3D Design and Analysis of Crushing Roller of High-pressure Grinding Roller

Crushing roller is one of the main parts of High-p re ssure Grinding Roller, which is a kind of high efficient ore crushing equipment. A kind of assembled roller, which is more convenient to renovate worn surface b y simply replacing segmented surface of the roller, was developed. The structura l models of assembled roller’s components were designed with SolidWorks softwar e based on feature modeling, these solid models of the roller were virtually ass embled. Through this work, not only was the assemble interference checked out so as to examine validity of the structure design, but also these solid models cou ld be recognized by COSMOS/Works software, through which the finite element an alysis can be done. Then the stress and displacement of the main shaft and sur face segment in two different working states were analyzed and detected quickly according to the analysis results with COSMOS/Works. In conclusion, the optimum clearance of 1.0～2.0 mm between concave-convex studded segments is determined to make the using life of assembled roller longer.

Cause analysis of and solution to furnace roller pick-up in the high strength automotive steel sheet processing line

Cold-rolled high strength steel sheets for automobiles contain more Mn and Si based alloy elements, which, under the reducing atmosphere in the annealing furnace, will get enriched on the strip surface. Since the furnace rollers and the strips contact frequently, alloy elements on the roller surface will form hard protuberance. We call this protuberance ＂pick-up＂. In addition, with the increase of the amount of dust in the furnace atmosphere, the occurrence of furnace roller pick-up will also increase. Through chemical reaction and physical accumulation analysis combined with practical experience, the causes of pick-up in different furnace sections were analyzed. Methods of preventing furnace roller pick-up in the high strength steel sheet processing line were discussed and solutions to improving the strip surface quality in the continous annealing furnace were provided.

Model Building of Backup Roller Diameter Effect Rate in 4-High Mill

Software for calculating the strip profile in 4-high hot rolling mill was developed using influence coefficient method. Regularity of backup roller diameter effect rate was studied systematically using the software. The results show that backup roller diameter effect rates decrease versus the increase of strip width, increase significantly versus the increase of backup roller diameter and obscurely increase versus the increase of reduction. The difference between backup roller diameter effect rate and it is reference value increases versus strip width increasing. When backup rollers diameter is set to be 1.64 m and strip width is 1.85 m, the error of strip profile calculated using the model of backup roller diameter effect rate reference value will be 3.55μm. Based on the results, reference values of roller diameter effect rate and six power polynomial fitting coefficients of modification coefficients were determined considering coherent parameters. The high precision model of backup roller diameter effect rate was established. When the model is used to predict strip profile, the accuracy is less than 5.0 μm.

HYDRAULIC ACTIVE GUIDE ROLLER SYSTEM FOR HIGH-SPEED ELEVATOR BASED ON FUZZY CONTROLLER

Increase of elevator speed brings about amplified vibrations of high-speed elevator. In order to reduce the horizontal vibrations of high-speed elevator, a new type of hydraulic active guide roller system based on fuzzy logic controller is developed. First the working principle of the hydraulic guide system is introduced, then the dynamic model of the horizontal vibrations for elevator cage with active guide roller system and the mathematical model of the hydraulic system are given. A fuzzy logic controller for the hydraulic system is designed to control the hydraulic actuator. To improve the control performance, preview compensation for the controller is provided. Finally, simulation and experiments are executed to verify the hydraulic active guide roller system and the control strategy. Both the simulation and experimental results indicate that the hydraulic active guide roller system can reduce the horizontal vibrations of the elevator effectively and has better effects than the passive one, and the fuzzy logic controller with preview compensation can give superior control performance.

Phase and CCT Diagram of an N-Containing 8%Cr Roller Steel

The pseudo-equilibrium phase diagram and continuous cooling transformation diagram of an N-containing 8％ Cr roller steel were investigated by using thermodynamic calculation,differential scanning calorimetry,Ⅹ-ray diffraction,expansion method,and so on.Under equilibrium conditions,the main carbonitrides are MX,M7C3,and M23C6 types.The measured Ac1,Ac3,start temperature of martensitic transformation,and M7C3 transformation temperatures are 811,855,324,and 1100 ℃,respectively.Bainite appears at cooling rates ranging from 0.5 to 5 ℃/s and ferrite forms at grain boundaries at a cooling rate lower than 0.5 ℃/s.Finally,the effects of adding N and lowering the C content on workability and mechanical properties of common 8％Cr steel were discussed.

