Search Documents

By Jason J. Crowder

Presentation Outline ? Introduction ? Costs of ground support and rehabilitation ? Why post-failure rock mass properties are necessary ? The Rock Mechanics Problem ? Present State of Modelling and Instrumentation in Mining ? Case Study Background ??Williams Mine ? Deriving Parameters for Modelling from Instrumentation ? Results from Case Study ??Back Analyses ? Discussion of Research Impact t Summary

May 1, 2006

By CIM Environmental, Social Responsibility Society

Within the mining industry, the pathway from exploration, to planning, construction, operation and closure has become more complex over the last few decades. The current financial, environmental and social influences present the mining industry with unprecedented challenges and opportunities. In addition, international environmental and social reporting standards and codes are becoming increasingly robust. The reporting requirements provide an added impetus for issuers to effectively manage environmental and social impacts and risks. Reporting requirements also provide the opportunity to be transparent. The intended audience for these Environmental, Social and Governance (ESG) Guidelines for Mineral Resource and Mineral Reserve Estimation includes practitioners, industry participants at all levels of skill and experience, corporate management and board members, government agencies, academic institutions and interested parties. For practitioners, this document provides underlying key principles of environmental, social and governance practices. The ESG Guidelines provide guidance for those using environmental, social, governmental and governance information when preparing and implementing mineral exploration programs and contributing to the preparation of mineral resource and mineral reserve estimates for mineral properties that are either at the study stage (i.e., scoping / preliminary economic assessment, pre-feasibility, or feasibility studies) or in operation. The guidelines can also be used to help mineral resource and mining companies apply good practice to manage their environmental and social risks and opportunities. Companies can identify and retain appropriate professionals to prepare environmental and social materials to support company studies. The guidelines are also a resource for companies developing effective environmental and social management strategies at any project stage. This document is not intended to be prescriptive and is not intended to provide exhaustive guidance on what to consider in terms of environmental, social, legal and governmental modifying factors in the preparation of MRMR estimates. Rather, it is intended as general guidance to assist companies and practitioners in considering and applying these modifying factors for MRMR estimates. This document is also not intended to guide environmental and social impact assessment (ESIA); however, the measures needed to manage impacts help inform the constraints and costs for defining mineral resources and mineral reserves and inform the costs and schedules of mineral project studies. All documentation of MRMR estimates made by an issuer and intended to be, or reasonably likely to be, made available to the public in a jurisdiction of Canada must comply with the requirements of National Instrument 43-101 Standards of Disclosure for Mineral Projects (NI 43-101), as amended from time to time (Canadian Securities Administrators, 2016a and 2016b). Disclosure is not addressed in these ESG Guidelines. Determination of what to include in disclosures is defined in the applicable Securities’ legal frameworks. Appendix A presents a summary table showing the linkage of the principles and topics in these ESG Guidelines to the potential effects on project costs, schedules, government permits and approvals, social licence to operate and financing.

Sep 8, 2023

By A. J. Sinclair, N. Champigny

"The Cinola gold deposit in the northern Queen Charlotte Islands, British Columbia, is in a clastic sequence consisting of a lower shale of the Late Cretaceous Haida Formation and an overlying interbedded sequence of pebble conglomerate and coarse-grained sandstone of the Middle Miocene Skonun Formation. Both formations are intruded by a stock and dykes of porphyritic rhyolite. Two K-Ar model ages indicate mineralization and probably porphyritic-rhyolite intrusion at about 14 Ma (middle Miocene). A splay of the Sandspit fault system constitutes the footwall on the west of the deposit.The Cinola deposit can be classed as Carlin-type based on features such as (1) small particle size for gold, (2) Tertiary age of mineralization, (3) element abundances (e.g. high Hg), (4) dominantly argillic alteration, (5) a structural setting associated with major faults, (6) porosity of the host rock and (7) spatial and possibly genetic association with felsic intrusions. Gold is widespread and occurs mainly as grains of< 0.5 11-m in silicified sedimentary rock, and in quartz veins. Locally, coarse > 100 11-m particles of native gold occur in quartz veins, especially in strongly brecciated porphyritic-rhyolite. Ore minerals are mainly pyrite and marcasite, but include small amounts of chalcopyrite, sphalerite, galena, pyrrhotite, cinnabar, tiemannite (HgSe), rutile, magnetite, hematite and limonite in addition to native gold and electrum. No silver minerals have been found; silver was found in gold particles in amounts varying from 6.2 to 24.2 weight per cent. Alteration products are sericite, illite, kaolinite and chlorite, with abundant quartz of several stages.The host rocks, specifically the Skonun Formation, formed as an alluvial plain facies in a braided river system discharging into a marine basin in early Middle Miocene time. During the Middle Miocene, this sequence was intruded by a rhyolitic stock. The highly porous and permeable Miocene clastic sequence apparently provided an optimum setting for the development of a large geothermal system, the energy for which probably derived from the rhyolite stock. Mineral deposition followed a well-defined paragenesis, which, from oldest to youngest, is: (1) precipitation of iron sulphide minerals, and early quartz; (2) several stqges of quartz veins, with deposition of sphalerite succeeded by galena, chalcopyrite and visible gold. Micron-size gold was precipitated throughout these two stages of mineral deposition. Argillitization of the host rocks probably in part coincided with the mineralization and continued during cooling of the geothermal cell.In-situ reserves have been estimated at 41.1 million metric tons averaging 1.85 g Au/tonne using a cutoff grade of0.86 g Au/ tonne."

