回收粉煤灰中未燃炭和降低碳含量的浮选研究

针对粉煤灰中未燃炭含量过高不利于大规模综合利用的问题,从理论上分析了浮选回收粉煤灰中未燃炭的基本原理,采用全浮选流程对粉煤灰中未燃炭进行了浮选回收试验,探讨了影响粉煤灰中未燃炭浮选效果的主要因素,确定了适宜的工艺条件。试验结果表明,采用全浮选流程可以使粉煤灰中可燃物降至4.1%左右。     

湿法分选粉煤灰中未燃炭的研究

本文介绍电厂湿排灰浮选脱炭的试验研究过程，目的在于优化二次分选粉煤灰中未燃炭的生产工艺，有效地指导本厂粉煤灰工程的施工和试产，从而生产出符合ＧＢ１５９６－９１的Ⅱ级粉煤灰。     

粉煤灰中未燃碳粒的浮选试验

针对神华宁夏煤业集团太西炭基工业有限公司自备电厂产生太西无烟煤基粉煤灰未燃炭含量偏高而不能直接利用的现状,对公司现有三种不同理化特性的粉煤灰进行了浮选脱碳试验研究。通过半工业化浮选试验,确定了初步的工艺流程,浮选脱碳后尾灰烧失量降至8％左右。     

某电厂粉煤灰浮选回收莫来石试验研究

某电厂粉煤灰中含有莫来石、石膏、石英、板钛矿、赤铁矿以及未完全燃烧的碳质,其中莫来石的含量为51％,试验对其进行回收.通过试验研究,采取预先脱碳、一次粗选、两次反浮选的浮选流程可以得到氧化铝含量为52.29％、回收率为79.65％的莫来石精矿,试验结果较为理想,可为粉煤灰的综合回收利用提供一种新的途径.     

用浮选柱分选高炭粉煤灰的试验研究

介绍了当前粉煤灰资源化利用中存在的未燃炭含量超标问题 ,比较了为解决这一问题而采用的浮选机和浮选柱两种工艺。试验结果得出 ,双射流浮选柱浮选工艺的各项技术和经济指标大大优于常规浮选机浮选工艺。分离出来的精炭比表面积为 63m2 /g ,微孔含量高 ,可与其它工艺结合用来处理废水 ,其生产成本明显低于商业活性炭。     

粉煤灰分选、脱炭及生产工艺研究

针对国内火力发电厂粉煤灰未燃炭含量过高的问题,对粉煤灰的理化特征、未燃炭在粉煤灰颗粒中的分布进行了研究,分析比较了不同分选、脱炭技术及分选、脱炭生产工艺流程,分析了粉煤灰分选脱炭的经济效益.     

粉煤灰及其混合料的路用性能分析

粉煤灰主要分为硅铝型和硫钙型两类.硅铝型灰具有火山灰性能,硫钙型灰具有水隐性能.对粉煤灰质量和工程性质有影响的成分是粉煤灰中的钙(游离石灰)镁含量和烧失量(未燃炭),游离石灰影响粉煤灰的火山灰反应,未燃炭则会影响其压实性能和强度.     

超声波辅助粉煤灰浮选脱碳

为了解决粉煤灰含碳高无法充分利用的问题,借助超声波对粉煤灰进行浮选脱碳。先用单因素试验,研究主要因素对粉煤灰脱碳的影响,再进行"一粗四精一扫"的全浮选工艺流程试验。结果表明:单因素试验矿浆质量浓度106.7 g/L、2号油用量976.5 g/t、煤油用量441.9 g/t、超声作用2min、浮选7 min时,浮选效果最好,获得精矿的烧失率和回收率分别为59.65%和68.41%,表明超声波能有效提升粉煤灰的浮选效果。"一粗四精一扫"试验获得精碳烧失率和回收率分别为75.96%和66.70%,实现了粉煤灰的有效回收。     

粉煤灰浮选脱碳试验研究

针对山东省胶南市双星热电厂产生的粉煤灰含炭量高而不能直接利用的现状,对其进行了浮选脱碳试验研究.通过小型浮选试验,确定了"一粗,一扫"的浮选流程,浮选脱炭后尾灰烧失量降低为4%以下.     

