GSF—120新型高效湿法粉粹机

<正> 一、前言 粉碎是将松散物料用机械方法粉碎为小粒度的过程。粉碎技术在采矿、食品、化工、医药、化肥、农药等部门得到广泛应用。尤其是微粉碎技术的开发、新颖微粉碎设备的研制,对于现代工业的发展,更具有十分重要的意义。     

物料粉碎与粒度分离的进展

近两年来,破碎、磨矿、筛分及分级方面进展很快,本文略述如下。 一.破碎 60年代以后,在固体物理方面,形成了关于弹性和塑性变形伴随晶格破裂的概念,出现了断裂力学这样一门新学科。利用上述理论及先进的测试手段,已可以解释破碎、磨矿能耗比按岩石强度理论计算高出许多倍的原因,并指出了降低能耗和克服物料过粉碎的技术方向,即所谓“物体的深层破裂”和“沿颗粒界面的选择性破裂”。如果在实际生产中能实现这一点,将是粉碎技术的重大突破。要实现沿颗粒界面的选择性破裂以     

矿物颗粒高压破碎的基本规律

本文系统研究了单颗粒破碎的基本规律。单颗粒破碎是指颗粒的受力和破裂是单独进行的,即颗粒之间无相互作用。破碎行为和变形的考察以及与粉碎技术有关的物料特性的研究常借助于单颗粒碎碎这一特殊方法。从某种意义上讲,单颗粒破碎是粉碎技术的基础。单颗粒高压破碎的实质是无边界约束的“微料层”粉碎,粉碎过程可以划分为“预损—碎裂—压实”三个阶段。不同矿物的挤压阻力大小顺序为:方铅矿>绿柱石>石英>黑钨矿>硬水铝石>闪锌矿>萤石。     

辊筒磨力学模型的探讨

本文通过对料层粉碎理论的研究，建立了辊筒磨力学模型，探讨了其物料粉碎力与物料钳角等参数间的关系。     

对粉碎过程的划分与易磨性试验的几点看法

１　引言　　　　为了恰当地设计和改造粉碎系统，最重要的一点是了解物料的易碎性和易磨性。在这方面国内外专家学者都作了大量工作，得出许多经验和实测数据。例如一般煤比石灰石易磨，石灰石比水泥熟料易磨。但试验表明［１］，石灰石比熟料和标准砂都难磨，这与人们的一般认识相差很大。由此引出一些问题，如物料的易磨性应如何测试？破碎与粉磨、易碎性与易磨性是否有所区别？本文对此发表一些个人看法，愿与同行探讨。２　破碎与粉磨的区分　　　　矿物质物料由大块变成细粉的过程通称为粉碎过程，人们常常又将其划分为破碎和粉磨两大…     

气流粉碎机的一般介绍(上)

现代工业的发展,要求许多粉体物料具有极细的粒子,从数微米到亚微米,甚至有百分之几微米的。气流粉碎技术正是适应这种需要而发展起来的。气流粉碎机又称流能磨,是一种高效的干法超微粉碎设备。虽然它的历史不长,但发展十分迅速,应用颇为广泛。据统计,用它粉碎的物料,从极坚硬的磨料到低熔点的热敏性有机化学品,已在一千种以上。     

粉碎

<正> 粉碎作业是一项必不可少的作业,它存在于各个产业领域的制备工程之中。这些领域中,根据所处理物料的程度,制品的粘度要求,以及物料的性质不同,使用着各种类型的粉碎机械,既有破碎数百mm大块矿石、岩石的粗碎机,也有将数十μm的微粒子进一步粉碎到若干个μm的超微粉碎机。     

破碎机的新发展

破碎作业是固体物料加工过程中的一个重要环节。尽管长期来，我国在这一技术领域中的进展较为缓慢，但对其的研究和探索一直没有中断，近十年来，一些教授、专家提出的新破碎理论和研制出的新破碎机械，便是所取得成果的很好佐证。在此基础上，应认识到只有加强技术研究和信息产流，积极提高产品质量和参与市场竞争，才能使我国的破碎机技术得到更大的发展。     

超音速气流粉碎技术应用研究新进展

超音速气流粉碎技术作为一种新型的材料深加工技术,具有无污染、耐热敏性、精度高等工艺特点,这使得其应用研究领域不断拓宽。为此综述了超音速气流粉碎技术应用研究进展,概述了超音速气流粉碎技术的工作原理和工艺特点;重点阐述了超音速气流粉碎技术在物料细化、食品加工、中药加工尤其是化学研究中的重要应用及其优势,最后对今后的应用研究工作进行了展望。     