Jan 1, 1982

By Carl Bertrand, Patrice Nadeau, Claude Bazin

"Rio Tinto Fer et Titane processes the ore extracted from the Lac Tio orebody to concentrate the hemo-ilmenite (FeO.TiO2-Fe2O3) mineral that is subsequently smelted to produce pig iron and titanium oxide slag. The ore is crushed, heat treated (roasted) and concentrated using dry magnetic separators. This paper describes a model to predict the magnetic susceptibility of the roasted ore and its behaviour in the magnetic separation plant. The model uses a classification of the ore as a function of the size and magnetic susceptibility of the particles. A subsequent division into mineral species allows the simulation of the magnetic separation process. The model is used to assess various operating options when process disturbances occur.INTRODUCTIONOre processing operations consist of ore size reduction followed by the recovery of valuable species in a concentrate that is subsequently sold for its minerals or metal content. The concentration processes are based on the physical and/or chemical properties of the minerals contained in the ore. Flotation is typically used to recover minerals of base metals such as copper, zinc, lead or nickel. Iron ore and other dense minerals are typically concentrated by gravity separation processes. Magnetic separation uses the magnetic properties of the minerals to concentrate magnetite and other minerals, to clean coal concentrate and to recycle ferrosilicon for dense separation processes (Brophy, 1985).Magnetic separators can be divided into low and high intensity separators and high gradient magnetic separators (Gillet, 2008). Most of the low gradient magnetic separators are built as rotary drums that are operated in wet or dry conditions. Dry magnetic drum separators are used by Rio Tinto Fer et Titane in Sorel-Tracy, Canada to concentrate hemo-ilmenite from the ore extracted at the Lac Tio Lake mine near Havre St-Pierre, Canada. The analysis of production data suggests that process improvement could be achieved by identifying key variables for the control of the magnetic separation circuit and/or by modification to the circuit flowsheet. The use of a process model was considered to be an effective approach to conduct a preliminary analysis of the circuit with a view toward process optimization. However, the literature contains few detailed studies dealing with the modelling of magnetic separation processes."

Jan 1, 2011

By A. M. A. Mohamed, F. H. Samuel, S. Valtierra, H. W. Doty, A. M. Samuel

"The influence of Fe, Mn, Cu and Mg alloying additions, Sr modification and grain refinement on the microstructure of as-cast and solution heat-treated Al-10.8% Si alloys was investigated using optical microscopy and EPMA techniques. The results showed that the modification effect of Sr diminished with increasing Cu and Mg additions, due to Sr-Cu-Mg interactions. Strontium caused segregation of AlzCu in areas away from eutectic Si regions, and altered the precipitation sequence of the a-Ah5(Fe,Mn)3Siz iron intermetallic from post-dendritic to pre-dendritic, with the phase observed within the a-Al dendrites. Depending upon the alloy Fe and Mn content, a coarser variation (""sludge"") of the a-Fe phase occurred, in the form of polyhedral shaped particles. The AhCu phase dissolved almost completely during solution heat treatment, while Al5Cu2Mg8Si6, sludge, and a-Aln(Fe,Mn)3Siz phases persisted in all alloys, particularly at high Mg and Fe levels. The f3-Al5(Fe,Mn)Si phase dissolved partially in Sr-modified alloys, the dissolution becoming more pronounced after solution heat treatment."

