铝合金中镁的快速测定

该文介绍的铝合金中镁的快速测定不需分离，采用DDTC、盐酸羟胺、三乙醇胺联合掩蔽剂掩蔽大量的铝及少量的铜、铁、锰离子，在pH10条件下，以铬黑T为指标剂，用EDTA滴至溶液由紫红色变为纯蓝色为终点。方法简单、快速、准确度高，适用于铝合金中镁含量的快速测定。     

铝合金中镁的快速测定

介绍了铝合金中镁的快速测定方法,提出了运用该方法应注意的问题及其优点。     

铝合金中镁的快速测定

介绍了铝合金中镁含量的快速测定。在不需分离的情况下,采用DDTC、盐酸羟胺、三乙醇胺联合掩蔽剂,掩蔽大量的铝及铜、铁、锰离子,在pH=10的缓冲液中以络黑T为指示剂,用EDTA滴至溶液由紫红色变为纯兰色为终点。该方法简单、快速、准确度高,适合于铝合金中各种镁含量的测定。     

Grain Size Hardening in Mg and Mg-Zn Solid Solutions

Cast specimens of Mg and of several Mg-Zn binary alloys with a wide range of grain sizes were deformed in tension and compression. The k values calculated from the Hall–Petch (H-P) plots of the tensile 0.2 pct proof stress increased with the Zn content, from 0.24 MPa m^1/2 for pure Mg to ~0.66 MPa m^1/2 for the 2.3 at. pct Zn alloy; k values measured from compression tests were larger, typically by 0.05 MPa m^1/2. When the strength measurements were corrected for the pseudoelastic strain resulting from elastic twinning, the k values generally increased, and the difference between tension and compression was eliminated. This showed that the larger k values obtained in compression using uncorrected data were an artifact of the pseudoelastic effect. The apparent friction stress varied between about 14 MPa for pure Mg to very low or negative values for the most dilute alloy, increasing again to about 8 MPa for the most concentrated alloy. The use of strength data corrected for pseudoelasticity effects is necessary for a consistent analysis of the grain size hardening.     

Determination of Activity Coefficients in Solid Solutions

Abstract

A method of determining activity coefficients in metallic solid solutions has been developed. This method, based on the measurement of solidification partition coefficients, has been tested for the tin-bismuth system, and used for a thermodynamic study of the Pb - 16.3% Sn alloy.

Résumé

Nous avons élaboré une méthode de détermination de coefficients d'activité d' éléments en solution solide. La méthode, basée sur la mesure de coefficients de partage en solidification, a été éprouvée par comparaison des résultats obtenus aux données publiées du système étain-bismuth, puis utilisée pour une étude de l'alliage Pb - 16.3% Sn.     

PDS脱硫液中硫化钠含量测定方法

本文根据工厂实际生产需要,提出一种分析脱硫液副盐中硫化钠含量的测定方法,达到准确分析硫化钠含量的目的.测定方法同时消除了硫化钠的干扰物影响,有利于开展其他副盐分析工作.     

Experimental Study on the Activities of Al and Ca in Ferrosilicon

Metallurgical and Materials Transactions B - Experiments were carried out to determine the activities of Al and Ca in liquid ferrosilicon (with about 50 wt pct Si) at...     

嗜酸氧化亚铁硫杆菌的耐Mg^2＋驯化试验研究

考察了嗜酸氧化亚铁硫杆菌(A.t)对Mg2 的耐受能力,进行了细菌耐Mg2 驯化试验.结果表明,通过驯化,细菌对Mg2 的耐受能力大幅度增强,可用于高MgO含量的硫化镍矿的细菌浸出.     

