铁尾矿对矿渣纤维制备中熔体流动性的影响

 为了探究以铁尾矿为调质剂制备高炉渣基矿渣纤维的可行性及最佳工艺参数，测定了不同铁尾矿添加量时调质高炉熔渣的变温黏度，研究了铁尾矿添加量对调质高炉熔渣黏度、流动度、质点移动活化能及渣系结构的影响。结果表明,随着铁尾矿添加量的增加，调质高炉熔渣的黏度逐渐增大，流动度逐渐减小；渣系质点移动活化能随着铁尾矿添加量的增加呈先增大后减小再增大的趋势；综合考虑矿渣纤维的质量和成纤条件的可行性，调质剂铁尾矿的最佳添加量为20%。     

Comprehensive recovery of metals from cyanidation tailing

Cyanidation tailing is the residue produced in gold plants which use cyanidation to extract gold. It can be used as a secondary resource to recover residual metals that are of great economic value. The cyanidation tailing investigated in this paper was obtained from Shandong Province, China. It contained valuable metals such as chalcopyrite, galena, sphalerite and pyrite. In this study, alkaline sodium hypochlorite was used as a regulator in the pretreatment stage. It was proved that the sodium hypochlorite played two roles in the flotation pulp: oxidant and pH regulator. On one hand, sodium hypochlorite oxidized cyanide to cyanate, eliminating the negative effect of residual cyanide towards the environment. On the other hand, with the pH of flotation pulp exceeding 10, sphalerite and pyrite were depressed enormously, which was beneficial to the recovery of chalcopyrite and galena. With the Cu–Pb bulk flotation flowsheet, the cyanidation tailing was processed to obtain qualified Cu concentrate with grade of 13.17% and recovery of 70.00% compared with the original Cu grade of 0.21%. The Cu–Pb tailing was processed to obtain qualified Zn concentrate with grade of 34.72% and recovery of 69.58% compared with the original Zn grade of 0.33%, constituting the comprehensive recovery routing for the cyanidation tailing.     

尾矿浆浓度与超声波衰减系数的关系研究

针对目前基于超声波法的尾矿浆浓度测量方法没有直接表达浓度与散射衰减系数、黏滞衰减系数的相关关系的问题,采用数值计算方法,研究了超声波在尾矿浆中的衰减特性,得到了声波衰减系数与浓度的相关关系,并通过实验数据的分析论证了数值计算的准确性。研究结果表明:浓度在10%以内时,浓度越大,声速越小;浓度在5%以内时,超声波的衰减系数与浓度近似成正比关系;当超声波频率、粒径一定,浓度在10%以内时,浓度越大,超声波的衰减系数越大。研究结果为超声波在尾矿浆浓度在线监测中的实际应用提供了依据。     

Study on seismic performance of rectangular concrete-filled steel tube columns made with tailings and recycled aggregates

为研究矩形截面钢管尾矿砂再生混凝土柱的抗震性能，设计并制作了6个该类柱试件并对其进行拟静力试验，变化参数为再生粗骨料取代率(0%，50%，100%)和轴压比(0.3，0.5)。观察了矩形截面钢管尾矿砂再生混凝土柱变形和破坏形态，分析了其滞回曲线、骨架曲线、承载力退化、刚度退化、延性及耗能能力等。采用ABAQUS软件对矩形截面钢管尾矿砂再生混凝土柱抗震性能进行有限元分析，并与试验结果进行对比，验证有限元模型的合理性。试验研究及数值分析结果表明：矩形截面钢管尾矿砂再生混凝土柱变形过程及破坏形态与普通钢管混凝土柱相似，表现为柱脚的鼓曲变形；轴压比为0.3时，再生骨料取代率为50%和100%的柱峰值荷载较取代率为0%的柱分别降低8.3%和13.1%；轴压比为0.5时峰值荷载较轴压比为0.3时降低约9%；平均位移延性系数接近2.7，说明其具有良好的变形能力；矩形截面钢管尾矿砂再生混凝土柱具有良好的抗震性能。     

Fecal indicator bacteria and Salmonella in ponds managed as bird habitat, San Francisco Bay, California, USA

