汞齐捕集－原子吸收光谱法测定铜精矿中汞含量

无需进行样品消化处理,铜精矿粉末样品在253.7 nm处用直接测汞仪进行分析,5～6 min即可获取结果。为减少样品中汞对仪器的毒害同时保证测定结果的准确,样品取样量选择为0.15 g;同时,采用单个测定方式可减少样品舟存在的记忆效应。方法的检出限为0.2 μg/kg。对3个不同含量范围铜精矿国家标准物质中的汞进行测定,结果同国标法的测定结果一致,相对标准偏差≤4.7%,回收率为98%～102%。     

Adsorption of mercury to urinary cells or particles

Urine of a young healthy man was added with varying amounts of mercuric chloride, incubated for 10 to 375 min, and separated into supernatant solution and precipitate by centrifugation at 105,000 X g for 60 min. Percentage of mercury amount in precipitate increased with the increase of mercury amount added. But this adsorption of mercury to urinary cells or particles could not completely account for the amount of mercury in human urine reported (Suzuki and Shishido 1975). The hypothesis that desquamation of tubular cells is a route of urinary mercury excretion in man is still sustained.     

氢化物发生-原子荧光光谱法同时测定地下水中砷和汞

建立了氢化物发生-原子荧光法同时测定地下水中砷和汞的方法。研究了灯电流、载气流速、原子化器高度、盐酸浓度和硼氢化钾浓度等因素对检测的影响。在仪器最佳工作条件下,砷和汞的质量浓度分别在1.2～100ng/mL和0.022～1.0ng/mL范围时呈现良好的线性关系,相关系数均在0.9994以上;砷和汞的检出限分别为0.21ng/mL和0.0038ng/mL;对不同含量的砷、汞混合溶液进行测定,相对标准偏差分别小于0.78%和1.2%(n=11)。加入硫脲-抗坏血酸混合掩蔽剂,提高了干扰元素的允许量及方法的灵敏度。应用于山东、河南、安徽及长三角地下水样检测,其结果符合地质矿产实验室有关水样测试的质量管理规范要求,回收率在96%～112%之间。     

Vacuum distillation of copper matte to remove lead,arsenic, bismuth,and antimony

Vacuum-refining experiments were carried out on copper matte melts, containing 35 to 73 pct Cu, to measure the removal rates of lead, bismuth, arsenic, and antimony over the temperature range of 1373 to 1523 K under pressures in the range of 50 to 130 Pa. High rates of refining, controlled by mass transport in the liquid phase, were achieved for all impurities in melts containing up to 65 pct Cu and for chamber pressures less than 100 Pa. After 40 to 60 minutes of treatment, lead elimination was between 70 and 96 pct, bismuth elimination was between 88 and 98 pct, arsenic, elimination was between 60 and 93 pct, and antimony elimination was between 40 and 92 pct. The overall mass transfer coefficients for vacuum refining for the impurities considered fell in the range of 5×10⁻⁵ to 2×10⁻⁴ m s⁻¹. The values were insensitive to small changes in melt temperature but decreased with increasing pressure above 250 Pa. Also, the rates of refining were seen to be influenced by the sulfur and oxygen activity in the melt. The evaporation and subsequent elimination of the impurities were mathematically modeled by extending previously published models beyond consideration only of evaporation of monomers to consideration of the evaporation of monomers and dimer compounds. The model showed that due to the contributions to the refining by evaporation of each of the metallic, oxide, or sulfide vapor species, arsenic and antimony exhibited a maximum in refining rates atP _{o 2} andP _{s 2} potentials corresponding to matte grades of about 55 pct copper, whereas lead showed a minimum at about the same matte grade, and bismuth showed a continuously decreasing rate of refining with increasing matte grade. The model was also used to simulate the refining behavior of copper matte melts. An example of a commercial-scale operation is given.     

Wounds of the hand contaminated by human or animal saliva

A prospective and retrospective evaluation of 75 patients with hand wounds contaminated by human saliva (35) or animal saliva (40) demonstrates that a program of outpatient management can be sufficient for optimal care in many patients. This series challenges the proposition that hospitalization, radiographs, and surgical debridement are necessary for most such wounds. Sixty-seven per cent did not have surgical intervention and no complications resulted. Ninety-two per cent received antibiotics. Radiographs were obtained only when bony injury or entry into a joint was suspected. Delay in seeking treatment until obvious signs of infection or pain are present is common. Literature review details the anatomic factors important in the natural history and control of these infections, and the changes with respect to modes of treatment for these potentially dangerous wounds. The injury is caused by bites with the hand extended or, in fight-bite wounds, with the metacarpal-phalangeal and interphalangeal joints flexed, allowing deeper penetration and then sealing of the wound when the first is opened. Staphylococcus and Streptococcus are the organisms most frequently found in human bites, and in animal bites; Pasteurella multocida should be considered in dog and cat bites.     

