谈对混合料预均化堆场的选择

预均化堆场从堆料形式上分为石灰石均化堆场及混合料均化堆场;从形状上分为圆形及矩形堆场。笔者从长期的生产实践中谈谈对混合料预均化堆场的看法,以便兄弟厂家在今后的生产建设中对预均化堆场进行选择时作为参考。     

原煤预均化堆场智能化控制系统研发与应用

原煤预均化堆场普遍存在设备故障率高、自动化程度和员工安全系数较低等问题。通过分析原煤预均化堆场原煤取料机的特点，设计了智能化控制系统，该系统由无人值守和智能化巡检、设备在线监测和故障预警、全自动取料系统三个部分组成，基本实现了原煤预均化堆场的智能化控制。本项目为堆取料系统的安全运行和智能化发展提供关键的技术依据，也为后续建设智能工厂奠定基础。     

圆形预均化堆场简介

一、引言: 随着干法生产在水泥工业中的比重日益增大,预均化设备在水泥厂中起着重要的作用。以前常见的预均化堆场是长条形,而近年来圆形预均化堆场则有较大的发展。它具有下列优点: 1.占地面积小,在容量相同的情况下,圆形预均化堆场比长条形的少占地40％左右。这是因为长条形堆场的堆料区和取料区的比为50:50,而圆形的约为60:40。 2.由于圆形预均化堆场的取料机只有一个方向运动(就象湿法厂料浆池的大车一样绕中     

预均化堆场输送系统工艺的改进

我公司2000t/d新型干法水泥生产线的预均化堆场,内有1台全自动堆料机和1台桥式刮板取料机,能储存两堆料,每堆料约为1.6万t。在预均化堆场内均化的物料有粘土、粉煤灰和石灰石,物料的均化效果较好,成分较为稳定。而在石灰石至预均化堆场的输送系统中存在一些问题。1存在的问题1)     

预均化堆场

预均化堆场是近十多年来在国际上迅速发展和广泛采用的一项颇为成功的新工艺、新技术,它适用于一切以矿石为原料的基础工业部门。一、预均化堆场的组成预均化堆场是将一种或几种物料在运输与储存的过程中,同时将物料混合均匀。它主要由进料主皮带机、堆料装置、料堆、取料装置、出料主皮带机和取样装置等六个部分组成,如图1所示。     

石灰石取料机提产改造

冀东水泥扶风有限责任公司一期熟料生产线设计生产能力4000t／d。石灰石堆场采用长形预均化堆场,露天布置。石灰石侧式悬臂堆料机最大堆料能力900t／h．桥式刮板取料机最大取料能力550t／h。     

水泥工厂长形堆场和圆形堆场选型分析

通常用于石灰石和原煤及辅助原料等预均化处理和存储的预均化堆场,其投资造价较高,占地面积大,且对征地和总图布置有明显的影响。目前,水泥工厂预均化堆场有屋盖落地或抬高的长形堆场和圆形堆场二类,其机械设备成本、土建成本大和生产运行电耗成本差别大,因此选择合理的堆场形式就非常重要。以已经建成的实际工程决算数据为基础,在满足类似工艺参数要求的情况下,进行落地长堆和抬高圆堆的投资成本、建设用地、生产运行方面对不同的堆场做了对比分析;在此基础上,进行了选型优劣的排序。     

均化技术的现状和展望

介绍了水泥生产过程中物料均化技术的发展阶段、均化效果的评价方法,各均化环节的均化功能、均化控制及相关控制参数的计算：详细介绍了石灰石预均化堆场的形式、设备和堆取料方式的选择,以及堆场参数（长度、宽度、高度和层数）的计算;介绍了新的在线快速分析仪的应用实例及其效果,并就在线快速分析仪的前馈控制可能对均化技术的影响进行了探讨。在此基础上,对大中型新型干法生产线的原燃料均化环节的设置及其均化技术的应用和前馈式控制,提出了6点建议。     

