfidic mining waste rock can be a potential candidate for alkali-activated materials after mechanochemical treatment. Curing regime has overwhelming effects on mechanical performance of final products. The introduction of PEHA can alter the rheological properties of the paste including altering sticky behaviour.

Globalization and ever-increasing growth of human progress require a continuous supply of materials, notably metals, to sustain these developments. However, metals production inadvertently generates environmental burdens due to tailings. These are the waste from metallurgical processing to separate unwanted materials from metal ore deposits and are disposed of in storage facilities. Despite advancements in metallurgical processing, there are still a fraction of metals lost in the tailings and they pose long-term pollution risks. Valorization of tailings are therefore having a twofold impact: First, metals leftover recovery can minimize the discharge of toxic metals into the environment. Second, after the purification process, the ground materials in the form of mineral matrices are another potential resource that could be exploited, thus reducing the need for primary production. However, the valorization technique requires processes causing environmental impacts and therefore we apply life cycle assessment (LCA) to account for tradeoffs. LCA enables evaluation of energy, materials, and waste along product life-cycle stages. Based on state-of-the-art upscaling frameworks in the metallurgical processing domain, we perform a case of prospective LCA for the alkali-activated materials fabricated by mechanochemical activated mining wastes. In this study, we develop systematic procedures to leverage bench-scale experiments into industrially optimized facility by means of process simulation. As takeaways, a comparative analysis is presented for the case studies with maturity levels. Ultimately, the results will be the critical inputs for process designers in steering the developments towards sustainable use of mine tailings., Proceedings of the 7th International Slag Valorisation Symposium. Shifting gears to a climate-neutral & resource efficient society

The over-current condition for a traction inverter can indicate flaws on control algorithms, interference on logic signals, hardware aging, or hardware misconduct. Thus, proper detection of over-current conditions during inverter operation is a critical item for inverter development and product validation. This paper reviews several widely used over-current detection methods and a few theoretically approved over-current detection methods. The main focus of this review includes the sensing bandwidth, sensing accuracy, and implementation complexity of the studied over-current detection methods. The advantages of those widely used methods and the application requirements for the theoretically and prototypingly approved methods are concluded by this review.

To investigate the safety and efficacy of intensive statin in the acute phase of ischemic stroke after intravenous thrombolysis therapy. A total of 310 stroke patients treated with rt-PA were randomly scheduled into the intensive statin group (rosuvastatin 20 mg daily × 14 days) and the control group (rosuvastatin 5 mg daily × 14 days). The primary clinical endpoint was excellent functional outcome (mRS ≤ 1) at 3 months, and the primary safety endpoint was symptomatic intracranial hemorrhage (sICH) in 90 days. The intensive statin users did not achieve a favorable outcome in excellent functional outcome (mRS ≤ 1) at 3 months compared with controls (70.3% vs. 66.5%, p = 0.464). Intensive statin also not significantly improved the overall distribution of scores on the modified Rankin scale, as compared with controls (p = 0.82 by the Cochran–Mantel–Haenszel test). The incidence of primary safety endpoint events (sICH) in 90 days did not significantly differ between the intensive statin group and control group (0.6% vs. 1.3%, p > 0.999). The INSPIRE study indicated that intensive statin therapy may not improve clinical outcomes compared with the low dose of statin therapy in AIS patients undergoing intravenous thrombolysis, and the two groups had similar safety profile. URL: http://www.chictr.org . Unique identifier: ChiCTR-IPR-16008642

The alkali activation of mine tailings is of interest to diminish the impoundment storage of large waste stream from mining industry. However, most of the mine tailings, like phosphate mine tailings generated in Finland, are rather inert and need pre-treatment to induce the reactivity for alkali activation. In this work, mechanochemical treatment was conducted to improve the reactivity of phosphate mine tailings. The ground specimens were subjected to the crystal structural analysis of X-Ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermal analyses by Thermogravimetry/Differential Thermal Analysis (TG/DTA), showing the increment of amorphous content and structural degradation as a function of grinding time. The subsequent alkaline reactivity test illustrated incremental alkaline dissolution of Si, Al and K and a schematic diagram of altered phlogopite structure (sources of aluminosilicates in tailings) was also proposed. Additionally, the mineralogical composition of individual particles was carried out by mineral liberation analysis (MLA), thereby evaluating the influence of pre-treatment on the mineralogy of tailings. The results indicate profound micromorphological changes and structural cleavage of the precursor due to grinding, which strongly increase alkaline reactivity.