This study aims to develop eco-friendly composite dust suppressants to mitigate the adverse impact of coal mine dust on worker health and the environment. An environmentally friendly dust suppressant with bonding and wetting effects was prepared by combining modified pectin as a binder and a non-toxic surfactant as a wetting agent. Optimal ratios of sodium carboxylate ethoxylate sulfate (LMES), isomeric alcohol ethoxylate (XL-70), and modified pectin were determined through experiments. The modified pectin exhibited stronger wetting properties on coal powder due to its increased hydrophilicity . Wetting performance tests confirmed its excellent performance. Film-forming and scanning electron microscope tests demonstrated the dust suppressant's ability to bond with coal dust, resulting in a smooth surface and closely connected particles. Environmental tests showed its non-toxicity and degradability. Spraying dust reduction tests revealed a significant average increase of 40.51 % in dust reduction rate compared to water spraying, effectively lowering dust concentration. These findings have practical implications for the development of eco-friendly composite dust suppressants and controlling underground dust in coal mines, benefiting worker health and environmental sustainability.
Lingyang Yao,Huan Tian,Zhengyu Bao,Shuyun Xie,Tao Feng,Min Sun,Hui Ma,Lingyun Yao,Qiangjun Lang
In this study, four Se species including selenite [Se (VI)], selenate [Se (VI)], potassium,2-selenocyanatoacetate (PSeCA), and selenium ore powder (SeOP) were used for biofortification of Pleurotus geesteranus to obtain Se-enriched mushroom. Based on their effects on mycelium growth of P. geesteranus Jinxiu, [Se (VI)] in the concentration range of 100–1000 μg/kg and other three Se species in the range of 100–2000 μg/kg were adopted in spawn running and fruiting body growth stage, with their effects on production yield and elements accumulation evaluated. The results revealed that PSeCA treatment (200 μg/kg) had the highest fruiting body production (290.61 g/bag), followed by 2000 μg/kg of SeOP treatment (286.24 g/bag). SeMet revealed to be dominant species detected in mushroom, with [Se (VI)] exhibited the highest biological efficiency among the four Se species, and 2000 μg/kg of PSeCA treatment exhibited the highest Se content (10.25 mg/kg) in terminal phase of fruiting body. The results suggested that high concentration of PSeCA would be more favored for the Se biofortification. Moreover, Se treatment could greatly alter the mineral elements content of fruiting bodies, both synergistic and antagonistic relationships on accumulation of mineral elements were observed for each tested Se species.
Jing Dai,Chenchen Gong,Yanfei Wang,Liuqing Huo,Lingchao Lu
Hydrating-hardening properties of high sulfate resistance Portland cement (HSRPC) mixed with 35 wt% mineral powder (MP) or fly ash (FA) and the action mechanism of nano-silica (NS) under the condition of low-calcium hydrating phase were studied in this paper. Rheology, fluidity, setting time and compressive strength were investigated to explore the effect of NS on the basic physical properties of HSRPC doped with MP or FA. Mercury intrusion porosimetry (MIP), ultrasonic crack analysis, hydration heat and thermogravimetry (TG) were investigated to analyze the hardened structure and the hydration mechanism. The conclusions were as follows: For HSRPC with MP, the 0.1–0.5 wt% NS increased the yield stress, decreased the fluidity and prolonged the setting time. However, when NS content increased from 0.1 wt% to 0.5 wt%, the cumulative porosity increased by 9.8% and the 60 h (60 h) cumulative hydration heat decreased by 14.6% because NS with high specific surface area inhibited the hydration of HSRPC, but its particle filling increased the porosity of harmless pores to improve the 3day (3d) compressive strength slightly. After 28d of hydration, the compressive strength increased by 2.8%, ultrasonic amplitude increased by 19.3%, and calcium hydroxide (CH) decreased by 6.6%, indicating that NS fully reacted with CH generated by HSRPC hydration. For HSRPC with FA, the 0.1–0.3 wt% NS increased the yield stress, setting time and 3d compressive strength and decreased the cumulative porosity. The 60 h cumulative hydration heat increased from 155.9 J/g to 198.5 J/g. The ultrasonic amplitude of 28d hardened paste increased from 10.91 V to 17.01 V and the CH content decreased from 15.29% to 14.1%. It indicated that the 0.1–0.3 wt% NS with high activity reacted with CH and further promote cement hydration to generate a large number of hydration products to improve the densification and performance, especially at the early age.
危险品化学品经营许可证（带存储）