Polysulphone and poly(phenylene sulphide) blends: 1. Thermal characterization and phase morphology

The phase behaviour and morphology of injection moulded specimens of polysulphone (PSF) and poly(phenylene sulphide) (PPS) blends were studied by differential scanning calorimetry (d.s.c.), dynamical mechanical thermal analysis (d.m.t.a.) and transmission electron microscopy (TEM). The blends are phase separated regardless of the blend composition as revealed by d.s.c., d.m.t.a. and TEM. Upon annealing at 160°C for 2 h, d.m.t.a. results indicate that the PPS phase remains in the amorphous state at compositions <10%. At compositions between 20 and 35%, the PPS appears to be dispersed in a mixed mode of amorphous and crystalline domains. Above 35% the PPS phase appears to become fully crystallized upon annealing of the blends. At 10% PPS, TEM results showed 35–200 nm size dispersion both in the as-moulded and in the annealed specimens. At 20% the PPS phase varied widely in size, from 35 nm to tens of micrometres but remained as an included phase. TEM also revealed a compound morphology of the included phase at a composition of 50 wt% of each component.     

镉质量浓度和鱼尺寸对罗非鱼积累和转移镉的影响

为研究尺寸和镉(Cd~(2+))质量浓度对罗非鱼积累和转移水环境中Cd~(2+)的影响,用室内培养的方法,选取4种尺寸的罗非鱼,设置不同质量浓度Cd~(2+)的暴露试验,分别测定其半致死率、Cd~(2+)积累量和对Cd~(2+)的转移系数以及罗非鱼的相对增长率.结果表明:不同尺寸的罗非鱼对Cd~(2+)的响应不同,其中,幼龄鱼的LC50浓度最低,体长为31.5±3.4 cm的罗非鱼LC50最高;低质量浓度Cd~(2+)(0.5 mg/kg)处理下,罗非鱼尺寸不同,相同鱼组织对Cd~(2+)的吸收积累量差异显著(P0.05),而高质量浓度Cd~(2+)处理时,不同尺寸罗非鱼的同一组织对Cd~(2+)的积累量无显著性差异;除体长27.4±2.9 cm罗非鱼外,相同尺寸的罗非鱼Cd~(2+)转移系数都是低质量浓度显著大于高质量浓度(P0.05);高质量浓度Cd~(2+)处理对各种尺寸罗非鱼质量增加的抑制率显著高于低质量浓度Cd~(2+)处理的抑制率.此外,不同Cd~(2+)质量浓度对相同尺寸的罗非鱼也产生不同的影响.因此,罗非鱼的尺寸和Cd~(2+)质量浓度都对罗非鱼积累和转移Cd~(2+)产生影响.     

Development of compositionally modulated multilayer Zn-Ni deposits as replacement for cadmium

Compositionally modulated multilayer (CMM) Zn-Ni deposits were electrodeposited from single acidic bath (pH = 4.7) by using a potentiostatic sequence. The Zn and Ni composition in the alloy was tailored as a function of distance from the steel substrate. X-ray diffraction studies of the deposit showed the presence of γ-phase with a composition of Ni₅Zn₂₁. The corrosion properties of modulated multilayer coatings were studied in 5% NaCl solution using electrochemical corrosion techniques. The polarization resistance of the deposits varied as a function of Ni content between 1700 and 3440 Ω. CMM Zn-Ni with 20 wt% Ni exposed in ASTM B117 salt spray test did not show any red rust formation after 400 h.     

镍硫化物阳极溶解的电化学研究

研究了合成镍硫化物的阳极过程。Ni_3S_2,Ni_7S_6和NiS的活性溶解伴随着生成表面产物层,其反应机理与电极电位有关。根据三种不同类型产物层生成规律的电化学研究,Ni溶出表观电子数的测定,以及产物层相组成分析和相的元素分析,认为存在三组平行反应:直接生成HSO_4~-或SO_(4-)~2的反应,生成中间硫化物的反应及生成元素硫的反应,每组反应具有不同的优势发展电位区。NiS_2阳极溶解时,基本上为生成HSO_(4-)或SO_(4-)~2的反应。     

THERMODYNAMIC AND STRUCTURAL CHEMISTRY DISCUSSIONS FOR OXIDATIVE LEACHING OF Cu－Ni SULPHIDE ORE UNDER ATMOSPHERIC PRESSURE

