常压盐酸浸出红土镍矿的研究

为有效提取红土矿中镍钴资源,研究了常压盐酸浸出工艺提取红土矿中的镍钴。结果表明,矿料粒度为-0.15 mm,初始酸浓度8 mol/L,浸出温度353 K,固液比S/L=1:4,搅拌速度300 r/min,反应时间2 h,镍、钴、锰、铁、镁的浸出率分别达到93.94%、60.5%、94%、56%9、4%。     

地面火炬源在大气预测中的探讨

基于HJ2.2-2008《环境影响评价技术导则-大气环境》和火炬设计规范的有关规定,分析地面火炬源与常规污染面源环境影响评价的区别,研究火炬源各参数的确定与修正方法。以碳化硅生产为实例,对比不同预测模式的污染物浓度分布的差异,进一步探讨了地面火炬源大气环境影响评价技术方法存在的问题,并提出解决方案和建议,对做好大气环评工作有重要的意义。     

Melting of High-Nitrogen Austenitic Steels at Atmospheric Pressure

Metallurgist - The article considers conditions for nitrogen bubble formation at the crystallization front for iron and stainless steels. Using the results obtained during plasma-arc remelting, a...     

硫化镍精矿常压浸出研究

本文研究了温度、通氧速率、pH值、硫酸浓度等条件对硫化镍精矿常压浸出的影响,发现在80℃→85℃之间,镍浸出率随温度的升高而迅速增加,通氧条件下,镍浸出率差值的变化与通氧速率存在数学关系:y=8.271x0.3003,pH值为2.1~2.2时,镍浸出率最高,且镍浸出率随硫酸用量和铜离子的增加而升高。     

钴冰镍常压浸出工艺研究

以镍转炉渣还原硫化熔炼得到的钴冰镍为原料,在常压下于硫酸体系中进行浸出,考察了硫酸浓度、液固比、浸出时间及浸出温度对钴冰镍中有价成分浸出率的影响。结果表明,液固比和硫酸浓度对钴、镍、铁的浸出率影响较大。当硫酸浓度为1.6mol/L、液固比5、浸出时间2.5h、浸出温度85℃时,铁浸出率达到69%,镍、钴浸出率分别控制在1%和5%以内,取得了很好的选择性浸出效果。     

内送粉等离子喷涂枪的研究与应用现状

内送粉等离子喷涂枪将难熔粉末送入喷枪内部的高温区,增强了粉末的熔化效果,可制备出高质量的涂层,同时获得较高的粉末沉积效率。本文总结了等离子喷涂枪内、外送粉方式的特点,综述了国内外典型内送粉等离子喷涂枪的研究与应用现状。     

常压酸浸法从硅镍矿中提取镍的研究

中国南方某硅镍矿矿石矿物组成复杂,多种矿物(包括脉石矿物)含镍,且粒度很细,不能用机械选矿方法予以富集,只能采用化学选矿或冶炼富集的方法来提取镍.本研究采用常压酸浸法对该硅镍矿进行了浸出试验研究,原矿在磨矿细度-0.074mm占78.60%、液固比6:1、硫酸浓度2.60mol·L-1、搅拌强度170 r·min-1、60℃条件下浸出6 h,浸出贵液中镍的浸出率为86%左右,浸渣中含镍0.12%左右,取得了较好的浸出指标,浸出液经3次浸取后,Ni2+离子浓度已达到沉镍要求.     

赤泥中镓铝在常压酸法浸出过程中的行为

采用盐酸为浸取剂,研究了常压下赤泥中镓和铝的浸出行为,考察盐酸添加量、温度、时间及液固比对镓、铝浸出行为的影响。结果表明,在盐酸添加系数1.2、浸出温度55℃、浸出时间4h、液固比8(mL/g)的条件下,镓浸出率高达94.77%,铝浸出率88.44%,浸出液含Ga2O33.68mg/L、Al2O322.73g/L。在该试验条件下,镓与铝的浸出效率成明显的正相关性。     

钒钛铁精矿常压盐酸浸出分离铁钛试验研究

在常压条件下,采用盐酸浸出法对钒钛铁精矿进行选择性浸出试验,研究了液固比、浸出温度、浸出时间和盐酸浓度对铁和二氧化钛浸出率的影响,并对浸出渣结构、形貌、粒度及元素分布进行了研究。结果表明,盐酸浸出过程破坏了钒钛铁精矿中的磁铁矿物相,浸出渣表面出现了较为明显的粉化现象,铁元素进入浸出液;而钛铁矿未被破坏,仍以钛铁矿的形式存在酸浸渣中。最优浸出条件为:液固比为9∶1,浸出时间为60 min,盐酸浓度为18.6%,浸出温度为85℃。最优条件下铁的浸出率为85.41%,二氧化钛的浸出率为7.22%;酸浸渣的产率为27%,Ti O2品位约为34%。     

