磨浮工艺流程的改进与指标提高

通过流程考察和分析,将原磨矿工艺增加一段闭路磨矿流程改为一段磨矿、分级机溢流进入旋流器分级再磨流程;浮选流程由原来的混选部分一粗一扫一精改为两粗,其中一粗直接产出混合精矿,三扫,一精,使金回收率提高4%,铜回收率提高3%,效益十分可观.     

磨浮工艺流程的改进与指标提高

通过流程考察和分析,将原磨矿工艺增加一段闭路磨矿流程改为一段磨矿、分级机溢流进入旋流器分级再磨流程;浮选流程由原来的混选部分一粗一扫一精改为两粗,其中一粗直接产出混合精矿,三扫,一精,使金回收率提高 4%,铜回收率提高 3%,效益十分可观。     

磨浮工艺流程的改进与指标提高

通过流程考察和分析，将原磨矿工艺增加一段闭路磨矿流程改为一段磨矿、分级机溢流进入旋流器分级再磨流程；浮选流程由原来的混选部分一粗一扫一精改为两粗，其中一粗直接产出混合精矿，三扫，一精，使金回收率提高4％，铜回收率提高3％，效益十分可观。     

青海某金矿选矿厂扩能改造实践

针对青海省某金矿选矿厂存在的部分工艺设备陈旧、设备能耗大以及处理能力低难以匹配采矿能力的问题,对选矿厂进行改扩建。其中,浮选工艺由一粗二精三扫改为二系列作业,流程改为一粗二精二扫,新增溢流型球磨机（MQY3660）作为一段磨矿设备,使用水力旋流器FX500替换原有的螺旋分级机,新增压滤机XMZGFS200/1250-U以满足金精矿压滤要求,新增部分渣浆泵、柱塞泵等辅助设备。改造后选矿厂处理量达到1 500 t/d,年增处理量16余万吨,选矿回收率提高1.54%,年增产金金属量330 kg,年新增利润1 000余万元。     

某低品位铜炉渣回收铜试验研究

某冶炼厂的铜渣含铜较低,生产采用二粗二精一扫工艺流程,产不出铜精矿品大于17%的出售指标,本文针对铜渣性质,在使用组合捕收剂的基础上,将二粗二精一扫的工艺流程改为一粗二精二扫的流程后,获得了铜品位17. 68%,回收率62. 04%的技术指标,实现了铜品位达标的目的。     

铜矿石粗磨优选工艺探索试验研究

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。     

难选赤铁矿浮选试验研究

研究了以FQ为捕收剂,采用正浮选流程浮选赤铁矿。考察了磨矿细度、药剂种类和用量对浮选指标的影响。闭路试验采用1粗4精2扫、中矿顺序返回流程,最终获得铁品位59.43%铁精矿,铁回收率72.74%。     

湖北某地铁矿石选矿试验研究

湖北某低品位贫铁矿原矿含铁18.56%(S0.42%,P0.16%),通过采用阶磨阶选磁选工艺流程,在一段磨矿细度-74mm69.4%、二段磨矿细度-43um84.4%条件下,通过"一粗一扫一精"磁选工艺流程,最终获得铁精矿品位62.41%,回收率69.27%的选矿指标(S0.13%,P0.082%,有害杂质含量均未超标)。     

云南某低品位高碳锑矿的浮选试验研究

云南某锑矿石中碳的含量为10.85%,属于高碳难选锑矿石。针对该低品位高碳锑矿进行了浮选试验研究,结果表明:在磨矿细度-0.074 mm占70%的条件下,以柴油为捕收剂、2号油为起泡剂,经一粗一精一扫闭路流程,进行了预选脱碳浮选试验,获得了碳精矿中锑的品位为2.02%,回收率为1.51%;对碳浮选尾矿中的锑进行选矿回收,以硝酸铅为活化剂、丁基黄药为捕收剂、2号油为起泡剂,经一粗两精两扫闭路流程,试验最终获得了锑品位为26.97%,回收率为85.28%的良好指标。     

