新城金矿改扩建工程设计总体布局

本文根据新城金矿矿体赋存特点及矿山生产现状,论述了改扩建工程设计的总体布局,并提出改扩建工程建成投产后矿山应注意的几个问题。     

钢铁企业改扩建工程总图设计探讨

根据酒钢公司不锈钢扩建工程的设计实例,介绍了钢铁企业改扩建工程总图设计的方法和特点.     

紫金109m^2焙烧炉封顶

2008年9月15日，巴彦淖尔紫金20万吨／年改扩建工程又一全国最大的109m^2鲁奇式焙烧炉最后一块高铝砖砌进炉顶，焙烧炉成功封顶，标志着该项改扩建工程火法系统的“龙头”——焙烧炉具备了开炉条件。     

巴彦淳尔紫金20万t／a改扩建工程109m^2培烧炉成功封顶

9月15日上午9时30分，巴彦淖尔紫金矿业集团20万t／a改扩建工程又一座全国最大的109m^2。鲁奇式焙烧炉最后一块高铝砖砌进炉顶．炉子成功封顶，这标志着该项改扩建工程火法系统的“龙头”——焙烧炉具备了开炉条件。     

粘胶废水处理系统改扩建工程设计介绍

本文介绍粘胶废水处理系统改扩建工程的设计 改扩建设计将原工艺中生化处理部分的传统活性污泥法改为SBR法 ,只需新建一座均合池和四座SBR反应池中的二座 ,就使得污水处理能力由 2 5 0 0 0m3/d增加到 45 0 0 0m3/d .而且出水水质仍能达到辽宁省污水排放标准     

鞍钢世界级钢铁企业竞争力第8位

鞍钢在世界级钢铁企业竞争力的最新排名中列第8位。4月1日，鞍钢西部改扩建工程——炼钢连鞍铸一号系统将生产出第一块优质钢坯。为鞍钢增加更强劲的竞争力。     

新疆万吨镍冶炼技改扩建项目开工

10月13日,新疆新鑫矿业股份有限公司万吨镍技改扩建工程冶炼新工艺技改扩建项目在富蕴县喀拉通克铜镍矿开工。     

大型井巷贯通工程测量实践

贯通测量是井下矿山开采中最重要的测量工作,它是所有其它开采工作的基础。金山金矿在2002年进行第四期改扩建工程中,曾经在116米副斜井0m中段与150m东风斜井相连通的大型井巷施工中,实现成功贯通。本文就贯通工程的测量工作中要注意的事项与同行探讨。     

刚果(金)某铜钴湿法冶炼改扩建工程总图设计实践和分析

以刚果(金)某铜钴湿法冶炼改扩建工程总图设计的实践为例,阐述了改扩建设施与厂区现有区域之间的内在联系。结合铜钴湿法冶炼厂的特点和场地地形因地制宜进行总图设计,分析总结了该类铜钴湿法冶炼改扩建工程总平面布置和竖向设计的要点。     

魏家地矿改扩建工程施工管理

在魏家地矿改扩建施工施工中,通过优化设计,合理组织施工,解决了改扩建工程与原有工程的衔接问题,根据矿改矿建工程的地址条件及周围巷道的布置状况,进行了井段双层钢筋混凝土支护,基岩段为素混凝土支护,最大成都组织平行作业,通过437d,全面完成了改扩建及相关工程施工。     

Addition of Cobalt to Lead Anodes Used for Oxygen Evolution—A Literature Review

A review of the literature dealing with the effect of cobalt on lead-based anodes for oxygen evolution during electrolysis of sulfuric acid solutions verifies that the presence of cobalt at the anode–electrolyte interface, either as constituent of the anode material or as ions in the electrolyte, catalyzes the evolution of oxygen and reduces the corrosion of the anodes and the contamination by lead of metal cathodes produced during electrowinning. However, due to harmful effects of cobalt ions on the cathodic reaction in some processes, these benefits are limited to the electrowinning of copper. Efforts to develop a way of introducing cobalt at the anode–electrolyte interface without interfering with the cathodic reactions are reviewed in this paper. The use of lead–cobalt alloy anodes has had limited success due to issues arising from the low solubility of cobalt in lead, segregation during casting of the alloys, and nonuniform distribution of cobalt which affects the integrity of the anodes. This has been overcome in part lately by inclusion of cobalt into only the surface layer of a lead or lead alloy substrate, by thermal treatment of a cobalt salt to form a catalytic cobalt oxide surface species, or by electrodeposition of composite lead–cobalt oxide anodes. The last approach in particular has been actively investigated by several groups, but to our knowledge it is yet to find application in the industry. The review also critically examines the likely reaction mechanisms involved.     