Seepage Mitigation in Hydropower Dams by Optimization in Roller Compacted Concrete Interlayer (Monoliths) Joint Bonding Technology

Roller Compacted Concrete (RCC) has gained favorable recognition in hydropower and water resource dam construction. With optimization in construction technology and materials used for RCC Dams, cost is no longer a major disadvantage as compared to environmental impact, that is, wildlife habitat disruption. In as much as it has become optimal for investment in hydropower dam construction, the scourge for dam failure is still eminent, which is as a result of excessive seepage compromising the integrity of the mechanical properties of the dam. The aim of the paper is to highlight successful application methods in joint bonding to avoid excessive seepage and reduce the autogenous healing to a few years of operation. In view of optimization, this paper presents a comprehensive study on the influences of interlayer joints bonding quality from RCC mix performances and how it consolidates the RCC layers to withstand the shear strength along the interface, especially on the high dams. The case study is the RCC dam at the 750 MW Kafue Gorge Lower Hydropower Station. The scope of the study reviews the joint type judged by Modified Maturity Factor (MMF) with joint surface long time exposed in regions with dry and high temperature, technical measures of layer bonding quality control under condition of long time joint surface exposure, effects of joints shear strength and impermeability of the RCC layers when under the conditions of plastic and elasticity. The subtle observations made during the dam construction phases were with respect to the optimal use of materials in relation to RCC mix designs and the basis for equipment calibration for monitoring important data that can be referenced during analysis of shear forces acting on the RCC dam over time.

Characteristic Analysis and Comprehensive Control for the Horizontal Stripes of High-Grade Automotive Panels in Continuous Annealing

As to the horizontal stripes defect which exist on the surface of the high-grade automotive panels in continuous annealing process, an effective comprehensive control method is proposed on the basis of full consideration of the equipment and technological features of continuous annealing line. With five field tests as basis, the generation mechanism of the defect was analysised in detail and the comprehensive control measures were put forward. According to actual situation, a detailed technical plan was worked out .Then the relevant technologies were applied to a 1850 continuous annealing line. The statistics shows that this program acquired good effects. The incidence of horizontal stripes defect decreased from 100% to 2.78%. Meanwhile, the surface quality of strip also improved effectively, which created a larger economic benefit.

基于超高压处理的猕猴桃原浆制备研究

为优化猕猴桃超高压灭菌条件下原浆制作工艺,对3种不同原浆制作工艺分别进行单因素优化试验,筛选出两种产品色泽和稳定性较好的工艺,并对这两种工艺所制作样品进行4℃储藏40 d的品质对比。结果表明,在最大程度保留猕猴桃原浆绿色,提高其稳定性的条件下,3种工艺的优选次序为:对辊式挤压制浆>胶体磨制浆>高压微射流制浆;与胶体磨工艺相比,对辊式挤压工艺制作的产品在4℃条件下储藏30 d内无明显的自然分层,产品VC损失较少;优化后的制浆工艺为:采用对辊式挤压工艺,挤压次数为1次。按照该工艺制作的猕猴桃原浆色泽相对均一,以青绿色为主,VC含量为40~50 mg/100 g。

辊模在高碳钢丝连续拉拔中的应用

采用2种拉拔应变对高碳钢丝进行辊模拉拔,并与传统拉拔对比。结果表明:在拉拔应变1.12时,辊模拉拔钢丝的抗拉强度、扭转性能、弯曲性能、金相组织、捻制断丝率与传统拉拔相近;在拉拔应变2.21时,辊模拉拔和传统拉拔相比,钢丝抗拉强度更高,扭转性能、弯曲性能较差,金相组织不均匀程度更大,捻制断丝率明显升高。在钢丝材质、机床功率、拉拔速度、道次压缩率等因素相同的情况下,辊模拉拔的能耗和传统拉拔相近。

高性能高精度铜合金带材六辊冷轧机组的研发与应用

针对高性能高精度铜带材生产的技术难点,首次开发了800 mm小辊径六辊可逆中精轧机组。介绍了机组的工艺设备组成、主要工艺技术参数配置和装机水平;重点阐述了开发的新技术:紧凑式弯辊小辊径六辊轧机、高精度自动厚度控制技术、高精度板形自动控制系统以及高效除油装置。机组投入使用后,产品质量得到有效提高,对于厚度为0.175 mm,宽度为620 mm的铜带,成品厚差不大于±1μm,板形均方差不大于0.55I。