Jan 1, 2006

By F. E. Lathe

RECENT events have emphasized with renewed force the well known fact that war greatly intensifies the demand for certain metals, particularly for iron, copper, and zinc. Any increase in the use of iron and steel, whether in war or peace, is also accompanied by increased consumption of those metals which find their chief application as ferro-alloys, such as nickel, chromium, manganese, molybdenum, tungsten, and vanadium. Further, since high temperatures are essential for the production of all these metals, activity in the metal industry is inevitably accompanied by an insistent demand for refractories. For example, in North American practice the consumption of magnesitic hearth refractories is frequently expressed in pounds per ton of steel. This quantity (not including straight dolomite) ranges on individual plants from about 7 to 12 pounds. When the industry is operating at approximately full capacity, the ratio of refractory to steel tends to increase, since the tonnage of steel produced is recognized as of paramount importance, and this leads to the harder driving of furnaces and less regard for the effect on refractories. It should also be observed that the cost of refractories per ton of metal produced is always so low, in comparison with other items, that it may even increase while the cost of metal per ton is being reduced through more continuous operation and the use of higher temperatures. As one prominent Canadian copper metallurgist has tersely expressed it, he is "not in business to save refractories but to smelt ore". The effect of war demands and of general industrial activity upon the production of basic and neutral refractories is clearly shown in Figure 1, which gives the value of chrome ore and magnesitic-dolomite produced in Canada during the period 1907 to 1937. Tonnages have not been shown, as these are not available for the full period; such figures as have been published from time to time are not strictly comparable, since both raw rock and finished products have on occasion been included. The preliminary figures for 1938, which are now available, have been prepared by the Dominion Bureau of Statistics on a different basis from those immediately preceding, and have therefore not been shown.

Jan 1, 1940

By Anand Raman, Steve Dixon

"Industry practice for defining acid consumption is based on column tests. Freeport-McMoRan (FCX) has adopted a practice of leach operation using a defined pH or gpl acid in the raffinate based on the column test program. The acid consumption can be easily calculated using the leach operating parameters of SX-EW efficiency, lift height, bulk density, irrigation rate, primary leach cycle time, acid cure dose and acid concentration in the raffinate. The column leach test results and a column to heap efficiency factor are used to define the copper extraction. The maximum acid consumption will occur when zero acid is contained in the raffinate. The term Net Extracted Value (NEV) is to define the maximum extracted value relative to acid consumed.This paper presents the operating logic and method used to calculate acid consumption based on column tests and operating parameters.INTRODUCTIONIndustry practice for defining acid consumption is based on column tests. This may result in lower economic value if the tests are not designed to account for operating variables. A test program is described to assist in defining lift height and the influence of gangue on solution chemistry. A simple spreadsheet is presented that will use the leach operating parameters of SXEW efficiency, lift height, bulk density, irrigation rate, primary leach cycle time, acid cure dose and acid concentration in the raffinate to calculate the acid consumption for a proposed operation.A review of current leach operations solution chemistry will help to define acid consumption. This is recommended for all current leach operations.DISCUSSIONThe current practice at Freeport-McMoRan (FCX) is the use of column test results to define operating parameters. The monitoring of operational solution chemistry and copper production addresses any changes needed in operational parameters. This practice maximizes the value extracted from each tonne of ore leached."

Jan 1, 2008

By John H. Nicholls

In this paper, Imperial Oil Limited reports briefly on the drilling by contract rigs of twenty-nine slim holes in the Virden, Smiley, and Souris Valley areas. The investigations showed that slim-hole penetration rates, as a result of careful control of drilling variables, can approach those achieved with 7 7/8-inch bits. It is concluded that slim-hole drilling is acceptable for development or exploratory work. Imperial also reports on the completion techniques and equipment that have been developed on twenty-seven tubingless 2 1/2-inch casing completions. Indications are that the method is economically desirable where excessive gas or water production is not anticipated.