次亚磷酸盐在电解铜氰废液同时回收铜和氰过程中的作用

以高浓度铜氰溶液为研究对象,通过添加次亚磷酸盐,进行了高碱条件下电积回收铜与氰化物的研究.研究了次亚磷酸盐用量、温度对铜和氰化物沉积过程的影响;利用线性循环伏安、恒电位电解并结合X射线衍射分析阳极沉淀物的物相,分析了阳极反应机理和次亚磷酸盐抑制氰化物分解的机理;采用电解后余液进行金的氰化浸出实验.结果表明：次亚磷酸盐可有效抑制电沉积过程中氰化物的分解,其抑制效果随温度升高而增强.电解过程中阳极表面生成的Cu²⁺是造成氰化物分解的主要原因;次亚磷酸盐通过优先与Cu²⁺发生氧化还原反应从而抑制氰化物的分解.处理后余液对金的氰化浸出无不良影响,通过电解可综合回收铜氰废水中金属与氰化物,处理后废水可循环利用.     

硫精矿除杂提纯浮选工艺回收利用硫酸烧渣中的铁

硫酸烧渣是硫铁矿制酸氧化焙烧产物;从硫酸烧渣中选铁的工艺技术指标一直不高,其主要原因是硫铁矿氧化焙烧过程中生成的氧化铁矿物颗粒微细,高温时新生成的氧化铁矿物颗粒会与杂质和脉石矿物颗粒相互包裹、相互黏结、相互污染。该文将硫酸烧渣选铁改为硫精矿再浮选提纯硫化铁,即通过提纯硫酸原料中硫化铁的质量分数,从而去除原料中的脉石和杂质,使硫酸原料中硫品位达到50%~52%(黄铁矿型原料)以上,硫、铁回收率均达到90%~92%;采用该高纯硫精矿制造硫酸,硫酸烧渣中铁品位达到63%~67%,使硫酸烧渣全部直接成为铁精矿,无需再选矿,达到了有效利用硫酸烧渣中铁的目的。该工艺能够获得较高技术指标的原因是硫精矿除杂提纯浮选是硫化矿选硫,采用高纯硫精矿制酸,避免了非目的矿物污染硫化铁的氧化焙烧过程以及硫酸烧渣选铁时杂质含量高、铁品位低、选矿技术指标低等问题。     

MAP法和折点氯化法联合工艺处理印制线路板铜氨废水试验研究

在废印刷电路板回收利用时通常会产生大量含重金属离子的废水,一般含有[Cu（NH₃）₄]2+、NH₄+和NH₃·H₂O,这些铜氨络离子稳定性高,处理难度极高。文中以废印刷电路板在回收利用有价金属时产生的铜氨废水为研究对象,通过MAP法和折点氯化法联合工艺对该废水进行处理,有效回收了氨氮和铜。该联合工艺不仅可以有效地节约经济成本,并且回收的铜和氨氮产物也能产生一定的经济效益。结果表明:MAP反应的较优条件为pH=9.5,废水中氨氮与投入磷盐和镁盐的摩尔比为4:1:1.1,对氨氮的去除率为23%,铜的去除率为2%,形成了磷酸氨镁沉淀。折点氯化法的较优pH为9.5,N/Cl的摩尔比为1:1.6,氨氮处理效果为98.8%,铜去除率99.8%。      

高铜贫液两步沉淀除杂全循环工业试验的研究

为实现含氰污水“拎排放”,达到保护环境、充分利用资源、可持续发展的目标,针对蓬莱市黄金冶炼厂氰化贫液中含铜质量浓度高的特殊刊物了系统的试验研究。在小型试验的基础上,设计并实施了两步沉淀除杂金循环的工业试验,回收了大部分贵金属和有价的贵金属,最大限度地回收利用了贫液中的氰化钠。在不降低金的氰化浸出率的情况下,使含氰污水全循环,实现了“零排放”,降低了生产运行成本,有效地保护了水环境。     

碘量法测定铜冶炼分银渣中铜

铜冶炼分银渣中含有较高含量的砷、锑、锡等元素,对碘量法测铜产生干扰,并且样品较难溶解完全.实验采用盐酸-硝酸-高氯酸-硫酸分解样品,用氢溴酸除去砷、锑、锡等干扰元素.控制溶液pH值为3～4,用氟化氢铵掩蔽铁,加入碘化钾与铜(Ⅱ)作用,析出的碘以淀粉为指示剂,用硫代硫酸钠标准滴定溶液滴定,建立了硫代硫酸钠碘量法测定铜冶炼...     