斗轮式取料机提产的几点措施

我厂4号、5号生产线石灰石均化堆场为长条形料堆设计，堆场整体外形为43mX6．6m×17m长方形钢结构房屋一座。均化堆场设有南北两座料堆，每堆料最大容量为28000t。一堆料在进行堆料作业时，另一堆进行取料，两料堆之间轮番作业。堆料采用人字形分层堆料，设计最大布料能力为500t／h。取料机采取断面斗轮取料，设计取料能力500t／h。所取物料可经胶带输送机返回堆料机重新堆放，亦可将不同品位的石灰石搭配均匀直接经胶带输送机送入原料磨前混合料仓。出堆场混合料氧化钙标准偏差为人堆场的1／8。     

桥式刮板取料机输送系统的改造

我公司一期2000t／d熟料生产线石灰石预均化长形堆场，采用屋顶人字形全自动堆料和端面桥式刮板取料机取料形式，该堆取料系统于1997年4月投入运行，其中取料机型号为QQB22032，额定取料能力为180t／h。2003年公司在同厂新建一规模为1000t／d的熟料生产线，为了节约基建投资，决定由同一堆场为新建的生产线提供石灰石原料，为此对该取料机及相关的系统进行了配套改造，以提高石灰白取料和输送能力，满足扩大的生产需求，本文主要介绍对该取料机的刮板传动系统进行改造的情况。     

基于性能老化量分布的单基发射药使用可靠性模型

通过对某型超期贮存弹药的单基发射药进行静态抗压强度试验,得到不同贮存年限发射药的抗压强度.利用可靠性理论和方法,对试验结果进行统计分析,得出超期贮存单基发射药的抗压强度随时间的变化规律.建立了基于性能老化量分布规律的发射药使用可靠性计算模型,对7/14单基发射药使用可靠性进行了预估.结果表明,随着贮存时间的增加,发射药的使用可靠性显著降低;在不同的压力波条件下,发射药的安全使用寿命相差较大.     

SELF-IGNITION AND CONVECTION PATTERNS IN AN INFINITE COAL LAYER

Spontaneous combustion can occur in a coal stockpile if the heat generated by oxidation cannot be dissipated at near ambient temperature. Determination of conditions for which combustion occurs is of great importance in designing coal stockpiles. An approximate analysis is used to obtain natural convection patterns in a laterally-unbounded layer of coal. Down-hexagons and two-dimensional rolls appear to be the stable flow planforms. A continuation procedure gives a simple criterion for the point of ignition in the layer in terms of easily measurable parameters. This criterion can be used to determine ignition points in the interior of a large coal stockpile and complements earlier work in which a similar criterion was developed for the edge of a stockpile.     

Distribution of free gaseous oxygen in coal stockpiles

This study confirms that the distribution of free gaseous oxygen in a coal stockpile agrees with a previously published model for self-heating within the stockpile. The simplified, isothermal model of the study predicts a hyperbolic cosine distribution which is characterized by a single parameter, the Thiele modulus. This depends on the stockpile properties of size, intraparticle porosity, oxygen diffusivity and the coal properties of density and reactivity towards oxygen. The Thiele modulus can be determined from two measurements of oxygen concentration at different depths in the pile. Changes in coal reactivity (weathering) on prolonged exposure to atmospheric oxygen are reflected in the magnitude of the Thiele modulus and thus can be measured in situ at storage temperatures.     

