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By R. F. Errington

"Radioactive minerals are found together with the more familiar ore minerals in veins, gossans, and pegmatites, Since they have a peculiar property, that of giving off penetrating radiation, the simplest means of field detection is by the use of some radiation detector.The two principal radioactive elements one may encounter are uranium and thorium. These may occur separately or together. At present there is very little demand for thorium and hence radioactive occurrences should be examined with some care to determine which element is present. To do this it may be necessary to have a chemical analysis made of samples from the occurrence. Uranium minerals that do not carry appreciable thorium have a conventional occurrence in quartz or carbonate veins. They are distinctive in appearance. Pitchblende, the principal ore, is hard, black, and very heavy. It weathers readily to soft, powdery minerals •brilliantly coloured orange, yellow, and sometimes green. It may be associated with familiar minerals such _as native silver, nickel-cobalt sulphides and arsenides, chalcopyrite, and hematite.It is the purpose of this paper to review very briefly the types of radiation detectors available .and to draw some general conclusions as to the types most suitable for particular applications.The highly penetrating gamma radiation is the most useful for detection of radioactive mineralization. The alpha rays have little or no penetration, and beta rays are stopped by thicknesses of a millimeter or so of material. We shall confine our remarks principally to those instruments intended to detect gamma radiation. These are of three types."

Jan 1, 1950

By Kai Bartram

The successful application of color sorting machines has established sensor-based sorting in the mineral industry in recent years and is considered today as a significant innovation in processing technology. However, we are only at the beginning of (market) introduction. New sensor systems have been developed, which exploit material properties such as electrical conductivity, magnetization, molecular structure, thermal conductivity etc. This opens up new exciting preconcentration and upgrading possibilities for many applications such as nickel, gold, copper and other ores as well as for industrial minerals, diamonds and other gem stones.

May 1, 2009

By B. Jakovljevic, M. D. Soderstrom, T. McCallum, A. J. Quilodrán

Cytec has developed a new organophosphorus based solvent extraction (SX) reagent for rare earth separations. The new product, CYANEX® 572, has been formulated to allow efficient extraction while minimizing the strip acid requirements. The optimization of formulation strength is expected to significantly reduce the operating costs of these circuits. Modeling capabilities for CYANEX® 572 (similar to those used successfully in Cu and Co/Ni SX) have also been developed to aid in the design and optimization of the SX circuits. Simulations will be shown comparing CYANEX® 572 to a traditional rare earth extractant.

Jan 1, 2014

By Eric Barnard, Andreas Nashitati, John Tero, Guy Deschênes, Setta Mbalamba, John Rajala

The Otjikoto Mine, owned at 90% by B2Gold Corporation, is located 300 km north of Namibia’s capital city of Windhoek. The reserves from the open pit mine, estimated at 25.9 million tons with an average grade of 1.28 g/t Au, contain gangue minerals, pyrite and pyrrhotite, and have an estimated 10 year mine life. The feasibility study included an optimisation of gold leaching using CSTR for the original design. The results of the test work were used to establish the design criteria. Gravity tails from three composites (drill cores), representing the major ore types, were used. The XR3 sample (gravity tails) contained 0.32 g/t Au, while the XR2 and XR1 gravity tails samples (used for variability) contained, respectively, 0.30 g/t Au, and 0.47 g/t Au. The optimum leaching conditions were: a pre-treatment of 7 h at pH 10.5 with 100 g/t lead nitrate, DO > 5 ppm followed by cyanidation at 300 ppm NaCN, pH 10.0, DO > 5 ppm for 48 h. The gold extraction was 91.5% (97.2% overall extraction gravity/leach) and the cyanide addition was 0.57 kg/t NaCN. Increasing the DO to 16 ppm did not show any economic benefits. No pre-treatment or a 4-h pre-treatment reduced the gold leaching kinetics. The XR2 and XR1 gravity tails samples had gold extractions of 92.9% and 92.3%, respectively. At the plant scale, an 11 h pre-treatment is used followed by 42 h cyanidation with 250 ppm NaCN and an average DO of 8 ppm and 230 g/t lead nitrate in 2016. The cyanide addition was 0.49 kg/t NaCN. The commercial operation started on February 28th, 2015. The overall gold recovery and production were 98.4% and 145,696 ounces for 2015 and 98.1% and 166,286 ounces for 2016. It was found that retention times, gold content of leach residues and cyanide addition are comparable for the lab and the plant. Details of the Otjikoto process flowsheet are discussed in this paper along with the results of the lab leach optimisation test program and the plant leach circuit performance and improvements.