考虑间隙时万向联接轴的受力研究

在冶金机械传动中,普遍采用滑块式的万向接轴。它具有构造简单、拆装容易、传动力矩大、允许倾角８°～１０°等优点。但是由于润滑条件不良、月牙形滑块磨损较快、配合间隙增大,引起冲击,因而又恶化了机械的工作条件。本文主要探讨存在间隙时万向接轴的压力分布及其计算方法     

锌的常压富氧直浸工艺及钙镁结晶特征研究

介绍了锌的常压富氧直接浸出新工艺及工艺中存在的主要问题。针对湖南株冶直浸系统中钙、镁结晶严重的问题,研究了结晶物的物相及温度对砷盐净化后溶液中钙离子、镁离子和锌离子质量浓度的影响。结果表明,直浸系统中,除镉一级溢流槽、除镉二级溢流槽和新液储罐中的结晶物主要成分为二水硫酸钙(CaSO4·2H2O);净化后冷却塔中的结晶物除含有二水硫酸钙(CaSO4·2H2O)外,也含有碱式硫酸锌[ZnSO4·3Zn(OH)3·3H2O]和七水硫酸镁(7MgSO4·7H2O);降温对净化后溶液中锌离子和镁离子质量浓度影响不明显,对钙离子浓度影响显著;温度降到42℃以下时,钙离子质量浓度从580mg/L降到460mg/L,钙析出量达0.12kg/m3。     

The Oxidation of Sulphur Dioxide and the Formation of Sulphuric Acid in Situ at Atmospheric Pressure in the Leaching of a Uranium Ore

Abstract

The oxidation of SO₂ to form H₂SO₄ in situ, at atmospheric pressure and temperatures from 25 to 80°C, was examined by passing a mixture of SO₂ dioxide and air for 7 hrs through a reaction vessel containing quartz- or uranium-bearing solids moistened with H₂O to 85% solids. At the end of the contact period the solution was analyzed for free acid and other constituents of SO₂ and extraction of Uranium.

In tests with quartz at 80°C, the addition of Fe₂(SO₄)₃ or Fe₂O₃ increased the amount of SO₂ converted to H₂SO₄. E.g. without Fe₂(SO₄)₃ added the conversion obtained was 2% with 0.7 and 2.3 1b/ton quartz of Fe₂(SO₄)₃ the conversions were 18 and 24% respectively.

Tests were conducted on a mixture of flotation tailings, and a residue, which contained 24.3 per cent Fe⁺⁺⁺ as oxide, derived from the roasting of a sulphide concentrate at 500°C. The tailings and sulphide concentrate were obtained from the flotation of a uranium ore containing brannerite and about 9 per cent pyrite Roasting of the sulphide concentrate yielded "160 to 180 lb per ton of ore of sulphur dioxide of which 80,to, 100 lb was introduced into the conversion system over a 7-hour period. At 80°C, 40 per cent of the sulphuric dioxide introduced was converted to sulphuric acid which dissolved 93 per cent of the uranium in the mixturet of solids.     

Coupling Experiment and Simulation in Electromagnetic Forming Using Photon Doppler Velocimetry

Modeling electromagnetic forming processes is in many ways simpler than modeling traditional metal forming processes. In electromagnetic forming the problem is often dominated by inertial acceleration by a magnetic field. This problem is better posed than the more common ones in metal forming that are often dominated by complex three‐dimensional constitutive behavior and frictional effects. However, important aspects of the problem are dominated by the constitutive properties of the material, and often electromagnetic forming is performed in a regime where there is little reliable material strength data. Strain rates are often high (10² to 10⁴ s^?1 is the typical range for electromagnetic forming). Also, heat is generated both by Joule heating as well as by plastic deformation, and peak temperatures can be quite high. Also, while high‐temperature, high‐strain‐rate data is scarce, there is very little data in cases where temperature rises significantly over very short time periods (tens of micro‐seconds) as in electromagnetic metal forming. This rapid temperature rise is very important to the material response because the short time scales largely preclude the material from recovery and recrystallization processes, and precipitates cannot dissolve as they normally would in an age‐hardening alloy in these time scales. This paper will show how advanced instrumentation, particularly the Photon Doppler Velocimeter (PDV) can be coupled with electromagnetic forming and provide both avenues to characterize the high strain rate strength of the material as well as to provide clear experimentally measured data that can be used to compare experiments with numerical models.     

