Optimization of Dry Ashing of Whole Blood Samples for Trace Metal Analysis

Dry ashing is an established method. Ashing whole blood samples are, however, often difficult to carry out with significant sample loss, and the procedure is not well documented. A new procedure has been devel- oped and optimized to dry-ash whole blood samples for trace metal analyses. The procedure reduces both the dry-ashing time by more than two thirds and sample loss. The ashed sample can be readily used in subse- quent, simultaneous or individual analysis of several metals by ICP-OES, as demonstrated in the analysis of a whole blood sample. The new procedure is simple, inexpensive, and faster than the established method.

Effect of Fly Ash on Drying Shrinkage of Thermal Insulation Mortar with Glazed Hollow Beads

Drying shrinkage of thermal insulation mortar with glazed hollow beads was measured by a vertical length comparator, and the influences of fly ash with different contents（0, 18%, 36%, and 54% were used） on the long-term drying shrinkage were discussed. The mass loss was measured by the weighting method and the pore structure was characterized using three different methods, including the light microscopy, the mercury intrusion porosimetry（MIP）, and the nitrogen adsorption/desorption（NAD） experiments, and the correlations among them were researched. The results show that drying shrinkage process of thermal insulation mortar includes three steps with increasing curing time： the acceleration period（before 7 d）, the deceleration period（7-365 d）, and the metastable period（after 365 d）. Drying shrinkage in the first stage（7 d before） increases quickly owing to the fast water loss, and its development in the last two stages is attributed to the increment of the pore volume of mortar with the radius below 50 nm, especially the increment of the pore volume fraction of the pore radius within the size range between 7.3 nm and 12.3 nm. There is no change in the drying shrinkage development trend of mortar with fly ash addition, and three steps in the service life, but fly ash addition in the mortar restrains its value. There is a linear relationship between the drying shrinkage and fly ash content, which means that drying shrinkage reduces with fly ash addition.

Research on physical and chemical properties and soundness of dry desulphurized fly ash used as a construction material

The physical and chemical properties and soundness of Baosteel Power Plant＇ s dry desulphurized fly ash were systematically investigated and compared with those of the similar byproducts produced by some other domestic power plants. The feasibility of these byproducts used as a construction material was also analyzed. The results show that Baosteel＇s dry desulphurized fly ash is a kind of ash with high calcium and high sulfur contents, which has the characteristics of volcanic ash activity. It contains sulfate and sulfite, and is easy to cause sulfate activation. It has higher activity compared with common fly ash. But higher calcium sulfite and free-CaO contents in ash will bring about soundness concerns to users. Therefore, quality tests and volume control will be necessary when fly ash is used as a construction material.

Application of Fly Ash and Organic Material as Dry Cover System in Prevention of Acid Mine Drainage Generation

The common practice in AMD prevention is a dry cover technique. In this technique, rock that is potential in producing acidity (PAF) will be placed below non-acid producing rock (NAF). Depends on NAF availability in the mine site situation, organic covers can be used to prevent diffusion of oxygen into reactive sulphide wastes and subsequently to eliminate sulphide compounds oxidation and generation of acidic waters. The utilization of additional material cover layer is proposed, by using fly ash and organic material combination. To investigate the possibility of using these materials, a column leaching test in the laboratory scale was conducted with several scenarios of simulation. By comparing between column with different thickness of fly ash and organic material, the leachate water behavior is observed in the experiment, including the measurement of water quality (pH and EC), major cations-anions. The result suggests the possible thickness of fly ash (FA) and organic material (OM) as cover layer material, especially in the case of mine with domination of PAF rock material.

