Investigation of the redox performance of pyrite cinder calcined at different temperature in chemical looping combustion

As an industrial solid waste, pyrite cinder exhibited excellent reactivity and cycle stability in chemical looping combustion. Prior to the experiment, oxygen carriers often experienced a high temperature calcination process to stabilize the physico-chemical properties, which presented significant influence on the redox performance of oxygen carriers. However, the effect of calcination temperature on the cyclic reaction performance of pyrite cinder has not been studied in detail. In this work, the effect of calcination temperature on the redox activity and attrition characteristic of pyrite cinder were studied in a fluidized-bed reactor using CH₄ as fuel. A series of pyrite cinder samples were prepared by controlling the calcination temperature. The redox activity and attrition rate of the obtained pyrite cinder samples were investigated deeply. The results showed that calcination temperature displayed significant impact on the redox performance of pyrite cinder. Considering CH₄ conversion (80%–85%) and attrition resistance, the pyrite cinder calcined at 1050?℃ presented excellent redox properties. In the whole experiment process, the CO₂ selectivity of the pyrite cinder samples were not affected by the calcination temperature and were still close to 100%. The results can provide reference for optimizing the calcination temperature of pyrite cinder during chemical looping process.     

河南某硫酸烧渣制备氯化铁铵的试验研究

以河南某硫酸烧渣为原料, 采用盐酸浸出-浓缩净化-氯化铵诱导-冷却结晶工艺制备优级纯氯化铁铵晶体。实验所得最佳工艺条件为: 盐酸溶液浓度40%、液固比8∶1、浸出温度85 ℃、浸出时间40 min、氯化铵过量系数0.9, 此条件下原料中铁浸出率为91.43%, 所制备的氯化铁铵纯度达到99.85%。     

Effect of Biochar as Reductant on Magnetizing-roasting Behavior of Pyrite Cinder

The effect of biochar substituted for anthracite as reductant on magnetizing-roasting pyrite cinder was investigated.The key of magnetizing-roasting is the gasification reaction between reductants and CO2.Since biochar could react with CO2 more rapidly at lower temperature,the reactivity of biochar is better than that of anthracite.The gasification of biochar could produce reducing condition ofφCO/(φCO+φCO2)about 10%-20% between 700-800 ℃,which is in accord with the atmosphere and temperature of Fe2O3 reduction.So it is beneficial to the reduction of iron mineral of pyrite cinder.Compared with anthracite,biochar could decrease the roasting temperature from825 to 750 ℃ and roasting time from 20 to 15min,which shows that a better effect of magnetization could be obtained in the condition of lower temperature and shorter time.Using biochar as reductant,iron concentrate extracted from pyrite cinder as about 64%iron grade could be produced,and the recovery is over 90% under the condition of above 90% grinding particle less than 0.045 mm and magnetic intensity of 0.124-0.194 T.     

燃烧法测定炉渣中硫的含量

用燃烧─碘酸钾容量法测定炉渣中硫的含量．实验表明，同传统的重量分析法相比较．此方法具有迅速、简单、精密度和准确度高等优点．     

工艺参数对陶瓷透水砖性能影响的研究

采用煤渣、废瓷粒等工业废渣为骨料,以石灰石、白云石、长石、高岭土、石英和瓷石粉的混合料为高温粘结剂制备陶瓷透水砖,研究工艺参数对透水砖性能的影响。结果表明,随着煤渣用量的增加或成型压力的降低,透水砖的透水性能提高而机械强度降低。通过DTA-TG分析确定了在800℃保温4 h的优化烧成制度,有效避免了黑心和变形缺陷的产生。FE-SEM显微照片表明,合理的煤渣颗粒级配能使煤渣粗颗粒间形成孔径为0.5～1.5 mm的大气孔,而煤渣颗粒本身由于其中可燃物燃烧形成了孔径为数十个微米的微孔,这种特殊的结构赋予透水砖强度高、透水好的性能。     

浅析火山渣轻骨料砌块墙裂缝的防止措施

针对火山渣轻骨料砌块墙体裂缝状况进行调查并结合试验研究,从火山渣轻骨料砌块本身质量及其影响墙体变形,如温度、干燥收缩等性能和施工方面角度,分析了火山渣砌块填充墙裂缝的成因以及相应的防止裂缝措施.     

重钙粉对粉煤灰/煤渣轻质墙板氡污染的研究

建筑墙体材料是室内氡放射污染的主要来源之一,利用重钙粉对粉煤灰/煤渣的墙板氡污染进行防治研究,通过设计正交试验,对墙板氡浓度及抗折抗压强度进行分析。重钙粉的加入使墙板孔隙被填充,提高了墙板的密实性,氡释放量明显降低,而且对抗压抗折强度影响相对较小。重钙粉取材便利,成本低廉,应用于建筑粉煤灰/煤渣轻质墙板的氡污染防护,具有良好的应用前景。     

硫酸渣体系中氧化铅的氯化焙烧动力学研究

在1 025~1 175℃模拟硫酸渣的氯化焙烧过程,考察了氧化铅的氯化焙烧动力学行为。结果表明,在硫酸渣体系中,氧化铅的氯化反应受扩散控制,表观活化能为14.19kJ/mol。     

磷酸铵产品防结块的新措施

介绍了一种磷酸铵产品防结块的途径，通过将硫铁矿制酸中产生的废渣，添加在磷酸铵料浆中改善料浆黏性，在解决磷酸铵类肥料结块的同时，使得产品中W（H：O）≤3．0％，总养分不低于58％，满足产品的国家标准规定，实现了硫铁矿制酸装置废物用于磷酸铵装置产品防结块的循环利用。     

粉煤灰和矿渣粉双掺在高性能混凝土中的应用

结合工作实践,介绍了双掺技术在高性能混凝土中的应用,通过在高性能混凝土中掺入粉煤灰和矿渣粉,提高了混凝土工作性能、抗渗性能及其强度,并辅之以较好的质量控制措施,从而在项目上产生一定的经济效益和社会效益。