钾长石石英无氟分离工艺研究及工业化试验

本文以河南钾长石矿作为研究对象,探讨应用浮选药剂油胺进行钾长石石英浮选分离,实现无氟分选的环保型选矿工艺流程。试验结果表明,采用脱泥浮选—云母浮选—钾长石石英分离浮选的选矿工艺流程,可以综合回收钾长石与石英。在实验室工艺流程的基础上进行了工业化扩大试验,在扩大试验的调试过程中发现试验流程存在一些问题,经过不断改进,最终扩大试验技术指标与试验流程技术指标基本一致。     

粉煤灰中残碳的特性和利用

介绍了粉煤灰中残碳和富碳颗粒的特性和分离技术, 论述了残碳特性对颗粒分离和利用的影响, 分析了残碳的利用途径和前景。     

Separation of unburned carbon from fly ash using a concurrent flotation column

In this study, a new concurrent flotation column that simulates the plug flow reactor was designed with the use of a static mixer, a froth separator column and an optional additional bubble generator for fly ash beneficiation. The objective was to improve the efficiency and effectiveness of unburned carbon removal from fly ash by minimizing energy costs. Cleaning tests were performed with and without the additional bubble genarator. Without the additional bubble generator unburned carbon in the ash product could be reduced to only 2.53%. Incidental loss of carbon particles and insufficient bubble generation were the main causes of poor carbon separation performance. By turning on the additional bubble generator it was aimed to assist bubble generation, to compensate bubble rupture and to recapture the detached or free carbon particles leaving the froth phase. With the additional bubble generator and under optimized conditions a froth product with 95% carbon recovery and a cleaned ash product with less than 1% unburned carbon was obtained. The separation process through the static mixer (feeder) and the separator column and the energy consumption of the unit were analyzed. It was seen that around 80% energy could be saved with the concurrent flotation column compared to conventional flotation.     

利用差示扫描量热法测定CFBC脱硫灰中残留碳的研究

借助差示扫描量热分析仪对煤与高硫石油焦混烧排放的CFBC(循环流化床)脱硫灰的残留碳含量进行了测定,研究表明:(1)CFBC脱硫灰的热反应过程主要分为水分和挥发分逸出,碳氧化和矿物分解及继续反应等三个阶段.(2)是否含有氢氧钙石对CFBC脱硫灰的热反应过程影响很大,含有氢氧钙石的CFBC脱硫灰在碳氧化和矿物分解阶段(约...     

Microwave attenuation characteristics of unburned carbon in fly ash

Experimental research was conducted on the relationship between the unburned carbon content in fly ash and the microwave power attenuation at frequencies ranging from 1.0 to 4.0 GHz. The experimental results show that the unburned carbon in fly ash exhibits the frequency characteristics of microwave power attenuation. At some frequencies, the microwave power attenuation increases with the carbon content. At other frequencies, the relationship between them changes. There is also a range of frequencies where the loss decreases while the unburned carbon content increases. A detailed analysis on the mechanisms of this phenomenon is made based on the conductivity loss, absorption and dispersion theories.     

Simultaneous Removal of Heavy Metals and PCDD/Fs from Hospital Waste Incinerator Fly Ash by Flotation Assisted with Hydrochloric Acid

