FUEL
·
2024
·
IF 6.7
Zhenfeng Sun,Kaiqiang Zhao,Chen Wang,Jie Li,Haisheng Xu,Chao Yang
Presulfiding agents are widely used in oil refining and chemical industry, how to produce safe and efficient presulfiding agent by more environmentally friendly synthesis process are still problems to be solved. In this study, the organic polysulfide FSA-55 was synthesized by a practical one-pot process using isobutene and sulfur as raw materials and organic amine as a catalysts. The product components were analyzed and the possible catalytic reaction pathways in the thermal conversion of sulfides were elucidated. The amine catalysts showed a catalytic activities in inducing the ring opening of the cyclic molecular structure of sulfur at high temperature, thereby releasing the reactive sulfur radicals, which react with unsaturated double bonds through addition reactions. Different molecular structures of polysulfide were generated through molecular rearrangement and cyclization reactions. The suitability of the product as a presulfiding agent was investigated by analyzing the thermal properties and studying the presulfiding effect on hydrogenation catalysts. The polysulfide has a wide decomposition temperature range (100–260 °C), which can effectively avoid the occurrence of concentrated exothermic phenomena during presulfiding of hydrogenation catalysts. The presulfiding degree of the catalysts can reach 58.32%, which shows the great potential of oil processing as a presulfiding agent.
研究领域:
石油化工
·
催化化学
✓ 已验证
DOI
高影响因子
MINERALS ENGINEERING
·
2023
·
IF 4.8
Zhihao Shen,Shuming Wen,Yongchao Miao,Han Wang,Qicheng Feng
Fe 2+ is ubiquitous in flotation pulp and circulating water during the purification of various minerals, and can affect floatation behavior. As such, separating target minerals from gangue minerals can become challenging. In the present work, the flotation performance and resulting surface features of cerussite following exposure to Fe 2+ were systematically and experimentally investigated. Micro-flotation studies indicated that initially introducing Fe 2+ markedly deteriorated the floatability of cerussite when employing a Na 2 S-KIX system. Analyses of using X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, inductively coupled plasma optical emission spectrometer, ultraviolet visible spectroscopy, and zeta potential determinations demonstrated that the active sites on the cerussite surfaces were reduced due to Fe 2+ and its hydrophilic derivatives. This effect, in turn, decreased the numbers of highly reactive S-based sulfidization products and attenuated the subsequent interaction of collector with cerussite, thus inhibiting the flotation performance of cerussite.
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2025
·
IF 3.9
Shuai Ning,Bin Pei,Jialei Li,Ruizeng Liu,Dianwen Liu
The sulfidization-xanthate flotation process has been used commercially with some success in recovering azurite, but it remains unsatisfactory in terms of the environmental impact and flotation index. To remediate these deficiencies, this study evaluated the flotation performance of sodium trithiocarbonate (Na2CS3) as a green sulfidizing agent for azurite. Flotation test results demonstrated that Na2CS3 has the same efficacy as sodium sulfide but markedly superior activation performance. At one-fifth the dose, the maximum flotation recovery for Na2CS3 is about 20 percentage points higher than that observed for sodium sulfide. Contact angle measurements and field emission scanning electron microscopy analysis revealed that Na2CS3 modifies the pristine azurite surface by forming a relatively uniform sulfur-rich layer composed of nanoparticles, which in turn increases the collector efficacy and thus improves flotation recovery. The results of X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry further suggest that this sulfur-rich hydrophobic layer could be cuprous trithiocarbonate. The reduction of Cu(II) in the azurite lattice is considered a key step in forming the sulfur-rich layer, and the resultant Cu(I) interacts with Na2CS3 through the latter’s carbon–sulfur bonds. The results of this study will facilitate the development of better technologies to process copper oxide ores.