50%丁莠悬浮剂的制备

以50％丁莠悬浮剂为例。介绍了用莠去津原粉直接研磨的方式制备悬浮剂时。助剂的选择和制备方法，研究了助剂对贮存稳定性的影响和研磨速率及研磨时间对莠去津粒度、悬浮刺贮存稳定性的影响。该方法制备的悬浮剂成本低、质量稳定、使用安全。     

Numerical simulation and application experiment of the spontaneous combustion tendency of a coal stockpile covered with pulverized coal

In this paper, we developed a new method for preventing the spontaneous combustion of a coal stockpile covered by pulverized coal. This technique is based on the numerical-simulation analysis of endothermic/exothermic balance in coal stockpile. Depth and height are confirmed to be the main factors influencing the endothermic/exothermic balance in coal stockpiles and the hot-spot region is easily formed at a coal stockpile height of 1-1.5 m and a depth of 2-3 m, where there is the highest tendency for spontaneous combustion. The numerical simulation and the 120-day application test both confirm that the diffusion process of oxidation can be prevented and the coal oxidation reaction can be hindered by covering the surface of the hot region with pulverized coal. As a result, the coal spontaneous combustion is prevented effectively.     

The effect of compressibility on the assessment of the contents of a stockpile

The compressibility of a number of granular materials was found using a simple compression cell. The stress—strain behaviour was very well correlated by the equation of Cooper and Eaton [4]. The data were then used to calculate the average bulk density in stockpiles of those materials with the size of the heap as parameter. Simple conical and prismatic heaps were considered.For large stockpiles it was found that no more than 1% error in estimation of the stockpile inventory will result by taking a bulk density found at the centre of the base of a stockpile twenty metres or more in height. Errors resulting from granular material compressibility are much greater for small stockpiles.     

煤矸石堆存区周边土壤重金属污染特征及风险评价

为探究长期堆存煤矸石中重金属在周边盛行风向土壤里的分布特征及潜在风险,以宁夏枣泉煤矿煤矸石堆存区周边土壤为研究对象,对煤矸石堆存区周边盛行风向土壤中5种重金属(Cu、Zn、Pb、Cr、Mn)总量及重金属赋存形态特征进行深入分析,开展了土壤重金属生物活性分析及评价。结果表明:由于煤矸石的长期堆放、风力、雨水淋溶等,堆存区边缘处重金属(Zn、Pb和Mn)含量较高,且随着距离的增大呈下降趋势;相关性分析中土壤pH值与Zn、Pb含量呈极显著负相关性,与Mn含量呈显著负相关性,与Pb和Cr的可交换态呈显著负相关性,总氮(TN)与Cu的有机质结合态呈极显著负相关性,与残渣态呈极显著正相关性;RAC评价结果表明Pb在土壤中具有较高风险水平,其余重金属潜在风险水平较低。     

The effect of water content and cement content on the strength of portland cement-stabilized compacted fly ash

Class F fly ash, when combined with portland cement and hydrated, forms a high-strength material whose strength increases with increasing cement content and compaction effort, and is highest near optimum water content of around 20–30%. However, fly ash in stockpiles can be at a water content of around 50%, so completely drying to optimum water content may not be practical. If the material is left at its stockpile water content, the cement content required to achieve a given strength is about 2.5–3 times higher than the cement content required if compacting at optimum water content. However, strength can be predicted as a function of water content for water contents between the stockpile water content and the optimum water content.     

反式-1,4-聚异戊二烯的后处理及质量稳定化

研究了以式-1，4-聚异戊二烯（TPI）的后处理及老化对其相对分子质量及结构与性能的影响。结果表明，TPI极易老化，其相对分子质量随老化时间的延长而迅速降低，熔点及结晶度也逐渐降低。用空气、水、乙醇终止的聚合产物的相对分子质量及老化行为相近，防老剂264的加入极大地延缓了TPI的老化降解。TPI较理想而廉价的后处理方式为用定量水终止聚合，同时加入质量分数1%的防老剂264进行处理，可以保证TPI贮存过程中的稳定性。     

强夯法处理矸石地基的工程应用

通过强夯法处理矸石地基的工程实例,提出了系统的强夯法施工工艺,通过强夯提高了承栽力矸石地基,用作工业园区和新农村建设用地。结果表明强夯加固效果显著,且经济易行、施工便捷,值得推广使用。