Labour challenges and mercury management at gold mills in Zimbabwe: Examining production processes and proposals for change

The use of mercury in small-scale gold mining has been a growing concern in many parts of Africa. However, although the negative effects of mercury pollution are increasingly reported, little has been written about how labour relationships and gold production challenges in mining communities affect mercury management practices. This article provides an integrative analysis of small-scale gold extraction processes, labour challenges, and mercury use at gold mills in Zimbabwe, focusing on a gold rush area in Mashonaland West Province. It examines practices employed by miners who have limited economic capacities to upgrade technologies, and how the complex relationships between miners, mill owners and government regulators affect environmental performance. The study draws attention to how poor environmental management practices relate to labour inequities, low gold recovery as well as the informal gold trade dynamics amid the country's economic crisis. Results of a United Nations-supported stakeholder consultation process are discussed, with proposals for improving labour conditions and reducing environmental risk. The article highlights why the government should develop and support local programs to assist miners, as well as the decisive roles mill owners could take in ensuring improved standards on their sites.     

WATER REUSE FROM SEWAGE EFFLUENT BY IRRIGATION: A PERSPECTIVE FOR HAWAII1

ABSTRACT: Surrounded by an ocean, the Hawaiian Islands are limited in their natural fresh water resources. The major readily developable potable sources are the high quality ground water sources which serve both domestic uses and sugarcane irrigation although irrigation water does not require as high a quality as drinking water. The increasing overall fresh water requirements for the island of Oahu will outstrip the potential yield of fresh ground water sources, as developed by present technology, by the year 2000 according to Honolulu Board of Water Supply projections. There are water shortage regions on other islands. Water reuse from sewage effluent for irrigation will augment natural water resources, furnish supplemental or alternative fertilizer, and reduce ocean water pollution and the costs of engineering systems. In cooperative field testing from 1971 to 1975, it was demonstrated that effluent can be applied as supplemental water for furrow irrigation of sugarcane without detriment to ground water quality and sugar yield. Studies are in progress to test different dilutions of effluent and its use with chemical ripeners to improve crop yield. Sugarcane plantations on Oahu, Maui, and Kauai are in various stages of water reuse by effluent irrigation. Reuse is presently practiced for irrigation of golf courses and is being planned for forage crops in Hawaii.     

江西金家坞金矿地质特征

通过地质大调查项目和资补费项目的地质工作,发现和评价了金家坞金矿。现有资料表明金家坞金矿具有大型以上规模的资源潜力。对初查、详查以及局部勘探工作中所获的地质资料作了归纳,对地质特征进行了探讨,旨在展开讨论并对在江西北部双桥山群中寻找同类矿床起到一定的指导作用。     

Incident, accident, catastrophe: cyanide on the Danube

It has been described as the worst disaster since Chernobyl. In January 2000, a retaining wall failed at the Aurul gold processing plant in Romania, releasing a wave of cyanide and heavy metals that moved quickly from one river to the next through Romania, Hungary, the Federal Republic of Yugoslavia and Bulgaria, killing tens of thousands of fish and other forms of wildlife and poisoning drinking-water supplies. This paper examines how and why the chemical spill at Baia Mare occurred and how responses to it emerged from circumstances at the global, local and immediate levels. The spill demonstrates the importance of the flow of information in framing and interpreting disasters, suggesting that such an event can go unnoticed or be viewed as catastrophic, depending on the political, historical and personal struggles that lead to its publicity. The paper offers a framework for understanding why the spill was alternately perceived as an incident, an accident and a catastrophe based on changing perceptions of culpability.     

Promoting sustainable development in Ghanaian small-scale gold mining operations

This paper provides an overview of the initiatives that have been undertaken by the Ghanaian government to promote more sustainable development in resident small-scale gold mining operations, and recommends a series of strategies for perpetuating a pattern of continued improvement. Since the passing of the Small Scale Gold Mining Law (PNDCL 218) in 1989, which effectively legalized small-scale gold mining as an industry in Ghana, the government, in particular, the Minerals Commission, has made a concerted effort to regularize operations, and to provide technical and financial support to miners. Under the auspices of the German non-profit Gesellschaft Technishe Zusannebarbeit (GTZ), a small-scale gold mining registration system has been implemented, district support centres for small miners have been constructed and the Precious Minerals Marketing Corporation (PMMC) has been created, which purchases products from small-scale miners at near-market prices. Careful analysis reveals, however, that these efforts have collectively only had a marginal impact, and that the industry is still in dire need of aid. Specifically, to perpetuate further a pattern of improved sustainability--improvements in both the socio-economic and environmental arenas--additional technical and financial support must be provided, and sound environmental management practices implemented. The Minerals Commission has been burdened with these tasks and challenges but because it is largely understaffed, it is highly unlikely that it will be able to facilitate sufficient improvement in the sector on its own. Nevertheless, marked improvements can be achieved if: (1) avenues for technological dissemination are created and improved; (2) research partnerships are forged with local universities; (3) experienced consultation is hired when needed; and (4) other governmental agencies, namely the Mines Department, Environmental Protection Agency (EPA) and Geological Survey, provide the Minerals Commission assistance with prospecting, monitoring, regulation and environmental auditing activities.     