Jan 1, 2017

By E. P. Cadwell

"Throughout the years Cyanamid has been a supplier of cyanide and a supplier of information to the mining industry. In general, the knowledge of mineralogy is greatly overlooked. Mineral deposits in the Western hemisphere have been exceedingly rich in the past but now they are becoming poorer. In other words, we will have to use our talents to the utmost to extract the precious metals and base metals from these ores. Modifications of some of the mineralogical equipment displayed here belong in the mill.Cyanidation of copper has been one of the main projects in our labs in recent years. De-rimming or de-filming of copper in order to upgrade copper concentrate was the main aspect investigated. A study was made as to how wide spread was the filming of secondary copper on pyrite, and to what extent it affected the copper industry. It was very wide.Often there is no conception as to what the minerals are. One open pit copper producer with a chalcopyrite ore was producing a copper concentrate with a 5% copper value whereas chalcopyrite contains 35% copper. They used primary and secondary grinding and a regrinding section. The ore contained about 8 parts chalcopyrite to one part of other copper minerals. In tests, a 3 1/ 2% copper rougher concentrate, cleaned without regrinding but conditioned with cyanide for a low contact time of 30 seconds produced a 30% copper concentrate with 90% recovery by removal of the film. It was of utmost importance that some quantitative mineralogical analysis be made before flow sheet changes were made. Every man should be trained to do his own microscopic examination in order to get quick answers. The fundamental thing in all mineral dressing is to first of all know the minerals and the mineral associations."

Jan 1, 1964

By Alexander Burns, David Dreisinger

The kinetics of the oxidation of uranium(IV) by oxygen gas in aqueous systems is dependent on acid concentration, oxygen partial pressure, and temperature. In order to better understand the relationship between these variables and the speed of oxidation, a series of experiments have been conducted where each parameter has been varied in turn. Data were collected continuously using UVVis spectroscopy, allowing for a detailed examination of the reaction rate over the course of each experiment. The data fit an overall apparent rate law that is 1.5order in uranium(IV), -2order in H+, first order in oxygen, and unaffected by uranium(VI). This relationship does not appear to hold for solutions with <0.2 mol/L initial acid, where a different kinetic mechanism appears to be dominant.

Jan 1, 2014

By G. Velarde

Agglomeration has as main objective to form a uniform and highly permeable heap for leaching. An inaccurate dosage of moisture during agglomeration leads directly to poor agglomerate quality and segregation of particle sizes during stacking. This causes a heterogeneous distribution of the leach solution inside the heap which invisibly and practically permanently affects the recovery. Unfortunately, only when this becomes serious and the mineral contains an excess amount of fine particles and/or clays then the poor permeability of the pile becomes obvious. This paper is based on the experience of Minera Cerro Verde in the development and application of a quantitative method to control moisture during agglomeration. As the amount of fine particles/clays varies, the quantity of moisture has to be altered in real time. The measurement of agglomerate electrical conductivity is used for it. This concept is based on the sharp change seen in conductivity when the mineral passes its absorption limit. A liquid conductive film then begins to form over the surface of the particles, which leads to the formation of agglomerates through liquid bridges, which are also electrical bridges. Moisture is adjusted to reproduce a value of conductivity established previously and is the guiding parameter. Moreover, moisture amount added to reach this conductivity parameter provides information about the fines/clays relative content for best leaching management.

