Rob Bowell

• SRK Consulting

This review provides an overview of the application of hydrogeochemistry in mineral exploration by compiling learnings and knowledge from past and present research. It includes guidance on survey design, sampling methodologies, field data collection, analysis, and interpretations. Hydrogeochemistry is a unique tool with the potential to detect and...

The Omatapati copper and silver prospect within the Kaoko Belt is located in the Opuwo district, Kunene region, Namibia. The prospect is hosted by dolomite and interbedded argillites of the Neoproterozoic Devede Formation, the Ombombo Subgroup. An ore body is exposed in shallow artisanal mining pits and drill‐cores of the prospect have grades of 0....

Editor’s note: The aim of the Geology and Mining series is to introduce early career professionals and students to various aspects of mineral exploration, development, and mining in order to share the experiences and insight of each author on the myriad of topics involved with the mineral industry and the ways in which geoscientists contribute to e...

Assessing the environmental impacts of underground mines requires that the mine water sources and the geochemical processes that alter their chemical composition be determined. At the Kittilä underground mine, located near the village of Kiistala in Finnish Lapland, we used chemical and water isotope composition to investigate the contribution of s...

The weathering signature of mining waste facilities is intrinsically linked to the availability, depletion, and transport of oxygen. Key to these processes is the oxygen consumption rate of the mining waste, often termed Oxygen Consumption Rate (OCR). This is a material specific parameter with the rate being influenced by many factors such as sulfi...

A critical issue in mine waste management is the management and mitigation of acid rock drainage and metal leaching (ARDML) particularly from waste rock. This requires good understanding and characterization of materials most likely to generate acid pH waters and generate leachable metals and metalloids, as well as the presence of minerals most lik...

Barite is an important industrial mineral used as a weighing agent in fluids during the drilling of oil and natural gas wells, with the majority of United States production originating from Nevada. This paper considers three barite properties at varying stages of development—Rossi, Heavy Spar, and Ann—all located within the northern Nevada barite b...

The Round Mountain mine in Nevada is one of the world’s largest volcanic-hosted precious metal deposits and has been commercially operated since 1976. The deposit is hosted by a thick sequence of Oligocene ash-flow tuffs and volcaniclastic rocks overlying a pre-Tertiary basement. Gold mineralization largely occurs as disseminated electrum in associ...

Gallium (Ga) and germanium (Ge) are technologically important critical elements. Lead blast furnace slags from Tsumeb, Namibia, comprise over two million metric tons of material that contains high levels of Ga (135–156 ppm) and Ge (128–441 ppm) in addition to significant Zn concentrations (up to 11 wt.%) and represent a potential resource for these...

Locating mineral deposits in areas of thick or transported overburden is notoriously difficult. Post-mineral cover is prevalent in many parts of the globe and has led to prospective geological sequences being missed by traditional methods of exploration. Hydrogeochemistry is particularly applicable for the exploration of Iron Oxide Copper Gold (IOC...

This study presents an evaluation of arsenic and other trace metals in the Hrazdan Iron-Ore project in Armenia using a methodology typically associated with Geometallurgical characterization. The principal host of the trace elements is pyrite and oxidized equivalents. Pyrite is a mineral of elemental concern as it has the potential to generate acid...

Many abandoned mine sites in Cornwall, UK, are characterised by elevated concentrations of arsenic (As), which can cause contamination of surrounding soil and water resources. These sites have important historical value that requires access to be maintained, despite exposure of humans to toxins that may lead to health issues including hyperpigmenta...

There are three broad types of economic lithium deposit: 1) peralkaline and peraluminous pegmatite deposits and their associated metasomatic rocks; 2) Li-rich hectorite clays derived from volcanic deposits; 3) salar evaporites and geothermal deposits. Spodumene-bearing pegmatites are the most important and easily exploitable Li deposits, typically...

An abundance of world-class copper deposits in the Atacama region of northern Chile has made Chile the world’s leading copper producer. However, despite extensive exploration activities, the region remains a conundrum, with mature outcropping exploration plays juxtaposed with largely unexplored, extensive areas of post-mineral cover. This scenario...

This project aimed to determine the chemical composition of the tailings and to assess the morphology, chemical characteristics and dispersion of the fall out dust as well as implications of this.

Vanadium is a critical metal for the transition to a low carbon economy but is very rarely extracted from ore deposits as a primary product. Although there are such deposits, vanadium is primarily extract from vanadiferous titanomagnetite deposits as a co-product with iron. This deposit type is the current dominant worldwide geological source of va...

The Tsumeb polymetallic carbonate-hosted replacement deposit in northern Namibia, although now closed, is a world-renowned deposit of unusual and complex minerals, particularly those of arsenic and germanium. Due to the presence of groundwater migrating through deep-seated faults that cross-cut the sulfide-bearing pipe two oxidation zones exist at...

