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By G. O. Prickett, P. Somasundaran

An application of the statistical and computer techniques in basic mineral processing research is illustrated by means of a case history involving the study of starch adsorption on calcite. Multi-factorial experimental designs and computer techniques were used for determining the effect of different system variables, such as solution pH, sodium oleate concentration and starch concentration, and to obtain a mathematical model of the response. Response maps enabled the investigators to see the effects clearly and to predict the results of changes in factor levels within the design region. Use of time-shared computers and plotters made data processing and analysis efficient and relatively inexpensive.

Jan 1, 1973

By H. T. Kennedy, D. L. Flock

"The project described in this pa-per was undertaken to provide a more thorough understanding of the effect of contamination by drilling fluids on the electrical properties of porous systems. The basic work per-formed was filtration tests on both consolidated and unconsolidated sands and the determination of their resistivity profiles with the aid of screen-type electrodes spaced at convenient intervals along the core.Four drilling fluids were selected, ranging in resistivity from 447.0 ohm-cm. to •5.76 ohm-cm. The permeability of three unconsolidated and four consolidated cores, on which resistivity measurements were made, varied from 1,257 md. to 4,560 md. Five additional cores with permeabilities as low as 49 md. were tested to investigate the effect of permeability on the depth of invasion of drilling fluids.The effect of drilling fluid invasion on resistivity profiles was determined on cores containing brine only, and on those containing 80 to 90 per cent oil and 20 to 10 per cent brine. The study included measurements of (a) clay content of different sections of the core, (b) saturation of the invaded fluids and oil in different parts of the core, and ( c) changes in resistivity as a result of gravitational re-distribution of fluids and diffusion of electrolytes.The data showed that the resistivity of an invaded core is, as was expected, controlled by the resistivity of the filtrate, the resistivity of residual core water, the resistivity of the clay particles, and the amount and distribution of the filtrate, clays, residual oil, and brine. In most cases there was a significant increase in resistivity owing to the presence of clay solids which had invaded the core. The change in resistivity, as a result of the diffusion of salts, was substantial after a period of five hours. There is evidence in some cases that the residual oil and core water saturations of the unconsolidated cores, after substantial invasion, are very low, indicating almost complete displacement by invading fluid."

Jan 1, 1959

By J B. Maughan

Gas and oil seeps have been known in Quebec for more than one hundred years. These occur in three main areas which contain sedimentary rocks with a total thickness estimated to vary from 6,000 to 20,000 feet. The strata in these areas are similar in many respects to those in producing areas of southwestern Ontario and the Appalachian basin, and the prospects for finding and developing commercial reserves of oil and gas in Quebec would therefore also appear to be favourable. Little of the exploratory drilling to date has been con-ducted in a systematic manner, and most of the drilling has utilized improper or inadequate equipment. Many wells have also failed to adequately test and fully evaluate the principal zones of interest. Relatively high drilling costs have hindered systematic exploration; however, with improved portable equipment, it is expected that future wells can be drilled with greater efficiency and at less cost. Most of the mineral rights in Quebec are held by the Provincial Government, and acreage can still be leased in large blocks on favourable terms.

Jan 1, 1964

By D. Gagnon, B. Dubreuil, J. -M. Lalancette, D. Lemieux

"The pilot scale extraction of gold with a brine of sodium chloride and bromide at 30 ºC, in an atmosphere of halogens at atmospheric pressure, leads to gold chloride with 95% gold recovery. The use of dilute hypohalites (1 – 3%) instead of free halogens, which is strong enough to oxidize hypobromite into bromine, simplifies the recycling of halogens by electrolysis. With the recycling of water and brine, the regeneration of hypohalites and with a barren solid that is inert and stable. The Nichromet Extraction technology is a green process where the protection of the environment does not preclude profitability.INTRODUCTIONThe use of chlorides for the extraction of gold predates the discovery of chlorine by Scheele in 1774. In the Plattner chlorination process (Christy, 1888) sodium chloride and copper salt were used to promote gold recovery by amalgamation with variable results. The introduction of the cyanide technology in 1889 has led to a general use of this method for gold recovery. In the last decades, a return to chlorine in extractive processes has been noted (Ferron, Fleming, O’Kane and Dreisinger, 2002), mostly because of environmental pressure for non-cyanide technologies.This paper describes a closed circuit proprietary approach (Lalancette, 2009) developed and piloted by Nichromet Extraction Inc. for the extraction of precious metals with recycled mixed halogens; chlorine and bromine from hypohalites. DESCRIPTION OF THE PROCESSThe attack of gold by halogens can vary significantly. The rate of reaction is substantially higher with bromine (Br2) than with chlorine (Cl2), by a factor of more than five, although the oxidation potential of Cl2 is higher than Br2, as shown in Equation 1a and Equation 1b (Latimer, 1952)."