A review of effects of silver,lead, sulfide and carbonaceous matter on gold cyanidation and mechanistic interpretation

Despite the wealth of published data on the beneficial or detrimental effects of silver, lead, sulfide, and carbonaceous matter on the rate of gold cyanidation at an anode or by dissolved oxygen, the lack of comparative studies on relative effects has hampered rationalisation of the role of these activators or passivators of gold. In the present study, the published rate data per unit surface area of gold, silver, and gold–silver alloys based on electrochemical or chemical dissolution of rotating discs or foils of constant surface area in aerated cyanide solutions at ambient temperatures are analysed on the basis of the Levich equation. The current status of the reaction mechanism is also reviewed and updated on the basis of species distribution and potential–pH diagrams, stoichiometric factors, and interim chemical species of gold(I), silver(I), and lead(II). The anodic peak potentials of reported voltammograms closely follow the potential–pH lines of Au(I)/Au(0) and Pb(II)/Pb(0) couples. Despite the formation of stable complexes between lead(II), nitrate, and hydroxide ions, the total calculated soluble lead(II) in alkaline solutions of pH range 10–11 saturated with lead hydroxide is shown to be < 0.1 g/m³. A comparison of the reported diffusion coefficients of cyanide ions and dissolved oxygen with the values based on the Levich plots of reported rates reveals the rate-controlling stoichiometric M/CN or M/O₂ molar ratios. The difference between some of these ratios and the generally accepted ratios of M/CN = 1/2 and M/O₂ = 1/0.5 or 1/0.25 based on the formation of M(CN)₂⁻, H₂O₂ or OH⁻ in the overall cyanidation reaction is attributed to the oxidation of cyanide to cyanate and passivation due to the formation of gold hydroxides/oxides. The alloyed or dissolved silver and lead eliminate passivation due to the involvement of mixed hydroxo–cyano complexes of silver and lead ions in the surface reaction. Gold dissolution by oxygen in cyanide-rich solutions is limited by oxygen diffusion, but enhanced by the presence of a low concentration of sodium sulfide due to the involvement of hydrosulfide ion in the surface reaction. However, excess lead or sulfide retards gold cyanidation due to surface blockage by metallic lead, lead hydroxide, or due to passivation by Au₂S/S. Even low concentrations of hydrosulfide passivate gold–silver alloys due to the formation of Ag₂S. This can be eliminated by adding stoichiometric quantities of lead(II) to precipitate sulfide as PbS. Large stoichiometric ratios of O₂/M for the cyanidation of graphite coated gold appears to be a result of the enhanced oxidation of cyanide by oxygen or hydrogen peroxide, leading to a cyanide deficiency at the surface and passivation of gold by hydroxide/oxide. The presence of excess cyanide or lead(II) does not override this effect.     

Sham reasoning, Humpty Dumpty, and the burden of proof.

Slife and Reber ask of psychologists that they recognize their prejudice against theism and the incompatibility between theistic and naturalistic worldviews. Yet, the subtext of their article is that theism and naturalism are equally valid and that psychology’s secularism is a mistake. Given that theism is not beyond reason, the only sufficient ground for charging psychologists with prejudice is if (i) theism has survived serious attempts at conceptual and empirical test, and (ii) psychology ignores or disguises this fact. So, the grounds for believing in the reality of a supernatural existent are highly relevant to the authors’ allegation. However, their concept of God affords no such grounds. They disavow the logic involved in the ordinary meaning of the term “incompatible” and they ignore a crucial distinction between conditions of existence and qualities of things or processes. The consequence is that either God is this-worldly, and there is no ontological basis to Slife and Reber’s incompatibility thesis, or God’s mode of existence is quite different from the mode of existence of ordinary things and all the problems of dualism follow. Either way, their charge of prejudice is without foundation. The burden of proof rests with the defender of theism and, for now, psychology’s secularism can be considered a mark of the discipline’s (sometimes questionable) rationality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Failure Resistance of Historic Stone Bridge Structure of Charles Bridge. II: Susceptibility to Floods

The paper is a follow-up to the first part devoted to an analogical problem investigated with a view to the degradation of the stone structure due to the effects of nonstress load, and it deals with the probability problem of the bridge structure collapse under the effect of an extreme flood wave. The paper presents the results of the numerical analysis of the response of the historic stone bridge structure of Charles Bridge of the 14th century to the flood wave effect simulated by angular rotation, subsidence, and shifting in the footing bottom of a bridge pier. Special focus is on the effect of interventions into the stone bridge structure dating back to the last major overhaul of 1967–1975, particularly, on the effect of the reinforced concrete slab (tie plate) connecting the opposite bridge breast walls increasing the rigidity of the breast walls and their structurally efficient connection to the vaults of the bridge arches. The numerical analyses performed point out the prevailing negative effects of the implemented interventions in terms of structural rigidity of the stone bridge structure exposed to the effect of a flood wave.     

