回转窑直接还原煤的选择

综合国内外的研究和生产实践,本文提出了回转窑用还原煤的技术要求:选用还原煤的灰分软化温度必须高于窑内最高作业温度100—150℃;选用反应性高的煤;灰分含量应小于20％;挥发分含量20％—30％为宜;硫含量低于1.0％;膨胀指数不应超过1;煤的平均粒度应与矿石平均粒度相近;注意控制小于1mm的粉末量。     

关汉卿曾到河南考

关汉卿是我国13世纪伟大的戏剧家,元杂剧奠基人之一.由于历史的原因,有关这位伟大戏剧家生平事迹的记载甚少,只知他是大都人,曾任太医院尹,晚年曾去过杭州.现在根据有限的文献推断,关汉卿很可能到过河南.其依据是:第一,关汉卿曾任太医院尹,应随金皇室生活在开封;第二,关汉卿自己说“曾玩府游州“;第三,关汉卿说自己玩过梁园月,饮过东京酒,赏过洛阳花;第四,在关汉卿现存剧目中,有一半剧目的剧情与河南有关.由此我们可以相信,关汉卿心中确实有河南情结.     

提高含铟锌精矿中锌铟回收率的方法

从含铟锌精矿中提取锌和铟常用的2种生产工艺都存在工艺流程长、铟回收率低的缺点,为此,进行工艺流程改进.原料经中性浸出后在中性浸出渣中配入还原剂,经制团、干燥和高温还原挥发,使铟和锌富集于挥发物中再进行回收.中性浸出渣高温还原挥发最佳试验条件如下：还原剂的质量分数为15%～20%,还原温度为1 250℃,进料量为5kg/h.在此条件下,铟和锌的挥发率分别达到97%和95%.挥发物酸性浸出结果表明：锌和铟的浸出率分别达到98.53%和93.38%,锌和铟的总回收率显著提高.     

天光云影 摇荡绿波──析秦观词语工而入律特色

秦观词具有“入律”“语工”的两个特点,入律主要是通过韵辙、四声、五音、清浊轻重的和洽所表现的声情之美;“语工”既有符词随境赋形,声情谐畅的因素,也指用辞的整饬。这些对于词来说几乎是纯美的品质,可称醇正的词人之词。     

Influence of the Motion Behavior on the Contact Heat Transfer Between the Covered Wall and Solid Bed in Rotary Kilns

The effect of the transverse motion behavior on contact heat transfer was experimentally investigated in an indirectly heated batch rotary drum. Inside the drum, one rotating and one stationary measuring rod were installed, each assembled with 16 K-type thermocouples to measure temperatures. Thus, the radial and circumferential temperature gradients within the solid bed were measured, and the contact heat transfer was determined. As test materials, quartz sand, alumina, and cement powder were used, and the parameters filling degree (10–20%) and rotational speed (1–6 rpm) were varied.     

Mass Spectrometric Methods for Colorative Mechanism Analysis of Yaozhou Porcelain GlazeSCIEI北大核心CSCD

An in-house-built femtosecond laser ionization time-of-flight mass spectrometry (fs-LI-TOFMS) has been applied to the multi-elemental analysis of porcelain glaze from Yaozhou kiln. The samples are selected representing products of different dynasties, including Tang, Five, Song, Jin, and Ming Dynasty. For exploring the colorative mechanism of Yaozhou porcelain through the elemental analysis of the glaze, the effects of all potential coloring elements, especially transition elements, were considered. There was a speculation that the typical Co-Cr-Fe-Mn recipe was used in the fabrication of Yaozhou black glaze; the low content of Fe and high content of Ni resulted in the porcelain of white glaze; an increase content of P could lead the porcelain to be yellow-glazed. Undoubtedly, this research is an important supplement to the study of the colorative mechanism of the Yaozhou porcelain system.     

In situ Raman study of mineral phases formed as by‐products in a rotary kiln for clinker production

Portland clinker production consists essentially in the burning of material with defined composition in a rotary kiln at temperatures around 1450 °C. The main fuel used in this process is coal, even though in the last few years the use of alternative fuels has been increasing. Four main minerals are formed, namely, tricalcium and dicalcium silicate, tricalcium aluminate and tetracalcium aluminoferrite. Along with these main phases, variations in burning conditions of fuels or in the local composition of raw materials can lead to the formation of relatively high amounts of secondary by‐products, which can negatively affect the quality of the final material. Characterization of these by‐products allows not only optimization of the process of clinker production but also the design of special refractory materials for the wall of kilns and preheaters. Being found as particles included in (or alternating to) a hard solid clinker matrix, a detailed characterization of these extra phases could be achieved only via microscopic techniques. In this work, micro‐Raman spectroscopy has been successfully tested as a highly selective method for characterization and localization of included minerals that formed as overlapped crusts deposited on the internal wall of a conventional rotary kiln for cement production, without any manipulation of the sample. Understanding the chronological order of deposition of these overlapped layers is extremely important, as it is the only way to go back up to the production process and to individuate the problem. Copyright © 2008 John Wiley & Sons, Ltd.     

利用水泥回转窑处理危险废物

危险废物具有化学反应性、毒性、易爆性、腐蚀性等特性,会对生态环境和人类健康构成严重危害,焚烧法处理危险废物是众多方法中比较有效的方式之一,其中,利用水泥回转窑处理危险废物最有潜力,不论是对水泥和环境都没有负面影响,并且,许多危险废物燃烧后可提供部分水泥制造过程中所需的热能,不仅可以解决废物的污染问题,还可以降低燃烧费用及生产成本.本文综述了利用水泥回转窑处理危险废物的工艺过程、优势和国内外发展现状.     

木材干燥室内部风速场的数值模拟与优化

为了改善木材干燥室内部风速场的均匀性以提高干燥质量,对材堆到侧墙距离为0.30 m,风机风速分别为2.0、3.0、4.0 m/s的工况下木材干燥室内部风速场,采用Fluent进行数值模拟与分析,得到风速分布最佳时的工况。此外,在最优风速场工况下,通过改变材堆到侧墙距离(0.25、0.30、0.35 m),对试验结论进行验证。结果表明:对于顶风式木材干燥室,选择风机风速为3.0 m/s、材堆到侧墙距离0.30 m时,木材内部风速场最均匀,采用Fluent得到的模拟值与实际值相差不大。通过Fluent方法对木材干燥室内部风速场进行数值模拟,可有效优化风速场的均匀性。