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1.
以氯化钴溶液为原料,以碳酸氢铵为沉淀剂,用液相法制备前驱体碳酸钴,考察碳酸钴合成过程中氯化钴溶液浓度、反应温度、加料速度、络合剂加入量及酸碱度等因素对碳酸钴松装密度和中粒径的影响,考察煅烧温度、氢还原温度、还原时间对钴粉松装密度、粒度和氧含量的影响。当反应终点pH值为6.87.0,n(NH_3):n(Co)为(1.47.0,n(NH_3):n(Co)为(1.41.5):1,反应时间为1201.5):1,反应时间为120150 min时合成理想的碳酸钴晶体,碳酸钴微观形貌为球形或类球形,D_(50)≤5.0μm,前驱体经洗涤、过滤、烘干,在600150 min时合成理想的碳酸钴晶体,碳酸钴微观形貌为球形或类球形,D_(50)≤5.0μm,前驱体经洗涤、过滤、烘干,在600700℃煅烧成氧化钴,用氢气在470700℃煅烧成氧化钴,用氢气在470500℃将氧化钴还原4500℃将氧化钴还原46 h后制备成钴粉,钴粉费氏粒度小于1.0μm,松装密度大干0.8g/cm6 h后制备成钴粉,钴粉费氏粒度小于1.0μm,松装密度大干0.8g/cm3,氧含量小于0.5%,微观形貌为球形或类球形。  相似文献   

2.
本文以氯化钴溶液为原料,以碳酸氢铵为沉淀剂,用液相法制备前驱体碳酸钴,着重考查了碳酸钴合成过程中氯化钴溶液浓度、反应温度、加料速度、络合剂加入量及酸碱度等因素对碳酸钴的成核、生长的影响,煅烧温度、氢还原温度、还原时间对钴粉松比、粒度、氧含量等性能的影响。通过以上条件的优化选择,当反应终点pH值为6.8-7.0,NH3:Co(摩尔比)为(1.4-1.5):1,反应时间为120-150min时合成理想的碳酸钴晶体,碳酸钴微观形貌为球形或类球形,粒度(D50)≤5.0μm,前驱体经洗涤、过滤、烘干、在600-700℃煅烧成氧化钴,用氢气在470-500℃将氧化钴还原4-6h后制备成钴粉,钴粉Fsss粒度小于1.0μm,松装比重大于0.8g/cm3,氧含量小于0.5%,微观形貌为球形或类球形。  相似文献   

3.
乙二醇还原生产硬质合金用钴粉   总被引:7,自引:0,他引:7  
以自制Co(OH) 2 为原料 ,乙二醇为溶剂和还原剂 ,制得了分散性很好的球形超细钴粉。研究了单位体积乙二醇中Co(OH ) 2加入量对钴粉的粒径和形貌的影响。用SEM、XRD、BET和激光粒度分析仪测试粉体的粒子形貌、晶体结构、比表面积和粒度分布。测试结果表明多元醇还原的钴粉为球形 ,晶体结构以面心立方为主 ,还有微量的简单六方 ;当Co(OH) 2 加入量为 6 0g/L时制得的钴粉粒度分布较窄 ,平均粒径为 0 .88μm ,比表面积为 3.46m2 /g ,钴含量 >99.5 %。  相似文献   

4.
以AlCl3和Al(NO3)3为原料,尿素为沉淀剂,草酸铵为添加剂,采用均匀沉淀法制备出超细球形Al(OH)3颗粒.通过SEM和粒度分布手段表征了产品的形貌和大小特征.结果表明,所制备的Al(OH)3颗粒呈球状且分布较均匀,平均粒径为0.85μm.同时对球形颗粒形成的机理进行了初步分析.该制备工艺简单,易实现工业化生产.  相似文献   

5.
熔盐电解制备细颗粒钛粉研究   总被引:1,自引:0,他引:1  
在氯化物熔融盐中电解海绵钛制取细颗粒钛粉,研究了可溶钛浓度、阴极电流密度以及加料方式等因素对阴极产品颗粒形貌及粒度的影响,制备了平均粒度约为60~70μm的细颗粒钛粉。实验结果表明,电解初期形成块状结晶,电解后期为树枝状;可溶钛浓度对钛粉粒度影响显著;采用气相加料容易使钛在熔盐表层形成鳞片状结构。  相似文献   

6.
在煤层气开采过程中,煤粉堵塞筛管问题严重影响煤层气井的连续稳定排采。针对煤粉堵塞筛管问题,提出了采用超声波技术对筛管进行解堵的方法,开展了超声波技术对不同粒度和不同成分的煤粉堵塞筛管的解堵实验,探讨了超声波技术对筛管的解堵效果和影响因素。结果表明:随着煤粉粒度(<63μm、63~125μm、>125~300μm)的增大,煤粉的比表面积减小,煤粉所受附着力减小,超声波技术对筛管的解堵效果增强;高岭土能改善煤粉的亲水性,随着煤粉中所含高岭土比例的增加,煤粉颗粒间的疏水引力减小,煤粉所受附着力减小,超声波技术对筛管的解堵效果增强;超声波技术解堵作用时间在0~30 min内,随超声波作用时间的增长,超声波解堵效率降低;在0~10 min内解堵效果最明显,建议超声波解堵时,作用时间大于10 min。  相似文献   

