Since 2010, Nigerian state and federal governments and the international community have been responding to an outbreak of lead poisoning caused by the processing of lead-containing gold ore in Zamfara State, Nigeria, that resulted in the deaths of approximately 400 children aged ≤ 5 years. Widespread education, surveys of high-risk villages, testing of blood lead levels (BLLs), medical treatmen...

We describe four men who had symptoms of acute mercury poisoning following exposure to mercury vapor. They were attempting home gold ore purification using a gold-mercury amalgam and sulfuric acid. Three of the four patients required treatment with penicillamine. The clinical and laboratory data are presented along with pulmonary function test results. Long-term follow-up of one patient indicat...

Nome placer offshore gold grade estimation is a challenging problem in light of extreme ore heterogeneity. However, this type of phenomenon is quite common in placer ore grade variation. Further, the characterization of spatial ore grade variability and subsequent ore grade modelling of the deposit becomes problematic due to the unavailability of adequate samples. Being located in the Arctic, t...

This article lists a number of geological data on the conditions of formation of some major gold deposits in the conglomerates of the Earth's crust. We analyze the metallogenic, tectonic, stratigraphic and other factors controlling the formation of gold-bearing conglomerates in certain fields, such as the Witwatersrand (S. Africa) and Darwaz (Tajikistan). The following tectonic factors play the...

 Cyanidation is a relatively simple and cheap technology to treat gold-containing ores. However, this process is not completely effective in refractory gold-bearing sulfide ores. In the case of very low-grade ores, biooxidation is an attractive alternative pre-treatment to render the gold amenable to extraction. This process utilizes the ability of acidophilic bacteria to oxidize the sulfide m...

The Chah-Bagh gold occurrence is located in Muteh mining district, in the central part of the Sanandaj-Sirjan zone. Gold mineralization occurs in ductile to ductile-brittle shear zones and is comparable with orogenic gold deposits. Silicification and sulfidization are the most important hydrothermal alteration features in the inner parts of altered shear zones and coincide most closely with the...

BACKGROUND During May-June 2010, a childhood lead poisoning outbreak related to gold ore processing was confirmed in two villages in Zamfara State, Nigeria. During June-September of that year, villages with suspected or confirmed childhood lead poisoning continued to be identified in Zamfara State. OBJECTIVES We investigated the extent of childhood lead poisoning [≥ 1 child with a blood lead ...

In this article, the efficiency of microwave pretreatment, which is an environmentally friendly, low-energy consuming method for recovery from refractory gold-silver ores, was investigated. The ore sample belonged to oxidized Bolkardağ deposit, contains carbonate (calcite, dolomite, smithsonite, hydrozincite), silicate (quartz, hemimorphite), sulfate (beudantite, plumbo-jarosite), and iron oxy/...

Integrated field studies on environmental levels, bioavailability, biological exposure, and effects SUMMARY Iron-ore is the source of primary iron for the world's iron and steel industries. Almost all (98%) iron-ore is used in steelmaking. Australia and Brazil together dominate the world's iron-ore production, while China is the world's largest iron-ore consumer. In Brazil, iron-ore mining is m...