Jan 1, 1958

By K. E. Barnes

"The IsaMill was developed for fine-grained ores that required at least double the grinding efficiency of ball or tower milling to be economic. This was achieved, but in practice, the benefits of using inert media (eg sand, slag, ore, ceramic) have proven to be at least as important as the higher grinding efficiency. Flotation selectivity and rate was improved for all particles, particularly fines. This allowed a dramatic simplification of the Mount Isa lead zinc flotation circuit – adding 6 MW of ultrafine grinding power reduced reagent addition and flotation volume and increased plant energy efficiency. This was quite unexpected.This paper examines four orebodies that were enabled by inert grinding – McArthur River, George Fisher and Black Star Open Cut Mines (complex fine-grained lead zinc orebodies in Australia), and the Western Limb Tailings Retreatment plant (a PGM operation in South Africa). In a unique case history, the operating performance of the Mt Isa lead zinc concentrator is explained by size-by-size mineralogical data collected over 25 years, systematically explaining the impact of declining ore quality, and the effects of additional conventional grinding, inert grinding, and circuit and reagent redesign.The mineralogical case histories are so compelling that it is argued that the advantages of inert grinding should not be confined to difficult, fine-grained orebodies. The availability of largescale efficient inert grinding mills could have profound impact on circuit design for many orebodies.INTRODUCTIONThe IsaMill was developed by MIM (now Xstrata) to enable the development of the McArthur River Orebody in the Northern Territory of Australia. This ultra-fine grained ore needed a grind size of 80% passing 7 microns to produce a saleable concentrate. Such a fine grind was not economic with conventional ball or tower milling. Below about 25 microns the low energy efficiency and high media consumption of these mills is prohibitive. Critically, the high steel consumption and associated change in pulp and surface chemistry also seriously affects flotation metallurgy."

Jan 1, 2006

By J. Shang, P. Howarth, B. Morris

Tailings from the nickel refinery in Copper Cliff, Ontario, consist of fine silicates mixed with a variable amount of conductive and magnetic minerals mainly associated with sulphides and iron oxides. Subsequent oxidation of sulphide- rich phases within the tailings results in the formation of an acidic leachate that may contain significant concentrations of trace metals. Mapping the spatial distribution of regions of higher sulphide concentration therefore provides insight into the distribution of the acidgenerating potential within the tailings. Electrical conductivity is constrained by two parameters — the concentration of metallic sulphides and the ionic concentration of acid in groundwater. Magnetic susceptibility is directly related to the pyrrhotite and magnetite content. It is proposed that combining information derived from airborne electromagnetic and magnetic surveys can provide an indication of metallic sulphide distribution. Preliminary investigations of airborne electromagnetic and magnetic data acquired concurrently over the sulphide-rich Copper Cliff tailings site reveal that these parameters can provide information on mine tailing extent and permit separation of tailings with varying compositional and alteration levels. Airborne geophysical data provide information about the subsurface while a digital elevation model (DEM) and hyperspectral imagery record surface conditions. Integration of the two data sets can reduce ambiguity when interpreting mine tailing distributions and their subsequent alterations.

Jan 1, 2001

By R. S. Douglas

THE Granby Consolidated Mining, Smelting and Power Company, Limited, is engaged in the mining and concentrating of copper ores, and, incidentally, in the mining of coal and the production of electric power. The Company has been engaged in these various operations both on the mainland of British Columbia and on Vancouver island for the past forty-five years. This paper will attempt to cover their present operations in the Similkameen mining district of southern interior British Columbia. GENERAL CHARACTER OF THE DISTRICT The Interior Plateau in southern British Columbia ranges in elevation from 3,000 feet to 6,000 feet. In the vicinity of Princet0n, a depression in the Plateau forms a well defined basin which is floored with a series of nearly flat-lying Tertiary sediments containing some workable seams of lignite. From this basin, the upland surface rises gradually t0ward the south, from an elevation of 2,000 feet at Princet0n to 4,000 feet at Copper mountain, and 6,000 feet in the upper parts of the Similkameen basin, where it merges into the rugged and diversified t0pography of the Cascade system, with glacier inhabited peaks rising to over 9,000 feet. The valleys of Similkameen river and its tributaries are wide, having flaring sides and gentle slopes, and are separated one from another by subdued rounded spurs, of which Copper mountain is typical. The drainage of this district is taken care of by Similkameen river and its larger tributaries, such as Pasayten river, and Wolfe, Friday, and Whipsaw creeks. The name Copper mountain is applied to a gently arched, nearly flat-topped spur between the deep valley of Similkameen river to the west and the shallower valley of Wolfe creek tO the east. The mountain is appro-priately named from the number of copper deposits occurring on its sides and summit, some of which have been developed int0 an important producer, known as the Copper Mountain mine.