硫酸锌沉淀法处理高铜氰化废水的动力学研究

采用硫酸锌沉淀工艺处理含有高浓度铜离子的氰化提金废水,利用二级反应动力学模型对铜离子和游离氰化物的沉淀过程进行了试验研究。研究结果表明,在试验条件下,铜离子和游离氰化物的沉淀过程均符合二级反应动力学模型,其反应速率常数分别为3.492 dm3/(mol·min)、1.837 dm3/(mol·min)。该研究结果对高浓度铜离子氰化提金废水的沉淀处理技术应用,具有一定的指导意义。     

铜-溴酸钾-天然花青素体系催化动力学光度法测定污水处理厂污泥中铜

从紫薯中提取天然花青素,作为测定铜(Ⅱ)的催化褪色反应指示剂。在盐酸介质中,铜(Ⅱ)对溴酸钾氧化天然花青素褪色反应有灵敏的催化作用,据此建立了测定铜(Ⅱ)的催化动力学光度法。研究了催化褪色反应测定条件和动力学参数。在最佳测定波长530 nm条件下,铜(Ⅱ)的质量浓度在0.01~0.30 μg/mL范围内与非催化反应溶液和催化反应溶液的吸光度差值符合比尔定律,检出限为3.09×10^-9 g/mL。催化褪色反应为准零级反应,表观活化能为41.99 kJ/mol,表观反应速率常数为5.42×10^-4 s^-1。实验考察了20多种共存离子的影响。按照实验方法测定污水处理厂污泥中铜(Ⅱ),结果的相对标准偏差(RSD,n=8)为2.0%～2.5%,并且与原子吸收光谱法测得结果一致。     

Fiberoptic delivery of laser energy to remove occlusions from ventricular shunts: technical report

OBJECTIVES: Shunts frequently require surgical replacement because occlusions block the ventricular tubing. We have examined the hypothesis that a surgical laser coupled to an optical fiber can deliver sufficient energy to disrupt the occlusion in situ and thus afford a less invasive method of repair. METHODS: Choroid plexus tissue found in shunts explanted from patients, model tissues such as polyacrylamide gel, and animal tissues inserted into shunts were examined. Occlusions were fragmented by pulsed laser energy of 2.09-microm wavelength and 300-microsecond duration delivered via a flexible optical fiber several meters in length. The methods and conditions were similar to those likely to be used for preclinical in vivo studies. RESULTS: Short-lived vapor bubbles generated at the fiber tip disrupted occlusions within the shunt and expelled tissue blocking the inflow holes. Energy requirements to disrupt and remove occlusions in vitro were determined. Laser pulse energies and exposure thresholds that cause intentional damage to shunts also were determined. CONCLUSION: Laser energies needed to disrupt occlusions were below the energy needed to damage the shunt components. Our results show that a strategy using surgical lasers and optical fibers is feasible and suggest that the procedure could be used to repair blocked shunts without requiring surgical replacement.     

金矿石焙烧脱砷新技术试验研究

通过分析砷及其相关化合物的物化性质，找到了一种保护条件下的 深度脱砷方法。对于含砷高达11．58％某金矿石，使用该法脱砷后渣含砷降到0．2％以下，工艺稳定可靠。该方法在技术、经济、环保上可行，容易实现工业化。     

Oxidation of low density lipoprotein by iron or copper at acidic pH

Oxidized low density lipoprotein (LDL) may play a significant role in atherosclerosis. We have investigated the effect of pH on the oxidation of LDL by iron or copper. When LDL was oxidized by iron in the presence of cysteine in either Hanks' balanced salt solution (HBSS) or Ham's F-10 medium, an acidic pH greatly decreased the lag period and increased the rate of formation of hydroperoxides and thiobarbituric acid-reactive substances (TBARS), and increased its uptake by macrophages. There was a dose-dependent increase of LDL oxidation at acidic pH in the presence of increasing concentrations of cysteine. When LDL was oxidized by copper in HBSS, an acidic pH increased the lag phase before the rapid formation of conjugated dienes, hydroperoxides, and TBARS, but increased its uptake by macrophages. Similar results were obtained using Ham's F-10 medium. Cysteine (100 microM) inhibited the modification of LDL by copper in HBSS at both pH 7.4 and 5.5 As atherosclerotic lesions may be acidic, these observations may help to explain why LDL oxidation occurs locally at these sites.     

铜锰渣酸浸及选择性硫化沉淀法回收铜工艺

系统开展了铜锰渣的H2SO4浸出及酸浸液Na2S2O3选择性沉铜研究,通过单因素实验,分别探究了2个工艺过程的影响因素.实验结果表明:铜锰渣酸浸的较优条件为:H2SO4用量200 g/L,液固体积质量比(mL/g)7:1,反应温度80℃,反应时间2 h,该条件下铜、钴、锌、锰的浸出率分别为99.81％,99.54％,9...     

有机改性膨润土法处理印钞废水

采用有机改性膨润土法对某印钞厂的高浓度有机难降解废水进行处理以降低水中的有机污染物和水体颜色.实验结果显示,聚合氯化铝(PAC)投加量对于处理效果的影响最大,当膨润土投加量为15 g·L^-1,聚合氯化铝投加量为3.5 g·L^-1,搅拌时间为0.5h时,处理效果最佳,印钞废水吸光度去除率高达96.55%,化学需氧量(COD)去除率最高达到73.31%.使用该方法对印钞废水处理,可以有效降低水体COD和表观颜色,并且不引入新的污染物,无浓水排放,非常适合作为废水深度处理的预处理工艺.