埃塞DMC项目5 600 t/d熟料线的生产调试

埃塞俄比亚DMC项目5600t/d熟料项目是目前非洲单条线生产能力最大的,也是建设难度最大的生产线。简要介绍了该线的主要设备;重点就矿山长皮带、原料磨系统、煤磨系统和窑系统这四个系统生产调试中出现的问题及解决措施进行了分析介绍。经过一系列的生产调试和技术改造,现生产线各项指标均达到并超过了设计要求。     

液化温度对混合原料酒精高浓度发酵的影响

从液化温度对混合原料高浓度发酵的影响角度出发,分析了不同混合原料对液化温度的需求。通过试验表明,玉米原料采用105℃液化,而其他原料采用95℃液化,原料液化后再混合进行发酵的方式比原料混合后液化的方式发酵酒度提高7.2%。     

固定床煤气炉偏火偏灰的原因分析和措施

偏灰偏火是煤气炉日常操作中的"常见病"。煤气炉出现偏灰偏火的危害很大,处理恢复的难度同样很大。采取主动措施预防是关键。从工艺、设备、操作、煤质等方面分析导致偏火偏灰的原因。     

煅烧温度对牡蛎壳陶粒磷吸附效果的影响

研究主要是制备一种牡蛎壳陶粒,并考察煅烧温度对牡蛎壳陶粒除磷性能的影响。结果表明煅烧温度对牡蛎壳载体磷吸附效果的影响较大,当牡蛎壳粉末∶粘土∶九水硅酸钠=7∶2∶1,煅烧温度为450℃时,制备的牡蛎壳陶粒对磷的吸附量为0.155 mg·g-1。牡蛎壳陶粒对磷的吸附符合Langmuir等温吸附模型,且在25℃下最大吸附量为0.432 mg·g-1。最佳条件下制备的牡蛎壳陶粒具有良好的亲水性,吸水率可以达到18.64%、载体的抗压强度可以达到2.15 MPa、空隙率为41.2%、比表面积为5.71 m2·g-1、破碎率与磨损率之和为2.95%、含泥量为0.61%,这些指标均满足《水处理用人工陶粒滤料CJ/T 299-2008》的指标,可以将此牡蛎壳陶粒用到水处理当中。     

乙烯装置原料多样性优化分析

武汉800 kt/a乙烯装置在开车成功后,结合中原地区原料来源多样,原料组成复杂的特点,通过对原料组成和裂解炉产品收率分析,得到原料种类优化方向,并对裂解炉工艺操作等方面进行细化,配合原料多样性的调整。     

我国煤系针状焦原料预处理技术工业化研究进展

针状焦是碳素材料中的优质品种,是生产超高功率石墨电极的主要原料。原料预处理的目的是脱除煤沥青的喹啉不溶物,溶剂法和改质法是已经实现工业化生产的煤系针状焦原料预处理方法。文章主要就这两种方法在我国煤系针状焦生产企业中的研究进展进行介绍。     

Quantitative risk assessment of Campylobacter in broiler chickens – Assessing interventions to reduce the level of contamination at the end of the rearing period