南芬选矿厂北山矿石选矿工艺试验

为配合南芬铁矿绿色矿山选矿提效及高效利用北山原矿石,在工艺矿物学研究的基础上,对北山矿石进行了选矿工艺流程试验。试验结果表明:采用辊磨前干抛—高压辊磨—辊磨产品湿式抛尾—阶段磨矿—弱磁选工艺,干抛和湿抛可提前抛除合计产率23.26%的尾矿,大幅降低了后续入磨矿量,提升了入磨矿样铁品位,最终获得的铁精矿产率为30.77%,TFe和mFe含量分别为68.17%和60.22%,TFe和mFe回收率分别为66.63%和98.16%。

基于神经网络预测方法的智能化高精度大型钢管高速托辊机构研究

大型钢管高速托辊机构在工作过程中受管节点偏心、滑动摩擦等不确定因素的影响,会使得主管转动距离与胶轮转动距离存在一定偏差。这种偏差给实际工程施工带来一定困难。对此,采用商用软件ANSYS中的Transient Structural模块建立基于某大型钢管高速托辊机构的有限元模型,通过仿真计算研究转动过程中主管和胶轮的运动特性,获得对应的旋转角度、旋转距离以及距离偏差,采用径向基神经网络方法对主管和胶轮旋转的偏差进行预测对比分析。研究结果表明,所建立的径向基神经网络方法能够很好地预测主管和胶轮旋转的转动距离偏差,能够为大型钢管高速托辊机构上主管与胶轮距离偏差的计算提供一定的参考。

高压辊磨对某铜矿浮选指标影响的研究

为了研究高压辊磨破碎对国内某低品位铜矿石后续浮选指标的影响,采用单因素分析方法进行了高压辊磨破碎试验、浮选优化条件试验和浮选开路对比试验。结果表明,在磨矿细度-0.074 mm占65%,粗选氧化钙用量1000 g/t、MAC-12用量20 g/t、丁基黄药用量10 g/t,扫选MAC-12用量10 g/t、丁基黄药用量5 g/t条件下,经1粗1扫浮选流程,常规破碎产品浮选可获得铜、硫品位分别为4.31%和22.46%,铜、硫回收率分别为74.382%和79.053%的粗精矿;辊压产品浮选粗精矿铜、硫品位分别为4.76%和23.06%,铜、硫回收率分别为88.137%和87.082%。铜、硫品位分别提高0.45和0.60个百分点,铜、硫回收率分别提高13.755和8.029个百分点。由此可知,通过高压辊磨破碎作业,可提高该铜矿石浮选精矿的铜、硫品位和回收率。

高压辊磨机用硬质合金柱钉的磨损和断裂行为

硬质合金柱钉性能的好坏直接影响高压辊磨机的使用寿命和生产效率,但关于柱钉的力学性能和使用性能的相互对应关系缺乏研究,导致在使用过程中缺乏硬质合金设计标准。本文通过研究柱钉硬度、抗弯强度和断裂韧性等性能特性对柱钉的耐磨性和抗断裂性能的影响规律,获得了破碎高硬石英岩的理想柱钉。结果表明:影响柱钉断裂数量的主要因素是断裂韧性,而非抗弯强度;随着断裂韧性从16.21 MPa·m^(1/2)增大至21.57 MPa·m^(1/2),抗疲劳断裂能力提升,断裂数量百分比从3.77%降低至0。柱钉的磨损主要为磨粒磨损,随着硬度从HRA 86.2增大至HRA 88.3,抗磨损性能提升,磨损速率从7.92μm/h降低至2.33μm/h。对于石英含量高达64.23%、单轴压缩抗压强度达159 MPa的矿石破碎,当柱钉的硬度达到HRA 87.8、断裂韧性达到19.55 MPa·m^(1/2)时,能有效抑制柱钉的磨损和断裂。

高压辊磨技术在铜冶炼渣选矿中的应用研究与探索

采用磨矿浮选工艺回收铜冶炼渣中有价金属元素时普遍存在磨矿能耗偏高、磨矿细度偏低、浮选尾矿有价金属含量偏高的问题。高压辊磨技术利用层压理论,物料在辊压时使矿物沿解离面产生裂纹,能够降低磨矿功指数,提高矿石的可磨性。国内外关于高压辊磨技术在铜冶炼渣选矿中的应用开展具体试验研究的较少。通过对某铜冶炼企业的冶炼熔炼渣开展高压辊磨试验,结果表明,高压辊磨设备能明显降低碎磨物料的粒度、增加入磨物料细粒级含量,物料邦德功指数下降幅度达到20.26%,物料可磨性得到较大改善。在此基础上又进行了磨矿、浮选试验,对试验进行对比,高压辊磨后的物料较常规破碎物料在相同磨矿条件下磨矿细度提高8.68个百分点,有价元素金、铜浮选回收率比常规破碎磨矿浮选分别提高了1.80、1.23个百分点,回收率提高显著。研究表明,高压辊磨技术在铜冶炼渣选矿中具有较好的应用价值。