研究领域:
矿物加工工程
·
环境科学
·
材料化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Lijuan Chen,Zhixin Jia,Xiaohui Guo,Bangchao Zhong,Yongjun Chen,Yuanfang Luo,Demin Jia
A novel functional rubber vulcanizator, halloysite nanotubes (HNTs) supported sulfur monochloride (HNTs-s-S) is prepared by chemically bonding sulfur monochloride (S 2 Cl 2 ) onto HNTs surface. Through this chemical reaction, high concentration of sulfur is supported onto HNTs inner and outer surface. Meanwhile, the functional nanotubes can not only vulcanize the rubber without sulfur and show the lower activation energy of vulcanization reaction, but also improve the filler-rubber interaction as a modifier due to the improved modification effect. Furthermore, the immobilized polymer layer and crosslinking density of rubber composites together indicate that this novel vulcanizing agent HNTs-s-S gives rise to significant improvement in the rubber-filler interfacial adhesion, which is on account of the promoted vulcanizing on the functional HNTs surface with the supported sulfur. After endowing the tubular nanofillers with vulcanized function, it may offer new scientific and technological opportunities for the preparation of high performance elastomer composites.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
·
2025
·
IF 3.1
Li Zhongchen,Tian Qinghua,Wang Qinmeng,Zulhan Zulfiadi,Wang Songsong,Hidayat Taufiq,Guo Xueyi
With the depletion of high-quality nickel sulfide ore resources, the reliance on laterite nickel ore as a primary raw material for nickel production has increased. The pyrometallurgical process for laterite nickel ore mainly yields ferronickel, which is used predominantly in stainless steel production and falls short of the needs of the burgeoning new energy sector. Consequently, there is an urgent need to develop a new process for producing nickel matte through sulphidizing smelting of laterite nickel ore. The study examines the impact of various parameters, including the sulfurizing agent, reducing agent, flux, and the proportion of ore, on the slag liquidus temperature and nickel and cobalt recovery ratios. The findings reveal that when maintaining the original system with a m (SiO2) /m (MgO) ratio of 1.2, the slag composition remains outside the liquid phase region when altering the CaO content. Increasing the CaO content expands the m (SiO2) /m (MgO) value range for the slag composition within the liquid phase region. Optimized conditions show that with an m (SiO2) /m (MgO) ratio of 2.5, 10 pct CaO addition, 6.5 pct sulfiding agent addition, 4 pct reducing agent addition, p O 2 at 10 −9 atm, and an SO 2 gas flow rate of 4 mL/min, the nickel and cobalt recovery ratios reach 98.72 and 81.92 pct, respectively. Most of the iron transitions to the slag phase, with 79.80 pct entering the slag and 20.20 pct remaining in the nickel matte. The resulting nickel matte contains 19.41 pct Ni, 0.84 pct Co, and 28.39 pct S, primarily comprising nickel-iron, nickel matte, and iron matte phases.
研究领域:
冶金学
·
材料科学
·
提取冶金
·
矿物加工
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2025
·
IF 2.8
Zhenyin Guo,Qingshan Yang,Songhan Wan,Kang Zhu,Hongtao Li,Chen Peng,Xianru He
Ethylene-vinyl acetate (EVM) rubber exhibits relatively poor elasticity, restricting its wide application. The effects of flexible vulcanization agents, ethylene glycol dimethacrylate (EGDMA) and tripropanediol diacrylate (TPGDA), on the mechanical properties and vulcanization characteristics of EVM were studied. At a 3 phr dosage, EGDMA and TPGDA increased elongation at break by 23.5% and 37.0%, respectively, while improving tension set recovery. These agents extended scorch time and reduced optimum vulcanization time. Vulcanization kinetics analysis demonstrated that these two agents shortened vulcanization time, improved production efficiency, and reduced initial reaction temperature (10°C–20°C) and activation energy (7–21 kJ/mol). This study offers a low-cost and simple method to enhance the elasticity and vulcanization properties of EVM and other rubber materials.
研究领域:
高分子科学
·
材料工程
·
化学工程
·
应用化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）