圆锥破碎机矿仓漏斗衬板的改进

德兴铜矿泗洲选矿厂二期碎矿工段圆锥矿仓漏斗衬板磨损过快,漏斗衬板更换频繁。为解决衬板磨损过快问题,对衬板使用要求、工况及耐磨特点进行了详细地分析,结合各种影响因素对衬板材质进行了更换,并对衬板结构形式进行了改进,改善了衬板的耐磨性。改进后的衬板使用寿命大大提高,也节约了大量的生产成本。     

鞍钢齐大山选矿厂衬板的质量分析及改进方案

鞍钢齐大山选矿厂衬板的质量分析及改进方案曹天顺（鞍钢职工工学院）１衬板使用情况的调查衬板主要有球磨衬板、磁选的托磁器等，种类有三角铁衬板、算铁衬板及长铁衬板等三类。选矿是鞍钢生产的主要环节，对衬板的需求量很大。衬板的质量问题主要是使用寿命短，消耗量大...     

球磨机筒体与衬板连接方法的改进

许多选矿厂是用螺栓连接球磨机筒体和衬板的。这种连接方法,在螺栓头磨损完了,衬板就会掉下来,需要更换新衬板。我厂的φ1200×1200毫米球磨机使用平滑式衬板(6厘米)。衬板与筒体是用螺栓连接,当衬板磨损约4厘米时,螺栓头便磨损掉了,因此需要更换新衬板。今年三月,我们将螺栓连接改用揷销连接(见图),即在衬板翻砂时,铸成两个有孔的小圆柱。在     

新华钼业更换球磨磁性衬板

日前,新华钼业选矿厂顺利将二系列Φ2.7 mm×3.6mm溢流型球磨机的锰钢衬板更换为磁性衬板。新华钼业由于设备长期运转,衬板螺栓几乎被锈蚀,只能用乙炔气进行切割,然后用撬棍、钎子、大锤等工具、耗时2天将衬板一块块卸下来。拆除的衬板除端盖衬板     

磨矿机筒体衬板的开发与应用

论述合金钢和铸铁衬板、橡胶衬板、金属磁性衬板和角螺旋衬板的研制现状、结构原理及应用效果。     

浅谈球磨机磁性衬板的研究及应用

磁性衬板是一种新型的球磨机衬板,应用于含磁性矿的矿石磨矿时,由于在衬板工作面能吸附一层磁性物质,可形成保护膜,减少衬板工作面与运动的介质和物料直接接触,从而可达到延长衬板寿命的目的。本文主要就磁性衬板的研究概况、特性及应用情况进行了阐述。     

1580 SP轧机衬板受力分析及对策研究

为了分析SP轧机衬板的受力状况, 建立了衬板受力的动力学模型.利用有限元软件Marc的非线性功能, 建立衬板与轮子接触的有限元模型,得到衬板上螺纹孔尺寸和最大应力的关系,提出了改善衬板受力的设计方案.现场实际应用表明,效果良好.     

TG-4036A型废钢压块机衬板国产化研制

本钢废钢厂从美国进口的TG-4036A型废钢压块机经多年运行，衬板磨损严重，急需进行国产化改造。辽宁科技学院承担了衬板、衬板螺钉的测绘和设计任务，并负责指导新衬板及衬板螺钉的制造与检验，节省了大量的资金和外汇，实现了TG-4036A型废钢压块机衬板及衬板螺钉的国产化。     

某金矿选矿厂球磨机衬板及分级设备优化改造

针对某金矿球磨机衬板使用寿命不统一、分级设备分级效果差异大等问题,对球磨机衬板及分级设备进行优化改造。将球磨机端盖衬板由合金钢衬板改为橡胶衬板,并对衬板参数、结构进行优化,使衬板总质量减少约2/3,并缩小了衬板使用寿命差异。在磨矿系统的分级设备水力旋流器上加装压力表,使水力旋流器的浓度差异控制在3%以内,细度差异控制在5%以内。同时,对比了水力旋流器损坏部件修复与购买新部件的成本,据相关数据统计,每年可节约部件投入成本40余万元。     

有效降低磨机衬板消耗途径的探讨

分析磨机衬板磨损的机理 ,从合理的粉磨工艺设计、磨机衬板的功能和结构设计 ,到磨机衬板材质的选择等方面 ,探讨了有效降低衬板消耗的途径 .     

