Impact of gypsum on flotation of scheelite and fluorite using sodium oleate as collector

ABSTRACT

In this study, effect of calcium and gypsum on scheelite and fluorite was investigated using sodium oleate as collector. Micro-flotation and contact angle results showed that the adsorption of calcium could inhibit the hydrophobicity of scheelite and fluorite. Moreover, sulfate could enhance the inhibition. FT-IR results showed that calcium could be priori precipitated into calcium oleate and adsorb on mineral surface. The adsorption of calcium could increase the scheelite potential to IEP, while it showed limited effect on fluorite potential. However, the interaction of calcium on scheelite and fluorite in gypsum solution was more complex than that in calcium solution.     

Rational Designs for Lithium-Sulfur Batteries with Low Electrolyte/Sulfur Ratio

Lithium-sulfur batteries (LSBs) are considered a promising next-generation energy storage device owing to their high theoretical energy density. However, their overall performance is limited by several critical issues such as lithium polysulfide (PS) shuttles, low sulfur utilization, and unstable Li metal anodes. Despite recent huge progress, the electrolyte/sulfur ratio (E/S) used is usually very high (≥20 µL mg⁻¹), which greatly reduces the practical energy density of devices. To push forward LSBs from the lab to the industry, considerable attention is devoted to reducing E/S while ensuring the electrochemical performance. To date, however, few reviews have comprehensively elucidated the possible strategies to achieve that purpose. In this review, recent advances in low E/S cathodes and anodes based on the issues resulting from low E/S and the corresponding solutions are summarized. These will be beneficial for a systematic understanding of the rational design ideas and research trends of low E/S LSBs. In particular, three strategies are proposed for cathodes: preventing PS formation/aggregation to avoid inadequate dissolution, designing multifunctional macroporous networks to address incomplete infiltration, and utilizing an imprison strategy to relieve the adsorption dependence on specific surface area. Finally, the challenges and future prospects for low E/S LSBs are discussed.     

Selective Analysis of Sulfur-Containing Species in a Heavy Crude Oil by Deuterium Labeling Reactions and Ultrahigh Resolution Mass Spectrometry

A heavy crude oil has been treated with deuterated alkylating reagents (CD₃I and C₂D₅I) and directly analyzed without any prior fractionation and chromatographic separation by high-field Orbitrap Fourier Transform Mass Spectrometry (FTMS) and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) using electrospray ionization (ESI). The reaction of a polycyclic aromatic sulfur heterocycles (PASHs) dibenzothiophene (DBT), in the presence of silver tetrafluoroborate (AgBF₄) with ethyl iodide (C₂H₅I) in anhydrous dichloroethane (DCE) was optimized as a sample reaction to study heavy crude oil mixtures, and the reaction yield was monitored and determined by proton nuclear magnetic resonance spectroscopy (¹H-NMR). The obtained conditions were then applied to a mixture of standard aromatic CH-, N-, O- and S-containing compounds and then a heavy crude oil, and only sulfur-containing compounds were selectively alkylated. The deuterium labeled alkylating reagents, iodomethane-d₃ (CD₃I) and iodoethane-d₅ (C₂D₅I), were employed to the alkylation of heavy crude oil to selectively differentiate the tagged sulfur species from the original crude oil.     

由含硫原油生产Ⅰ类润滑油基础油中的问题

论述了由含硫原油生产Ⅰ类润滑油基础油的重要性,并介绍了由含硫原油生产Ⅰ类润滑油基础油加工过程中存在的问题,认为并非由含硫原油不能生产优质的基础油,而是我国现有的基础油生产装置是按加工大庆原油设计,不能完全适合加工含硫原油的需要,所以应适当改造。例如:增加丙烷脱沥青的溶剂比,用加氢补充精制代替白土精制等,此外,在含硫原油生产基础油时,对原油也应适当选择。     

石膏转化制硫酸钾结晶动力学及结晶添加剂研究

研究了浓氨介质中石膏与氯化钾直接转化制硫酸钾的结晶动力学及结晶添加剂的作用效果。结果表明 ,硫酸钾在氨介质中的成核速率与晶体生长速率、悬浮密度、搅拌速率存在如下关联式 :B0 =5 .64 13×10 8G3.32 0 8Mt0 .0 559np0 .2 92 8。加入异丙醇、OP乳化剂及十二烷基苯磺酸钠等添加剂 ,可使硫酸钾结晶产品纯度提高 ,晶体形态整齐均匀     

渣油中硫化物类型分布与化学转化性能

用X射线光电子能谱（XPS）定量研究了Athabasca渣油及其加氢裂化渣油，流化焦化渣油中的硫化物类型，用超临界流体萃取分馏将3种渣油分别分离成9－14个窄馏分及残渣，测定其中的硫醚，噻吩，亚砜和砜类硫原子的分布，讨论了加氢裂化和热裂化反应脱除硫化物的反应性能。     

SO2转化温度异常情况分析

结合凤山实业总公司硫酸车间 SO2 转化系统的具体工艺流程 ,分析近几年转化系统出现温度不正常的原因 ,提出解决方法     

含葡萄糖基水溶性硫化黑的合成

本文以C.I.硫化黑1为原料,经葡萄糖还原成隐色体后,再与葡萄糖缩合,合成出含葡萄糖基水溶性硫化黑。合成方法分别采用了焙烘法和水介质中合成。结果表明,水介质中合成的含葡萄糖基水溶性硫化黑溶解度好于焙烘法。     

用膜电解法处理低浓度SO2吸收液的三室电解槽材料的选择

提出了用膜电解法处理低浓度SO2吸收液的方法，介绍了三室电解槽的设计原理及在电场作用下，电解槽内离子的迁移和电解反应机理，系统地讨论了电解槽组成单元材料（如阳离子交换器）的选择及在H2SO4－NaHSO3-Na2SO3体系中金属阳极的选择等，并进行了试验验证，得到了很好的结果。     

Continuous precipitation of calcium sulfate dihydrate from waste sulfuric acid and lime

Precipitation of calcium sulfate dihydrate, gypsum, from (i) a pure sulfuric acid/lime suspension and (ii) a waste sulfuric acid/lime suspension in a continuous pilot plant in the temperature range from 40 °C to 80 °C was studied. It was observed that in the case of waste sulfuric acid with a high content of Mg²⁺ and Fe²⁺ ions, several hours after the beginning of the precipitation, partial dissolution of the product and modification of the crystals from needle‐ and plate‐like to agglomerated structures occurred. It is suggested that the secondary changes occur due to the increased concentration of Mg²⁺ and Fe²⁺ ions in the reactor. Below 60 °C, and above 70 °C plate‐like and needle‐like single crystals respectively were formed. The mean size (d₅₀) of the crystals was found to increase with increasing temperature and decrease with the initial concentration of lime. Gypsum produced between 70 °C and 80 °C is suitable for further processing for construction plaster. In a precipitation process with pure sulfuric acid only single perfect needle‐like crystals occurred. Copyright © 2005 Society of Chemical Industry