Hospital solid waste (HSW) incinerator fly ash was designated as a special controlled waste because of its high concentrations of toxic heavy metals, polychlorinated dibenzo-p-dioxins, and dibenzofurans (PCDD/Fs). Most of the PCDD/Fs along with carbon constituents including powder activated carbon and unburned carbon in fly ash could be removed by column flotation on the basis of their hydrophobicity. The feasibility of extracting heavy metals from fly ash by adding a little of hydrochloric acid to the slurry during the flotation process was examined in this paper. The results showed that the acidic pulp could contribute to the high extraction ratio of the heavy metals, but the performance of decarburization and removal of PCDD/Fs was inhibited at very low pH value. Given consideration to the removal of two toxic matter including PCDD/Fs and heavy metals in HSW incinerator fly ash, the appropriate pulp pH value should be controlled at about 5. After flotation, both PCDD/Fs and heavy metals in the tailings could simultaneously meet the permitted limits of a landfill site of municipal solid waste in China. It was suggested that flotation with the assistance of an appropriate amount of acid might be a potential technology for the treatment of HSW incinerator fly ash.     

Influences of Jameson flotation operation variables on the kinetics and recovery of unburned carbon

The purpose of this study was to investigate the influences of Jameson flotation operation variables on the recovery and kinetics of unburned carbon (UC). The waste sample of petroleum coke, filter powder or fly ash, used in the experiments was collected from lime calcination plant tailings. The effect of Jameson flotation parameters on the recovery and kinetics efficiencies of UC was systematically studied. The feasibility of separating unburned carbon and refuse was determined from the combustible recovery (CR) and ash reduction (AR) (%) curves. Within the range studied, the optimum diesel oil dosage was 3500 g/tonne, pine oil dosage was 2500 g/tonne, pulp density was 15%, wash water rate was 0.17 cm/s and downcomer immersion depth was 50 cm. The results indicate that the Jameson flotation technique is effective in removing the UC from waste filter powder. Furthermore, the classical first-order kinetic flotation model (R = R_∞ [1 − exp (− k ? t)]) was applied to data from the tests. The model was evaluated by statistical technique, after non-linear regression on the model parameters. It is found that the classical first order flotation kinetic model, most extensively used among flotation models, fits the tests data very well.     

煤粉炉和循环流化床锅炉飞灰特性对其汞吸附能力的影响

通过分析两台容量相近的循环流化床锅炉和煤粉锅炉飞灰样品的粒径分布、表面结构特性、未燃尽碳含量、反应性和汞含量，探究两种类型锅炉飞灰特性差异及其与飞灰汞吸附能力的关系。结果表明：循环流化床和煤粉锅炉尾端除尘设备排灰口飞灰汞的含量分别为1584.0 ng/g和503.7 ng/g，其原因与飞灰粒径、未燃尽碳含量和表面特性相关。对于循环流化床锅炉，飞灰中汞含量随其粒径和反应性温度的减小而增加，随未燃尽碳含量增加而增加，且与比表面积和吸附量呈正相关关系。对于煤粉锅炉，粒径为75～53 μm的飞灰对汞吸附能力较强，未燃尽碳含量明显小于循环流化床所产生飞灰的含量，飞灰比表面积随粒径变化不大，由此导致煤粉锅炉除尘设备排灰口所取样品对汞的吸附能力远低于循环流化床锅炉相对应位置飞灰对汞的吸附能力。     

粉煤灰脱炭的流态化实验研究

粉煤灰的利用价值与其残余炭含量密切有关 .在采用现代分析测试技术的基础上 ,提出了采用流态化干法脱炭技术降低粉煤灰中残余炭含量并提高粉煤灰活性的基本思路 .流态化分选实验表明 :这种干法脱炭的思路是有效的 ,这一思路将为解决我国粉煤灰的综合利用问题提供有益的借鉴     

软测量技术在电站锅炉优化燃烧上的应用

针对阜新电厂200 MW机组燃煤锅炉进行了多工况热态测试,获得了飞灰含碳量的现场数据样本,运用Back Propagation(BP)神经网络和Levenberg Marquardt(LM)算法建立了电站锅炉飞灰含碳量的软测量模型,并构造了飞灰含碳量的测量系统. 在此基础上开发了电站锅炉燃烧优化系统,实现了阜新电厂200 MW机组锅炉燃烧优化控制.