Search

Your search keyword '"Zhang, Yonghang"' showing total 26 results
Start Over Author "Zhang, Yonghang"
26 results on '"Zhang, Yonghang"'

10. Enhancing Flame Retardancy and Smoke Suppression in Epoxy Resin Composites with Sulfur–Phosphorous Reactive Flame Retardant.

Author

Ma, Xulong, Kang, Ni, Zhang, Yonghang, Min, Yang, Yang, Jianhua, Ban, Daming, and Zhao, Wei

Subjects
FIREPROOFING, FIREPROOFING agents, FLAMMABILITY, EPOXY resins, HEAT release rates, SMOKE, LAMINATED materials
Abstract

The presence of massive amounts of toxic volatiles and smoke during combustion is a very serious problem facing epoxy resin (EP) composites. Therefore, flame retardants (FRs) can simultaneously enhance flame retardancy and reduce the release of smoke and fatal gases. Herein, a novel sulfur–phosphorous reactive flame retardant (SPMS) was synthesized for epoxy resin. The high efficiency of smoke suppression and flame retardancy of the EP/SPMS-APP hybrid was investigated using a cone calorimeter, a vertical burning test, and limited oxygen index measurements. Compared with those of pure EP, the composite with 20 wt% SPMS-APP reduced the peak heat release rate (pHRR), the peak smoke production rate (SPR), and total smoke production rate (TSR) by 82%, 94%, and 84%, respectively. The results showed a remarkable suppressed effect of alleviating the fire hazard of EP using a sulfur–phosphorus flame retardant. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

12. Purification of Waste Graphite from Crucibles Used in Photovoltaic Crystallization by an Alkali-Acid Method.

Author

Zhang, Yonghang, Chen, Zhengjie, Xie, Keqiang, Chen, Xiaowei, Hu, Yiyou, and Ma, Wenhui

Subjects
LEACHING, GRAPHITE, ROASTING (Metallurgy), DECOMPOSITION method, METAL inclusions, CRUCIBLES
Abstract

The photovoltaic industry generates large amounts of waste graphite (WG) that contains useful metals that can be recycled into high-value products. This study elucidated the impurity elements and their existence states in WG, analyzed and verified the source of the main impurity phase SiC, and determined the SiC content to be 4.66%. WG was purified using an alkaline-acid method, whose optimal process parameters were a solid alkali ratio of 3, calcination temperature of 600 °C, calcination time of 120 min, HCl concentration of 1 M, and acid leaching time of 40 min. Under these conditions, a graphite product with a fixed carbon content of 98.45% was obtained. Impurities were determined to migrate via three pathways: (1) Most main elements (Al, K, and Si) in silicates were removed by alkaline roasting, while the remaining elements were dissolved in acid. (2) Impurities containing metal elements such as Fe, Mg, Ca, and Zn were decomposed in NaOH to form hydroxides or oxides that were dissolved in HCl. (3) Silicon carbide impurities were removed by the alkaline-acid method without decomposition and often existed with graphite in the acid-leaching slag. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

16. A pilot study on using biochars as sustainable amendments to inhibit rice uptake of Hg from a historically polluted soil in a Karst region of China

Author

Ying Xing, Ying Du, Zhang Yonghang, Jianxu Wang, Zhenmei Liu, Jicheng Xia, and Wanli Wei

Subjects
China, Health, Toxicology and Mutagenesis, 0211 other engineering and technologies, Plant Development, Pilot Projects, 02 engineering and technology, 010501 environmental sciences, 01 natural sciences, chemistry.chemical_compound, Pore water pressure, Soil, Dissolved organic carbon, Biochar, Soil Pollutants, Biomass, Sulfate, Charcoal, Triticum, 0105 earth and related environmental sciences, 021110 strategic, defence & security studies, Bran, Dose-Response Relationship, Drug, Chemistry, Public Health, Environmental and Occupational Health, food and beverages, Oryza, General Medicine, Mercury, Straw, Pollution, visual_art, Environmental chemistry, visual_art.visual_art_medium, Paddy field
Abstract

We studied the addition of two biochars (rice shell biochar (RSB) and wheat straw biochar (WSB)) to soil at doses of 24–72 t/ha on the dynamics of pH, dissolved organic carbon (DOC), sulfate, Fe(III), and Fe(II), as well as on mercury (Hg) mobility in the pore water of a polluted paddy soil, throughout the rice-growing season. The effect of biochar addition to soil on rice biomass and Hg accumulation was also investigated. The key results showed that the addition of RSB or WSB to soil improved significantly the biomass of aboveground tissues of rice plants, particularly at higher dose treatments, compared with the control. The RSB treatment noticeably decreased Hg concentration in the pore water compared to the control, throughout the rice-growing season, and this decrease was likely due to the decreased Hg mobility by the RSB by promoting the level of sulfate in the pore water, which might be reduced to sulfide to combine with Hg to form Hg sulfides. The extent of Hg concentration reduction in the pore water was less pronounced in the WSB treatments relative to the RSB treatments. Addition of RSB to soil at doses of 24–72 t/ha decreased significantly Hg contents in the stalk, bran, hull and polish rice of rice plants compared to the non-treated rice (control), particularly Hg content in the polished rice was below the Chinese safety level (

Published
2018

26. Enhancing Flame Retardancy and Smoke Suppression in Epoxy Resin Composites with Sulfur-Phosphorous Reactive Flame Retardant.

Author

Ma X, Kang N, Zhang Y, Min Y, Yang J, Ban D, and Zhao W

Abstract

The presence of massive amounts of toxic volatiles and smoke during combustion is a very serious problem facing epoxy resin (EP) composites. Therefore, flame retardants (FRs) can simultaneously enhance flame retardancy and reduce the release of smoke and fatal gases. Herein, a novel sulfur-phosphorous reactive flame retardant (SPMS) was synthesized for epoxy resin. The high efficiency of smoke suppression and flame retardancy of the EP/SPMS-APP hybrid was investigated using a cone calorimeter, a vertical burning test, and limited oxygen index measurements. Compared with those of pure EP, the composite with 20 wt% SPMS-APP reduced the peak heat release rate (pHRR), the peak smoke production rate (SPR), and total smoke production rate (TSR) by 82%, 94%, and 84%, respectively. The results showed a remarkable suppressed effect of alleviating the fire hazard of EP using a sulfur-phosphorus flame retardant.

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results