Jan 1, 2004

By K. M. Mayhew, G. D. Barr, T. M. McCoy, C. T. Knilans

"Teck Resources Limited (“Teck”) has developed and extensively tested on a continuous basis the CESL Technology hydrometallurgical process for treating copper and nickel sulphide concentrates, including bulk copper-nickel concentrates. Copper, nickel and cobalt are leached efficiently into solution, utilizing CESL process conditions. Total precious metals including gold, silver, platinum and palladium are recovered from the residue stream via sulphur flotation. This paper describes the CESL Technology testwork on a bulk copper-nickel concentrate derived from Twin Metals Minnesota?s (TMM) deposits within the Duluth complex and evaluates the economic benefits (increased cash flow, increased revenue certainty) and investment criteria (capital cost, payback and cash flow) of incorporating CESL Technology into the staged development of TMM?s deposits.INTRODUCTION Mineral Processing and the Role of Hydromet in the Duluth Complex The Duluth Complex in northern Minnesota, United States (US), represents one of the largest undeveloped accumulations of copper, nickel, gold, and platinum group metals (PGMs) in the world, ranking second in copper and PMs and third in accumulation of nickel. The figure below identifies some of the larger known deposits within the Complex (see Figure 1). Copper, nickel, PM and PGM mineralization within the Duluth Complex is hosted by mafic to ultramafic intrusive rocks that are part of the overall intrusive complex.One of the mineral processing challenges of Cu-Ni-PM-PGM deposits in this Complex is the complicated, polymetallic nature of the mineralization1: copper occurs primarily as chalcopyrite and cubanite with minor occurrence of talnakhite; nickel occurs as pentlandite and refractory nickel oxide/silicates; iron sulphides are present as both pyrrhotite and troilite; and PMs/PGMs occur in both the sulphide matrix as well as discrete minerals. An additional challenge for the Duluth Complex is the ratio between copper and nickel; in most of the identified deposits, copper grade is three to four times greater than the nickel grade, which precludes the production of a simple bulk concentrate due to the lack of a traditional smelting market for a bulk concentrate of this character."

Jan 1, 2017

By Engin Burak Anil

Objective, accurate, and fast assessment of damage to buildings after an earthquake is crucial for timely remediation of material losses and safety of occupants of buildings. Laser scanners are promising sensors for collecting geometrical data regarding the damaged states of buildings, as they are able to provide high coverage and accuracy at long ranges. Yet, we have limited knowledge on the performance of laser scanners for detecting earthquake damage, and requirements of such data collection. This paper focuses on characterizing the performance of laser scanners for detecting thin cracks for damage assessment of reinforced concrete frames. We identified a series of crack parameters based on the state-of-the-art damage assessment codes and standards. Similarly, we identified parameters, which affect the performance of laser scanners for detecting cracks, based on prior research in this area. We studied the width, depth, and orientation of cracks; sampling interval of the scanner, and the range of the laser beam from the surface. Effects of these parameters on the detection of the minimum crack size were determined in an experimental setting. An automated algorithm was used to analyze the data. The results show that it is possible to detect as small as ~1mm cracks.