Reliability-Based Design for External Stability of Mechanically Stabilized Earth Walls

A two-phase approach was used to develop a reliability-based design (RBD) method for external stability of mechanically stabilized earth (MSE) walls. In the first phase, a parametric study was conducted using Monte Carlo simulation to identify parameters that affect the probability of external failure of MSE walls. Three modes of failure were considered: sliding, overturning, and bearing capacity. External stability was assessed by treating the reinforced soil as a rigid mass using the same procedures employed for conventional gravity-type wall systems. Results from the parametric study indicate that the mean and coefficient of variation of the backfill friction angle are significant for sliding, the mean and coefficient of variation of the friction angle of the backfill and coefficient of variation of the unit weight of the backfill are significant for overturning, and the mean and coefficient of variation of the friction angle of the foundation soil and the mean of the backfill friction angle are significant for bearing capacity. In the second phase, a series of additional simulations was conducted where the significant parameters identified in the parametric study were varied over a broad range. Results of these simulations were used to develop a set of RBD charts for external stability of MSE walls. A comparison indicates that similar reinforcement lengths are obtained using RBD and conventional methods and that the inherent probability of external failure in conventional deterministic design is ? 0.001. This probability of external failure is similar to inherent probability of failure reported by other investigators for similar geotechnical structures.     

Response Surface Models to Detect and Localize Distributed Cracks in a Complex Continuum

Linear response surface (RS) models are used to represent the relationship between samples of response time histories measured by sensors placed across a structure. Different structural states of a general time-variant system are considered for short intervals capturing a linearized model of each state. Within this framework, the error associated with each RS model is sensitive to a modification of the structural state. A method that relates the changes of the statistical characterization of the error to the occurrence of a structural modification is developed for damage detection. The localization of damage is then pursued by identifying the largest discrepancies resulting from the comparison between the statistics of the sum of the squares of the error obtained at each sensor location. The generality of the method is shown by applying it to the experimental data of a realistic structure, which is representative of a continuous body affected by distributed cracking.     

New Orleans Levee System Performance during Hurricane Katrina: London Avenue and Orleans Canal South

Hurricane Katrina was one of the worst natural disasters in U.S. history. The effects of the hurricane were particularly devastating in the city of New Orleans. Most of the damage was due to the failure of the levee system that surrounds the city to protect it from flooding. This paper presents the results of centrifuge models conducted at Rensselaer Polytechnic Institute and the U.S. Army Corps of Engineers simulating the behavior of the levees at London Avenue North and South that failed during Hurricane Katrina. Those levees failed without being overtopped by the storm surge. Also included are the results of a centrifuge model of one levee section at Orleans Canal South, which did not fail during the hurricane. The key factor of the failure mechanism of the London Avenue levees was the formation of a gap between the flooded side of the levee and the sheetpile. This gap triggered a reduction of the strength at the foundation of the protected side of the levee. The results are fully consistent with field observations.     

铜,砷矿物类型对金氰化浸出的影响及如何提高其浸出率的探讨

本文引用了某些理论研究的成果，考察了含铜，含砷矿物在氰化溶液中的行为和对金氰化浸出的影响的规律，找出金浸出率与各种有害矿物含量的相关关系，为制定难选金工艺方案时参考。并结合小型试验和工业实践，对矿石性质作深入了研究，同时其浸出工艺条件也进行了最佳选择和应用，为提高金的浸出率进行了讨论。     

Measuring students' connectedness to school, teachers, and family: Validation of three scales.

Connectedness to school, teachers, and family are all significant protective factors in adolescents' lives, yet the measurement of each varies considerably. This article describes the measurement properties of three composite scales of adolescent connectedness, adapted from the Add Health study and the California Healthy Kids Survey. These composite scales are created by either summing or taking the mean of all individual items, measured on an ordinal scale. This approach fails to account for the ordinal, non-normal nature of the data. Using a covariance approach, this article describes the measurement properties of the latent constructs of connectedness to school, teachers, and family and the contribution of each of the items used to compile the relevant composite score. The outcomes of this study will provide researchers and practitioners with information about the validity, reliability, and overall usefulness of each of the measures of adolescents' perception of their connectedness to school, teachers, and family. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social psychoanalytic research and the twenty-first-century family: Comment on Wallerstein and Lewis (2007).

Seligman regards Wallerstein and Lewis' paper (see record 2007-10890-004) as an exemplary piece of social-developmental psychoanalytic research, finding it accessible, activist and empirical. He admires Wallerstein and Lewis' careful attention to the influence of social reality on the development of the internal worlds of both children and adults, following a psychoanalytic tradition which has been neglected recently. Since actual family configurations are changing so rapidly in the current American situation, analysts should develop new theoretical and research approaches that reflect these changing realities. Seligman highlights two specific implications of such adaptive shifts: the de-centering of the Oedipus complex as the standard form of psychosocial-family organization of the personality, and increased attention to the role of sibling relationships in development. He calls for more analytic clinical research efforts that will apply the substantial potentials of social-psychoanalytic research in service of the varying groups of children who are suffering in the midst of the array of psychosocial strains in the contemporary culture. (PsycINFO Database Record (c) 2010 APA, all rights reserved)