CZJ自磨型超微粉碎机

非金属矿深加工的关键问题是物料的超微粉碎问题。发展非金属矿精细提纯技术、超细粉碎技术等列入了《当前优先发展的高技术产业化重点领域指南》。     

废旧轮胎粉碎技术及其应用进展

世界各国的废旧轮胎数量日益增加,废旧轮胎堆放不仅造成环境污染,还导致橡胶资源浪费,对废旧轮胎进行合理的回收利用已经势在必行。现阶段,粉碎废旧轮胎以制备胶粉因工艺优势而成为废旧轮胎的主要回收方式。综述国内外粉碎废旧轮胎制备胶粉技术,详细介绍干法粉碎和湿法粉碎技术及相关工艺,其中干法粉碎包括常温和低温粉碎,湿法粉碎主要包括RAPRA法、常温浸混粉碎法、全水相法和高压水射流冲击粉碎法。对主要粉碎设备及其粉碎原理进行概述。指出全水相法因制得的胶粉性能更加优异,且工艺成本低及环保性表现突出,有望成为未来废旧轮胎粉碎技术主要发展方向。     

Crushing characteristics

A method of measuring the basic characteristics of comminution was developed. These characteristics are expressed by the major comminution functions: crushing probability function, energy function and breakage function. The crushing probability function is the strength distribution of particles of a given size. The energy function is the strength of the particles as a function of their sizes. And finally, the breakage function is the size distribution of the crushed material. The functions are defined mathematically. Several natural minerals were tested by drop tests in order to determine their individual comminution functions. From the tests, several crushing properties of the particulate materials can be derived. The comminution functions given in this paper would be the basic elements in developing mathematical models for various crushing and grinding processes.     

The application of the attainable region analysis to comminution

The aim of any comminution circuit is to produce material of a desired particle size distribution (PSD) at a minimum operational cost. Currently, the comminution process is energy intensive and operates at very low efficiency when the input energy is compared to the breakage achieved. The attainable region (AR) technique has been successfully used to solve optimization problems simultaneously with the process synthesis formulation of reactor systems. The AR looks at the fundamental processes of a given system and determines all the possible outputs to which the objective function can be applied and an optimal process solution selected.Particle breakage, separation (classification) and mixing are identified as the three fundamental processes of interest taking place during comminution. Breakage and mixing processes are used in this paper to illustrate the applicability of the AR theory in comminution. We develop a fundamentally based model which is equipment independent to describe breakage. Specific energy is the independent variable and the production of particles with a certain PSD is the objective function. We use geometric construction to represent this PSD as a point in an n-dimensional space in relation to an input specific energy. Output PSDs are dependent on the input PSDs, allowing connectivity of the batch grinding stages to form a pseudo-continuous process.Specific energy is used as the control variable to obtain sharper product PSDs. It is shown that the same net energy consumed in the system can produce different product PSDs. Therefore, this implies that the design of comminution circuits should achieve better control of the specific energy. Once the candidate AR is constructed, operational process targets can be defined more accurately. This establishment of targets permits a measure of the actual process efficiency against a theoretical target. The advantage of the AR method lies in its ability to develop not only the performance of the optimal circuit but also the operational conditions to be used in the optimal process circuit. This also answers the process synthesis question of the type of equipment to be used which is a function of the specific energy.     

Data mining on technical trends and international collaborations in the refractory ceramic area

The refractory field is a complex network in which long-term trends are determined based on the interaction between different players such as raw material producers, refractory manufacturers, end users, research centres and universities. As it is a complex system, it is very difficult to know who the leading participants are in the scientific development and what the future technologies and trends will be in the area. In order to retrieve this information, data mining and the graph theory were used to analyse publications from the major technical journals in the refractory area over the last 21 years. Based on this study, a complete map of the international collaboration of the different leading countries in the refractory field was attained. A common factor of these countries is the active working interaction, which helps them to tackle challenging problems with a high degree of complexity. In depth, technological trends were obtained from the analysis of selected keyword over the period considered showing a lack of technological breakthrough in the past 10 years. Furthermore, a strong increasing trend using different types of computer simulations to support the technological development of the refractories was observed.     