Environmental impact assessment of tailings storage facilities focuses on defining the reactivity and potential for acid rock drainage and metal leaching (ARDML) through geochemical testing of representative samples and numerical predictive calculations. The acid generation potential of tailings is dependent on the reactivity of their sulphide cont...

At the former Daisy mine gold heap leach operations in Nevada, long term solution draindown is c. 0.25 m ³ /day (0.045 gpm) and hosts arsenic concentrations in the order of 0.27 – 0.61 mg/L. This draindown solution is infiltrated into the ground where it eventually contacts groundwater. To assess the potential for natural attenuation of arsenic in...

Extensive surficial uranium mineralization has been identified in the Namib Desert in central Namibia. The mineralization comprises of uranium-rich zones in excess of 500 ppm for more than 3 m in tertiary sediment channels within the Kalahari succession. In places zones over 10 000 ppm over 3 m were observed in the near surface sediments. The miner...

Heap leaching is a common technique used to extract gold and other metals from generally low grade ore. Gold is typically mobilized by leaching with cyanide; the success of this technique is driven by its reasonable cost. However cyanide toxicity requires that management strategies be put in place during operation and after closure to prevent any i...

The prediction of source term water quality from mine waste disposal facilities is an important aspect of the design and management of mining operations. Predictive numerical calculations have been completed for the assessment of long-term leachate chemistry emanating from a proposed Waste Rock Dump (WRD) at an iron ore deposit in Northern Sweden....

Parc mine in north Wales was abandoned after closure in 1963 and spoil heaps were left to erode into the Nant Gwydyr and Conwy River. A storm event in 1964 caused the west slope of the tailings dam to collapse into the river, polluting 11 ha of farmland with lead and zinc. Reclamation work commenced in 1978 and involved reshaping the tailings pile...

The former Bicapa–Tarnaveni sodium dichromate production plant in Romania was closed in 2001 after almost 50 years of operation, leaving behind a legacy of hexavalent chromium-contaminated groundwater and an exposed waste storage facility (WSF). The WSF contains chromite ore processing residues (COPR) consisting of residual hexavalent chromium, par...

Introduction: Acid Base Accounting (ABA) remains the standard first tier assessment tool for evaluating the acid generating potential of mining waste materials. This is done through the calculation of the materials Acid generating Potential (AP) from measured sulfur and / or sulfide sulfur, and the comparison of this to the materials acid Neutralis...

Kinetic testing is one of the key tools for predicting the long-term weathering of mine waste materials and their potential environmental impacts. The standard methodology commonly undertaken for kinetic testing of mine waste is the ASTM D 5744 humidity cell test procedure. However, this test requires a significant time period to generate represent...

The geochemical test program completed for the Rossi Mine produced interesting results that illustrate the complexity of interpreting Acid Base Accounting (ABA) data for material containing barite. This highlights the importance of Application of ABA Methods to Barite Projects in Nevada

Hydrogen peroxide leach tests (NAG tests) are increasing in use by the mining industry for determining acid rock drainage characteristics of mine wastes. The test uses an excess of hydrogen peroxide (H2O2) to rapidly oxidise sulfide minerals in a sample, thus releasing acidity related to sulfide oxidation. The acidity released is neutralized by ava...

A process for recovering a metal chloride or mixed metal chloride from a solid waste material comprising recoverable metal containing constituents produced by lead, copper or zinc smelting and refining processes, said process comprising the steps of: (i) heating the solid waste material; (ii) treating the heated material of step (i) with a gaseous...

Arsenic is one of the most prevalent toxic elements in the environment. The toxicity, mobility, and fate of arsenic in the environment are determined by a complex series of controls dependent on mineralogy, chemical speciation, and biological processes. The element was first described by Theophrastus in 300 B.C. and named arsenikon (also arrhenicon...

Arsenic contamination of mine and metallurgical waters has long been recognized as a global problem. More stringent guidelines, based on demonstration of potential toxicity to humans and ecological receptors, have motivated regulators and operators to address both legacy sites and existing or future operational discharges to mitigate potential impa...

The Tsumeb base-metal deposit contained one of the most diverse examples of mineralogical paragenesis ever observed within a single mineral deposit (Keller 1977). The deposit hosted approximately 307 minerals and 232 of those minerals are most likely formed in the oxidation zone. Of the total number, 69 minerals were first described from the deposi...

Geochemistry is a major contributor to many mineral exploration programs - from regional reconnaissance to individual deposit scales. This broad field spans fundamental studies on the interaction between mineralization and host lithologies, the evolution and geochemical characteristics of the regolith, the factors controlling the mobility and form...