Comparative Effects of Cocoa Pod Husk and Oil Palm Bunch Ash on Nutrient Uptake, Growth and Dry Matter Yield of Cocoa (The-obroma cacao) in Ibadan, Southwest Nigeria

The high premium placed on the organically produced cocoa in the international market coupled with its health and environmental benefits necessitated recent focus on research into the use of agricultural wastes as source of nutrients in cocoa (T. cacao) production. The study was carried out at the Cocoa Research Institute of Nigeria (CRIN), Ibadan (Lat. 7&deg25'N Long. 3&deg25'E), South-western, Nigeria during the 2010/2011 seedling production season to compare the effects of NPK (20:10:10) fertilizer, Cocoa Pod Husk and Oil Palm Bunch Ash (CPHA and OPA) on the seedling growth and dry matter yield of cocoa (T. cacao). Equivalent amount of different rates of two nutrients sources CPHA and OPA were applied one month after planting at 0, 1, 2, 3, 4 and 5 t/ha respectively, recommended rate of 10 kg·N of the conventional NPK (20:10:10). Fertilizer was used as reference fertilizer. Results indicated that all the fertilizer materials positively and significantly (p > 0.05) increased the growth parameters considered. The influence of the ash materials irrespective of sources on the nutrient uptake, dry matter yield of cocoa seedlings and shoot to root ratio were either higher than or had a comparable results with the reference fertilizer (NPK 20:10:10). CPHA and OPA applied at a rate of 4 t/ha significantly (p > 0.05) increased the plant height and root length of cocoa seedlings respectively relative to control and in—organic fertilizer and could therefore be recommended for the prospective and existing Nigerian cocoa farmers for raising their seedlings in the nursery before transplanting to the field.

Complex Processing of Pulverized Fly Ash by Dry Separation Methods

Pulverized fly ash (PFA) is produced about 500 billions tons every year in the world in a result of coals combustion. Most of the fly ash collected in power plants is disposed by deposition in landfills, situated as a rule near big cities with well developed infrastructure and high cost of land. Moreover, the pollution of environmental by fine solid wastes is inevitable and takes place in area of residing of a basic part of the population. The only solution is a complex processing of fine wastes with a production of value added materials. New conception of complex processing of PFA is proposed on the base of facilities of Electro-mass-classifier (EMC) and other techniques. The characterization of separated fractions was carried out by SEM and optic microscopy, XRD, laser diffraction, M?ssbauer spectroscopy and other methods. A fine fraction of glass microspheres presents the main interest as filler in various materials.

潮湿细粒煤复合式干法分选特性研究

为研究潮湿细粒煤复合式干法分选效率,对潮湿细粒煤进行了振动强度和气速的单因素试验,结合RSM-BBD预测模型获得了最优参数;并探索了不同水分的原煤在不同分选时间内的分选效果,同时分析了气流对潮湿细粒煤分选过程的影响,并评价了分选效果。结果表明:随着分选时长的增加,分选效果明显提高,最大灰分离析度可达12.05。试验煤样在气速为0.78 m/s,振动频率为25 Hz,振幅为3 mm时达到最佳分选效果,此时可能偏差E=0.135 g/cm^(3),且在此条件下分选产品有很好的脱水效果,复合式干法分选可实现潮湿煤炭的提质。该研究可以对细粒煤炭的干法分选工艺提供理论和技术支持。

锌浮渣干湿法处理工艺对比与干法处理工艺关键设备选型及应用

在湿法炼锌的工业生产中,电解阴极锌片在熔锌感应电炉内熔化除杂时产出副产品锌浮渣,锌浮渣中含锌约80%,其中70%以上锌以单质形态存在。本文对比了干法和湿法两种处理工艺的优缺点,重点介绍了干法处理工艺中关键设备选择和能力计算,并结合实际生产情况对投产后的工艺设备进行改进和完善。

地聚物混凝土干燥收缩性能及活性氧化镁补偿收缩研究

制备粉煤灰-矿渣基地聚物混凝土,并进行地聚物混凝土28 d抗压强度和干燥收缩测试,探究分析活性氧化镁含量、水玻璃模数、碱当量和矿渣含量对其抗压强度和干燥收缩的影响机理。结果表明:随着活性氧化镁掺量增大,地聚物混凝土28 d抗压强度下降,干燥收缩变形显著减小;与0%(质量分数,下同)活性氧化镁混凝土相比,掺量为3%、6%和9%时混凝土28 d抗压强度分别下降8.0%、8.2%和18.2%,干燥收缩分别减小21.5%、26.4%和38.2%,此外,当活性氧化镁掺量为3%和6%时,不仅有效补偿了干燥收缩,且抗压强度损失较小;随着水玻璃模数升高,地聚物混凝土28 d抗压强度和干燥收缩变形增大;随着碱当量升高,地聚物混凝土28 d抗压强度下降、干燥收缩变形增大;随着矿渣含量增加,地聚物混凝土28 d抗压强度增大、干燥收缩变形减小。综合考虑抗压强度及收缩的要求,建议实际应用中选择高活性、大掺量氧化镁,掺量宜控制在3%~6%。

