高铁硫化镍精矿富氧加压酸浸工艺研究

以高铁硫化镍精矿为原料,采用富氧加压工艺浸出铜、镍。研究液固比、硫酸浓度、氧压、温度与时间等条件对加压浸出过程的影响。结果表明对于粒度为-270目占95％以上,平均粒度为17.25μm的精矿,在LS=3：1,硫酸浓度50g／L,氧气压力12MPa,反应温度150℃,反应时间2h的条件下,镍、铜、钴的浸出率分别为：98.70％、80.30％、98％,Fe的浸出率控制在6％以下。     

陕西某高碳质金矿石氧化焙烧-氰化试验研究

论文以陕西商洛地区某高碳质金矿石为研究对象,采用焙烧-氰化法对高碳质金矿石进行金的浸取。分别考察了焙烧温度、焙烧时间、氰化钠用量、浸出时间对矿石中碳、硫脱除率及金的浸出率的影响。结果显示,在选定焙烧温度700℃,焙烧时间2h的条件下对原矿石氧化焙烧,矿石中碳的脱除率可达89.47%,硫的脱除率可达87.83%;在上述条件下,将焙砂冷却磨细至-200目~92%后氰化浸出,在浸出过程液固比2:1,矿浆p H=10~11,选取煤油用量400g/t,氰化钠用量400g/t,浸出时间18h的优化条件下,金的浸出率可达91.2%。     

某铀矿石不同氧化剂浸出对比试验

针对我国南方某铀矿该矿石进行室内以氯酸钾或菌液作为氧化剂的柱浸对比试验。结果表明,该矿石浸出周期较长,耗酸高,属难浸铀矿石。微生物浸出比化学氧化剂浸出耗酸仅高出0.14%情况下提高浸出率2.24%,缩短浸铀周期30天以上。综合浸出周期、浸出率、平均铀浓度等指标及工业化实际条件,认为微生物浸出方式可以作为该矿石的浸出方式。     

新疆某铜尾矿磁-浮联合选矿试验研究

新疆某铜矿原矿石属于难选细泥质混合氧化铜矿,浮选作业段产生的尾矿含铜0.21%,仍有回收价值。本文通过对浮选尾矿开展磁-浮联合选别试验研究,以品位为0.69%的磁选精矿作为浮选作业段的给矿,最终经"一粗二精三扫"的浮选流程得到了产率为0.456%、品位为9.98%、回收率为5.69%的铜精矿,最终选矿综合回收率提升至85.69%。     

细粒级低品位钽铌矿浮选研究

宜春钽铌矿细粒级低品位钽铌尾矿浮选试验研究,在原矿钽含量102ppm时,精矿1产率为1.12%,钽品位3330ppm,回收率36.61%,精矿中铌含量1210ppm,精矿2产率为1.72%,钽品位1620ppm,回收率27.24%。     

黄金：走入寻常百姓家

前不久,央行正式启动黄金价格周报价制度。近日,国家计委公布了《中央定价目录》,将部分商品和服务项目价格彻底放开。此次放开的产品包括:金精矿、金块矿、金银产品、足金饰     

部分金银制品采用“盎司”等非法定计量单位

正近日,国家质检总局公布了2013年对全国金银制品加工、销售和收购领域进行专项计量监督检查结果。检查发现,金银制品加工、销售企业计量器具不合格率分别为12.92%、11.29%,部分金银制品使用"盎司"等非法定计量单位。本次监督检查在生产单位和销售单位分别抽查金银制品样品9 278件和11.1 957万件。其中未使用法定计量单位的样品分别占0.64%和1.46%;在     

贵州某金矿硫代硫酸盐法浸金工艺研究

针对贵州安龙某金矿山矿样特点进行了硫代硫酸盐法浸金工艺研究,考察了硫代硫酸钠浸金体系中各个因素对浸金效果的影响,结果显示,在硫代硫酸钠浓度为0.7 mol/L,氨浓度1.2mol/L,pH值为10,浸出时间为5h,浸出温度为45℃的此条件下,金浸出率达到90%以上。     

黑色页岩中硫元素的浸出最佳实验条件探索研究

本研究采用盐酸浸出黑色页岩中的硫元素,考察了反应温度,液固比(v/w),酸的浓度和反应时间对硫元素的浸出效果的影响,根据实验条件,得出反应条件在20℃,液固比为4:1,盐酸浓度为1mol/L,反应时间为3小时的条件下,硫的浸出率达到38.38%。     

浅议难处理金精矿的酸性热压预氧化工艺

采用酸性热压氧化工艺对某难处理金精矿进行预处理，其金回收率可由常规浸出的35．6％提高到94.3％，很值得推广。     

金矿浮选中矿及尾矿再磨工艺改造实践

某金矿浮选系统采用一粗二扫一精工艺流程,根据流程考察结果分析,浮选回收率较低,扫选精矿的粗粒级品位严重偏高。根据某研究院实验结果,浮选系统确定采用一粗、一精、两扫,同时中矿再磨后浮选的工艺流程。     