Many abandoned mine sites are characterised by elevated concentrations of environmentally sensitive elements such as arsenic, lead and mercury that can cause contamination of surrounding soil and water resources and may have associated ecological and health impacts. Often these sites have important historic and cultural values that require access t...

The Kaokoveld. copper district is currently an excellent source of fine minerals, particularly dioptase, wulfenite, malachite, the world's best shattuckite, and other secondary copper and lead species. Ongoing exploration and mining activity in the area will likely continue to provide specimens for some time to come.

The Hycroft Mine is an open pit gold mine situated along the eastern edge of the Black Rock Desert in NW Nevada, a semi-arid region where annual evaporation significantly exceeds precipitation. The Hycroft deposit is hosted in volcanic breccias and conglomerates of the Tertiary Kamma Mountain volcanic group that have been faulted by north-trending...

Many abandoned mine sites in Cornwall, UK, are characterised by elevated concentrations of arsenic which can cause contamination of surrounding soil and water resources. Often these sites have important historical and cultural value that requires access to be maintained, despite the potential toxicity of As. In west Cornwall, the potential for As c...

Uranium mineralisation within the Letlhakane tenement, Botswana, is complex and characterised by three different ores (primary, oxidised and secondary). From a geometallurgical viewpoint, most uranium occurs in coarse grained, and/or highly soluble minerals; favourable characteristics for conventional extractive metallurgical methods. However, ther...

This paper presents data from laboratory leaching of a mineralogically complex low grade ore containing uranium (U), thorium (Th), yttrium (Y), rare earth elements (REEs) and accessory pyrite. The study examines the influence of varying the leaching protocol on the rate of release of U, Th, Y and REEs. Leaching protocols were designed to simulate a...

Predictive geochemical modelling has been carried out for the Turquoise Ridge and Valmy pits, Getchell gold mine, Nevada (USA) as part of an updated evaluation of waste rock management. The purpose of the modelling exercise was to predict the concentrations of solutes that may emanate from the waste rock backfilled pits and to assess the impact of...

Erratum to: Mine Water and the Environment (2004)23:162–182DOI 10.1007/s10230-004-0060-0The names of some of the authors of this section wereinadvertently omitted in the original publication. We regretthis omission and provide all of the authors’ names here:Wolkersdorfer, Christian; Bowell, Rob; Amezaga, JaimeM.; Kroll, Adeline; Jarvis, Adam P.; Re...

Mineralogical controls exert significant control over the extraction of uranium from its ores. Uranium speciation, associated mineralogy, deportment and uranium mineral availability are all factors for consideration when assessing leachability. This study presents data from laboratory uranium extractions undertaken on several contrasting uranium or...

This paper addresses the ability of five low-cost reactive materials to remove Zn, Pb, and Cd from Fe-poor, circum-neutral pH metal mine water in Mid-Wales, UK. Compost, fly ash, waste shell material, iron ochre, and a mixture of blast furnace slag (BFS) and basic oxygen furnace slag (BOS) were used in a series of small-scale passive treatment cell...

A preliminary geochemical study on gold mine tailings proposed for marine tailings disposal has been undertaken to identify the potential release of acidity and ecotoxic elements. Laboratory tests investigated the effects of flushing media, temperatures and light-exposure on the reactivity and acid generation potential of the tailing. Based on low...

At the Justice mine, in the Ashanti goldfields of southwestern Ghana, chemical weathering of gold- bearing sulfide-rich lodes has produced a series of characteristic mineralogical and geochemical features that are diagnostic. In this type of gold mineralization, the most abundant sulfides are arsenopyrite, pyrite, pyrrhotite, and chalcopyrite with...

Although gold is a noble metal and is effectively insoluble even in strong acids, we have known for nearly 500 years that it can be concentrated to mineable levels by being transported as dissolved species in crustal fluids (indeed, most economic gold deposits owe their origin to this mode of transport). From alchemy and later experimental chemistr...

This paper presents a summary of field and laboratory studies conducted to determine the need and extent of rinsing requirements for a spent oxide gold heap. The testwork utilized the Gold Acres Heap in Nevada. Monitoring data was reviewed to examine the geochemical processes occurring within the heap and predict the chemistry of future heap soluti...

This paper presents a study of various geochemical humidity-style weathering tests that were carried out on waste mine rock from Avoca, County Wicklow, Ireland. The aim of this paper is to present data that demonstrate some of the geochemical controls on weathering rates together with release rates from laboratory testwork. These data are used to d...

This study compares data from kinetic NAG tests with data from static tests, and humidity cell tests on five different rock samples. The paper presents pH data over time in both types of kinetic tests and seeks to determine what useful information is discernable from such data. Total amounts of metals leached by the different methods are also compa...

