我国煤中氯含量分布特性的试验研究

在比较了煤中氯含量的测定方法后，确定了采用国标里煤中氯的测定方法之一－艾士卡混合剂熔样－磙氰酸钾滴定法测定煤中的氯含量，测定了41种我国煤中的氯含量，分析了煤中氯含量与有机物与无机物之间的关系。     

煤中氯的赋存形态与释放特性的研究进展

从煤中氯的赋存形式、测定方法、释放特性和控制技术等方面,对国内外的煤中氯研究现状进行了评述到目前为止,氯在煤中的赋存形式仍未有统一的结论,但都认为燃烧过程煤中氯主要以氯化氢的形式释放,将对燃烧设备燃烧区、加热器等部位产生腐蚀并污染环境．研究结果表明采用洗煤技术可以有效降低煤中的氯含量．     

艾氏剂分解——沉淀滴定法测煤中的氯含量

探索了“沉淀滴定法”测定煤中氯含量的最佳条件，测得氯含量在０．１￣１．０ｍｇ时，回收率可达９８％以上。     

分光光度法测定PVB中微量氯含量

建立了PVB树脂中氯含量的测定方法.采用添加混合试剂高温灰化,沸水浸取,分光光度法测定PVB树脂样品中的氯含量.该方法具有良好的精密度和准确度,分析成本低.     

不同电位滴定装置测定煤中氯含量的探讨

介绍了高温燃烧水解-电位滴定法测定煤中总氯含量的方法,探讨两种不同电位滴定装置测得的煤中氯含量的区别。通过多个实验结果的比对,采用两种电位滴定装置测得的煤中氯含量的差别不大,结果准确。     

煤中氯的赋存形态与释放特性的研究进展

从煤中氯的赋存形式、测定方法、释放特性和控制技术等方面,对国内外的煤中氯研究现状进行了评述。到目前为止,氯在煤中的赋存形式仍未有统一的结论,但都认为燃烧过程煤中氯主要以氯化氢的形式释放,将对燃烧设备燃烧区、加热器等部位产生腐蚀并污染环境。研究结果表明采用洗煤技术可以有效降低煤中的氯含量。     

煤炭直接液化产品中氯含量测定

采用高温裂解燃烧/离子色谱法建立了测定煤直接液化产品微量氯含量分析方法。样品在高温裂解燃烧炉燃烧,其中氯化合物生成HCl气体或Cl2,经水吸收形成含Cl-的水溶液,离子色谱测出水溶液中的Cl-含量,进而计算出样品中的氯含量。优化的测定条件:燃烧炉温度1300℃,燃烧时间10 min,载气流速1.5 mL/min,样品进样量为0.10～0.16 g。2种不同添加量加标样品的平均回收率为106.61%和94.82%,分析结果的相对标准偏差为3.24%和0.18%。通过对多种煤直接液化产品氯含量分析,获得了煤液化产品中氯含量分布信息。     

能量色散X射线荧光光谱法测定煤中氯的应用初探

探讨了能量色散X射线荧光光谱法测定煤中氯含量的试验方法。采用煤中氯成分分析国家一级标准物质单配及混配结合的方式绘制校准曲线。采用微晶纤维素与煤样混合、硼酸镶边垫底粉末压片法制备样片。结果表明：应用能量色散X射线荧光光谱法测定煤中氯含量操作简便,单个样品测定时间仅需5～7 min;随测定次数及时间的增加,煤中氯含量的测定值逐渐增高,制备好的样片应及时放入干燥器中保存并尽快测定;应用能量色散X射线荧光光谱法测定5种煤中氯标准物质,其测定值均在标准值的不确定度范围内,测定结果准确,值得后续加大研究力度并推广应用。     

