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The generation of complex tailings from iron mining is continuously increasing, reaching a reserve of 500 million tons. The iron tailings mainly contain 0.10–0.50 wt% ultrafine SnO2 (−9.6 μm, >50 %), acid-solule Sn (MgSn(OH)6) and 0.20–1.50 wt% Zn and are recognized as an important secondary Sn resource. Unfortunately, traditional mineral processing techniques have a low Sn recovery ratio. In this study, a novel method is proposed for effectively recovering Sn and Zn from complex iron tailings through reduction-sulfurization roasting, and their transformation behavior is determined. The results reveal that MgSn(OH)6 is first transformed into MgSnO3 at 1073 K, and SnO2 is reduced to SnO(g) and then sulfurized to SnS(g). COS acts as the main curing agent during the roasting process, which originates from the oxidation of FeS. As the temperature increases from 1173 to 1273 K, part of SnO2 can combine with CaO to form Ca2SnO4, and the generated CaSnO3 and MgSnO3 are further reduced to Sn(l) and Fe–Sn alloy. Meanwhile, ZnO and ZnS can be efficiently converted to Zn(g). Interestingly, the Fe–Sn alloy cannot be removed due to low Sn activity (a[Sn]). However, the Sn recovery ratio increases to 90 % due to low SnS partial pressure (PSnS) at 1373 K. Under optimal conditions, 90.10 wt% Sn and 94.90 wt% Zn can be extracted in the dust, which can be further processed into higher value-added Sn concentrate. Compared with current beneficiation process, the recovery ratio of SnO2 increased by 20 %. More importantly, MgSn(OH)6 can be efficiently recovered. This is of great significance for sustainable metallurgy of Sn.

Pulmonary actinomycosis is a rare chronic purulent granulomatous disease, which can be easily misdiagnosed as lung cancer, tuberculosis, and other diseases. However, diagnosis relies on histopathological evidence, and early diagnosis is conducive to the patient's recovery. In this study, a case of a 70-year-old man with a soft tissue density mass at the right lower lung was studied, with initial chest CT suggesting lung cancer, pulmonary actinomycosis was confirmed by subsequent pathological biopsy of lung tissues eventually. The patient responded well to antibiotics treatment. This paper is to explore the clinical characteristics of the disease, providing insight into the disease, and its diagnosis and treatment.

Spent cathode carbon (SCC) is a hazardous solid waste discharged from the aluminium electrolysis industry that poses a serious environmental pollution risk. In this paper, the migration transformation route and distribution ratio of fluorine during the reduction of copper slag by SCC were investigated. The results show that fluorine accounts for 57.92% of the slag phase, and the main phase is CaF2, which accounts for 41.75% of the gas phase and 0.33% of the alloy phase when reduced at 1460 °C with 10 wt% SCC for 90 min. The recoveries of reduced Cu and Fe reached 94.42% and 40.32%, respectively. After reduction by metallization, the F− leaching toxicity in the leaching slag was 38 mg/L, which is far below the regulatory limit (100 mg/L). In the process of copper slag reduction by SCC metallization, the copper and iron in the slag were effectively recovered, thus realizing the resourceful and harmless utilization of SCC. This achieves the goal of “treating waste with waste” and significantly reduces the treatment cost of SCC.

The traditional fossil reductant used in the copper slag cleaning process cannot fulfill the requirements of sustainable development of the copper industry and environmental protection. Therefore, a new approach of employing renewable rubber seed oil (RSO) instead of a non-renewable fossil reductant to clean copper slag (reduce magnetite concentration and improve matte recovery) was put forward in this study. The cracking characteristics of RSO at high temperature and the effects of technical parameters (such as reduction temperature, oil amount and settling time) on the copper loss, magnetite concentration and RSO utilization degree were thoroughly investigated. The results indicated that the cracking products of RSO at high temperature were mainly composed of C and H2. Under the conditions of a temperature of 1250 °C, an injection of 4 mL of RSO, and a settling time of no less than 1.5 h, the content of magnetite was reduced to less than 1 wt.%, and the content of copper in the upper level of the slag was lowered to be less than 0.57 wt.%, which met the criteria for discarding slag industrially. The copper slag cleaning by RSO is a process of carbon neutrality. The results provide a theoretic basis for the application of bioenergy in non-ferrous metal smelting process.

The cleaning of copper slag is an important way to realize the sustainable development of the copper metallurgy industry. MgO is a commonly used additive in the cleaning process and has an important impact on the physicochemical properties of copper slag. However, there are few studies on the mechanism of the phase transformation of the ISASMELT copper slag with different additive amounts of MgO. In this study, the mechanism of the phase transformation of copper slag with different additive amounts of MgO and the effect of MgO on the mass action concentration of slag component, physicochemical properties of copper slag and copper loss were elucidated. The results showed that when the MgO was added to copper slag, high melting point hortonolite was formed in the slag. When the additive amount of MgO was more than 4%, high melting point pleonaste was formed. With increasing MgO additive amount, the slag viscosity increased, and the silicate structure tended to be complex. Adding MgO to slag was not conducive to the recovery of matte from copper slag. The results provide a theoretical basis for selecting the most reasonable slag type in the cleaning process of ISASMELT copper slag and selecting the reasonable raw material in the ISASMELT process of copper concentrate.

Settling time, system temperature and reductant amount play an important role in the recovery of matte from copper slag. This study investigated the settling behavior of matte particles in copper slag and the effects of the settling time, system temperature, and reductant amount on the macrostructure of slag, microstructure of matte particles, and copper loss. The results showed that the settling behavior of matte particles in slag at the experimental temperature was a process of aggregation and growth. With an increase in settling time and temperature, as well as the addition of an appropriate amount of anthracite, the foaming slag layer of the slowly cooled slag gradually disappeared, while the recovery of matte increased. However, when the amount of anthracite was too high, Fe–Cu alloy formed at the experimental temperature, which resulted in worsened fluidity of the matte in the molten slag and copper loss increased. At the experimental temperature, the settling environment of matte particles in the liquid phase layer was superior to that of the foaming slag layer. The novel idea of using rubber seed oil instead of a traditional fossil reductant to clean the copper slag was put forward. At the temperature of 1250 °C, 4 mL of rubber seed oil was injected, resulting in a settling time of ≥90 min, after which the copper content in the upper part of the slowly cooled slag was less than 0.57 wt.%, reaching the acceptable level of discardable slag in industry.