共查询到19条相似文献,搜索用时 250 毫秒
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试样用过氧化钠熔融后酸化的方法处理,样品中的铬、硅、磷、锰元素,经高温熔融后,都已经全部成高价状态,用酸调节至不同的酸度后,用硫酸亚铁铵直接滴定法分析铬,钼蓝光度法测定硅和磷,以过硫酸铵银盐氧化光度法测定锰。通过控制测定的酸度,各元素线性良好,测得铬、硅、锰、磷的相对标准差分别小于0.24%、1.46%、1.64%、2.95%。该法操作简便、快捷,缩短了分析周期。 相似文献
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采用一次称样、硝酸和氢氟酸溶样、水浴加热的方法制成母液后,分别用分光光度法测定了硅铁中锰、磷元素含量,滴定法测定了硅铁中铬元素含量。通过试验确定了溶样方式,氢氟酸加入量等溶样条件;进行了锰和铬之间的相互干扰试验,结果表明,样品中的铬不干扰锰含量的测定,采用亚硝酸钠和尿素可消除锰对铬测定的干扰。按此方法对4批次硅铁样品进行了分析,其测定值与国标法测定的结果相一致,测定锰、磷、铬3元素的相对标准偏差(n=6)依次为10%~14%、01%~05%和08%~15%,适用于工厂实验室的日常分析。 相似文献
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用过硫酸铵—银盐氧化光度法测定钢铁中的锰时,三价铬离子同时被氧化为橙红色的重铬酸根离子。因重铬酸根离子的表观摩尔吸光系数小(ε_(450)=200),其显色反应的灵敏度很低,通常是不用重铬酸根光度法测定钢铁中的铬,笔者通过增加取样量,加大吸收皿厚度及采用差示比色,可用重铬酸根光度法测定钢铁中的低铬。木法可直接联合测定合金铸铁、炭钢、中低合金钢、高速工具钢中0.05~2%的锰和0.05~7%的铬。 分析步骤 称取0.2000~0.6000g试洋于100ml两用瓶中①,加入15ml硫、磷混酸(硫酸+磷酸+水= 相似文献
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试样以稀硝酸溶解,在过硫酸铵存在下氧化硅、磷为正硅酸、正磷酸,棕色二氧化锰沉淀滴加亚硝酸钠溶液还原分解之。定容后,分别以钼蓝光度法测定硅,磷铋钼蓝光度法测定磷,高碘酸钾光度法测定锰。 相似文献
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提出了一种快速测定高碳铬铁中磷和锰的方法。采用无水碳酸钠-硼酸混合熔剂在石墨碳粉垫底坩埚中高温熔融分解试样,使试样中大部分铬形成难溶于酸的硼化铬或碳硼化铬而与磷、锰分离。熔块用酸溶解后,用磷铋钼蓝光度法测定磷,高碘酸钾光度法测定锰。磷、锰的线性回归方程分别为:A=0.01417+11.0895ρ和A=0.01278+0.6906ρ。对熔样温度、时间和浸取酸进行了选择;讨论了干扰离子的影响及消除。方法用于高碳铬铁中磷和锰的测定,加标回收率分别为93.8%~103.3%和98.6%~101.6%,相对标准偏差 相似文献
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硅铁中锰、铬、磷的分析,锰常采用过硫酸铵氧化光度法,铬常采用Na_2CO_3分离,二苯卡巴肼光度法;磷常采用重量法或铋磷钼蓝光度法。为了解决三元素连续测定问题,我们在同一份样品试液中进行试验,并改进了Mn、Cr、P的分析,现在Mn 相似文献
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利用原子吸收光度法连续测定渣样中的Mg、Mn、Pb、Zn、Cu、K、Na、Li含量,称样、溶样只需一次,就可完成8种元素的连续测定。该方法操作简便、快速,而且测定结果准确可靠,测定各元素的相对标准偏差为0.3%~25%,回收率达97%~102%。 相似文献
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ICP—AES法测定铝锰合金中的铝锰硅磷含量 总被引:2,自引:2,他引:0
用稀王水溶解试样,ICP—AES法直接测定铝锰合金中的铝、锰、硅、磷的含量。对样品溶解酸度、元素谱线选择、背景校正扣除、样品基体及待测元素间干扰等因素进行了试验研究。采用基体匹配与背景扣除法消除铁基体对待测元素的光谱干扰,确定了最佳实验条件。结果表明:各元素的加标回收率为97.6%-105.0%,相对标准偏差小于0.88。本法与化学分析方法对照,测定结果一致,已用于铝锰合金产品的检验。 相似文献
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Chandrakant V. Sharma J. R. Trivedi S. K. Chaudhury 《Transactions of the Indian Institute of Metals》2017,70(10):2651-2660
Recovery of Mn in steel making process depends on various processing parameters such as temperature, flow rate ratio of oxygen and argon gas in AOD process, carbon content, slag basicity, and V-ratio, Si content etc. The effect of these process parameters on Mn recovery in Mn-based stainless steel production is studied and optimized to maximize Mn recovery. It is observed that highest Mn recovery is achieved when slag basicity is maintained in the range of 1.7–1.8 and V-ratio is kept at 