Aug 1, 2013

By John C. Lyons

"The Wabana iron ore deposits occur as flat-dipping beds of oolitic hematite and chamosite, of Lower Ordovician age, which outcrop for 3 miles along the northwest coast of Bell Island, Conception Bay, Newfound-land, about 16 miles from St. John's.The deposits occur in three zones, Upper, Middle, and Lower beds, separated respectively by 30 feet and 215 feet of shale and sandstone. They are primary sediments laid down in a shallow tidal basin by the precipitating action of a marine environment on iron-rich fresh waters flowing into the basin.The ore-bearing zones, while of wide areal extent, are not uniform beds of hematite that can be mined wholesale. The action of waves and currents during sedimentation; the delta pattern, velocity, and transporting power of streams flowing into the basin; the contours and oscillations of the sea bottom on which the sediments were laid have all been fundamental in the emplacement of richer and thicker mineable sections, and of lean zones so intercalated with shale as to be unmineable.The preservation of the deposits is due to their location in the Conception Bay syncline and to a considerable upthrust of the country east of the bay in post-Ordovician time.The hematite deposits were first recognized as such in 1892, and soon after were acquired by the Nova Scotia Steel and Coal Co. They are now being mined by Dominion Wabana Iron Ore, Limfred, a wholly owned subsidiary of the Dominion Steel and Coal Corporation, Limited. Production started in 1895, and up to the end of 1955 totaled 58,588,516 long tons of hematite ore, having an average dry analysis of about 51 5 per cent iron, 11 8 per cent silica, 0·9 per cent phosphorus, and l ·5 per cent moisture. About 40 per cent of the total tonnage mined has come from surface stripping and on-shore mines. These areas have now been almost completely depleted, and operations are confined to submarine mines extending for two miles off shore under the waters of Conception Bay. Three sub-marine slopes are currently in operation, Nos. 3 and 4 working in the Lower Bed and No. 6 in the Middle Bed. A general picture of the workings is shown in isometric projection in Figure 1. Submarine mining has been entirely by the room-and-pillar method, with an extraction of 60 per cent. The deepest workings, at a vertical depth of 1,850 feet below sea-level, have a rock cover of about 1,500 feet. No mining is done in areas where the rock cover is less than 200 feet. To date mining has explored six square miles of a potential area that may exceed 50 square miles."

Jan 1, 1949

By W W. Moorhouse

A survey of recent literature indicates that sulphides occur in the volcanic rocks of the Archean, or in sedimentary rocks intercalated with the volcanic rocks. The thick sedimentary sections are generally poor in sulphides. Thus, the widespread pyrite and pyrrhotite mineralization in the Archean may be largely of volcanic origin. Introduction I N this paper, commercial base-metal deposits will not be considered, as they are dealt with in other papers of the Symposium. Instead, attention will be focused on those sulphides, often associated with graphitic argillites or tuffs, which have appeared in such embarrassing abundance in electromagnetic surveys of Archean areas. The data on which the paper is based are drawn from recent reports of the Ontario Department of Mines, the Quebec Department of Natural Resources and the Geological Survey of Canada. The information available from these sources is unfortunately limited, because sulphides commonly occur in sheared rocks, such as black argillites and tuffs, which rarely form conspicuous outcrops, and may not be exposed at all. Thus, in the absence of geophysical information, even detailed mapping may fail to reveal the presence of sulphide-rich rocks.

Jan 1, 1965

By J. Chao, C. Tan, N. Stubina

"Since J978, Falconbridge Limited has operated two electric furnaces at its nickel-copper smelter in Sudbury. As part of its S02 Abatement Program, the smelter has undergone many changes over the last seven years.This paper describes the impact of these changes on the operation of the furnaces. Some of the topics to be covered include: the installation of sidewall copper coolers; current operating conditions; and furnace heat and mass balances. HistoricalFalconbridge began smelting ores in the Sudbury area in 1930. The original smelter consisted of a 1.3 m by 3 m blast furnace and two 4 m by 6 m converters. The blast furnace was supplied with untreated mine are and molten slag/matte was discharged into a round settler.In 1933 the smelter began treating flotation concentrates. The concentrates were mixed with fine magnetic ore and flue dust, then sintered on down-draught Dwight Lloyd machines. This provided an agglomerate suitable for furnace burden which was charged to the blast furnace while still hot.Between 1930 and 1954 nickel production was increased by lengthening the 3 m furnace to 4.6 m, then to 6 m, and later by constructing additional furnaces. By 1958, the plant consisted of one 7.5 m blast furnace, a settler, and three 4 m by 9 m converters."

