热喷涂（焊）技术及其在冶金工业的应用

对热喷涂（焊）技术的原理、特点和发展趋势作了简单介绍，列举了国内冶金工业部门应用热喷涂技术修复和制造设备零件的典型实例。指出，目前在我国冶金工业资金能源均严重紧张的情况下，应继续大力推广热喷涂（焊）技术，兴废利旧，挖潜增效。     

热喷涂（焊）层结构性能分析

我厂采用喷雾法生产的PHNi60A及PHFe50B等自熔合金粉末,具有自熔性好、硬度高、耐磨、耐蚀的特点,已被广泛应用。对PHNi60A、PHFe50B等合金粉末及涂层,使用光学显微镜、电子显微镜、x射线衍射仪、电子探针,进行相结构分析及机械性能测定,并对分析结果进行讨论。     

热喷涂技术在循环流化床锅炉中的运用与质量控制

水冷壁管磨损是循环流化床锅炉受热面磨损中最突出的问题。采取炉膛内直接热喷涂的方法,在水冷壁管磨损区域喷涂金属耐磨涂层来提高耐磨性,是方便快捷和有效的方法。磨损状况检查、喷涂前管壁表面预处理、喷涂质量检查验收,是炉内热喷涂质量控制的关键环节。     

热喷涂技术在循环经济中的作用

综述了热喷涂技术在循环经济中的作用,重点介绍了热喷涂技术对推动我国汽车、电力、石油化工和钢铁冶金等领域的循环经济发展所发挥的重要作用。热喷涂作为零部件再制造的主要技术手段,符合"循环经济、可持续发展"的基本国策,具有广阔的市场和发展前景。     

热喷涂行业专利现状与企业专利运用

对热喷涂行业专利进行了初步分析,我国热喷涂行业专利申请量较少,申请质量不高,企业专利申请有较大的提升空间。专利具有多方面的价值,是市场竞争中的重要武器,如何充分运用专利取得竞争优势,是热喷涂企业需要面对的重要课题。     

Effect of rare earth elements addition on thermal fatigue behaviors of AZ91 magnesium alloy

Influences of rare earth (RE) elements addition on thermal fatigue behaviors of AZ91 alloy were studied. Repeated heating and cooling cycles were applied on the samples at 170 and 210 ℃ to develop thermal fatigue cracks. Crack growth mechanisms and microstruc-tural influences were investigated by optical and scanning electron microscopy (SEM) as well as energy dispersive X-ray spectroscopy (EDS). Thermal fatigue behaviors were observed to improve successively by addition of the RE up to 2wt.%. This improvement was attrib-uted to the consummation of aluminum in melt by precipitation of the needle shaped A11IRE3 phases. This process was attributed to the re-duction of Mg17Al12 phase volume fraction and consequent decrease of the brittle Mg/Mg17Al12 interface which was the main reason for weak thermal properties of the alloy at rather high temperatures. Further additions of RE, however, reduced the thermal shock resistance of the samples by increasing the mean length of the brittle needle shaped phases.     

Global rare earth resources and scenarios of future rare earth industry

It is known to all that China is abundant in rare earth resources.But rare earth deposits are really not that rare in the earth crust.In the five continents,i.e.Asia,Europe,Australia,North and South America,and Africa,there are about thirty four countries found to have rare earth deposits;Brazil might surpass China and rank the first in rare earth deposits.At present,investment in rare earth production was surged,there have been about 200 projects,and the total production for 25 of them would be more than 170 thousand tons after 2015,a multi-supply system on rare earths is being established worldwide.Cautions on the investment of rare earth production are involved.     

电感耦合等离子质谱法测定离子型稀土原矿中离子相稀土总量

采用电感耦合等离子质谱法(ICP-MS)直接测定离子型稀土原矿中离子相稀土总量,实验对浸取溶液、浸取溶液的浓度及用量、被测元素的同位素、样品酸度、内标元素、仪器的最佳工作参数进行了选择,建立了优化分析条件.单一元素标准加入的回收率为95%~105%,离子相稀土总量回收率为98.4%,相对标准偏差小于5%,测定范围为:0.010%~0.50%.方法准确可靠,操作简单,精密度和准确度都能满足分析要求.     