阻燃聚氨酯软质泡沫塑料中氯含量的测定

叙述了阻燃聚氨酯软质泡沫塑料中氯含量的测定方法:在助燃剂存在下,氧瓶燃烧使聚氨酯软质泡沫塑料中的有机氯转化为HCl,用稀NaOH吸收,使用硫氰酸汞分光光度法测定聚氨酯软质泡沫塑料中阻燃剂的氯含量。该方法简单快捷、精确度高,回收率为99.64%～102.41%。     

结晶次氯酸锑分析方法探索

在次氯酸锑的测定中，用酒石酸根离子或酒石酸使不溶性锑变成可溶性锑后，利用容量法可对次氯酸锑中的锑和氯含量作出令人满意的测定，文中较详细地介绍了测定方法和可行性。     

Total chlorine in coal seam profiles from the South Staffordshire (Cannock) coalfield

In a coalfield of noted high-chlorine coals, seam profiles were taken from two collieries. Three seam profiles from each colliery were analysed for total chlorine to try to correlate chlorine level with position in the seam. Moisture contents and ash yields were determined for four of the seams. Total chlorine is highest in the coals, reaching 1 wt%, and low in the mudrocks, down to 0.08 wt%. Intermediate chlorine values are associated with dirty coals and carbonaceous mudrocks. Water centrifuged from an intraseam dirt band showed that the moisture held the total chlorine content. Similar element ratios were achieved from water centrifuged from coal. These results, together with National Coal Board groundwater data, suggest that the majority of chlorine in coal has been introduced by chloride-rich groundwaters which evolved during diagenesis, as has been suggested for Illinois and Nottinghamshire coals. There is a very significant positive correlation between coal moisture and total chlorine contents. Total chlorine levels are thus thought to be controlled by groundwater concentration levels and coal porosity, hence the positive relationship between organic carbon and chlorine concentrations. Total chlorine levels vary through the seams, but there is not a consistent change with position in the seam. There exists a correlation between coal type and total chlorine content. Bright coals hold significantly more chlorine than dull coals, owing to different porosities of the coal macerals. Departures from this relationship with coal type may be explained by mineral matter dilution or the ingress of recent groundwaters, overriding the original coal type-chlorine relationship.     

The removal of chlorine from Illinois coal by high temperature leaching

This paper describes our current research into the removal of chlorine from Illinois coal in an economical and environmentally acceptable manner using a high temperature leaching technique. The process variables studied are: water temperature, coal particle size, chemical additive and coal type. The experimental data indicate that the chlorine removal efficiency is increased by higher temperatures (up to 93.3°C) and is increased with smaller particle sizes (minus 100 mesh). Furthermore, the time required for the leaching process to reach equilibrium is dependent upon the amount of soluble chlorine in coal. By adding 1.5% CaO (based on coal), a considerable improvement in chlorine removal is observed. Based on the determination of coal characteristics before and after leaching, it was found that a sufficient amount of chlorine can be removed from coal to meet the design criterion of chlorine for Illinois Number 6 coal, which is set at a level of 0.2%. The quality of coal is actually improved after leaching due to a reduction in ash content.     

Estimation of the inorganic-to-organic chlorine ratio in coal

Dimethyl sulphoxide is demonstrated to quantitatively extract soluble chloride salts from coal whereas water does not completely leach such salts. The chloride held by ion exchange is also extracted if 0.1 M KNO₃ is included in the DMSO. The use of DMSO as a solvent therefore provides a means for determining the inorganic-to-organic chlorine ratio in coal by comparing the extracted to the total chlorine concentration in a sample. The latter value is determined by an independent method.     