电容器薄膜用聚丙烯原料微量元素分析方法

为了精确分析电容器薄膜用聚丙烯原料中微量元素,介绍了电容器薄膜用聚丙烯原料进行元素测定时的干法灰化法以及微波消解法两种预处理方法,比较了不同方法对分析结果的影响。对比了几种分析手段的特点,选择电感耦合等离子体质谱法作为分析手段。相比于干法灰化法,微波消解法的准确度和精密度都较高,微波消解法结合ICP-MS法适用于测定电容器薄膜用聚丙烯原料中的微量金属元素,建立了基于ICP-MS法测定电容器薄膜用聚丙烯原料中微量金属元素含量的方法。

改性瓦斯灰干法脱除NO的实验研究

用不同碱改性固体废物瓦斯灰制备出一种能够脱除烟气中NO的催化剂。考察了浸渍浓度、固液比、超声时间等制备条件对瓦斯灰脱硝性能的影响,并对材料进行了XRF、XRD、SEM、EDS-Mapping、FT-IR表征。结果表明,利用KOH改性的瓦斯灰脱硝性能最佳,在KOH浓度为2 mol/L、固液比为1∶2、超声时间为40 min的最佳制备条件下脱硝率约达100%。改性后,K成功负载在材料表面,瓦斯灰微观结构发生了变化,生成的新物质为NO的去除提供了更多活性位点。

钢铁行业钙基半干法脱硫灰渣资源化利用进展

对首钢和唐钢循环流化床(CFB)、密相塔(DFA)烟气脱硫灰氧化改性进行了深入研究,脱硫灰分的矿物相组成主要包括CaSO_(3)·0.5H_(2)O、CaSO_(4)、CaCO_(3)、Ca(OH)_(2),平均粒径为7.252μm、中位粒径(D_(50))为4.521μm、80%的粒子粒径处于1.039~16.162μm、比表面积为2.25 m^(2)·g^(–1),比表面积相对较大,且喷雾干燥(SDA)法脱硫灰粒径明显大于CFB与DFA法;脱硫灰含水率0.02%~0.36%,体积密度0.85~1.0 t·m^(–3),容积密度0.55~1.0 t·m^(–3),真密度2.25~2.69 t·m^(–3),压实密度为1.4 t·m^(–3);脱硫灰粒大小不一,形状多为不规则的小类球体且孔道直径在0.1~0.2μm.结合半干法脱硫灰理化性质系统表征、改性与工业化应用等成果,系统分析目前钢铁企业及其他半干法脱硫灰资源化利用研究的主要方向和进展情况,提出利用半干法脱硫灰制备多种新型材料实现半干法脱硫灰资源化利用.

干法脱硫灰制备高纯硫酸钙的实验研究

为了实现干法脱硫灰的资源化利用,通过亚硫酸钙氧化等工艺制备出了高纯硫酸钙粉体,并确定了最佳实验方法:将70 g脱硫灰投入300 mL水中,加入45 g过氧化氢,反应90 min,再加入550 g稀硫酸反应60 min。亚硫酸钙的转化率为97.86%,产品中硫酸钙的含量为98.84%。该工艺技术方法对干法脱硫灰的资源化利用具有较高的借鉴价值。

火焰原子吸收光谱法检测牛奶中钙方法的研究

准确检测牛奶中钙含量,进一步探究国标方法中干灰化法。[方法]通过单因素和正交试验,以牛奶中钙加标回收率为指标优化其检测方法,验证和应用该方法。试验结果表明镧溶液添加量2.5 mL,(1+1)硝酸溶液添加量5 mL,(180℃加热5 min、230℃加热5 min、300℃加热5 min、400℃加热10 min、500℃加热20 min)逐步升温炭化,550℃灰化4 h为最佳检测条件,可以保证检测结果的准确性。