The European Food Safety Authority (EFSA) has estimated that a proportion ranging from 20% to 30% of campylobacteriosis in humans may be attributed to the consumption of broiler meat and a reduction in the numbers of Campylobacter in the intestines of infected birds at slaughter by 3 log units would reduce the public health risk by at least 90%. In this study, a stochastic model was implemented to reproduce the dynamics of Campylobacter transmission in broiler flocks and explore the effects of several management conditions and/or on-farm mitigation strategies on the estimated level of contamination of infected flocks at slaughter. Results were expressed as ‘proportion of highly contaminated flocks’ (%HCFs) and estimated as a function of the proportion of infected birds in the flock the day of final depopulation and the individual level of contamination in infected birds. The effects of the mitigation strategies aimed at reducing the level of contamination in infected birds were modelled assuming that those effects are exerted on the distribution describing the bacterial load in infected birds. The impact of management conditions such as the adoption of enhanced biosecurity measures (B+) and/or partial depopulation during the production cycle (T+) were quantified using results of an extensive epidemiological study conducted in UK. A standard broiler flock was reproduced and used as baseline to make comparisons and simulate the effects of the mitigation strategies of interest. The baseline model predicted 18.8% probability of HCFs at slaughter. A positive effect ranging from −32.44% to −4.78% was attributed to B+ while T+ had negative effect ranging from +17.55% to +86.70%. When both the effects were tested simultaneously (B+T+), results were not conclusive with %HCFs ranging from −20.21% to +77.65%. When mitigation strategies operating on Campylobacter concentration in intestine were tested, a reduction of 100% and 99.6% in %HFCs were estimated following a generic treatment with bacteriocins and bacteriophages. Reduction in %HCFs as a function of immunization measures were explored and a reduction of 15% in the rate of transmission led to a %HCFs at slaughter reduced by almost 50%. The model was developed to be flexible, easily reproducible, updatable and adaptable to several baseline scenarios. The main parameters and assumptions underlying the baseline model were tested and a sensitivity analysis was performed to identify and discuss the impact that the uncertainty in the baseline information might have on the outcomes.     

半水磷石膏参与固化原状磷石膏制备复合胶凝材料

利用半水磷石膏（HPG）协同灰钙粉和水泥固化原状磷石膏（RPG）制备磷石膏基复合胶凝材料（PBCM）。采用单因素实验探究了HPG掺量对PBCM浆体性能的影响,并通过正交实验进一步探究各掺合料对PBCM强度及耐水性的影响。结果表明：HPG可作为RPG的固化材料,既高效又环保,掺量在20%（质量分数,下同）以上的HPG可彻底解决PBCM浆体的泌水问题,显著缩短浆体凝结时间,掺量在40%以上的HPG可有效改善浆体流动性;HPG、灰钙粉和水泥可有效提高PBCM强度,其中水泥对耐水性影响显著。微观形貌分析显示,PBCM的主要水化物二水硫酸钙和钙矾石晶体交织生长于RPG晶体之间,从而实现了对RPG的有效固化。     

铬铁原矿粉激光制备高熵合金复合涂层的组织与性能

目的用铬铁原矿粉快速直接制备高熵合金复合涂层,研究其组织结构及性能,提高基体表面硬度和耐磨性。方法采用激光熔覆技术在40Cr钢表面制备高熵合金复合涂层,运用金相显微镜(OM)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)及硬度计、磨粒磨损机,分析高熵合金复合涂层不同深度的显微组织、物相结构及力学性能。结果高熵合金复合涂层与基体结合良好,物相结构为简单BCC结构的过饱和固溶体,显微组织为典型胞状和树枝晶组织,且原位自生形成的细小碳化物颗粒强化相弥散分布于基体。深度为0.1 mm时,复合涂层的显微组织形貌最细小,且存在一定程度的成分偏析。复合涂层显微硬度平均为6.48 GPa,为基材40Cr钢的2倍以上。高熵合金复合涂层不同深度的磨损率均低于基体的磨损率,且随着深度的增加,磨损率逐渐升高,当深度为0.1 mm时,磨损率最低,为0.17 mg/mm2,耐磨性最好。结论以铬铁原矿粉为掺杂组元,采用激光熔覆技术成功制备出掺杂原位自生颗粒强化相的高熵合金复合涂层,显著提高了基体表面硬度和耐磨性。     

水运工程施工中的混凝土质量的影响因素及对策探讨

随着社会经济的快速发展,水运工程的建设得到了良好的发展契机。混凝土的质量优劣与工程设施的质量息息相关,同时也对工程的整体质量起着决定性的影响。笔者就影响混凝土质量的几个因素进行了分析,并提出了几条合理化的建议。