碎边剪稳定运行影响因素分析

针对冷轧酸洗机组碎边剪使用过程中刀片剪切公里数少、刀头更换次数多和维修费用高等问题,经过对碎边剪刀片的材质、硬度和结构间隙及更换刀片方式的研究,改进后碎边剪刀片剪切公里数有了大幅度提高,取得良好的效果。     

Development of electrolyte filtration system for ECM taking into account removal of chromium (VI) ions

During the ECM process, the metal workpiece is dissolved and turns into sludge which contaminates the electrolyte. To realize precise ECM with high cost-effectiveness, an electrolyte treatment system which can realize reuse of the electrolyte and maintain the electrolyte quality constant is significantly important and essential. Especially, in the ECM of alloys containing a certain level of chromium, it is very likely chromium dissolves to the toxic carcinogen Cr(VI). Therefore, an electrolyte filtration system is required for removing not only the sludge but also residual toxic ions in the electrolyte for health and environment conservation reasons. In this study, activated carbon and scrap iron, which are low cost and easily available materials, were newly utilized to reduce and remove toxic Cr(VI) ions. Experiments clarified that use of activated carbon has no influence on the machining ability of NaNO₃ aqueous solution serving as the electrolyte. By adjusting the pH of the electrolyte to acidic, activated carbon can remove Cr(VI) from the NaNO₃ aqueous solution electrolyte to a concentration of less than 0.1 mg/L. On the other hand, scrap iron generated from metal cutting processes can be used to reduce Cr(VI) to non-toxic Cr(III). By mixing HNO₃ into the electrolyte solution, the reduction efficiency of scrap iron on Cr(VI) improves significantly.     

废铁屑还原软锰矿制备高纯硫酸锰工艺研究

研究了采用废铁屑作为还原剂,在稀硫酸介质中湿法还原软锰矿制备硫酸锰的工艺过程。通过单因素实验确定最佳工艺参数,结果表明：当Fe/MnO2的摩尔比为0.78∶1,H2SO4/MnO2的摩尔比为2.1∶1,反应温度50℃,反应时间80 min时,锰的浸出率在95%以上。加入碳酸钙中和调节溶液pH值至5~6,使溶液中的铁、铝等杂质离子水解为氢氧化铁、氢氧化铝等沉淀除去,加入硫化钡使浸出溶液中的重金属离子以硫化物沉淀除去,减压过滤得到硫酸锰粗滤液,向粗滤液中加入二氟化锰使溶液中的Ca2＋、Mg2＋等离子生成氟化物沉淀,然后溶液经过静置过滤得到硫酸锰净化液,滤液经浓缩、结晶制备硫酸锰产品。经检测产品纯度在99%以上,杂质含量低于国家标准。     

废钢加工处理过程中二次污染的防治

随着国家对环境方面的要求不断提高和企业对环保的重视,废钢加工处理过程中二次污染的防治问题逐渐成为物流分公司急需解决的重要问题,为了对废钢加工处理过程中的二次污染起到有效防治,为攀长特灾后重建废钢的合理环保利用提供一定的技术支撑,本文重点分析了废钢铁加工处理过程中二次污染的表现形式和有效防治途径,并提出了相应防治办法,以便为攀长特的二次创业提供更优质的废钢资源。     

炮弹水刀切割装置结构设计

报废炮弹的处理销毁及贮运工作是非常危险的,稍有不慎,极易发生事故,造成人员伤亡与财产损失。采用水刀切割装置处理报废炮弹,安全可靠且不污染环境。设计水刀切割装置,采用超高压水射流冷态切割技术将弹体切开,并利用高压水射流冲洗使炸药和弹体分离,销毁炮弹并回收有用金属。采用液动三爪卡盘实现炮弹的自动定位与夹紧,利用旋转切割的方法切割炮弹,提高了整个水刀系统的寿命。     