简述常压热水锅炉优点及应用

常压热水锅炉因有诸多优点,具有广阔的发展前景。因此,对常压热水锅炉技术进行研究不仅是必要的,而且具有重要意义。     

黑铜泥常压浸出工艺的优化

黑铜泥是铜冶炼系统电解液净化脱杂时的产物。通过对黑铜泥常压氧化浸出工艺进行优化,在反应酸度为130～140g/L、反应温度为80～90℃、初始砷浓度为45～50g/L、液固比为11～12时,可显著改善黑铜泥浸出效果。黑铜泥中铜浸出率可达到98%,渣率在6.9%左右,浸出效果较好。     

高、低喷涂功率下内送粉等离子喷涂YSZ粒子熔化状态研究

等离子喷枪采用内送粉方式后,喷涂功率对YSZ热障涂层微观结构和性能有着独特的作用,高功率下制备的涂层结合强度反而较低。本文研究了内送粉等离子喷枪在高功率(42.5 kW)和低功率(33.6 kW)时距喷嘴出口90 mm处的粒子熔化状态(粒子温度、粒子飞行速度、粒度分布及扁平粒子形貌)。研究结果表明,采用高喷涂功率时,由于等离子射流较高的热焓值使粒子迅速熔化并细化成粒径较小的熔滴,熔滴在撞击基体前发生再凝固降低了扁平粒子间的粘结。涂层出现横向裂纹,结合强度平均值仅为22.58 MPa。采用小喷涂功率时,既能保证粒子熔化良好又不会导致粒子发生明显细化。涂层结合强度平均值为37.25 MPa,随试片弯曲180(°)后仅出现一处剥落,1100℃炉中保温10 min取出后迅速置于水中淬冷130次后,试片中部涂层完好,显示出良好的抗热震性能。     

声发射在油田常压储罐检测中的应用

介绍了声发射检测技术的基本原理和特点,针对油田在用常压储罐检验存在的问题,应用德国VALLEN AMSY-5声发射仪对油田在用的常压储罐罐底进行了检测,对现场检验情况和实测数据进行分析,根据现场检验存在的问题,提出了常压储罐声发射检测研究的下一步工作打算.     

高效洁净常压下碳脱氧技术研究与实践

介绍了常压下碳脱氧技术的机理和在炼钢生产中的实践.该技术利用LF电弧的高温、碳素脱氧剂和渣料中的白灰造电石渣,对沸腾钢的钢渣和钢水脱氧,具有LF升温效率高、处理后的钢水洁净度高的特点.鞍钢股份有限公司炼钢总厂采用该技术生产低碳铝镇静钢,不考虑钢水质量提升带来的效益,仅降低合金成本创效可达10～20元/t钢.该技术也可用于大多数高、中、低碳钢的生产.     

Effect of Electromagnetic Frequency on Magnetic Flux Coupling by Traveling Magnetic Field

The effect of frequency on magnetic flux coupling field were analyzed with traveling-wave electromagnetic stirring system using a coupled model of magnetic induction and fluid dynamics.Simulations were performed to investigate the influences of the frequency on magnetic flux density,electromagnetic body force and flow field.The results showed that the magnetic flux density decreased with increasing frequency.The electromagnetic body force wavy moved along the same direction and increased with increasing the frequency when the traveling magnetic field is applied.The core area of the stirring was in the bottom of the alloy melt.A large circulation in the vertical section of the alloy melt can be produced by the electromagnetic body and the maximum flow rate first increased and then decreased with increasing frequency.     

CaO对铝酸钠溶液常压脱硅影响研究

利用XRD和SEM-EDS等检测手段系统分析了铝酸钠溶液常压脱硅过程中脱硅产物的生成量、物相组成和微观形貌,研究CaO在脱硅过程中的反应行为。研究结果表明,随着钙硅比和脱硅时间的增加,脱硅产物的生成量逐渐增加,脱硅产物主要包括六水合铝酸钙、水化石榴石、沸石和A型沸石四种物相;钙硅比和脱硅时间的增加,有利于脱硅产物六水铝酸三钙向水化石榴石转化,同时脱硅产物的晶格常数和晶胞体积不断增加;不同类型脱硅产物微观形貌差异较大,脱硅产物物相析出次序依次为六水铝酸三钙、水化石榴石、A型沸石、沸石。