1.5. Further, it is noted that at high temperature, recovery of Mn is less because loss of Mn due to oxidation increases exponentially with the increase in temperature. Maximum Mn recovery is observed at 1585 °C bath temperature. Reduction of MnO with coke forms CO2 gas and free Mn in the melt. To maximize recovery of Mn in stainless steel, it is of paramount importance that oxidation of Mn is reduced and reduction of MnO is accelerated. Oxidation of Mn is minimized by reducing the flow rate of oxygen and reduction of MnO is accelerated by adding adequate amount of coke to the molten charge. 相似文献
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测量不确定度可用于对钼蓝光度法测定锰硅合金中磷含量的结果进行评估。通过建立数学模型,找出影响钼蓝光度法测定锰硅合金中磷含量的不确定度因素,计算各个不确定度分量,并合成不确定度,最终给出扩展不确定度和置信水平。 相似文献
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EJ Parks JB German PA Davis EN Frankel CT Kappagoda JC Rutledge DA Hyson BO Schneeman 《Canadian Metallurgical Quarterly》1998,68(4):778-785
The goal of this investigation was to determine whether participation in an atherosclerosis treatment program would reduce the oxidative susceptibility of LDL from patients with coronary artery disease. The treatment program included intensive exercise therapy, stress management, and consumption of a diet containing 10% fat. The size and antioxidant and lipid contents of LDL particles from 25 patients were analyzed at baseline and after 3 mo of therapy. The susceptibility of LDL to copper-mediated oxidation was measured by a conjugated diene assay and headspace gas chromatography (HSGC). Atherosclerosis treatment significantly reduced plasma total cholesterol and apolipoprotein B concentrations and the molar ratio of LDL cholesterol ester to apolipoprotein B (P < 0.01). The LDL content of alpha-tocopherol and beta-carotene was increased (27% and 17%, respectively, P < 0.04) and the molar ratio of LDL cholesterol ester the sum of LDL alpha-tocopherol and LDL beta-carotene decreased from 159 at baseline to 122 at 3 mo (P < 0.01). The lag phase of LDL conjugated diene formation increased 24%, whereas the maximum rate of oxidation slowed 29% (P < 0.01). As assessed by HSGC, copper-catalyzed formation of volatile lipid oxidation products was reduced 15% (P < 0.007); the reduction in volatiles was correlated with an increase in the alpha-tocopherol content of LDL (r=-0.48, P < 0.01). The principal determinants of reduced LDL oxidative susceptibility were the particle contents of alpha-tocopherol and beta-carotene. To our knowledge, this is the first report to document a reduction in LDL oxidation in coronary artery disease patients undergoing atherosclerosis-reversal therapy. 相似文献