共查询到19条相似文献,搜索用时 187 毫秒
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采用ZKB-1剪切破碎机和冲击破碎机将废旧计算机印刷电路板(PCB)和印刷线路板(PWC)进行了两段破碎,使用电子显微镜、磁选、筛分和浮沉试验等方法研究了不同粒度级破碎产物的组成,发现PCB和PWC破碎到1.2mm以下便可以解离;PCB的破碎产物有30%的解离的金属,而PWC的破碎产物中只有10%的解离金属;解离金属中有大量的铜,可以用物理方法回收;小于0.125mm的破碎产物中金属含量很少,可以直接作为非金属产品,研究重点是如何从1.2~0.125mm物料中用机械分选方法选出金属.树脂、玻璃纤维、塑料及其他非金属在破碎产物中占有70%~90%,这部分物料的处置和资源化也是今后值得研究的课题. 相似文献
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脉石英矿制备高纯石英砂工艺的试验研究 总被引:1,自引:0,他引:1
为了使天然脉石英达到高纯石英砂的标准,通过煅烧—水淬—浮选—酸洗—乙醇-去离子水洗等工艺提纯石英砂,采用光学显微镜、扫描电镜、X射线衍射、激光粒度仪、电感耦合等离子体光谱仪等手段分析石英砂试样的显微结构、形貌、物相、粒度和成分。结果表明,脉石英矿粗砂粒径分布较均匀,浮选精砂及高温煅烧精砂的粒径明显增大,比表面积明显减小;浮选后精砂的大颗粒为纯石英;筛分、高温处理对石英砂杂质元素去除不明显,浮选、酸浸去除杂质效果显著,脉石英矿经处理后的石英砂中SiO2的质量分数达到99.99%以上。 相似文献
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《中国粉体技术》2017,(4):77-81
针对目前粉煤灰综合利用问题,通过使用直径150 mm旋流器,对粉煤灰进行分级试验研究。通过控制变量的方法,改变旋流器的底流口直径、粉煤灰质量分数和进料压力等参数,得到粉煤灰在底流和溢流中的不同粒度分布,研究各变量对分级性能的影响规律。研究结果表明,随旋流器底流口直径增大,粉煤灰质量分数减小,进料压力增大,得到溢流中粉煤灰的质量分数减小,溢流中小于45μm颗粒质量分数增大,粉煤灰的分级效率相应提高。当底流口直径为18 mm,粉煤灰的质量分数为15.53%,进料压力为0.04 MPa时,溢流中分离粒度d50为43.9μm,质效率达到64.18%,量效率为88.09%,溢流中小于45μm粉煤灰质量分数达到90.58%,达到一级粉煤灰标准。 相似文献
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NiZnCo铁氧体包覆铁填充碳纳米管的吸波性能 总被引:1,自引:0,他引:1
利用溶胶凝胶法制备了Ni0.5 Zn0.45 Co0.05 FezO4/铁填充碳纳米管复合粉末,实现了Ni0.5Zn0.45 Co0.05Fe2O4纳米颗粒对碳管的包覆.并用同轴法测量了纳米复合粉末与石蜡混合物的电磁参数,其中纳米复合粉末的添加量分别为30%和60%,根据电磁参数计算了材料的反射率.结果表明纳米复合粉末的主要吸波频段在2~6GHz,当纳米复合粉末添加量为60%(质量分数),厚度为2mm时,微波吸收峰值出现在大约4GHz处,达到5.8dB.与纯Ni0.5Zn0.45 Co0.05Fe2O4纳米粉末相比有了比较明显的提高. 相似文献
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分级式冲击磨破碎废弃印刷电路板实验及功耗分析 总被引:1,自引:0,他引:1
《中国粉体技术》2016,(2):55-58
针对废弃印刷电路板具有硬度高、韧性强的特点,采用具有冲击、剪切作用的分级式冲击磨对粗碎后的废弃印刷电路板物料进行细碎实验研究,根据实验数据,利用Rittinger面积学说对破碎功耗进行分析。结果表明:使用分级式冲击磨能够实现对废弃印刷电路板的充分破碎,并且当破碎粒径小于0.6 mm时,金属与非金属能够完全解离;分级式冲击磨破碎废弃印刷电路板过程中粒度分布规律符合Rosin-Rammler粒度特性方程式;随着破碎粒径的减小,破碎比表面功耗增大,当平均粒径小于0.312 mm时,比表面功耗急剧增加。 相似文献
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H. Kursun 《Particulate Science and Technology》2014,32(3):251-256
The entrainment of particles in a flotation has been considered as one of the significant factors affecting both concentrate grade and recovery for a decades. It is based on the changes depending on the establishment of linear relationship between water recovery and solid recovery. In this study, entrainment of fine particle using a mixture of artificial ore (celestite:calcite; 1:1) was investigated in conventional and column flotation. The effects of frother concentration and particle size were tested. The results showed that the particle size and frother concentration had significant effect on the grade and recovery, flotation time, and fine gangue entrainment. Entrainment factors for the conventional and column flotation were compared. Kirjaveinen (1989) model was used for describing a specific entrained factor (P i ) of hydrophilic particles. It has been found that Kirjaveinen model supports the results of this study. 相似文献
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《Advanced Powder Technology》2022,33(11):103762
Particle size is an important parameter to determine the surface modification degree of sulfide minerals by plasma as well as the floatability of minerals. However, little studies have been reported to quantitatively relate surface oxidation and sample particle size to flotation performance. In this study, X-ray photoelectron spectroscopy (XPS) was used to characterize the surface species of arsenopyrite and pyrite at different plasma modification times. The critical oxidation degree was quantified as the proportion of hydrophilic oxidation species to hydrophobic species and correlated with flotation recovery. The results showed that the flotation recoveries of minerals with different particle sizes were determined by surface oxidation rate and critical oxidation degree. Fine particles were more likely to become hydrophilic under low-temperature plasma modification and yet the critical oxidation degree was also higher. The coarse particles being plasma modification presented a poor flotation recovery due to its low adsorption density of collector, although its oxidation degree was lower than the fine size fraction. The critical oxidation degree of pyrite was expected to be less than arsenopyrite, but its flotation recovery was higher under the same plasma medication time because of its slower oxidation rate. 相似文献