Throughout the world, coastal resource managers are encouraging the restoration of previously modified coastal habitats back into wetlands and managed ponds for their ecosystem value. Because many coastal wetlands are adjacent to urban centers and waters used for human recreation, it is important to understand how wildlife can affect water quality. We measured fecal indicator bacteria (FIB) concentrations, presence/absence of Salmonella, bird abundance, and physico-chemical parameters in two coastal, managed ponds and adjacent sloughs for 4 weeks during the summer and winter in 2006. We characterized the microbial water quality in these waters relative to state water-quality standards and examined the relationship between FIB, bird abundance, and physico-chemical parameters. A box model approach was utilized to determine the net source or sink of FIB in the ponds during the study periods. FIB concentrations often exceeded state standards, particularly in the summer, and microbial water quality in the sloughs was generally lower than in ponds during both seasons. Specifically, the inflow of water from the sloughs to the ponds during the summer, more so than waterfowl use, appeared to increase the FIB concentrations in the ponds. The box model results suggested that the ponds served as net wetland sources and sinks for FIB, and high bird abundances in the winter likely contributed to net winter source terms for two of the three FIB in both ponds. Eight serovars of the human pathogen Salmonella were isolated from slough and pond waters, although the source of the pathogen to these wetlands was not identified. Thus, it appeared that factors other than bird abundance were most important in modulating FIB concentrations in these ponds.     

尾矿玻璃对碳化硅和二硅化钼侵蚀机理研究

运用静态实验的方法，以尾矿玻璃熔体对碳化硅和二硅化钼耐火材料进行了侵蚀试验．利用X射线衍射、扫描电镜等方法，对侵蚀前后的耐火材料的晶相组成和显微结构进行了研究，探讨了尾矿玻璃对耐火材料的侵蚀机理．实验结果表明：尾矿玻璃对耐火材料的侵蚀是一个复杂的物理化学过程，耐火材料不仅受到玻璃液的物理侵蚀，同时还受到其化学侵蚀．     

桃花岛面源污染示范工程的汇处理系统设计

汉阳地区桃花岛示范工程的汇处理系统是为了净化源处理系统所收集的雨水和道路排水。汇处理系统的设计包括人工湿地系统设计和多塘系统设计。人工湿地设为2组,其中,水平潜流人工湿地处理水量为560 m3/d,面积为4 500 m2;复合潜流人工湿地处理水量为700 m3/d,面积为5 200 m2。系统出水水质达到《再生水回用于景观水体的水质标准(CJ/T95—2000)》。     

NATURAL SEWAGE TREATMENT IN THE UK: SELECTION GUIDELINES

The design of septic tanks, constructed wetlands, waste-stabilisation ponds and rock filters is detailed, and their applicability in the UK is discussed. Septic tanks are a suitable primary treatment system for villages with a population of less than 500. Constructed wetlands, which are secondary or tertiary treatment units, have the disadvantage that their plants do not play any significant role in their performance, except for nitrogen removal. Secondary facultative waste-stabilisation ponds, with pre-treatment in septic tanks and post-treatment in rock filters, provide primary, secondary and tertiary treatment and can produce high-quality effluents. The costs of these processes for small rural communities in the UK are compared.     

AERATED ROCK FILTERS FOR ENHANCED AMMONIA AND FAECAL COLIFORM REMOVAL FROM FACULTATIVE POND EFFLUENTS

Nitrogen removal from wastewater is rapidly becoming an essential but expensive upgrade for many small wastewater treatment works in the UK. Using a pilot-scale waste stabilization pond effluent, this paper highlights a low-cost upgrading unit, capable of removing BOD, SS, ammonia and faecal colliforms. Results are given for 12 months of operation and it is suggested that these units could be used by the water companies when ammonia removal is necessary to meet with current legislative demands and prevent eutrophication of receiving watercourses.     

Waste Stabilization Ponds: A Viable Alternative for Small Community Treatment Systems

Waste stabilization ponds are widely used in many European countries, such as France and Germany, for the treatment of wastewater from mainly small communities. There would seem to be no reason why they should not also be a suitable treatment process for populations of under 2000 in the UK. The relative advantages and disadvantages of ponds are compared to other small community treatment systems, such as rotary biological contactors, biological filters and reed-bed systems, particularly in relation to effluent standards with respect to algae, nutrient removal and relative costs.