共查询到19条相似文献,搜索用时 250 毫秒
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为研制一种适用于直接碳固体氧化物燃料电池(DC-SOFC)的高温脱硫剂,以Zr OCl2·8H2O和Mn(NO3)2为原料,通过分步沉淀法制备出不同Mn负载量的Mn-Zr-O复合高温脱硫剂。通过X射线衍射仪(XRD)、BET比表面积等手段对脱硫剂进行表征,并在800℃高温条件下进行脱硫性能评价。研究结果表明:当Zr与Mn物质的量比为10∶4时比表面积最大,脱硫评价时穿透时间最长;当Zr与Mn物质的量比为10∶1时,Mn2O3在Zr O2上的分散性最好,脱硫精度最高,能够达到2×10-6以下,满足直接碳固体氧化物燃料电池对合成气中最低硫含量(9×10-6)的要求。 相似文献
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对强化氧化法脱除铝酸钠溶液中的S~(2-)进行了研究,挑选出能强化氧化除S~(2-)的物质,并通过改变添加物质的浓度来验证其是否具有强化氧化作用。实验结果表明:硫酸锰具有强化氧化作用,氯化铜通过化学反应除S~(2-),二氧化钛、氯化亚锡、硫酸高铈、三氧化二铁、三氧化钨、钨酸钠、五氧化二钒、三氧化二铬及活性炭没有强化氧化作用。在90℃、转速300 r/min、流量0.08 m3/h、反应时间60 min条件下,1.014 g/L的硫酸锰强化氧化除S~(2-)率达到100%。 相似文献
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以电解锰阳极泥经还原焙烧-酸浸-深度净化除杂获得的硫酸锰溶液和工业氨水为原料,采用共沉淀法,制备高纯Mn3O4。考察了搅拌速度、反应温度、气体流速、反应时间以及Mn2+/NH4+物质的量比对Mn3O4纯度的影响。结果表明,在搅拌速度250 r/min、反应温度60℃、气体流速2.5 L/min、反应时间40 min、Mn2+/NH4+物质的量比1:2的条件下,成功制备出球形Mn3O4,其锰含量为71.45%,满足高纯Mn3O4的要求。 相似文献
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采用碳化法去除硫酸锰溶液中的钴、镍离子。以CO2为碳化剂,NaOH为pH调节剂,将硫酸锰溶液中的Mn2+以碳酸锰沉淀的形式从原溶液中分离出来,然后用硫酸将沉淀物溶解,从而达到除杂的目的。考察CO2流量、反应温度、pH值及反应时间对钴、镍离子去除效果的影响。结果表明,反应温度25℃,溶液pH值为7.5,二氧化碳流量为0.9 L/min,反应时间为60 min时最为适宜,此时碳酸锰产品中钴、镍元素含量比硫酸锰一次结晶产物分别降低了0.031 29%和0.088 5%,其含量分别为0.003%和0.005%,符合高纯碳酸锰GB10503-89 I型品的标准。 相似文献
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以富锰渣为原料制备碳酸锰 总被引:1,自引:0,他引:1
以98%的浓硫酸为浸取介质,浓硫酸(ml):富锰渣(g)=0.57;1,不加热,强搅拌下反应三个小时,将富锰渣中锰、铁、钙、镁等可溶性物质溶出,锰的浸出率可达97.85%,过滤,洗涤,以MnO2为氧化剂将Fe^2+氧化为Fe^3+,以NH2·H2O和BaS为联合除杂剂以除去铁、钙、镁及其它重金属离子,得到纯度较高的硫酸锰溶液,调节硫酸锰溶液浓度及温度,以NH3·H2O调节溶液pH值,向硫酸锰溶液加入碳酸氨溶液,缓慢搅拌,即有碳酸锰沉淀析出。
通过正交实验得到如下最佳的碳化条件:碳酸铵与硫酸锰的摩尔比为1.5:1;碳酸铵的浓度为2mol/L;硫酸锰浓度为0.4mol/L;碳化时,pH值调节为5.5;温度为75℃。将以上得到的较纯净的硫酸锰溶液,在此条件下可制得碳酸锰沉淀,过滤,于70-80℃下干燥得到产品,该产品符合GB10503-89. 相似文献
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将化学计量比的LiOH·H_2O、Ni(NO_3)_2·6H_2O与超细α-MnO_2纳米线前驱体均匀混合,在800℃下煅烧12 h合成LiNi_(0.5)Mn_(1.5)O_4纳米棒。通过XRD、TEM和电化学测试对样品的晶体结构、表面形貌及电化学性能进行了表征。结果表明:超细α-MnO_2纳米线平均直径为10 nm,多根α-MnO_2纳米线聚集成簇。LiNi_(0.5)Mn_(1.5)O_4纳米棒直径为50 nm,与α-MnO_2纳米团簇的直径相仿。电化学测试结果表明:LiNi_(0.5)Mn_(1.5)O_4纳米棒的初始放电比能量为475 Wh/kg,循环500圈后容量保持率为99%。 相似文献
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本工作采用恒电流库仑法分析铀氧化物中的铀。方法基于铀在硫-磷混合酸中以Cr(Ⅱ)还原U(Ⅵ)为U(Ⅳ),过量的Cr(Ⅱ)在空气中被氧化,准确加入比铀的化学计量略过量的重铬酸钾,以精密恒电流电生Fe(Ⅱ)库仑滴定过量的Cr(Ⅳ)。方法的精密度优于0.01%。 相似文献
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In order to improve the properties of NiFe2O4 spinel based inert anode, some additive MnO2 were added to raw materials. NiFe2O4 spinel with MnO2 was made by solid-phase reaction at 1200℃for 6 h. XRD were carried out and the effects of MnO2 on density, conductivity and corrosion resistance were measured. XRD shows when MnO2 was added no new phases exist and MnO2 and NiFe2O4 formed solid solution; Mn4+ replaced parts of Fe3+ and the sample still had the structure of NiFe2O4 spinel. The crystal lattice of NiFe2 O4 spinel became aberrated when MnO2 was added, which can promote sintering, and improve density. Because Mn4+ replaces parts of Fe3+ and produces conduction electron, which can improve conductivity.The corrosion resistance of the samples was enhanced. When MnO2 is 1.0,, the sample''s corrosion rate is 1/5 of that of the sample without MnO2. The reason is that Al2 O3 in the melt reacts with Mn4+ in the sample to produce MnAl2O4. MnAl2 O4 forms a dense protecting coat, which can prevent melt from eroding further.Because the key problem with inert anodes is anode corrosion, so we consider the optimal amount of MnO2 is 1.0,. 相似文献