干燥环境下粉煤灰混凝土表面假性碳化研究

回弹法检测混凝土强度需要测量混凝土表面的碳化深度,混凝土表面的碳化深度测量在干燥环境下将受到一定的影响。该文通过设置烘干组、干燥组、标养组试块及墩柱A、墩柱B进行回弹法试验。从试验中发现,干燥环境下混凝土的碳化,在喷上酚酞时出现明显分界线,随着时间推移,碳化区颜色变粉再变红,碳化分界线往混凝土表面移动。干燥环境下粉煤灰混凝土的碳化受三方面影响,一是由于水泥熟料占比减少,产生的Ca(OH)2减少;二是由于粉煤灰的二次水化消耗Ca(OH)2;三是干燥环境会进一步影响水泥的水化反应及碳化,导致Ca(OH)2结晶析出。

原料煤灰分含量对气流床煤气化的影响分析

分析原料煤灰分变化对气流床煤气化的影响对气化炉的设计选型、生产运行有重要意义。通过建立干煤粉气化炉和水煤浆气化炉的气化过程模型,研究了原料煤灰分发生变化时对有效气含量、产气量、氧耗等的影响。研究结果表明:在相同负荷及操作温度下,随着原料煤灰分含量的增大,两种气化炉的有效气产量降低,有效气含量未发生明显变化;干煤粉气化炉较水煤浆气化炉氧耗低,相较而言,干煤粉气化炉更能够适应高灰分煤种。

粉煤灰加气混凝土干燥收缩性能分析

为给粉煤灰加气混凝土应用提供导向数据,本文提出粉煤灰加气混凝土干燥收缩性能分析方法。以某厂家生产的粉煤灰加气混凝土砌块作为试验对象,按照不同砂浆类型和养护条件砌筑4面粉煤灰加气混凝土砌块墙,在200 d龄期内使用千分表获取不同砌块监测点处的收缩值。试验结果表明:粉煤灰加气混凝土砌块的干燥收缩值受其砌筑砂浆类型、养护条件以及环境温湿度和其初始含水率影响均较高,且在不同条件下,粉煤灰加气混凝土砌块的干燥收缩数值均随着龄期的增加而增加。专用砂浆和标准养护的粉煤灰加气混凝土砌块墙的收缩数值较低。

掺粉煤灰混凝土强度劣化试验研究

为研究掺粉煤灰混凝土的抗压强度劣化规律,以碎石、水泥、粉煤灰、中砂与自来水为原材料,制备掺粉煤灰混凝土试件。在碳化与干湿循环等环境作用下,利用万能压力试验机,展开试件强度劣化试验。试验结果表明:粉煤灰掺量未超过30%(包含30%)时,试件抗压强度未出现劣化现象;粉煤灰掺量超过30%时,粉煤灰掺量越多,试件抗压强度劣化程度越大。龄期延长,各试件抗压强度均有所提升;增加粉煤灰掺量,会提升试件劈拉强度的劣化程度;延长龄期,会减缓试件劈拉强度的劣化速度。增加水胶比含量,导致试件劈拉、抗压强度劣化程度提升;碳化作用下,试件抗压及劈拉强度有所提升,碳化时间为13 d时,试件抗压及劈拉强度达到峰值;干湿循环作用下,试件的抗压及劈拉强度均会出现劣化情况,粉煤灰掺量为30%时,试件的抗压及劈拉强度均值相对较高。

砂胶比对地聚合物砂浆强度与干缩性能的影响

为了研究砂胶比对地聚合物砂浆强度与干缩性能的影响,对不同砂胶比条件下砂浆的抗折强度、抗压强度、折压比、干缩率以及孔隙率进行了测试。实验结果表明,地聚合物砂浆的抗折强度和抗压强度随着砂胶比的增大而先增加后降低,且分别在砂胶比为0.4和0.2时达到最大;在探究范围内,折压比随着砂胶比的增大而增大;干缩率随砂胶比的增加呈现出先降低后升高的变化趋势,且砂胶比在0.3时最小;随着砂胶比的增大,地聚合物砂浆的孔隙率和孔径增大,砂浆的致密性明显降低。试验可为地聚合物砂浆的配比优化和后续研究提供有益参考。