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41.
The flotation tests,zeta potential measurements,and Fourier transform infrared spectroscopy(FTIR) analysis on galena,sphalerite,and pyrite were studied in a collecting-depressing-reactivating(CDR) system.In this system,sulphide minerals were first collected and acti-vated by the collector,and then depressed strongly by Ca(OH)2 in a strong alkaline solution.Finally,they were reactivated by H2SO4.The flotation tests of pure minerals showed that in the Ca(OH)2 depressing process sulphide minerals had similar flotation characteristics because they had already been influenced by the collector.Hence,the flotability differences between them were reduced.However,in the H2SO4 re-activating process considerable differences in the flotability between galena and sphalerite/pyrite were produced.That is to say,galena was relatively easy to be reactivated by H2SO4,but sphalerite and pyrite were not reactivated at pH 11.The zeta potentials of sulfide minerals measured by the Zeta Plus presented irreversible characteristics on the change of pH values.The results of the FTIR spectra analysis indi-cated that the collectors already adsorbed on the mineral surface were removed partially by Ca(OH)2. 相似文献
42.
寇瑶 《重庆科技学院学报(社会科学版)》2010,(17)
在近代理性主义哲学精神盛行的时期,法国18世纪启蒙运动思想家卢梭开始以与同时代其他启蒙思想家截然不同的观点看待科学和文明.他对强化的"人类中心主义"进行强烈批判,对人与自然的关系进行了深入思考,其文明观对于我们今天建设生态文明社会具有重要的理论及实践意义. 相似文献
43.
Recently ,therehasbeenconsiderablein terestinlanthanide(Ⅲ )hexacyanoferratesandtheanalogouscobalt(Ⅲ )aswellaschromium(Ⅲ )complexesbecauseoftheirpotentialascatalytic ,semiconductive ,andmagneticmate rials[1~ 4] .Forexample ,magneticstudiesonaseriesofthree dimensio… 相似文献
44.
针对某钢铁企业厂内大宗料运输量大、车辆多、物流秩序急需规范的现状,经过论证,开发了物流车辆排队系统.应用该系统,实现了物流车辆进厂的规范秩序,达到了物流高效、低耗、清洁、低成本目标. 相似文献
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Iron was recovered from blast furnace dust and high-phosphorus oolitic hematite in the presence of Na2CO3 and CaCO3 additives. The functions of Na2CO3 and CaCO3 during the coreduction roasting process were investigated by XRD and SEM-EDS analyses. Results indicate that these additives not only hinder the reduction of fluorapatite, CaCO3 also decreases the P content of direct reduced iron (DRI) by increasing the reduction alkalinity. P remains as fluorapatite in the slag, which can be removed by grinding and magnetic separation under optimal conditions. The Na2CO3 promotes hematite reduction and improves the iron recovery (εFe) by replacing the FeO from fayalite, which results in quick growth and aggregation of metallic iron and improvement of εFe in DRI. A DRI with 91.88 mass% Fe, and 0.065 mass% P can be achieved at a recovery of 87.86 mass% under the optimal condition. 相似文献
48.
AbstractChina has experienced a surge in innovation output in which state-owned enterprises (SOE) play an essential role. Using panel data of Chinese listed firms, this paper examines the influence of state ownership on innovation output at the firm level. Controlling for size, we analyse the effects of central and local government control on the number of firms’ patent applications in different time periods. Doing so, standard assumptions on state ownership’s inhibiting character are confirmed. However, we then qualify these findings by running separate models for different regions and sectors finding that the impact of state-control on innovation performance depends on a number of conditions. More precisely, state control of firms has a negative impact on innovation output in particular in China’s Northeast region and in mid-tech sectors whereas under other circumstances it does either not matter or can even exert a positive influence. 相似文献
49.
G. Wang X. Tuo L. Kou W. Zhao X. Zhu 《Materialwissenschaft und Werkstofftechnik》2020,51(12):1686-1699
Salt spray corrosion test was carried out on 6061 aluminum alloy, and quasi-static tensile test at room temperature was carried out on the sample with universal testing machine. The effect of salt spray corrosion on the mechanical properties of 6061 aluminum alloy was studied by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and electrochemistry. The corrosion rate of 6061 aluminum alloy was quantitatively characterized by different corrosion parameters. It was found that local corrosion of 6061 aluminum alloy occurred in salt spray environment, mainly pitting corrosion and intergranular corrosion. With the increase of corrosion time, the polarization resistance of 6061 aluminum alloy decreases, and the corrosion rate significantly increases. The average corrosion rate and the maximum corrosion rate of 6061 aluminum alloy were characterized by corrosion weight loss and corrosion pit depth. And they can be transformed into each other. The mechanical properties of 6061 aluminum alloy were mainly affected by the depth of corrosion pit. With the increase of corrosion time, the tensile strength and fracture strain decreased, resulting in poor plasticity of the sample. At the same time, the change of elongation of 6061 aluminum alloy can be accurately predicted by the depth of corrosion pit. 相似文献
50.