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NH_4H_2PO_4粉体的吸热分解热效应一直被认为是NH_4H_2PO_4粉体抑爆的重要原因。为了进一步揭示NH_4H_2PO_4粉体吸热分解后对甲烷爆炸的作用,采用自主改进的XKWB-1型20 L近球型密闭式气体爆炸实验系统,测试NH_4H_2PO_4粉体热分解产物氨气和五氧化二磷加入后的甲烷爆炸压力参数,分析NH_4H_2PO_4粉体热分解产物对甲烷爆炸过程的影响。结果表明:NH_4H_2PO_4粉体热分解产物氨气和五氧化二磷对甲烷爆炸过程的影响均呈现出了一定的弱化作用,且氨气对高体积分数甲烷爆炸弱化效果更明显。另外,分解产物氨气对甲烷爆炸的弱化作用明显大于五氧化二磷,这一贡献对比对于高体积分数的甲烷更加显著。 相似文献
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陈小兰 《广东有色金属学报》2003,13(1):73-75
先用硝酸 氢氟酸溶解磷酸锆银钠样品,再加氨水(1 1)使其转换成氨性溶液,然后用原子吸收分光光度法测定磷酸锆银钠中的银.本法测定结果与火试金法测定结果一致,相对标准偏差小于0.37%,回收率大于95%. 相似文献
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通过化学共沉积法制备纳米Fe3O4/凹凸棒石复合粉体,并采用XRD、XPS、HRTEM和矢量网络分析仪等手段对其微结构和吸波性能进行表征和分析。XRD和XPS分别证明了复合粉体的物相和铁的氧化价态。 HRTEM图像显示,Fe3O4磁性粒子均匀分布在凹凸棒石黏土表面,颗粒尺寸为10~80 nm。使用矢量网络分析仪在2~18 GHz范围测试不同厚度的Fe3O4/凹凸棒石的反射率。结果显示,不同厚度样品的峰值均超过-13 dB,其中厚度为3.5 mm的样品在12.6 GHz处反射峰为-28 dB,说明Fe3O4/凹凸棒石具有优良的吸波性能,有望成为一种新型的吸波材料。 相似文献
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Al2O3包覆LiMn2O4正极材料的合成和电化学性能研究 总被引:4,自引:1,他引:4
研究了在锂离子电池尖晶石LiMn2O4正极材料上包覆Al2O3来改善材料在循环过程中的容量衰减问题。通过SEM和X射线衍射研究材料的表观形貌和晶体结构,在电化学性能测试中,发现包覆Al2O3可以减少材料与电解液的直接接触,阻止了电解液对尖晶石的侵蚀,抑制锰离子在电解液中的溶解和由此带来材料结构的改变,以及与电解液中微量的HF反应,避免了HF对锰离子溶解的加速作用。从电化学循环测试后材料的X射线图谱上可以发现,LiMn2O4材料包覆Al2O3后,可以在很大程度上抑制循环过程中MN5O8杂相峰的出现。 相似文献
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Keri M. Petritz Christopher H. Gammons Suzzann Nordwick 《Mine Water and the Environment》2009,28(4):264-273
The mines of Butte, Montana include over 16,000 km of abandoned underground workings, most of which are now filled with water.
The feasibility of using the flooded mine workings as a source of irrigation water was investigated. The geochemistry and
stable isotopic composition of water produced during a 59 day pumping test of the flooded Belmont Mine workings are described.
Although static water in the pumping well initially met proposed irrigation standards, the quality deteriorated during pumping
as water from deeper in the mine complex was drawn into the well. Stable isotopes show that this lower-quality water was not
sourced from the nearby Berkeley Pit lake, but most likely came from the mine shaft itself. At steady state, the water pumped
to the surface had pH 5.5–6.0 with high concentrations (in mg/L) of dissolved SO4 (1,600), Fe (160), Mn (19), Zn (15), and As (1.8). Despite substantial bicarbonate alkalinity (≈150 mg/L as CaCO3), the water became strongly acidic after equilibration with air due to oxidation and hydrolysis of Fe2+. Benchtop experiments were performed to test different strategies for low-cost chemical treatment prior to irrigation. The
most feasible alternative involved aeration (to remove large quantities of dissolved CO2) prior to pH adjustment to >9 with lime or NaOH. Further work is needed to see if such treatment is economically viable compared
to the cost of using municipal water. Another concern is whether irrigation of grass with high TDS, high sulfate water is
sustainable. The mine water reached a steady-state temperature of 19°C during pumping, and therefore the possibility of using
this water to help heat nearby buildings should also be explored. 相似文献