Jan 1, 1994

By Li Qihou, Li Yuhu, Liu Zhihong, Liu Zhiyong, Yang Xiaofeng

Scorodite samples were synthesized, in adding or without crystal seed respectively by using Atmospheric Scorodite Process (ASP), Hydrothermal Scorodite Process (HSP), and Improved Atmospheric Scorodite Process (IASP) individually; and their crystal structure, crystallinity, morphology, particle size, specific surface area, Fe/As mole ratio, as well as the leaching stability were characterized, aimed to reveal the relationships among the synthesis methods, the compositional and structural properties, and the leaching stabilities of scorodite. The results show that synthesis methods have significant effects on the compositional and structural properties of scorodite. Scorodite samples of high crystallinity, small specific surface area, and low Fe/As mole ratio, possess high leaching stability. The order in the leaching stability of scorodite samples synthesized in this study is as follow: ASP<HSP<IASP. Scorodite particles in the sample synthesized by IASP without crystal seed are in large sizes and of pyramidal morphology enclosed mainly by crystal planes of {111}; and the sample possesses the crystallinity of 84.5%, the particle size (D50) of 28.2 m, the BET specific surface area of 3.72 m2/g, and the Fe/As mole ratio of 1.05; after leaching this sample by using acetate buffer solution of pH 4.95 for 10 days, the total arsenic concentration in the leaching solution is merely 1.14 mg/L.

Jan 1, 2015

By T. P. Johnson, A. Vathavooran

"Conventional mining operations can produce a wide range of wastes containing gold and other precious metals but which are less suitable for processing by traditional methods. There are also types of ore that do not fit easily into a traditional processing flowsheet, e.g. because the refractory nature of their minerology or the combination of valuable metals is less suitable for traditional processes. Nevertheless, these potential sources of valuable metals remain unexploited resources that have attracted growing interest in the metals and mining industries over recent years. The challenge is therefore to develop and use alternative processing methods that have the flexibility of operation to cope with a wide variety of material types and tonnages, whilst providing high recoveries for valuable metals. Tetronics’ DC plasma smelting technology achieves industry-leading recovery rates for precious metals from a wide range of input materials and initial precious metal concentrations, whilst generating an inert slag-based material as a by-product (even when starting from a hazardous waste input material), approved within the EU for use in construction applications. This paper describes how this technology can be used as a key part of an overall process for the recovery of precious metals from these interesting materials.INTRODUCTION The extraction of gold from its ores by various forms of cyanide leaching has been practised by the mining industry for over a century (Minerals Council of Australia, 2005) and it remains the primary extraction method in a wide range of mining operations. The ability of cyanide to extract gold efficiently and quickly from lower grade ores without extensive additional processing, coupled with well-known methods to recycle the cyanide for re-use within the process mean it is often both the most economically preferable and environmentally acceptable method for recovering gold. As a result, 88% of all gold produced from mines in the USA in 2014 was recovered via leaching of open heaps or dumps (UGGS, 2016). Nevertheless, there are occasions where certain combinations of mineralogy and other circumstances reduce the effectiveness of cyanidation techniques, so that ever more elaborate additional processing steps are required, with inevitable increases in operating costs (Swash, 1988). In these circumstances, which are likely to be more common in future as ore qualities diminish, other methods of extraction may offer better alternatives. Whilst much less commonly used for Au extraction at present, pyrometallurgical methods are amongst the longest-established of these alternative approaches and merit serious consideration in such cases."

Jan 1, 2017

By S. Usui, Y. Shinohara, C. Tokoro, K. Horiuchi, S. Owada

Process optimization of heating and physical separation for Cobalt (Co) recycling from spent lithium ion battery (LIB) was investigated. LiCoO2 in spent LIB was transformed to LixCoO2 which was more easily decomposed than LiCoO2 by heating. Coexisting materials of aluminum and carbon, and sealed atmosphere of the LIB promoted LixCoO2 decomposition. In an atmosphere of Argon, 95 % of LixCoO2 in the spent LIB was decomposed to 76 % of Co oxide and 19 % of Co metal in 10 min at 823 K; a lower temperature than the theoretical value for LiCoO2. The Co oxide and Co metal exhibited magnetic properties and could be recovered by wet magnetic separation. Furthermore, slow heating was effective for grain growth of Co oxide and Co metal. At 2 K/min rate of heating, average grain size of Co oxide and Co metal were 239 µm and 28 µm respectively, whereas at 30 K/min they were 190 µm and 15 µm respectively. Therefore, separation efficiency for Co recovery by wet magnetic separation was increased when spent LIB was slowly heated at 2 K/min.