进路分层干式充填采矿法在鹤庆锰矿的应用

介绍了在鹤庆锰矿急倾斜破碎富锰矿体中试验成功的充填采矿法,其特点是结合进路式和分层两种方法的优点,成功地回采了上盘断层已冒落的破碎富锰矿体;利用控顶高度控制采场的地压活动,圆满的完成了试验任务,取得了较好的技术经济指标。     

A review of the beneficiation of low-grade manganese ores by magnetic separation

ABSTRACT

Magnetic separation is an effective strategy for the upgrading of a variety of lean ores, including the beneficiation of low-grade manganese ores. This work reviews 24 studies on the magnetic separation of manganese ores; 6 of these studies report both a sufficiently high Mn grade (>44% Mn) and Mn/Fe ratio (>7.5) in the concentrate as to be suitable for use as high-grade feed materials in the production of ferromanganese. Of these 24 studies, the most efficient separation and enrichment was generally achieved by the reduction roasting of the ore prior to magnetic separation, rather than the direct separation of the ore. In both cases there was sufficient evidence for correlation, depending on the mineralogy, between the Mn and Fe grades of the ore and the final concentrate grade and Mn/Fe ratio. To yield a concentrate suitable for use in ferromanganese production, it is recommended that the ore contain a minimum initial concentration of ～25% Mn and ～10% Fe.     

Anticonvulsant-induced changes in tissue manganese, zinc, copper, and iron concentrations in Wistar rats

Human epileptics have been reported to have low blood manganese (Mn) concentrations in comparison to nonepileptics, an observation that is important because Mn deficiency can increase seizure susceptibility in experimental animals. Factors that have been suggested to contribute to the low blood Mn levels in epileptics include anticonvulsant use, seizure-induced tissue redistribution of Mn, and genetics; in the present study, the first of these possibilities was tested. Wistar rats were fed semipurified diets containing diphenylhydantoin ([DPH] 3 g/kg diet), phenobarbital ([PB] 2 g/kg diet), or primidone ([PRIM] 3 g/kg diet) for 7 weeks, at which time they were killed and tissues collected and analyzed for Mn, zinc (Zn), copper (Cu), and iron (Fe) concentrations. In comparison to pair-fed rats, DPH- and PRIM-fed rats had significantly elevated liver Mn concentrations, while Mn concentrations in blood, brain, heart, and kidney were unaffected by anticonvulsant exposure. Changes in the concentrations of Zn, Cu, and Fe in specific tissues were also found. Overall, these findings suggest that the anticonvulsants tested do not lead to significant derangements in the metabolism of Mn.     

遵义锰矿区锰资源综合评价

论述了该矿的成矿特性、基本特性 、对矿区资源进行了综合评价,并对资源的综合利用提出建议。     

X-ray absorption spectroscopy on layered photosystem II membrane particles suggests manganese-centered oxidation of the oxygen-evolving complex for the S0-S1, S1-S2, and S2-S3 transitions of the water oxidation cycle

By application of microsecond light flashes the oxygen-evolving complex (OEC) was driven through its functional cycle, the S-state cycle. The S-state population distribution obtained by the application of n flashes (n = 0. 6) was determined by analysis of EPR spectra; Mn K-edge X-ray absorption spectra were collected. Taking into consideration the likely statistical error in the data and the variability stemming from the use of three different approaches for the determination of edge positions, we obtained an upshift of the edge position by 0.8-1.5, 0.5-0.9, and 0.6-1.3 eV for the S0-S1, S1-S2, and S2-S3 transitions, respectively, and a downshift by 2.3-3.1 eV for the S3-S0 transition. These results are highly suggestive of Mn oxidation state changes for all four S-state transitions. In the S0-state spectrum, a clearly resolved shoulder in the X-ray spectrum around 6555 eV points toward the presence of Mn(II). We propose that photosynthetic oxygen evolution involves cycling of the photosystem II manganese complex through four distinct oxidation states of this tetranuclear complex: Mn(II)-Mn(III)-Mn(IV)2 in the S0-state, Mn(III)2-Mn(IV)2 in the S1-state, Mn(III)1-Mn(IV)3 in the S2-state, and Mn(IV)4 in the S3-state.     

Fat: can''t live with it, can''t live without it. Part I

Manganese (Mn) complexes are unstable and dissociate in vivo. Because of the release of this metal, there exists some concern about the potential long-term neurotoxicity associated with the use of Mn-based contrast agents. This latter problem arises because manganese is known to accumulate in specific regions of the brain of people intoxicated by this metal. It was previously demonstrated that Mn can accumulate in the mice brain after administration of 5 micromol/kg of MnCl2, Mn-diethylenetriaminepentaacetate (Mn-DTPA), or Mn-dipyridoxal diphosphate (Mn-DPDP). In order to better characterize the behavior of Mn complexes after administration, this study assesses the regional distribution of Mn in the brain after i.v. injection of a single dose of MnCl2 or Mn-DTPA. Male Wistar rats received an i.v. injection of 5 micromol/kg of 54Mn as MnCl2 or Mn-DTPA. The rats were killed at one and two weeks post exposure. The distribution of the radioactivity in the slices was monitored by autoradiography. For both MnCl2 or Mn-DTPA, we observed that the radioactivity was dispersed in the entire brain, but the radioactivity was higher in several regions. No difference was observed between MnCl2 or Mn-DTPA in the regional distribution of Mn, and no difference was observed between the two times of exposure (1 week or 2 weeks). The uptake of Mn was minimal in corpus callosum. Maximal Mn concentration was observed in the hippocampal region, thalamus, colliculi, amygdala, olfactory nuclei, and cerebellum.     