湖南郴州某白钨矿选矿试验研究

湖南郴州某白钨矿WO_3品位为0.31%,因矿石中含钙脉石矿物较高、钨华含量较高,导致白钨选别困难。针对该矿石分别进行了磨矿细度、碳酸钠用量、氢氧化钠用量、水玻璃用量、捕收剂种类和用量、加温精选等浮选条件试验。试验结果表明,在最佳条件试验的基础上,采用"优先浮硫—白钨常温粗选—钨粗精矿加温搅拌-精选"的工艺流程。白钨矿常温粗选闭路试验采用一粗二精二扫的试验流程,获得WO_3品位为4.42%,WO_3作业回收率为84.85%的白钨粗精矿;对白钨粗精矿进行加温搅拌-精选闭路试验,精选闭路试验流程为一粗二精一扫,获得WO_3品位为61.25%,作业回收率为95.62%,综合回收率为80.05%的白钨精矿,实现了对该白钨的有效回收。     

细筛再磨工艺改造的实验研究与生产实践

为进一步提高铁精矿质量,降低杂质量,增加企业经济效益,采用MVS2020电磁振动网筛取代一段旋流器,解决旋流器分级反富集问题,实现选择性磨矿,提高最终磨矿产品粒度,实验结果表明,磨矿粒度比原流程有所提高,再磨铁精矿质量明显改善.     

改进钢锭断面形状提高厚板成材率的变形实验

简述了钢锭断面形状对厚板成材率的作用。着重阐述模拟舞阳钢铁公司４２００ｍｍ厚板轧机的轧制工艺条件，轧制８．０ｔ镇静钢扁锭，采用正交设计法确定钢锭断面最佳尺寸。得到了在确定轧制工艺条件下，正确确定最佳钢锭断面尺寸的正交回归数学模型。在本实验最佳断面形状的锭型与合适的工艺相匹配下，厚板成材率约提高５．２７６％，边部切损率约降低３．６３５％。     

The fine structure of a microplate-microtubule array, microfilaments and polyhedral body associated microtubules in several species of Anabaena

A microplate-microtubule array was observed in Anabaena sp. (B-378). This structure consists of an arched plate, about 8 nm thick, and various microtubules, 12 nm in diameter and 50 nm long, arranged in rows. The microtubules project at right angles from one side of the plate into the cytoplasm or towards the plasma membrane. Up to twelve microplate-microtubule arrays were observed in a single section of a cell. Microfilaments, about 2.8 nm in diameter and of undetermined length, were observed in four isolates of Anabaena. The microfilaments were always found in bundles, nwhich varied in size, up to 0.63 mum across and 0.91 mum long. Microtubules, 10 nm in diameter and about 150 nm in length, were observed associated with one facet of polyhedral bodies in 8 out of 20 isolates of Anabaena. The microtubules occurred in groups of up to 20 or more, and were always oriented with the long axis parallel to the facet of a polyhedral body. In cross section, the microtubules had an electron transparent lumen 5 nm wide and a wall 2.5 nm thick. These structures are compared to previously described microtubules and microfilaments.     

三价铬电沉积过程强化规律研究

铬镀层具有优异的机械和抗腐蚀性能，传统六价铬电镀存在高毒、高污染等问题，三价铬绿色电镀工艺受到普遍关注，但铬镀层不能持续增厚和镀液稳定性差是关键瓶颈.文中研究了脉冲电流和镀液流动对铬电沉积的影响规律，发现两者均可促进电镀过程中生成的副产物向镀液主体的传递.然而，脉冲电镀会降低铬电沉积效率，镀液流动可以提高铬电沉积效率，并能促进铬镀层的持续增厚.在50 mL/min的镀液流动条件下，直流电镀60 min，可获得41 μm的厚铬镀层，沉积速率为0.68 μm/min，镀层表面平整致密.      