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The flotation behaviour of low grade, coarse composite particles for two porphyry copper ores was studied. Different grinding times were employed to obtain size distributions for the flotation feed (d80) ranging from 150 to 320 μm. Copper containing particles in the fine to intermediate size ranges were recovered in the rougher flotation stage. The rougher tailing was then screened through a 75 μm laboratory sieve. The +75 μm fraction was conditioned with a longer chain collector and floated in either normal viscosity (water) or high viscosity (glycerol–water mixture) medium. The recovery of copper was analysed on an un-sized and size-by-size basis. The recovery of coarse composite copper bearing particles was found to increase in high viscosity medium, even when the liberation of copper bearing minerals was only as low as 10%. The ability to recover these types of particles may result in a reduction in energy consumption in grinding due to the ability to achieve higher overall recovery of valuable mineral at coarse particle size distribution. 相似文献
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采用相反转悬浮液体系中不同表面活性剂同步修饰的方法制备超细低熔点金属颗粒,研究阳离子和阴离子表面活性剂对金属颗粒的影响。通过沉降实验观察不同表面活性剂修饰的金属颗粒在水中的分散及稳定性,并采用激光粒度仪、扫描电镜对低熔点金属颗粒的粒径和形貌进行表征分析。结果表明:表面活性剂的种类对制备低熔点金属颗粒有重要的影响,其中阴离子表面活性剂的效果最好。对几种阴离子表面活性剂的研究表明:油酸钠的作用最明显,其浓度大小对低熔点金属颗粒的粒径、形貌和分散效果有显著的作用。采用质量分数为1%的油酸钠水溶液可制备出分散稳定、粒径分布窄和球状的超细低熔点金属颗粒,平均粒径为0.343μm。 相似文献
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Md. Shahjahan Kaisar Alam Sarkar S.W. Donne G.M. Evans 《Advanced Powder Technology》2010,21(4):412-418
In this study the flotation recovery of silica using air, and molecular and electrolytically-generated hydrogen was investigated. For comparison of air and molecular hydrogen recoveries, a laboratory Denver, type D12, flotation machine was used. For both gases, pH of the suspension, gas flow rate, concentration of collector and frother, solids concentration, particle size and speed of impeller were kept constant. Almost identical recoveries were obtained for both gases, suggesting that gas composition played no significant role in silica flotation. Electroflotation experiments were carried out using 12.6 μm mean diameter silica particles. While fine particles had very poor recovery in the Denver cell, greater than 70% recoveries were achieved in the electroflotation cell. This was thought to be the result of the very small (less than 40 μm) bubbles generated by the electroflotation process. A population-balance model, incorporating the hydrogen generation process, supported the conclusion that increased recovery for electroflotation, for very fine silica particles at least, was attributed to the reduced bubble size and not by the composition of the gas. 相似文献
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This study investigates the effects of particle size, volume fraction, random dispersion and local concentration underneath a spherical indenter on the indentation response of particle reinforced metal matrix Al 1080/SiC composites. The ceramic particles in certain sizes and volume fractions were randomly distributed through the composite structure in order to achieve a similar structure to an actual microstructure as possible. The particle size and volume fraction affected considerably indentation depths and deformed indentation surface profiles. The indentation depth increases with increasing particle size, but decreases with increasing particle volume fraction. The experimental indentation depths were in agreement with numerical indentation depths in case the local particle concentration effect is considered. The local particle concentration plays an important role on the peak indentation depth. For small particle sizes and large volume fractions the random particle distribution affects the deformed surface profiles as well as the indentation depths. However, its effect is minor on residual stress and strain distributions rather than levels in the indentation region. 相似文献
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The objective of this study is to relate the flotation of coarse composite particles with their mineral composition. For this purpose, composites of quartz particles in lead borate matrix were fabricated in different size fractions. The quartz in the composite particles was selectively hydrophobised. The composite particles were floated and backscattered scanning electron microscopy was used to measure the number of particles in each flotation product, their size and liberation class. Results showed that the flotation of these composite particles decreased with increasing particle size, and decreasing the quartz (the hydrophobic phase) liberation class. Furthermore, it was also found that diesel oil addition improves the adhesion of composite particles with bubbles, and consequently enhances their flotation recovery. 相似文献
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某金矿石中的金属矿物主要有黄铁矿、毒砂等,金矿物以自然金的形式存在且颗粒细小,属于微细粒金,大部分被金属硫化矿包裹。试验采用浮选法富集金矿物,获得了金品位63.8g/t,金回收率92.08%的金精矿,并对金精矿进行了常温常压碱性氧化预处理,处理后的精矿金氰化浸出率达到88.56%,该金矿石选冶总回收率达到81.55%。 相似文献