Jan 1, 1943

By Ross Nairn

"Tulawaka Mine is a joint venture between Pangea Minerals Limited 70% (a wholly-owned subsidiary of Barrick Gold Corporation) and Northern Mining 30%. Tulawaka Mine is located in North West of Tanzania in the Lake Victoria Goldfields. Tulawaka Mine is scheduled to process 360,000 tonnes per year at an average 11.5 g/t head grade over a 4 year mine life.The Tulawaka Process Plant uses single stage crushing, single stage SAG milling, gravity, intensive leach of gravity concentrates, CIL, Zadra desorption and cyanide detoxification to process the ore. Gold recovery exceeds (or is expected to) 95%.The Process Plant was designed and constructed under the supervision of Ausenco Engineering of Australia. Site works commenced in January 2004, Process Plant construction commenced in July 2004 and the first ore was presented to the Process Plant 26th February 2005. The first gold was poured on 15th March 2005. All construction contractors were demobilized from site 7th April 2005. Major achievements have been 3.4 million hrs LTI free during construction and operation to date, training of the Tanzanian workforce at Bulyanhulu Mine prior to commissioning, a succession plan to replace expatriate personnel with Tanzanian staff and significant over performance of the Process Plant against design.INTRODUCTIONTulawaka Mine is situated approximately 160 km south west of Mwanza in the western Lake Victoria Goldfields District of north western Tanzania. The property is held under a joint venture between Pangea Goldfields Inc (70%), a wholly owned subsidiary of Barrick Gold Corporation, and Explorations Minieres Du Nord Ltée (30%). A location map showing the position of the operation in Tanzania is shown in Figure 1.Mine site staff at Tulawaka comprises a combination of Tanzanian and Expatriate personnel. All Pangea personnel live on site and commute to their place of residence for their R&R on a 9 weeks on 4 weeks off roster."

Jan 1, 2006

By D. M. Wyslouzil

"Micron or sub-micron size gold inclusions in sulphide minerals cannot be extracted by conventional cyanidation. The gold surfaces must first be exposed by decomposition of the sulphides. As an alternative to roasting, pressure oxidation was found to be a most satisfactory method to decompose the sulphides and expose the gold particles. For cyanidation the pressure oxidation pulp has to be neutralized and stabilized with lime. It was found that thiourea can extract the gold directly from the pressure oxidation pulp without pH adjustment and oxidant addition. The main obstacles against the common use of thiourea are circumvented by a recently described control method of the emf during leaching.INTRODUCTION Amalgamation and cyanidation are the most conventional processes for gold extraction. The prerequisite for gold extraction is the possibility of gold surface to be contacted by mercury or by the cyanide solution. Encapsulated gold has little chance of contact and this leads to poor extractions.The reasons why a gold ore may be refractory are: micron or sub-micron size gold particles included in the sulphide minerals, such as pyrite and arsenopyrite; presence of and association with antimony, arsenic, tellurium and carbonaceous minerals. Some alternative processes, such as double oxidation(1,2), pretreatment with lime , H202, chlorine and Caro's acid, roasting and thiourea leach, have solved some of the problems of ""refractory"", but the sub-micron gold in sulphide minerals still shows little response. Roasting and the cyanidation of the calcine was one of the most successful approaches for this type of gold ore.There are two disadvantages to the roasting process: (1) the generation of sulphur, arsenic, antimony and mercury containing gases is undesirable and the control is extremely expensive; (2) gold particles might be fused in the roasted product and the oxidized base metals in the calcine might reduce the cyanidation efficiency. In recent years the pressure oxidation process has been considered as one of the more effective and satisfactory methods to decompose the sulphide minerals and expose the gold surface to the cyanide leach solution. The pollution problem could be better controlled and the gold extraction is more amenable."