中薄板坯连铸结晶器浸入式水口的优化设计

应用数值模拟软件对唐钢中薄板坯连铸结晶器及浸入式水口内的钢水流场、温度场进行数值模拟,分析了水口结构、拉速、浸入深度和铸坯断面对流场和温度场的影响,在此基础上确定了水口的最佳结构和浸入深度,并在生产中进行了验证,不但提高了铸坯质量和产量且稳定了连铸生产。     

某磷矿擦洗厂采用旋流器分选的技改实践

为解决某磷矿长期以来尾矿品位高、回收率和产率低的难题,对原设计的生产流程进行考察和取样分析,查找到流程存在的问题,为旋流器的结构参数和配置不合理,并进行了生产流程改造。将各段旋流器的结构参数进行优化后,使其分选效果大大提高,可将四段旋流器闭路流程改造为三段旋流器开路的分选流程,不但简化了生产流程,同时实现降低了尾矿品位,提高精矿回收率和产率的目标。     

The orofacial formalin test in rats: effects of different formalin concentrations

In this study of the orofacial formalin test in rats, the effects of different formalin concentrations (0.2%, 0.5%, 1.5%, 2.5%, 5% and 10%) on the behavioural nociceptive response (face rubbing) was investigated. The histological responses of the skin were also evaluated. Increasing the concentration of formalin caused a parallel aggravation of histological signs of tissue inflammation and injury. All concentrations provoked an early phase of nociceptive response, but its intensity was not concentration-dependent. The 2nd phase of response to formalin only occurred for concentrations of 1.5% and higher. A positive relationship between the formalin concentration and the amplitude of the rubbing activity measured between 12 and 45 min after injection could be observed until 2.5% but with the highest concentrations (5 and 10%), the amplitude of the response decreased. Our findings indicate that the orofacial formalin test should be carried out using concentration between 0.5 and 2.5%. This is essential to assess increase as well as decrease in pain intensity. Moreover, this will have the effect of minimizing the suffering of the experimental animal.     

Experimental Studies on Supersonic Cold Flow Mixing with Ramp Mixers

The mixing field in a supersonic cold flow past a set of compression–expansion ramps mounted at the downstream end of a strut, with staged injection at two tandem locations on the strut upstream of the ramps, has been experimentally investigated. Air and helium have been used to inject into a primary stream of air at an inlet Mach number of 2.0. Two test section geometries, one having a flow cross section twice that of the other, have been considered. The larger test section has wall struts as well as a middle strut, whereas the smaller one has the strut only in the middle. Terminal bulk pressure and wall static pressure measurements, and Schlieren visualization have been performed. The Mie scattering technique has been used to obtain the concentration contours of the injectant across the flow cross section at several axial locations downstream of the injection points. The results indicate better mixing with helium injection and less influence of the boundary layer along the test section walls with the larger test section, as expected.     

Isoflurane- and halothane-mediated dilation of distal bronchi in the rat depends on the epithelium

BACKGROUND: Respiratory epithelium releases substance(s) that can modulate bronchoconstriction in response to constrictive agonists and enhance bronchodilation in response to certain bronchodilators. The hypothesis that the bronchodilatory effect of isoflurane and halothane depends on the epithelium was tested in rat distal bronchial segments. METHODS: Wistar rat bronchial segments of the fourth order (diameter approximately 100 microns) were dissected. After preconstriction with 5-hydroxytryptamine, each bronchial segment was exposed to increasing concentrations of 0% to 3% isoflurane or 0% to 3% halothane under four conditions: after epithelial rubbing, after pretreatment with the nitric oxide synthase inhibitor NG-nitro-L-arginine, after pretreatment with the cyclooxygenase inhibitor indomethacin, or with no preintervention (control). Changes in bronchial diameter were monitored using an in vitro video detection system. RESULTS: Both isoflurane and halothane produced concentration-dependent bronchodilation (P < 0.001 for either anesthetic; 40% +/- 11% [mean +/- SD] dilation for 3% isoflurane and 57% +/- 10% dilation for 3% halothane). For both anesthetics, bronchodilation was significantly but incompletely attenuated by epithelial rubbing (12% +/- 7% dilation for 3% isoflurane [P < 0.01] and 31% +/- 10% dilation for 3% halothane [P < 0.01]), by pretreatment with indomethacin (20% +/- 8% dilation for 3% isoflurane [P < 0.02] and 21% +/- 9% dilation for 3% halothane [P < 0.001]), or by L-NNA (9% +/- 7% dilation for 3% isoflurane [P < 0.005] and 39% +/- 12% dilation for 3% halothane [P < 0.05]). Epithelial rubbing did not impair nitroprusside-associated bronchodilation. CONCLUSIONS: Isoflurane- and halothane-mediated bronchodilation depends at least partially on the epithelium and may involve both a prostanoid and nitric oxide in distal rat bronchi.