铅试金法一次试金中金补偿系数研究

用铅试金法分剐对铜精矿、粗铜、镍精矿、低冰镍、高冰镍等冶金物料进行一次试金，将熔渣和灰皿进行二次试金，测得一次试金和二次试金所得贵金属合粒中的金量，得到一次试金中金的回收率。随样品中金量的增力口，一次试金中金的回收率随之增加。     

The influence of ETFs on the price discovery of gold, silver and oil

In this study we examine gold, silver and oil exchange traded funds (ETFs) and their relation to their respective futures instruments and underlying commodities by using intradaily data. We find that the gold, silver and oil ETFs closely track the performance of their underlying assets by using tracking error and pricing deviation metrics. It has been documented in the finance literature that price discovery occurs in the futures market. We test whether in recent times the existence of ETFs has changed the dominating role of the futures market in price discovery. We find that the availability of ETFs has shifted price discovery for gold and silver to the ETF market, while the oil market has price discovery occurring still predominantly in the futures market.     

Information from successive changes in gold and silver prices during phases of the business cycles

This paper concerns the behavior of gold and silver prices on a daily, weekly and monthly time span during January 1970 to December 1989. The methodology consists of extracting the predictive power of time series of changes in past prices for obtaining optimal forecasts for next-period changes in prices. Optimizations are made in the context of information theory via minimizing the degree of diversity between the actual and predicted changes in prices. This methodology has merit in that it does not rest on, generally speaking, unacceptable assumptions regarding the shape of the distribution, stationarity of variance or its existence. The behavior of gold and silver prices are studied during peak to trough and trough to peak of the business cycles over 1970–1989. It is generally shown that information contained in past prices of gold and silver does not allow one to predict next-period changes in prices in the short run. However, longer-term predictions are possible. This study further reveals that as the length of the time interval expands, gold prices exhibit a higher degree of dependency on past prices than silver.     

西岭秋喝银多金属矿矿床地质特征及找矿前景分析

西岭秋喝银多金属矿位于鄂拉山中段,是青海省铜、铅、锌、锡、金、银矿的重点规划区之一。长期以来,矿区仅进行金矿的普查工作,工作思路单一、局限性大,虽发现了多处金异常区,但没有实质的突破。通过对区内的以往资料的综合研究分析,结合邻区(索拉沟银多金属矿床)的找矿模式,进行了综合找矿,并取得了一定的突破。但从目前的矿体规模看,均为小矿体,因此能否在已有矿体的周围找到新类型矿床(就矿找矿),在浅成热液矿床或矿化蚀变的深部取得找矿的重大突破十分必要。在此基础上建立了该区的成矿地质特征,并对该区的成矿前景进行了浅析。     

白银外流、银钱比价与物价水平(1644-1850):基于计量史学的研究

本文尝试应用计量经济史学方法,以复本位下银钱比价浮动为研究轴线,以早期中外贸易引起的白银内外流动对银钱比价的影响为突破口,结合现代货币理论、经济学理论与最新计量方法,根据史料记载,分析论证清朝1644到1850年间,银钱本位币浮动的形成过程及其对经济社会、民众生活的影响。     

A note on forecasting the prices of gold and silver: Asymmetric loss and forecast rationality

Given that the prices of gold and silver have witnessed large and substantial swings in recent years, policymakers and investors need readily available and reliable forecasts of the prices of these two precious metals. Survey data of forecasts of the prices of gold and silver provide a particularly rich data environment for policymakers and investors to study developments in the markets for gold and silver. Our research helps to develop a deeper understanding of the properties of survey data of the prices of gold and silver. We study the shape of forecasters’ loss function and the rationality of their forecasts. Assuming an asymmetric loss function weakens evidence against forecast rationality, but results depend on the empirical model being studied.     

某选冶厂增产扩能改造实践

某选矿厂在现有厂房有限空间里对磨矿系统进行了改造、扩建,主要包括更换球磨机、增加浸出槽、浓密机高效化改造等,使处理规模从1800t/d扩大到2000t/d。生产实践证明,改造后流程更合理,效果更好,真正达到了优化设计。     

Downside/upside price spillovers between precious metals: A vine copula approach

We studied downside and upside price spillovers between four precious metals (gold, silver, platinum and palladium), characterizing the multivariate dependence structure using a vine copula model and computing downside and upside value-at-risk and conditional value-at-risk. We found that the dependence structure differed across precious metals, all of which displayed different average and tail dependence features. Gold and silver prices were highly dependent except at the upper tail, whereas silver prices were integrated with those for platinum and palladium except at the upper tail. The gold market was very little integrated with the platinum and palladium markets. We document asymmetric downside and upside price spillover effects that differed in magnitude across precious metals; silver, in particular, had a greater downside and upside price impact on gold. Our results, indicating that precious metals do not behave as a single asset class, have implications for risk management, trading and hedging strategies for portfolios that include precious metals.     

Echo Awards. DMA (Direct Marketing Association) honors nine non-profit campaigns

This year the Direct Marketing Association has chosen nine winners in the Non-Profit Echo Awards competition--two gold, three silver and four bronze. Overall, the DMA bestowed 92 Echo Awards in its annual international competition. These creative campaigns are worth studying. In studying them, you may find your own creative idea.