7.
本文采用液相沉淀法制备了坡缕石-CaCO3(PG-nanoCaCO3)纳米复合粉体,用X-射线衍射(XRD)法和透射电子显微镜(TEM)对其物相组成和微观形貌进行了表征,以热重分析法对其热稳定性进行了分析,并对其相对白度进行了测试,结果证明:所制备的坡缕石-CaCO3纳米复合粉体的微观形貌为菊状单分散结构,平均粒度为2μm左右,相对白度达到95.83,热稳定性比纯坡缕石有极其显著的提高。  相似文献   

8.
以不规则形态TC4钛合金粉末为原料,采用感应等离子球化技术制备出3D打印选区激光熔化工艺(SLM)用细粒径球形钛合金粉,通过扫描电子显微镜(SEM)、激光粒度分析仪对粉末形貌、粒度进行表征分析。结果表明:原料粒度、送粉速率以及等离子功率等对球化后钛合金粉末颗粒的球化率及表面状态有重要影响,在其他工艺参数不变的前提下,送粉速率过小、等离子功率过大,球形钛合金粉末表面状态欠佳;送粉速率过大、等离子功率过小,球形钛合金粉末球形率欠佳。根据影响规律,选定最优工艺参数,等离子功率14kW,对制备的球形钛合金粉基本性能进行表征,其中球形钛合金粉粒径主要分布在20~50μm,占比达95.62%,Fe、O等总杂质含量为0.51%,松装密度、振实密度、流动性分别为2.40g/cm3、2.68g/cm3、38s/50g,产品性能达到SLM工艺要求。  相似文献   

9.
以AlCl3和Al(NO3)3-为原料,尿素为沉淀剂,草酸铵为添加剂,采用均匀沉淀法制备出超细球形Al(OH)3颗粒.通过SEM和粒度分布手段表征了产品的形貌和大小特征.结果表明.所制备的Al(OH)。颗粒呈球状且分布较均匀,平均粒径为0.85μm.同时对球形颗粒形成的机理进行了初步分析.该制备工艺简单,易实现工业化生产.  相似文献   

10.
MLCC电极用超细铜粉的制备及其形貌研究   总被引:2,自引:0,他引:2       下载免费PDF全文
以CuSO4为原料,对用NaOH沉淀-葡萄糖预还原-水合肼还原工艺制备的超细铜粉进行了研究.结果表明:葡萄糖预还原和分步添加水合肼均有利于超细铜粒子的均匀生长,加入适量的PVP有助于超细铜粉颗粒均匀和球形度更高.用该工艺可制得粒度均匀且可控、分散性好的MLCC电极用球形超细铜粉.  相似文献   

11.
正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium  相似文献   

12.
<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy  相似文献   

13.
正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared  相似文献   

14.
<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth  相似文献   

15.
正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products  相似文献   

16.
文奇 《中州煤炭》2018,(6):175-178
高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。  相似文献   

17.
<正>Developing ecological lighting source The world is facing the big problem of energy shortage today and the contradiction between economy development and environmental protection is worsened.Therefore,people are more likely to choose an ecological light source that is more energy efficient and environmental friendly.The choice provides great opportunity for the development of rare earth optical material industry in China.The concept of green lighting positions rare earth luminescent material as a leading player in illumination market.The light source of both rare earth luminescent lamp and LED lamp is ecological and energy saving.This is why  相似文献   

18.
正Galaxy Magnet announced its financial results for the first half of 2014 on August 14.For the first six months ended on 30 June 2014,Galaxy Magnet achieved operation income of RMB 182.3 million,up8.40% over the same period of 2013,and the net profit attributable to the shareholders of the listed company of 34.02 million yuan,increasing 35.49% over the same period of last year.Stable performance increase was led by development of new customers and application market of magnets.  相似文献   

19.
<正>China has rich rare earth resources.Output of rare earth and steel in China ranks the top first in the world.However,there is still certain distance between the steel produced in China and developed countries from the point of varieties and quality.China still has to import some types of steel.Improving the quality should be emphasiZed in future development of steel industry in China.Rare earth can be used to upgrade traditional steel  相似文献   

20.
正November 21~30,2014Due to weak demand from downstream industries,transactions of rare earth in Chinese domestic market were inactive.It was difficult to sell any rare earth products except for dysprosium oxide and terbium oxide.Suppliers lost confidence in recent market.Demand for rare earth products was soft.Consumers continued to take a wait-and-see attitude.Rare earth export market remained slow.  相似文献   

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