煤碳中氯的测定方法探讨

用Na2C03为灰化剂，NaOH为熔剂，以标准加入比浊法测定煤炭中的氯。解决了使用艾氏卡熔剂空白值高，测定低含量氯方法不稳定的问题。本方法经国家一级标准物质验证，分析结果与标准值基本相符。方法适用于0.005％-1％各种煤样的测定。     

含氯废弃物燃烧过程中HCl排放特性

引　言生活垃圾中含有的有机氯主要以PVC塑料的形式存在 ,我国塑料制品中PVC占 30 %以上 ;无机氯通常以NaCl的形式存在于厨余中 ,单独焚烧厨余物 (主要含无机氯化物 )会导致大部分氯化物转化为HCl[1] .郭小汾等[2 ] 研究了PVC的燃烧特性和HCl的析出机理 ,认为PVC的燃烧过程分为     

Mercury transformation across particulate control devices in six power plants of China: The co-effect of chlorine and ash composition

This paper presents the results of field measurements on mercury speciation in six power plants of China by applying the Ontario hydro method. During the tests, flue gas was sampled simultaneously before and after particulate control devices (electrostatic precipitator and fabric filter baghouse) along with the pulverized coal, bottom ash and fly ash sampling. The amount of oxidized mercury in gas phase before and after ESP/FF suggests that mercury oxidation after combustion is a kinetically controlled process. The comparison of mercury speciation in different power plant indicates a clear relationship with coal type, especially the chlorine concentration and the basic ash compositions in coal. Both of the factors are analyzed quantitatively in this study. A new parameter C (ratio of chlorine in coal to base/acid ratio) has been introduced to evaluate the co-effect of the two factors above on mercury speciation.     

Distribution of water-soluble chlorine in coals using stains and acetate peels

A technique has been developed to show the distribution of readily leachable chlorine in high chlorine coals using silver nitrate as a stain. Acetate peels may be taken of the precipitated silver chloride for closer investigation of the relations between the water-soluble chlorine and the coal lithotypes. High chlorine coals from Yorkshire Main Colliery (Barnsley Seam) and Thoresby Colliery (Top Hard Seam), showed that the durain fraction of coal will rapidly yield at least some of its water-soluble chlorine. However, vitrinite is the major host of water-soluble chlorine and the predominant component of bright coal. Bright coal shows no water-soluble chlorine component. This apparent discrepancy is explained by the size and distribution of pores and the permeability of different coal macerals. The water-soluble chlorine component is believed to be a NaCl solution held within coal pores. Pores found within the dull coal are much larger than those found in bright coal especially where the former has a high detrital mineral matter component. Bedding planes within durain bands which are coated by fossil remains or thin fusain layers are seen to be the major contributory fractions of the dull coal.     

烯丙氧基单草酰氯分析方法研究

建立了间接法测定烯丙氧基单草酰氯的新方法。用苯提取样品中烯丙氧基单草酰氯,提取液在氢氧化钠溶液中水解,用汞量法测定水解出的氯离子,计算出烯丙氧基单草酰氯的含量。该方法的RSD为1.1%,测定结果与色谱法测定结果无显著差异,方法简便快速。     

Transformations of sodium during gasification of low-rank coal

Specially prepared forms of a high-sulphur South Australian lignite containing sodium in two forms; as a carboxylate, forming a part of the coal organic matter or as soluble salt (NaCl) were investigated. The influence of gasification environment (gas type, temperature and time) on the transformations of sodium and the extent of vaporisation were studied. Contrary to theoretical equilibrium calculations for the high levels of sulphur present in the coal, no sodium sulphide formation was found upon the transformation of carboxylate sodium. Experiments confirmed rather the formation of sodium carbonate during gasification or pyrolysis of the sulphur-rich coal. Sodium was found to evaporate, with sodium release higher during gasification in steam or carbon dioxide than for pyrolysis in nitrogen. The release of sodium and chlorine from coal containing sodium chloride was disproportionate. Almost all of the chlorine was measured to have been released during gasification and pyrolysis by 850 °C. The release of sodium was nearly half of that of chlorine and inferred to be in the form of sodium chloride vapour. Identification of sodium carbonate in the residual pyrolysed char confirms the reaction of sodium chloride with hydrogen from coal carboxylic acid groups. Neither sodium sulphide nor sodium hydroxide was identified in char for coal containing sodium chloride.