An investigation into the influence of microwave treatment on mineral ore comminution

The influence of microwave pre-treatment on mineral ore breakage has been investigated. Samples of lead-zinc ore were microwave pre-treated prior to strength testing and change in strength with microwave exposure time determined. Comparisons of change in strength were made between microwave-treated and -untreated material. Using a multimode microwave cavity, it was found that strength could be significantly reduced in 0.5 s when using 15 kW of microwave power. Lower powers in this type of cavity were found to be less effective. Drop weight tests were used to quantify the change in strength in terms of reduction in required comminution energy. Reductions of up to 40% were achieved for particles of mean size 14.53 mm. Preliminary tests in a single-mode microwave cavity gave strength reductions of 50% at 10 kW of microwave power with a residence time of only 0.1 s, indicating that high electric field strength is important in the failure of ore. A preliminary energy balance indicating the benefits of single-mode heating is presented.     

泡沫塑料加工过程中的气泡成核理论(Ⅱ)——剪切能成核理论及其发展

介绍了剪切流场中泡沫塑料加工的气泡成核理论,分析评述了剪切流场中泡核拉伸模型、空穴成核模型对气泡成核机理的解释及存在的不足;对静态熔体中气泡成核过程进行了能量描述;介绍了最新的气泡成核中的剪切能成核理论,该理论较完善地解释了剪切流场中气泡成核过程;最后指出了气泡成核理论研究的发展方向。     

粒度和含水率对秸秆成型燃料生产能耗的影响

针对成型燃料规模化生产中原料参数的优化问题,以陕西某年产2万吨的秸秆成型燃料加工生产线为例,采用离散系统仿真软件ExtendSim对成型燃料生产线进行仿真。研究了粉碎粒度和干燥后的含水率对成型燃料的生产率及整体比能耗的影响,得出理论能耗的最优参数组合并与调研的生产性试验结果进行比较。敏感性分析发现,压块燃料的整体比能耗对参数变化更敏感,而颗粒燃料的生产率对参数变化更敏感。因此,按对参数变化敏感性更高的性能指标进行最优化参数选择。结果表明:与原经验参数相比,压块燃料按参数(15%,20～30mm)优化后理论节能11.64%,相关生产性试验节能10.36%;颗粒燃料按参数(10%,10mm)优化后理论节能5.58%,相关生产性试验节能6.36%.本文提出的按对参数变化更敏感的性能指标选择最优参数组合的方法使生产能耗更低,为成型燃料原料参数选择提供理论依据,指导工程实践。     

Strength distribution of particles under compression

From time immemorial people dealt with size reduction processes (mill, mineral liberation, etc.). As time has passed industrial units for comminution processes have become larger and more sophisticated, but still they perform with low efficiencies [1], [2] and [3]. The strength of a particle is one of its most crucial characteristics due to the mechanical stresses experienced by each particle within an industrial unit. This is because the final size of particles is mostly dependant on the strength distribution of the raw material [4]. In this present study, the ability of a number of statistical formulations to accurately describe the strength distribution of particles was examined. Additionally, selected equations were analyzed and a general expression including the effect of the material and particle size was developed. A number of approaches to define particle strength were considered, and strength in terms of crushing force was chosen. Particle strength in terms of force and in terms of energy was also compared and found to be size independent. Finally, particle strength in terms of stress was examined and compared to the particle strength in terms of force.The ability to describe the compression strength distribution will significantly improve the accuracy of the comminution processes simulation, design and optimization.     

高速水射流粉碎中射流冲击区水垫的增阻效应

为了解高速水射流冲击区特性和对物料粉碎效果的影响,通过理论分析、数值计算方法和采用自主研制的后混式高压水射流粉碎装置进行粉碎实验(以煤为粉碎物料),针对水射流在冲击区产生的水垫及其对物料粉碎的影响进行了研究。结果表明:高速水射流在靶体冲击区范围内存在水垫,水垫范围约为10倍喷嘴半径r0;射流冲击区水垫对粉碎不利,在有水垫增阻情况下,水垫对粉碎效率具有一定影响,特别是对低粒级产品减产影响明显;无水垫增阻情况下,物料粉碎较前者更加高效,产率也更高;研究水射流冲击区水垫增阻减产机理,对高速水射流粉碎技术及设备研究实践具有一定理论和设计参考价值。