Jan 1, 2012

By J. J. Barakso, C. Tarnocai

This paper outlines a method of testing for the mercury content of rocks, soils and plants. Techniques of sample collecting are described and the analytical procedures outlined. Examples are given of mercury determinations in two known mineralized areas in British Columbia - Copper Mountain Mines and Pacific Nickel Mines.

Jan 1, 1970

By Azadeh Riahi

The main goal of this paper is to investigate the effects of permeability anisotropy in Large Open Pit (LOP) mines for problems that exhibit homogeneous anisotropic characteristics. The most important effect of the groundwater flow in open pit mines is on the stability of the pit slopes. This study will investigate the effects of having increased permeability in both horizontal and vertical directions on three aspects of LOP behavior, location of phreatic surface, pore pressure distribution and stability of slopes. The hydromechanical coupling is simulated using a one-way coupling approach. The Shear Strength Reduction method (SSR) is applied to assess the stability of slopes. The studies performed in this paper suggest that anisotropy in permeability leads to a significantly different regime of pore pressure dissipation depending on two aspects, ratio of anisotropy and the relative magnitude of permeability to simulated time. As a result, variation in safety factors and the location and depth of the failure surface must be expected.

Jun 1, 2012

By P. Au, P. Patnaik, H. Saari, D. Y. Seo, S. Bulmer

Ti-48Al-2Cr-2Nb-xW (where x = 0, 0.5, and 1 at. %) powders were consolidated by hot isostatic pressing (HIP). The consolidated samples were solution heat treated above the a-transus followed by stepped cooling to room temperature. Selected samples were subsequently aged at 950 °C for up to 72 hours. The post-heat treatment microstructure was examined by optical and electron microscopy. It was found that increasing holding time above the a-transus generated a more homogenous microstructure. Utilizing the stepped cooling sequence, especially with a transition temperature of 1270 °C, massively transformed gamma (Ym) was diminished. Aging caused coarsening of the fully lamellar microstructure in the 0%W and 0.5%W samples while almost no coarsening occurred in the 1 % W sample. Precipitates began to form during aging in samples containing W. The precipitates at the lamellar interfaces are fine and have a needle like shape, while precipitates at the lamellar grain boundaries are coarse and circular in shape. The size and number of the precipitates depend on aging time and the level ofW content.

Jan 1, 2006

By J-S. Marois, F. Cappucitti, Y. Dodier, D. Downey, G. Matton

"The flotation processes of the Niobec Mine have been affected by a seasonal loss of recovery and a significant increase in reagent consumption over the past few winters. This paper discusses the problem-solving methodology that was used to identify the root causes, to develop solutions and to implement changes that resolved the problem to restore the process to summer-like conditions year-round. Mainly, it was found that the process water was contaminated by phosphates ions, which adversely affected the carbonate pre-flotation, and caused detrimental effects on the subsequent niobium flotation. The phosphate ions were being generated by the process itself, but were consumed by algae in summer conditions. It was determined in laboratory studies that concentrations as low as 5 ppm were enough to affect the circuit and that the multiple additions of process water throughout the circuit was worsening the effect. Also, temperature was found to have an impact on the reagent performance. The performance of the plant was restored by implementing a natural treatment of our process water with a simple cost-free rearrangement of our circuit streams. In addition to that, our extensive geometallurgical program was used to provide ore to the plant restricting phosphate generation in the process. Also, a modification of the collector was developed and introduced in the carbonate pre-flotation that provided improved performance during the periods of low pulp temperature.INTRODUCTION Niobec is one the three major global producers of niobium presently in operation. Situated in the Saguenay-Lac-St-Jean region of Quebec and in operation since 1976, the site produces ferroniobium (FeNb) to be used mainly in High Strength Low Alloy (HSLA) steel, which is known to have better mechanical properties than carbon steel. The Niobec operation consists of an underground mine, a concentrator and a converter plant. The concentrator concentrates niobium-bearing minerals, mainly pyrochlore and columbite, to produce a high-content Nb2O5 concentrate which is then converted to FeNb in the converter plant by an aluminothermic reaction. The Niobec concentrator flowsheet, which has gone through many expansions and optimisation over the years, consists of grinding, desliming, flotation and leaching steps. The flotation steps are numerous, sensitive and difficult to operate due to the non-selective nature of oxide mineral collectors. Thus, the pyrochlore concentration process at Niobec still faces many challenges and is constantly going through periods of continuous improvement."

Jan 1, 2018

By A. Ashrafi

The electrochemical deposition of polypyrrole coating on different pretreated aluminum-alloy 7075 substrates was carried out using cyclic voltammetry, The pretreatment of specimens consisted of mechanical polishing and/or electrochemical etching, In the latter case, an aqueous solution of phosphoric acid and ethanol was used, The electrodeposition solution was 0,25 M pyrrole and 0,1 M oxalic acid in double-distilled water, The cyclic voltammetry scan rate used was 700mv/s, Morphology of the coatings was examined using scanning electron microscope (SEM), Using the Tafel experiment, corrosion resistance of the coated substrates was investigated in 0.1 M NaC1 solutions, Results obtained revealed that electropolymerization of polypyrrole on 7075 aluminum alloy would increase the resistance against corrosion in 0,1M NaC1 solution, Also it was observed that, compared with mechanical polishing, electroetching pretreatment would be more effective.