Optimum condition for smelting high carbon ferromanganese

Abstract

In the present study, pilot plant experimental heats were designed and carried out to determine the optimum condition for smelting high carbon ferromanganese through investigating some parameters affecting the smelting process including Mn/Fe ratio of the blend, coke ratio, slag basicity and dolomite/limestone ratio of the flux. The results of pilot plant experimental heats showed that using Mn blend with high Mn/Fe ratio decreases the consumption of charging materials: Mn ores, coke and fluxing materials (limestone and dolomite). This means that lower amounts of Mn ores, coke and flux materials can be used for attaining the same output alloy weight by increasing the Mn/Fe ratio of the blend. Furthermore, the produced slag decreases as Mn/Fe ratio of the blend increases. The higher Mn/Fe ratio of the blend does not only reduce the input materials and the produced slag, but also improves the produced alloy quality by increasing the Mn percent and Mn/Fe ratio of the produced high carbon ferromanganese. For obtaining standard HCFeMn alloy containing minimum 75%Mn, it is necessary to use Mn blend with the Mn/Fe ratio of higher than 6·2. The added coke must be adjusted according to the material balance and stoichiometric to prevent the over-coke and minimise the highly endothermic ‘Boudouard reaction’ to attain the highest Mn recovery and metallic yield. Furthermore, the slag basicity should be optimised with flux addition to attain the highest Mn recovery and metallic yield. The optimum slag basicity for attaining the highest manganese recovery and metallic yield depends on the used formula. The slag basicity can be determined from the chemical composition of raw material mixture with taking into consideration that about 2% of silicon in the raw material mixture will be reduced and goes into metal phase. Much higher slag basicity is not recommended as this practice produces viscous slag accompanied with lower Mn recovery and metallic yield. The results also revealed the negative effect of increasing MgO/CaO ratio of slag on manganese recovery and metallic yield. The MgO/CaO ratio in the slag decreases by decreasing the dolomite/limestone ratio in the flux.     

Precipitation Effect on Mechanical Properties and Phase Stability of High Manganese Steel

High manganese (Mn) steels are attractive for automotive applications due to their excellent tensile strength and superior elongation. However, the relatively low yield strength of Mn steels compared to other advanced high-strength steels is a critical problem limiting their use in structural parts. In order to increase the yield strength, the precipitation hardening effect of Mn steels was investigated by the addition of carbide-forming elements. Changes in the austenite phase stability were also evaluated in terms of stacking fault energy (SFE). As a result, fine V(C,N) precipitates were found to increase the yield strength effectively but to lower the SFE by the consumption of matrix carbons. For achieving precipitation hardening without sacrificing austenite stability, the soluble carbon content was discussed.     

Seizure outcome after epilepsy surgery in children and adolescents

Development of efficient imaging techniques to trace neuronal connections would be very useful. Manganese ion (Mn2+) is an excellent T1 contrast agent for magnetic resonance imaging (MRI). Four reports utilizing radioactive Mn2+ in fish and rat brain indicate that Mn2+ may be useful for tracing neuronal connections. Therefore, the purpose of this work was to determine if Mn2+ can be used as an in vivo MRI neuronal tract tracer. The results indicate that topical administration of MnCI2 solution to the naris of mice as well as to the retinal ganglion cells via intravitreal injection leads to enhancement of contrast along the respective pathways. Therefore, application of Mn2+ to neurons allows the use of MRI to visualize neuronal connections.     

高锰钢铸渗SiC颗粒过程中粒子分解特性研究

分析了铁基体复合SiC陶瓷颗粒的前景,提出改善SiC在铁基中分解的新方法,并在实验室条件下,采用V-EPC法(真空负压实型铸造法)制备了SiCp/高锰钢基复合材料.通过金相分析、扫描电镜(SEM)、能谱仪(EDS)及X射线衍射(XRD)等测试手段,研究了SiC颗粒铸渗高锰钢过程中SiC粒子的分解特征及粒子周围合金元素分...