Jan 1, 2015

By Mohan R. Srivastava

- OUTLINE - apologies and explanations - a quick bit of history - the wisdom of Wikipedia - ?Matheronian geostatistics continued to convert Bre-X?s bogus grades and Busang?s barren rock into a massive phantom gold resource?? - variogram analysis for Busang - would variogram analysis (or variance analysis) have revealed the fraud? - what went right, what went wrong

May 1, 2007

By D. Laguitton

The basic chemistry of a1•senic related to its dissolution and subsequent precipitation in gold-mine waste waters is discussed. The lime addition methods provides the most economic treatment of arsenical slurries, but requires a careful control of the oxidation of Asm into Asv, of the pH (>12) and the filtration of the precipitate. If arsenic levels below 0.5 mg/ l are required, a modification of the method by phosphate addition must be considered.

Jan 1, 1976

By C. A. Y. Shephard, H. L. Brusset

Pressure maintenance by water flooding in the Pembina Field made consideration of wet crude dehydration and disposal of the produced water mandatory. Crude dehydration, the treatment and disposal of produced water, as well as the sale of gas and crude oil were expected to be handled more efficiently at one central point than at several conventional batteries. This plan was effected by routing the produced fluids to the central station by way of several well testing batteries referred to as satellites. To realize the full efficiency inherent in such consolidation the entire system was made self-regulating. Programming ensures the testing and proper routing of all products to their destination. Forty producing wells have been self-operated during the winter 1959 -1960 with gratifying results.

Jan 1, 1960

By C. H. Sleeman

"The Iron Ore Company of Canada constructed a beneficiation complex in Sept-Iles, Quebec, to concentrate and pelletize earthy red hematite iron ores from the Knob Lake area. The plants were scheduled for initial production during the first quarter of 1973.Many problems have been experienced to date. Difficulties in controlling the process, excessive mechanical failures, design deficiencies and manpower-staffing problems have caused an extended start-up. The problems are now essentially solved and, with the completion of some additional minor modifications, it is expected that the plants will be producing premium iron ore pellets at or near rated capacity within the next immediate period."

Jan 1, 1976

By H. J. Conolly

The area around Osisko lake, the Horne mine, and the town of Rouyn, in northwestern Quebec, presents a most interesting structural problem. The present discussion is confined to an area around Osisko lake, about six miles long and three miles wide, shown in Figure 1. The writers are particularly indebted to Mr. Thayer Lindsley, of Ventures Limited, who sponsored the investigation and gave permission to publish this paper. Mr. H. L. Roscoe and Mr. Oliver Hall, of Noranda Mines, Limited, gave every possible assistance; and the Noranda geologists, Mr. H. M. Butterfield, Dr. Peter Priee, and Dr. G. G. Suffel, contributed many data and ideas. It is a pleasure to acknowledge also the fuidance of Dr. W. F. James and Dr. B. S. Buffam and the full use made o their maps and criticism. Dr. M. E. Wilson and Dr. A. Lang, of the Geological Survey of Canada, kindly furnished data on the geology in neighbouring fields. Mr. E. Bailey assisted ably in the field, and Mr. H. F. King kindly reviewed the text. Memoir 166 of the Geological Survey of Canada, The Geology and Ore Deposits of the Roztyn-Harricanaw Region, Quebec, by Cooke, James, and Mawdsley, proved an invaluable source of information. STRATIGRAPHY The following stratigraphie sequence is based in part upon the interpretation of the structure as outlined in this paper:

Jan 1, 1936