ＴＨＥＲＭＯＤＹＮＡＭＩＣＡＮＤＳＴＲＵＣＴＵＲＡＬＣＨＥＭＩＳＴＲＹＤＩＳＣＵＳＳＩＯＮＳＦＯＲＯＸＩＤＡＴＩＶＥＬＥＡＣＨＩＮＧＯＦＣｕ－ＮｉＳＵＬＰＨＩＤＥＯＲＥＵＮＤＥＲＡＴＭＯＳＰＨＥＲＩＣＰＲＥＳＳＵＲＥ￥Ｗｕ，Ｗｅｎｊｉａｎ（Ｄｅｐａｒ...     

易切削钢硫化物特性分布数理统计分析

用定量金相对易切削钢硫化物特性——数量、面积、宽度、长度和长宽比进行数值分析，用数理统计频数分析对硫化物分布特性进行了表征，用聚类分析对易切削钢硫化物特性分布进行了分类。     

FeCl3浸取含Au复杂硫化矿的动力学研究

研究了FeCl_3溶液浸取复杂含金硫化精矿中有价金属Cu,Ag,Pb和Zh的过程,考察了主要过程参量对浸取速率的影响.实验数据用非线性回归方法处理,给出动力学模型,说明精矿中Cu的溶解过程由表面化学反应控制,其速率是Fe~(3+)的0.5级和Cl~(-)的零级反应.实验条件下Cu,Ag,Ph和Zn的最终浸取率分别达到96,95,90和91%,超过90%的Fe进入浸取液,总硫的70%以上转化为元素硫,而Au的浸取率则小于3%表明FeCl_3溶液浸取是含Au复杂硫化精矿预处理并回收有价金属的有潜力的方法     

Leaching of complex sulphide concentrate in acidic cupric chloride solutions

The chemical analysis of a complex sulphide concentrate by emission spectrometry and X-ray diffraction shows that it contains essentially copper, lead, zinc and iron in the form of chalcopyrite, sphalerite and galena. A small amount of pyrite is also present in the ore but does not be detected with X-ray diffraction. The cupric chloride leaching of the sulphide concentrate at various durations and solid/liquid ratios at 100 ℃ shows that the rate of dissolution of the ore is the fastest in the first several hours, and after 12 h it does not evolve significantly. If oxygen is excluded from the aqueous cupric chloride solution during the leaching experiment at 100 ℃, the pyrite in the ore will not be leached. The determination of principal dissolved metals in the leaching liquor by flame atomic absorption spectrometry, and the chemical analysis of solid residues by emission spectrometry and X-ray diffraction allow to conclude that the rate of dissolution of the minerals contained in the complex sulphide concentrate are in the order of galena 〉 sphalerite 〉 chalcopyrite.     

氯化物介质矿浆电解法浸出硫化铜精矿

研究了在ＦｅＣｌ３ＨＣｌＮａＣｌ体系中直接电解浸出硫化铜精矿矿浆制取铜粉的工艺条件及机理。试验表明，在阳极初始溶液含Ｆｅ３＋６０ｇ／Ｌ、ＨＣｌ３０ｇ／Ｌ、ＮａＣｌ１５０ｇ／Ｌ，阴阳极电流密度分别为３５０和６００Ａ／ｍ２，１００℃的条件下浸出５ｈ，可获得铜浸出率９８．８％、渣含铜０．３４％、铜粉纯度９７．５％的结果；Ｆｅ３＋浓度是影响铜浸出率最显著的因素，阳极上发生的主要反应是Ｆｅ２＋的氧化；元素硫产生的机理是酸直接分解黄铜矿生成Ｈ２Ｓ，Ｈ２Ｓ溶解后再被Ｆｅ３＋氧化。     

电镀废水处理站DTCR辅助氢氧化物沉淀工艺改造

某废水处理站改造前采用传统氢氧化物沉淀工艺处理高浓度含铬、氰镉电镀废水,运行不稳定,出水不能达标排放。工艺改造后增加了高分子重金属捕集沉淀剂DTCR辅助去除重金属,在含铬废水DTCR投加量为50 mg/L、含氰镉废水DTCR投加量为10 mg/L条件下,出水总铬、镉分别稳定在0.5 mg/L、0.2 mg/L以下,远低于《电镀污染物排放标准》(GB 21900—2008)限值。