轴承制造技术综述

轴承制造技术是制约国内高精密轴承行业发展的瓶颈,轴承钢作为轴承内外圈和滚动体的主体材料,其加工工艺直接影响轴承最终使用性能。综述了国内轴承内外圈和滚动体的制造技术,通过对国内轴承内外圈和滚动体车加工、热处理、磨加工的分析与研究,总结出了国内轴承制造技术的发展现状,对高端轴承的国产化进行了展望并提出建议。

安徽某镜铁矿石磨前辊压—预选抛废工艺研究

安徽某低硫磷酸性镜铁矿石中主要有用成分为Fe,主要脉石成分为SiO2,以镜铁矿形式存在的铁占总铁的96.11%,铁矿物呈稠密、中等稠密、稀疏—星散等不同密集程度的浸染条带状嵌布,部分解离较容易。为解决细粒尾矿产生量过大对尾矿库库容的过快消耗,并降低选矿生产成本,对原入磨前矿石进行了高压辊磨机闭路辊压—强磁选抛废可行性研究。结果表明,立环脉动高梯度磁选机2次粗选抛废,可抛出产率22.33%的废石,得到铁品位42.99%、铁回收率96.03%的预选粗精矿;预选尾矿中隔出的粗粒(+0.3 mm)可作为建筑用砂出售。在原磨矿前增设高压辊磨机闭路辊压—立环脉动高梯度磁选机湿式粗粒预选抛废—废石捞砂流程,不仅可以显著减少入磨矿量,降低入磨粒度,提高入磨品位,减少细粒尾矿产生量,还可以获得大量的建筑用砂,增加企业的经济效益。

云南金厂河铁矿石高效节能选矿工艺试验

云南金厂河铁矿为合理开发利用全铁品位30.47%的铁矿石,确定有效的选矿工艺流程,针对矿石中有用铁矿物嵌布粒度较细,且与脉石矿物紧密共生,导致矿石难以高效抛废的问题,在碎选工艺引入了高压辊磨超细碎选择性碎解技术,并与常规破碎(-10 mm)湿式磁选预选抛尾工艺进行了对比试验。试验结果表明:在磁性铁回收率相近的情况下,采用高压辊磨—湿式预选工艺抛出的尾矿量明显提高,高压辊磨湿式预选精矿分别采用两段阶段磨矿—单一磁选工艺和两段阶段磨矿—磁选—磁选柱分选工艺,最终获得的分选指标相近,基于降本增效及节能减排的目标,推荐高压辊磨—湿式磁选—两段阶段磨矿—磁选—磁选柱分选工艺,作为该铁矿石的原则选矿工艺流程。

生料辊压机终粉磨系统节能减碳实践中存在的问题与对策

因原材料水分大、系统烘干能力不足、设备阻力大、高效选粉机结构缺陷等原因造成生料辊压机终粉磨系统运行不稳定且循环负荷大、停机次数较多、系统阻力大、循环风机拉风过大、细度跑粗现象,导致生料工段电耗偏高、成品细度合格率低。对物料特性、工艺流程、设备选型及运行、成品细度进行热工诊断和研究分析,并实施相应的设备、工艺及系统操作优化措施。优化后,生料辊压机终粉磨系统工段电耗降低了2.2kWh/t,选粉效率提升,成品细度明显改善,实现提质增效,节能减碳的目的。

陕西某铁矿选厂扩产节能改造实践

陕西某磁铁矿为将选矿厂原矿处理能力由70万t/a扩产到200万t/a,提高铁精矿产量,进行了高压辊磨及湿式预选试验研究。通过多技术方案对比得出,选矿厂新增高压辊磨及预选工艺,每年可减少入磨矿量86万t,每吨原矿处理电耗可降低11.94%,每年可减排固体废弃物50万t,选矿厂实现了节能减排及降耗增效,企业经济效益和社会效益显著,达到了提高铁精矿产能的目的。