Jan 1, 1985

The purpose of this paper is to present the methods used in ground water control and the considerations that affected the development of these techniques. Production at Knob Lake is currently proceeding at depths which may be as much as 200 feet below the original standing water table. In order to produce a more saleable product and to improve operating and maintenance conditions, it is necessary to depress the water table below the mining level. Considerable success has been achieved by drilling deep wells in strategic locations and installing vertical tur-bine pumps at depths of up to 400 feet. This method is especially suitable for operation under severe winter conditions and has reduced the detrimental effects by a far greater extent than other methods of water control, Spring runoff is handled in open sumps, but all other water from four mines, with flows exceeding 16,000 g.p.m., is pumped all year &apos;round from about thirty-five wells. THE Knob Lake operation of the. Iron Ore Company of Canada is located on the Quebec-Labrador border, 320 miles north of Sept-lies, a seaport

Jan 1, 1965

By James Scott

Outline Deposit Overview and Brief History ?Geologic Setting ?Local Geology ?Petrography ?Geochemistry ?Mineralization ?Geochronology ?Conclusions Deposit Overview ?Porphyry Cu-Mo-Au ?Discovered 1957 (BIK Syndicate) ?Various programs, most significant: ?Hecla(1970s) ?Teck(Late 1970s Early 1980s) ?Copper Fox Metals (2005 -Ongoing ?optioned from TeckComincoin 2002) ?Measured and Indicated Resources: ?847Mt grading: ?0.292% Cu ?0.019% Mo ?0.202g/t Au ?1.796g/t Ag ?Total ~ 0.485 % Cu Eq.

May 1, 2006

By W. Roy Dunbar

"The Porcupine area is in northern Ontario at the intersection of N. Lat. 48° 30' and 81° W. Long. It is 125 miles due north of the Sudbury nickel range. Practically all the mineral production of this area has come from the townships of Tisdale, Deloro, Whitney, and Ogden, in order of importance. The accompanying map of the Porcupine area and its extensions to the east and west (Fig. 4) has been included to show what I consider to be an essential objective of this paper, a perspective for exploration.The discovery of gold ore in the Porcupine area at such an early date resulted from the extension of the Temiskaming and Northern Ontario railway and exploratory survey lines north into unexplored territory, for the early history of Porcupine is inextricably tied to the exploration along Niven's survey lines and the extension of the railway north from Cobalt to Nellie Lake. The following are the more significant events leading to the discovery of gold in Porcupine.1896-E. M. Burwash, employed by the Ontario Bureau of Mines, examined the country along Niven's base line and noted quartz veins that carried traces of gold. He was attached to Niven's survey party.1899-The late W. A. Parks reported on the geology of the portage route from Mattagami river to Night Hawk lake, for the Ontario Bureau of Mines. He noted the occurrence of gold in quartz veins and reported “I regard the region south of the trail to Porcupine lake as giving promise to the prospector"". He also was attached to Niven's survey party.1901-Charles Camsell, while prospecting for the Algoma Central railway, did some work on a vein occurrence carrying low gold on ground now known to be part of the Hollinger mine (3).1907- Extension of the Temiskaming and Northern Ontario railway to Nellie Lake.1909- Bannerman followed up Indian story about occurrence of coal, and found iron formation. He remained to prospect and found the gold-bearing vein of the Scottish Ontario property."

Jan 1, 1954

By R. B. Barlow, J. A. C. Fortescue

Originally developed for use in mineral exploration, regional geochemical mapping based on stream (and lake) sediment sampling is showing broader application in other areas of the earth sciences and in environmental science. The purpose of this paper is to focus attention on the role of regional geochemical mapping in relation to geological and environmental studies. This is achieved using a descriptive equation for the chemical composition of a stream-sediment sample and then relating it to the use of successive approximations in geochemical and environmental investigations. The procedure is further qualified with reference to time and process in the formation of regional geochemical patterns. Examples are included of studies based on stream sediments related to bedrock geology, surficial geology, ecology and man&apos;s effect on the geochemistry of the environment. The range of applications of regional geochemical mapping in earth and environmental studies is outlined and some conclusions drawn regarding the future development of geochemical mapping under Canadian conditions.