An algorithm for the kinetics of tire pyrolysis under different heating rates

Tires exhibit different kinetic behaviors when pyrolyzed under different heating rates. A new algorithm has been developed to investigate pyrolysis behavior of scrap tires. The algorithm includes heat and mass transfer equations to account for the different extents of thermal lag as the tire is heated at different heating rates. The algorithm uses an iterative approach to fit model equations to experimental data to obtain quantitative values of kinetic parameters. These parameters describe the pyrolysis process well, with good agreement (r² > 0.96) between the model and experimental data when the model is applied to three different brands of automobile tires heated under five different heating rates in a pure nitrogen atmosphere. The model agrees with other researchers’ results that frequencies factors increased and time constants decreased with increasing heating rates. The model also shows the change in the behavior of individual tire components when the heating rates are increased above 30 K min⁻¹. This result indicates that heating rates, rather than temperature, can significantly affect pyrolysis reactions. This algorithm is simple in structure and yet accurate in describing tire pyrolysis under a wide range of heating rates (10–50 K min⁻¹). It improves our understanding of the tire pyrolysis process by showing the relationship between the heating rate and the many components in a tire that depolymerize as parallel reactions.     

Kinematics and Wear of Tool Blades for Scrap Tire Shredding

Abstract

The wear of tool blades for cost-effective scrap tire shredding is investigated. Rotary disk cutters are widely used for cutting scrap tires into small pieces. The hard, wear-resistant tool blades mounted on the periphery of disk cutters maintain a narrow gap between blades and generate the cutting action. The kinematics of the relative motion of two adjacent disk cutters is derived to model the overlap region on blades during cutting. The model predictions match well with the actual shapes of the worn regions on used tool blades. The wear of tool blades made of AISI D2 and CRU-WEAR (CW) tool steels for scrap tire shredding is evaluated. A coordinate measurement machine was used to measure the tool wear. The wear on the blade surface is not uniform. Regions with high wear rate are explained using the kinematics analysis. The CW blades show a lower wear rate, about half of that of D2 blades, and a potential choice for cost savings.     

工业遗产转型发展规划研究——以废船厂为例

近年来,随着城市更新、产业结构升级,城市用地特别是占据滨江景观优势的地段越来越受到人们的关注,这其中废船厂成为主要转型目标之一。由于目前国内废船厂转型案例尚不多见,该文从工业遗产与废船厂的共性与个性角度切入,共性方面从工业遗产入手,实地调研北、上、广三大城市典型案例,分析总结其功能定位和主要经济指标量化的规律性和指导原则;个性方面参考国内已有的少数案例以及从事相关工作的经验,得出相应结论,从而形成完整的废船厂转型发展规划前期思考方法。     

化学法处理铜合金屑工艺的热力学和动力学分析

本文对化学法处理普通黄铜屑，直接制备纯铜粉末进行了热力学和动力学分析研究及试验表明：Zn，Fe等元素的酸浸反应容易进行，氧化及还原速度快．酸浸过程受扩散控制，其动力学方程为进一步的热力学分析指出，本工艺适合于处理各种铜合金尾料，尤其适合于黄铜类铜合金尾料。     

Seismic base isolation using low-cost Scrap Tire Pads (STP)

This paper focuses on the experimental studies conducted on the development of no-cost seismic base isolation pads using scrap automobile tire pads (STP). The mechanical and dynamic properties of STP specimens made from different tire brands, with different number of layers, and orientations are evaluated experimentally. The tests are conducted using (a) axial compression tests, (b) lumped mass small displacement free vibration, and (c) large displacement (inclined plate and reverse-cyclic) static shear tests. The results of these STP tests are compared among themselves and against a commercially available laminated rubber bearing specimen. A general relationship has been proposed which formulates the stiffness differences between the two principal directions of rectangular pads. The paper includes three hypothetical design applications for the use of STPs. STPs are prepared by placing 18 cm × 20 cm cut tread sections layers of car tires on top each other. Larger size STPs can also be formed by placing longer strips of tread sections (integer multiples of tread width) side by side in alternating direction layers or using a woven structure. Test results have shown that the friction between tire layers is sufficient to keep layers intact. Although STP application cannot eliminate foundation-basement structural requirements, it presents advantages such as low-technology no-cost pad, weight reduction, ease of handling, simple shear stiffness adjustment by changing the number of layers, and environmental benefits by recycling scrap tires.