Activities in the spinel solid solution Fe X Mg1−X Al2O4

Activities in the spinel solid solution Fe _X Mg_1−X Al₂O₄ saturated with α-Al₂O₃ have been measured for the compositional range 0<X<1 between 1100 and 1350 K using a bielectrolyte solid-state galvanic cell, which may be represented as Pt, Fe + Fe _X Mg_1−X Al₂O₄+α-Al₂O₃//(Y₂O₃)ThO₂/(CaO)ZrO₂//Fe + FeAl₂O₄+α-Al₂O₃, Pt Activities of ferrous and magnesium aluminates exhibit small negative deviations from Raoult’s law. The excess free energy of mixing of the solid solution is a symmetric function of composition and is independent of temperature: ΔG ^E=−1990 X(1−X) J/mol. Theoretical analysis of cation distribution in spinel solid solution also suggests mild negative deviations from ideality. The lattice parameter varies linearly with composition in samples quenched from 1300 K. Phase relations in the FeO-MgO-Al₂O₃ system at 1300 K are deduced from the results of this study and auxiliary thermodynamic data from the literature. The calculation demonstrates the influence of intracrystalline ion exchange equilibrium between nonequivalent crystallographic sites in the spinel structure on intercrystalline ion exchange equilibrium between the monoxide and spinel solid solutions (tie-lines). The composition dependence of oxygen partial pressure at 1300 K is evaluated for three-phase equilibria involving the solid solutions Fe + Fe _X Mg_1−X Al₂O₄+α-Al₂O₃ and Fe + Fe _y Mg_1−Y O+Fe _X Mg_1−X Al₂O₄. Dependence of X, denoting the composition of the spinel solid solution, on parameter Y, characterizing the composition of the monoxide solid solution with rock salt structure, in phase fields involving the two solid solutions is elucidated. The tie-lines are slightly skewed toward the MgAl₂O₄ corner.     

湿法炼锑浸出液及电解液中硫化钠的测定

为测定湿法炼锑槽液中的硫化钠、对各种有关因素进行试验,在最佳条件下,对其总还原物及硫代硫酸钠进行分析测定,以减差法求得硫化钠的含量。     

磷钼黄分光光度法测定溶液中磷含量

以EDTA-2Na络合掩蔽钨及共存杂质,采用磷钼黄分光光度法测定仲钨酸铵工艺流程中溶液的磷含量,测定结果显示,方法的加标回收率在102.4%~109.6%之间,相对标准偏差为0.50%~2.22%,检出限为5.38μg/mL。该方法已用于仲钨酸铵生产工艺过程中磷的监控和检验。     

Research and Development Activities for the Recovery of Gold From Alkaline Cyanide Solutions

The use of autotrophic and heterotrophic microorganisms in the solublisation of gold from refractory sulphides and oxide ores is discussed. Basic microbiological characteristics of the leaching bacteria are outlined. Reaction mechanisms in the biooxidation of gold-bearing arscnopyrite and pyrite an: illustrated with special reference of Thiobacillus ferrooxidans. Biological and engineering factors influencing biooxidation for the liberation of gold are critically examined. Available reactor designs as welt as pilot-plant operations are brought out. The utility of heterotrophs in the direct leaching of gold is also evaluated. The role of biosorption in the recovery of precious metals from solutions and in environmental control is also examined. The potential of biomineral technology for processing gold-bearing ores and concentrates in the Indian context is highlighted.     

Mg3N2基复合脱硫工艺的实验研究

低成本铁水在线脱硫工艺研究是水城钢铁公司（简称水钢）当前应对钢铁工业发展低迷,提高企业运营质量,强化质量管控的重点攻关课题研究.通过对铁水复合脱硫工艺热力学计算,优化复合脱硫剂成分配比并创造适宜的脱硫动力学条件为研究基准,通过对复合脱硫工艺的实验室研究,达到提高铁水脱硫效率,优化高炉炉料结构,提高钢材质量,降低生产成本的目的.研究得出：CaO和CaO/CaF2对Mg基脱硫剂的优化配料及强化脱硫的动力学条件对Mg3 N2基脱硫剂脱硫深度和脱硫率有明显的提升,实验最佳脱硫率达到63.8％.Mg3N2基脱硫工艺在水钢的工业化利用对水钢的质量管控、降本增效方面具有可观效益.     