Effect of rare earth elements on the thermal cracking resistance of high speed steel rolls

The effect of rare earth elements on the thermal cracking resistance of high speed steel (HSS) rolls was investigated. Laser rapid heating was used for thermal fatigue experiments. Thermal cracks and microstructure were observed using metalloscopy and scanning electron microscopy. The results showed that thermal cracks initiated from the interface between the matrix and eutectic carbides (including M6C and M7C3 type carbides),and propagated along the interface between the two phases. MC type carbides enriched with vanadium could prevent the propagation of thermal cracks. The presence of rare earth elements decreased the quantity of big eutectic carbides,and proportionally increased spherical and rod-shaped MC type carbide content. HSS0 (0.00% RE) had approximately three times the thermal cracking density of HSS3 (0.12 wt.% RE). Rare earth elements were shown to significantly improve the microstructure and thermal cracking resistance of HSS rolls.     

电感耦合等离子体质谱法测定离子吸附型稀土矿中全相稀土总量

采用硝酸-氢氟酸-高氯酸混酸溶解试样,以电感耦合等离子体质谱法(ICP-MS)对试样溶解液进行测定,提出了以ICP-MS测定离子吸附型稀土矿中全相稀土总量的方法。对氢氟酸用量和测定液中硝酸的含量进行了考察,最终确定氢氟酸用量为5.0mL,测定液介质为体积分数为2%的硝酸。在优化的仪器条件下,15种单一稀土元素校准曲线的线性相关系数均大于0.9999,方法检出限为2.4μg/g。采用实验方法对稀土矿石国家标准物质GBW07158、GBW07160、GBW07161(用于标样制定的样品均采自江西省龙南离子吸附型稀土矿区)中的稀土总量进行测定,测定结果与认定值基本一致。将实验方法应用于稀土矿石国家标准物质GBW07159、GBW07160与离子吸附型稀土矿实际试样中稀土总量的测定,测得结果的相对标准偏差(RSD,n=11)为1.7%~3.1%。     

从废稀土荧光粉回收稀土

稀土荧光粉广泛应用于发光材料行业,并且用量每年都在不断增长,同时产生的废旧稀土荧光粉也越来越多.因此,从中回收稀土不仅有利于保护环境,而且有利于资源的充分利用.物理方法难以从废旧稀土荧光粉中分离得到高纯度单一稀土,化学方法则可以获得单一高纯稀土.而它的瓶颈在于浸出和分离的高效性及经济性.本文对废稀土荧光粉回收稀土技术的现状进行了分析,认为已具有从废旧稀土荧光粉中提取单一、高纯稀土的成套新技术.     

含稀土高岭土精矿回收离子相稀土工艺研究

高岭土精矿具有粒度细、黏度大、渗透性能差、固液分离难、含铝高等特点,南方高岭土常伴有稀土,怎样从精矿中提取合格的稀土,目前国内外还没有一套成熟的工艺技术应用于工业生产上。依据高岭土矿中的稀土赋存特点,通过实验室小试、扩试和工业试验,探索出了一套成熟的工艺技术流程,把浸矿液与高岭土精矿加入到捣浆池中进行搅拌浸取,将矿浆通过板框压滤机压滤,得到的滤饼即是提取稀土后的高岭土精矿,滤液经后续处理即得到稀土产品。同时建成了生产线,已生产稀土10余t,为回收高岭土精矿中的离子型稀土提供了有效工艺。     

风化壳淋积型稀土矿的基础研究

文章评述了40年来风化壳淋积型稀土矿的基础研究,包括矿床的成因及特征、稀土矿物的组成及性质,稀土与黏土矿物的关系、稀土在黏土矿物中的吸附及迁移理论,论述了风化壳淋积型稀土矿的稀土元素配分的特征及四大效应,并探讨了稀土浸出机理和风化壳淋积型稀土矿稀土浸取的三代工艺,提出了风化壳淋积型稀土矿基础研究和浸出工艺的发展方向及亟待解决的问题.      

EGTA滴定法测定稀土合金中稀土总量

通过对稀土中干扰元素的掩蔽 ,用EGTA对稀土总量进行快速测定     

ICP-AES法测定稀土(镁)硅铁中La和Ce

采用ICP AES法测定稀土(镁)硅铁中La和Ce含量,并对样品的溶解方法、基体及共存元素的影响、分析谱线进行了研究。方法简便、快速,精密度和准确度较好。