The Summer Camp Pit (SCP) is situated on the Placer Dome owned Getchell Property in Northern Nevada. The deposit is a typical Carlin type partly oxidized disseminated sulfide-micron gold deposit in strongly deformed and altered Paleozoic metasediments. The pit was mined by a former site owner from March 1990 to December 1991. Although the pit was m...

This paper presents data from a number of humidity cell style weathering tests for the evaluation of ARD behaviour. These tests indicate that the results of such test work can be influenced by particle size, mineralogy, as well as the effects of aeration versus non-aeration; of sample mass; of flushing frequency; solution-mineral interaction in the...

PADRE has been established as a permanent commission of the International Mine Water Association (IMWA), with the aim of fostering best practice, based on the latest research, in the remediation of acidic drainage from active and abandoned mine sites throughout Europe. PADRE activities include: maintaining best practice guidelines on passive remedi...

PADRE ist eine permanente Kommission der International Mine Water Association (IMWA) und verfolgt das Ziel, in Europa die besten Praktiken für die Sanierung saurer Grubenwässer bekannt zu machen, die derzeit weltweit in der Erforschung sind oder angewendet werden. In die Aktivitäten sind sowohl aktive Bergwerke als auch Altbergbaue eingeschlossen....

The Sä Dena Hes Mine produced Pb and Zn concentrates from a polymetallic Manto deposit in 1991 and 1992. Ownership of the mine was assumed by Sä Dena Hes Operating Corporation (Teck Cominco Ltd and Pan-Pacific Metal Mining Corporation) in 1994. Sphalerite and galena ore bodies with negligible Fe sulphide were processed by conventional flotation met...

A study has been conducted on Au-bearing complex sulfide ore feed and autoclave tailings from the Getchell mine, Nevada. In this study products at different stages of an autoclave process were studied and identification of the source of low recovery in some Au-bearing sulfide ores located. All samples were studied to assess the occurrence of gold a...

At the Summer Camp pit of the Getchell mine in northern Nevada, the sulfate mineralogy is complex and includes gypsum, jarosite, pickeringite–halotrichite, copiapite, melanterite, langite, and bukovskyite that occur along with scorodite–mansfieldite and Ca–Cu–Zn arsenate minerals. Leaching of these minerals by meteoric water seasonally contributes...

Europe was once the most important mining region in the world and nearly every European country has remnants of historic and even pre-historic mining sites. Though the importance of mining activities in most European countries declines, the abandoned sites are still there and can cause environmental dangers as well as technological challenges. On t...

Europe once was the most important mining region in the world and nearly every European country has remnants of historic and even pre-historic mining sites. Though the importance of mining activities in most European countries declines, the abandoned sites are still there and can cause environmental dangers as well as technological challenges. On t...

Europe once was the most important mining region in the world and nearly every European country has remnants of historic and even pre-historic mining sites. Though the importance of mining activities in most European countries declines, the abandoned sites are still there and can cause environmental dangers as well as technological challenges. On t...

Europe was once the most important mining region in the world and nearly every European country has remnants of historic and even pre-historic mining sites. Though the importance of mining activities in most European countries declines, the abandoned sites are still there and can cause environmental dangers as well as technological challenges. On t...

Sulfide oxidation is a common phenomenon associated with many mined ore bodies and extracted or processed waste. Where the products of these chemical reactions can enter a water body the result is often a reduc- tion in water quality through the increase of acidity, metals and dissolved salts. Due to an attributed lower environmental impact the rel...

Challenge in the mining sector. Within Europe, the problem is manifest at both active and abandoned mine sites, from as far north as Spitzbergen (only 640 km from the North Pole) down to the arid regions near the Mediterranean coast. Given the present status of mining in Europe, it is not surprising that most European mine water problems are associ...

Surface water bodies are expected to form in several pits at the Getchell Open Pit Mine after mining has ceased due to inflowing surface and ground water. Predicting the long-term geochemical behavior of the pit water is important in assessing potential environmental effects. One of the pits, the Summer Camp Pit, began to develop a pit lake in 1991...

Note from the editor-in-chief: The articles assembled for this issue overflowed the space available; we had an abundance of riches. As a result, one article, by Gammons et al., was printed in the last issue of this journal [22(3): 141-148] and another, by Dowling et al. will appear in the next issue [23(1)]. The Gammons et al. article was not integ...

Arsenic is a common constituent that requires removal prior to the discharge of water from metal and from some coal mines. The release of the element in high concentration can lead to toxic and carcinogenic risks. Current worldwide standards require a concentration of less than 50 μg/L, except in Australia and the USA where the standard has been ti...