富镁软锰矿中镁的预脱除实验研究

河北省唐山迁西地区的软锰矿成分复杂,含有较高的镁含量,必须将镁去除才可进行后续利用。该实验采用在软锰矿浸锰流程之前,对于其中的镁进行预脱除。实验结果表明:在最优条件下,该方法的脱镁率可以达到78%以上。脱镁处理后的软锰矿浸锰实验结果表明:镁脱除后的软锰矿的Mn浸出率未受到影响,Mn/Mg大幅提高,而且浸出过程中的酸耗降为脱镁处理后的1/2,具有较好的工业推广价值。     

ICP-AES法测定稀土镁合金中钙镁锰钛

研究了用ICP-AES光谱仪测定稀土镁合金中钙、镁、锰、钛的方法,建立了最佳工作条件,测定了元素的检出限,测定下限,进行了干扰试验、准确度试验、回收率试验.试验证明,本方法简便、快速、准确,分析结果满意.     

高铁低硅低镁烧结矿试验研究

介绍了在宝钢不锈钢事业部目前的烧结生产原料和工艺条件下,调整烧结矿的二氧化硅含量,进行烧结杯试验.研究了不同氧化镁含量对烧结矿转鼓强度的影响.结果表明,单纯降低烧结矿中的二氧化硅含量,会造成烧结矿的转鼓强度明显下降;通过不同氧化镁含量与二氧化硅的匹配,烧结矿各项指标可得到优化,满足高炉生产要求.     

Activities of Phosphorus in Copper‐Iron Liquid Alloys Saturated with Copper‐Iron Solid Solutions

In order to determine the activities of phosphorus and iron in liquid {Cu‐Fe‐P} alloys, the two coexisting phases of liquid {Cu‐Fe‐P} alloys + <Cu‐Fe‐P> solid solutions were brought into equilibrium with a mixture of Al₂O₃ + AlPO₄ + Fe_xAl₂O₄ at temperatures of 1416K and 1526K. The oxygen partial pressures were measured with the aid of a solid‐oxide galvanic cell of the type: (+)Mo / Mo + MoO₂/ ZrO₂(MgO) / {Cu‐Fe‐P} + <Cu‐Fe‐P> + <Al₂O₃> + <AlPO₄> + <FeAl₂O₄> / Fe(‐) The equilibrium reactions underlying the experiments can be expressed by 2[P]_cu + (5/2) (O₂) + <Al₂O₃> = 2 <AlPO₄> and x[Fe]_Cu + (1/2) (O₂) + <Al₂O₃> = <Fe_xAl₂O₄> The Henrian activity coefficient referred to 1 wt pct solution in pure liquid copper could be well expressed by the formula log f_P° = (4.46±0.40) ‐ (8.67±0.59)/(T/K). The iron activities referred to pure solid iron could be formulated as log a_Fe =‐ (0.37 ± 0.12) + (500 ±200) /(T/K).     

钛铁矿钛铁连续测定试验研究

在测定方法基本原理不变的基础上提出使用钛一铁连测分析方法,可实现一次称样即可完成钛和铁的测定。在钛铁矿钛铁连测条件试验中,对选定的4个主要因素：硫-磷混酸用量、指示剂二苯胺磺酸钠浓度、溶液体积、滴定温度进行了正交试验研究,选定了最佳试验条件。在此条件下,以钛铁矿样品为基准进行3次实验,验证该实验条件的可行性,钛和铁的回收率在98．0％～102％区间内。应用钛铁连测方法测定结果与标准样对照,测定结果与标准样的结果接近。钛铁连测法测定结果与国标分别测定钛和铁的结果比较差异较小。     

Fabrication and Experimental Investigation on Deformation Behaviour of AlSi10Mg Foam-Filled Mild Steel Tubes

Aluminium (Al) alloy foam is an engineering material which has emerged in the automobile sector where crash energy absorption, vibration and sound damping and weight reduction are required. Al-alloy foam is a lightweight material providing high strength and stiffness at relatively low density. The paper aims to study the innovative approach of manufacturing AlSi10Mg foam. The low-density and high-strength Al-alloy foam (AlSi10Mg) is fabricated using the melt route process resulting in a density of 0.70–0.90 g/cm3. After that, square mild steel thin-walled empty tubes and Al-alloy foam-filled mild steel tubes are tested to study enhanced energy absorption characteristics. The tests are carried out on universal testing machine with strain rate 10/s. Al-alloy foam, AlSi10Mg, is assessed macroscopically and microscopically using field emission scanning electron microscope and energy-dispersive X-ray analysis. The experimental results indicate that foam-filled tubes feature more energy absorption than empty tubes at strain rate 10/s.