共查询到19条相似文献,搜索用时 453 毫秒
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用活性氧化钨制取中细W和WC工艺研究 总被引:3,自引:1,他引:2
利用活性氧化钨粉末细、表面能发达、活性高、相成分单一等特点,经过工艺试验和优化,生产出粒度分布较用蓝色氧化钨生产的中细钨、碳化钨粉末均匀,同时也减少了中细钨、碳化钨粉末中的粗大晶粒和聚集颗粒,从而提高了中细钨、碳化钨粉末的质量,并且利用此碳化钨粉末还可以生产出高质量的合金产品。 相似文献
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《稀有金属与硬质合金》2021,(3)
对高品质超细WC粉末制备过程APT煅烧、氧化钨还原、W粉碳化工序的质量控制研究进展进行综述。APT原料的质量与生产过程中工艺参数的控制是超细WC粉末制备的关键。单一性质的APT有利于控制煅烧产物的质量,优化煅烧工艺参数可避免"夹生"硬颗粒;氧化钨还原过程难以控制反应条件一致,多相反应同时发生时控制WO_2的生成和还原及W粉的长大是关键;碳化过程既要考虑WC颗粒成分的均匀性,也要考虑晶粒度的均匀性。 相似文献
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带式无舟皿连续还原炉制备粒度均匀的细颗粒钨粉 总被引:1,自引:1,他引:0
细晶粒、超细及纳米硬质合金的用途越来越广泛,制备粒度均匀的细钨粉是制备此类合金的关键.本试验研究以工业蓝色氧化钨和超细黄色氧化钨为原料,在带式无舟皿连续还原炉中用氢气还原制备钨粉.试验结果表明,采用带式无舟皿连续还原炉,以蓝色氧化钨为原料制备的细颗粒钨粉粒度均匀性明显优于四管炉生产的钨粉;以超细黄色氧化钨为原料可制备出粒度均匀、氧含量低、比表面在3.5 m2/g左右、粒度为90 nm左右的纳米钨粉;钨粉性能主要受还原温度、氢气流量、钢带传动速度及料层厚度等工艺参数的影响. 相似文献
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紫色氧化钨制取T艺的研究及其应用 总被引:1,自引:0,他引:1
对紫色氧化钨的制取工艺、原料APT对紫色氧化钨生产的影响等进行了研究.对紫色氧化钨产品进行了X射线衍射成分分析、扫描电镜外观形貌观察及透射电镜微观性能检测,并对用紫色氧化钨制取的细钨粉、细碳化钨粉的性能进行了研究.结果表明,紫钨制取工艺先进合理,由紫钨制得的钨粉、碳化钨粉细而均匀,分散性好,是制取高性能硬质合金的优质原料. 相似文献
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本文综述了近年来我国首先开发的从新型胺类钨酸盐制取纯组分蓝色氧化钨、超细钨粉及超细碳化钨粉的新方法。较详细地介绍了新型胺类钨酸盐的制备方法和特性,从新型胺类钨酸盐制取各种氧化钨、超细钨粉及超细碳化钨粉的工艺,在工业生产中的应用前景和有关的理论研究。 相似文献
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Microporosity Structure of Coarse Granular Soils 总被引:2,自引:0,他引:2
To date the microporosity structures of coarse soils with various coarse/fines contents are still not fully understood. In this study, the pore-size distributions (PSDs) of five types of soil varying from gravel to clay were characterized using mercury intrusion porosimetry. The soil with a coarse content below 70% (i.e., fines content above 30%) is found to have a fines-controlled microstructure, which is sensitive to water content changes. Such soil forms a dual-porosity structure due to compaction, in which both intraaggregate pores and interaggregate pores are dominant. After saturation, the dual-porosity structure evolves into a unimodal porosity structure dominated by the intraaggregate pores. During drying, such soil exhibits a significant reduction of total volume. The soil with a coarse content above 70% instead has a coarse-controlled microstructure, which is stable upon water content changes. Such soil maintains dual-porosity structures no matter if the soil is compacted, saturated, or dried. As an example of application, the measured PSDs are used to predict the soil water characteristic curves (SWCCs) for the test soils and the predictions are consistent with the SWCCs measured in the laboratory. 相似文献
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针对贵溪冶炼厂一车间铜阳极泥处理湿法亚硫酸钠分银工艺过程中出现的分银渣中杂质进入上清液、粗银粉品位低等情况,应用生产实践的方法对其粗银粉品位进行研究,研究结果表明:在增设分银液压滤机过滤系统和全自动离心机的分银工艺中,粗银粉品位含量在97%以上,其杂质大大降低,避免了银电解液的污染。 相似文献
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包钢粗苯催化加氢精制工艺的选择 总被引:1,自引:0,他引:1
文章对目前国内焦化行业粗苯加氢精制工艺进行了比较,并对美国Lyondell公司研制开发的以环丁砜为溶剂的低温加氢工艺(简称环丁砜法)进行了详细介绍,指出了这一工艺的先进性和创新性。 相似文献
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1 前言 钢材的组织结构决定了其性能,尤其是强度和韧性.晶粒越细,钢材的强度和韧性就越高.近年来,人们针对细化晶粒组织做了大量的研究,开发了铁素体粒径达1μm的晶粒细化技术,其中主要是形变热处理(TMCP)技术. 相似文献
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在铅锌密闭鼓风炉生产粗锌控制过程中,粗锌含铅合格率是标志生产出粗锌质量高低的一个重要质量指标,针对第三冶炼厂熔炼车间在粗锌生产过程中粗锌含铅超标的问题,研究了铅液温度与金属锌溶解度之间的关系,及生产操作实际的控制措施,分析了锌液中含铅超标的原因,在生产中采取有效的措施,使粗锌含铅得到了有效的控制,提高了粗锌含铅合格率,提升了产品质量。 相似文献
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某矽卡岩型铜矿原矿含铜0.98%,试验研究通过采用混合用药、延长浮选时间及中矿再磨等工艺优化措施,实现了一段粗磨选矿。在一段磨矿细度-74μm55.2%、中矿再磨细度-74μm81.3%条件下,经"二粗二扫一精"浮选流程,获得铜精矿品位20.37%(Au9.04g/t;Ag93.27 g/t),铜回收率94.40% (Au71.85%;Ag71.78%)的选矿技术指标。 相似文献
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Laboratory experiments were conducted with steady wind velocities to measure pressure drops in pipes used to ventilate passive dry barriers. Two vent pipe diameters (100 and 150 mm) and several pipe end geometries were tested. Nondimensional ventilator equations were developed using the pressure drop data that, when combined with Darcy’s law, can be used to estimate airflow rates in passive dry barriers. A field experiment was conducted to verify the laboratory results. Comparisons were also made between flow rates predicted using the airflow rate equations and flow rates measured in two field-scale tests of dry barriers, one of which was constructed by the writers. Results of the laboratory tests indicate that a unique ventilator equation exists for each pipe end geometry, and that more than one equation may exist if the pipe end is not symmetrical (i.e., the pressure drop depends on wind direction relative to the pipe end). The field experiment indicated that the equations developed based on the laboratory data are in general agreement with average field conditions, but more scatter exists in the field due to varying wind velocities. Good correspondence exists between predicted flow rates and those measured in the field scale tests of passive dry barriers. 相似文献