黄铁矿吸附-还原金络合物的实验研究进展

金的吸附成矿作用是表生和低温条件下的一种重要成矿机制。本文综述了黄铁矿吸附-还原金络合物的实验研究方法,探讨了黄铁矿吸附-还原不同金络合物的反应机制和影响因素。黄铁矿对Au-S络合物的吸附作用主要是黄铁矿与Au-S络合物之间的静电吸附以及表面络合,由于吸附的Au-S络合物的还原反应相当缓慢,随着周围环境的变化很容易发生解吸附作用;而黄铁矿对Au-Cl络合物的吸附作用实质上是黄铁矿表面金络合物迅速的还原反应,通过还原作用形成自然金而使得解吸附率极低。As掺杂形成的p型黄铁矿以及和n型黄铁矿构成p-n结是导致金络合物在黄铁矿表面发生电化学沉淀的驱动因素。目前有关金的吸附实验都是在温度小于90℃的表生条件下进行的,开展一定温度和压力条件下的吸附成矿实验,尤其是利用电化学方法原位研究高温高压下黄铁矿-金络合物溶液之间的界面反应以及原电池效应对金络合物还原作用的影响,是今后研究的重点。     

松花江上游夹皮沟金矿土壤与大气汞污染特征

在松花江上游夹皮沟金矿开采区内,混汞法提金工艺已使用180余年,导致严重的环境介质汞污染问题.为研究土壤和大气汞污染特征,使用塞曼效应汞分析仪(Zeeman RA915+)测定了大气汞含量,使用冷原子吸收分光光度法(GB/T17136-1997)测定了土壤汞含量,使用动态通量箱法测定了老金厂、二道沟、二道岔和夹皮沟镇小区四处土/气间汞交换通量;对土壤汞含量和大气汞含量进行了线性回归分析;并对土/气间汞交换通量与气象因子进行了相关性分析.结果表明:①区域大气汞含量均值为(71.08±38.22)ng.m-3.②区域土壤汞含量均值为(0.913 1±0.040 8)mg.kg-1;土壤汞含量与大气汞含量显著正相关.③各采样点土/气间汞交换通量为:老金厂(129.13±496.07)ng.(m2.h)-1,二道沟(98.64±43.96)ng.(m2.h)-1,二道岔(23.17±171.23)ng.(m2.h)-1,夹皮沟镇小区(7.12±46.33)ng.(m2.h)-1.④太阳辐射是老金厂、二道岔和夹皮沟镇小区土/气间汞交换通量主要影响因子,太阳辐射、大气温度和土壤温度共同控制二道沟土/气汞交换通量过程;地形条件的干扰,形成三类迥异的土/气间汞交换通量日变化特征形态.     

Challenges to measuring,monitoring, and addressing the cumulative impacts of artisanal and small-scale gold mining in Ecuador

Portovelo-Zaruma, Ecuador is an artisanal and small-scale gold mining (ASGM) region with approximately 6000 gold miners working with mercury and cyanide. Although artisanal gold mining (AGM) has taken place in Portovelo-Zaruma for centuries, highly mechanized small-scale gold mining (SGM) processing plants capable of increased throughput began being built in the 1990s. While there are benefits associated with ASGM, there are also negative impacts experienced by the miners and the surrounding communities. To take advantage of ASGM as a poverty-alleviating mechanism while reducing unwanted externalities, the cumulative impacts must be understood. Numerous challenges to measuring, monitoring, and addressing ASGM impacts result from the complexity of the impacts themselves, the nature of the gold mining as an informal industry, and the shortfalls in the current regulatory framework. These are discussed in the context of ongoing, unresolved issues including efforts to address trans-boundary water pollution, management of mining waste, and conflicts regarding priorities, ambiguities, and enforcement of existing regulations and policies. Internationally, interventions to address both AGM and SGM impacts have typically focused almost exclusively on technological changes through the elimination of mercury use. Our analysis suggests that to better address ASGM and their cumulative impacts in Ecuador, it will be beneficial to revisit the legal definitions of AGM and SGM. Additionally, promotion of information-based strategies including educational outreach programs and cross-scale and cross-level mitigation methods may also be beneficial. The success of these strategies to reduce ASGM-related cumulative impacts will depend on sufficient funding and the commitment of stakeholders.     

遥感技术寻找内生金矿床的机理及方法探讨

论述了通过遥感技术寻找内生金矿床的可能性。首先 ,讨论了运用遥感技术寻找内生金矿床的基本原理 ;其次 ,提出了运用遥感技术寻找内生金矿床的一些具体方法步骤 ;最后 ;介绍了两个应用实例。     

Preparation of colloidal gold immunochromatography strip for detection of methamidophos residue

Methamidophos (Met) is a broad spectrum organophosphorus insecticide and acaricide.Even a trace of its residue is harmful to humans and many animals.In this study,the synthesis and identification of colloidal gold particles and antibody-colloidal gold conjugates were performed,and the preparation of colloidal gold immunochromatography strip was conducted for detection of Met residue.The size of colloidal gold particles was checked using a transmission electron microscope (TEM).The formation of antibody-coll...