Jan 1, 1980

By Niels Verbaan, Ernesto Bourricaudy, Ronald Molnar, James Brown, Sunil Jayasekera

"SGS Minerals commissioned an internal R&D program to develop in-house expertise to design, set up and operate REE separation pilot campaigns at its Lakefield, Canada site. A team approach was used that included expert consultants in the field of REE separation as well as in-house expertise supported by the on-site Analytical Laboratories.A mini pilot scale SX circuit was designed and constructed consisting of several modular banks of 30 stages each. About 80 stages of mixer-settlers were used to separate Pr and Nd from La and Ce contained in a synthetic REE chloride stream simulating the raffinate from an initial La-Nd|Sm-Lu+Y separation.Two pilot campaigns were operated totalling 25 days of 24/7 operation with 99.4% plant availability in the final 20 day campaign. Purities of > 99.9% in the Pr-Nd strip liquor and > 99% in the La- Ce raffinate were achieved and simultaneously sustained in the second campaign for prolonged operating periods. Key to controlling and adjusting the circuit was the rapid assay turnaround (as low as 2 hours) provided by the on-site SGS analytical lab. This permitted the operating team to modify conditions and observe the effect of changes relatively quickly considering the large number of stages. A portable XRF analyser was also used to track evolving assay trends in the circuit. The small physical size of the circuit enabled longer operation with a limited amount of sample.This paper discusses the design of the circuit, operating conditions, some of the key operating factors and controls and results obtained.INTRODUCTIONSGS Minerals commissioned the design of and built a solvent extraction (SX) pilot plant for the separation of rare earth elements (REE). The plant consists of a battery of 120 mixer-settlers set up in a dedicated piloting facility.The purpose of the programme was to develop capabilities and in-house expertise in REE SX separation technology. The program aimed to establish operating procedures, sampling regimes, and analytical methodologies and protocols for this type of process/plant. A team comprised of SGS personnel and several external consultants with prior industrial and REE separation piloting experience was assembled to achieve these objectives."

Jan 1, 2016

By F. Habashi

"The rare earths industry started in Austria in 1887 by Carl Auer von Welsbach (1858-1929) Professor of Chemistry at the University of Vienna. The process was based on monazite sand transported from Brazil as shipping ballast free of charge. This made possible producing thorium, cerium, and other rare earths at a low cost, thus permitting the growth of the industry. However, once the Brazilian authorities realized the strategic importance of the sand, shipping was stopped. Brazil then started its own processing of the sand in 1949. The background for Auer’s work, the role of Robert Bunsen in Heidelberg, and the invention of the spectroscope will be presented. INTRODUCTIONHeidelberg on the Neckar (Figure 1) was the meeting place for chemistry students from all over Europe in the nineteenth century. Her university founded in 1386 had already a famous professor of chemistry and medecine in the Faculty of Medicine by the name Leopold Gmelin whose three - volume Handbuch der theoretischen Chemie appeared in 1817-1819, that became later a multi-volume monumental work. As successor to Gmelin came Robert Bunsen (Figure 2) in 1852 who made this university town the Mecca of chemistry students. One of his students, the English Henry Roscoe (1833-1915) who became later a distinguished professor in Manchester, described him as follows: ""As an investigator he was great, as a teacher he was greater, as a man and a friend he was greatest""."

Jan 1, 2012

By M. Drozd, M. Somppi, Z. Yamak

"Granular activated carbon is widely used in the gold mining industry for gold extraction from aurocyanide-containing slurry. The extraction process can employ carbon as part of the gold recovery operation for various circuit designs including carbon-in-pulp (CIP), carbon-in-column (CIC), and carbon-in-leach (CIL) circuits. However, various qualities of activated carbon exist and the durability of the material can change significantly from source to source. Handling this expensive reagent can pose challenges when fine carbon losses occur in the CIP, CIC, and CIL circuits. Additionally, any gold that is adsorbed to these carbon fines can also be lost by various mechanisms including carbon attrition and fracturing, inefficient coarse-fine separation, and poor carbon fines capture. With the above in mind, a series of tests were conducted to investigate standardizing simple laboratory methods for testing carbon quality. A standard procedure beyond or enhancing ASTM methods can serve as additional starting points for evaluating carbon specific to the gold industry. The investigation focused on size distribution, flatness, wet attrition resistance, surface area, gold kinetics, and gold loading. The final results provided information to generate an equation for ranking carbon samples to plant performance.IntroductionActivated carbon for use in gold extraction is amongst the most commonly found processes in modern gold-milling plants. Although gold losses are inevitable in the milling process, operators often focus on the importance of maximizing gold recovery. One focus area that is important in gold recovery is optimizing the use of activated carbon and examining potential changes to realize improved economics for carbon-in-pulp (CIP), carbon-in-column (CIC), and carbon-in-leach (CIL) processes."

Jan 1, 2017