Jan 1, 2005

By M. Lundström

The Outotec HydroCopper® process is a novel technology, developed and registered by Outotec Technology Oy, for leaching copper from chalcopyrite using cupric chloride solution. The leaching process is operated at atmospheric pressure in a stirred tank reactor, at temperatures near the boiling point of water and pH values between 1.5 and 2.5. During the leaching of chalcopyrite in cupric chloride solution, a reaction product layer forms on the mineral surface. In the present work, the formation and the composition of the reaction product layer was studied in an environment similar to that of the HydroCopper® process. The effect of the process parameters on the reaction product layer was investigated. Electrochemical measurements, including A.C. impedance spectroscopy and microscopic observations were carried out and an equivalent circuit was used to determine the surface parameters, such as the reaction product layer capacitance and the charge transfer resistance. The results suggest that, at low pH, a passivating sulfur-rich layer forms, whereas at high pH, a more porous iron-rich layer was detected. The values measured can give useful information for optimising the leaching parameters of the HydroCopper® process. Cu2007

Jan 1, 2007

By Trent Hamilton

Cameco ? McArthur River Operation is a high-grade uranium mine in northern Saskatchewan. Average grades mined are nearly 20%, more than 20 times higher than other operating uranium mines in the world. The significant risks involved with mining this grade has been effectively mitigated using innovative and unique controls, implemented from development and production mining through to ore processing. The types and sources of radiation are presented and protection measures are discussed. McArthur River?s strong radiation culture is evidenced by continually low radiation exposures while transitioning to new mining zones.

Aug 1, 2010

By J. Cui, Z. Meng, W. Zhao

"The decomposition of rare earth concentrates containing bastnasite and monazite by alkali solutions has been investigated. A slurry of the rare earth concentrate and the alkali solutions was calcined at different temperatures. The impacts of calcination temperature on the decomposition of rare earth minerals, the oxidation of cerium, the deportment of fluorine and phosphorous, and the adaptability of the method to the different grades of rare earth concentrate were all studied. A possible technique for comprehensive recovery is proposed in which the chemical elements such as rare earth, fluorine, phosphorus, calcium, iron and thorium could be recycled or recovered. INTRODUCTIONThe liquid alkali decomposition method is an important technique for the decomposition of mixed rare earth concentrates. The technique is relatively clean compared with the sulfuric acid roasting method. However, its operation is intermittent rather than continuous. The two-step solid-liquid reaction and the subsequent water washing make it not very suitable for mass production and application. An important reason for the disadvantage is that an additional process of ""calcium removal by acid leaching"" is needed for the technique. The content of calcium in Baotou rare earth concentrates is usually 6-12%. The requirement of the current technique is that the content of calcium should be reduced to about 0.2% after the calcium removal process. Otherwise, the decomposition and leaching of rare earth will be affected. Therefore, calcium removal by acid leaching is a necessity before the alkali decomposition process is carried out. Research on different alkali decomposition techniques has been conducted with prior calcium removal by acid leaching (Xu, 1995; Yu, 1993; Han, Li, Chang, Liu & Xu, 1985). There have been some investigations of direct decomposition of the bastnasite (Feng, Pan & Li, 1998; Zhao, Zhang, Yang & Liu, 2002)and monazite (Sun, Li, Li, Su, Zhao & Liu, 1998; Zhou, 2005) by alkali-liquid, however, all studies were carried out in solid-liquid reaction system, and continuous calcination studies have not been reported.This paper investigates the process of direct decomposition of Baotou rare earth concentrates by continuous calcination with concentrated alkali. Using the rotary tubular electric furnace, the mixture of rare earth concentrate and concentrated alkali solution were decomposed continuously. Satisfactory decomposition results were achieved. A method for clean processing and comprehensive resource recovery from Baotou rare earth concentrates is proposed."

Jan 1, 2012

By Joseph Daniels

When Dame Nature shook her horn of plenty and distributed her bounties over the face of the earth, she blessed the Pacific coast with many riches, but with these she added many offsetting disadvantages or handicaps, designed, no doubt, to effect a proper balance between wealth and economy. Nowhere is the application of the law of compensation more aptly illustrated than in the matter of fuel and power resources. A glance at the map of the Pacific northwest will show that west of the Coast Range batholith we are bounteously supplied with coal, with timber, with water power, and with tributary resources of oil from California. Alaska, British Columbia, Washington, all contain large resources of coal; Oregon and California to a lesser degree, but, compensating the golden state for its deficiency in this respect, oil was placed in the treasure ,chest. Timber, of wide variety and in lavish quantity, covers the forests from tidewater to mountain slope, and within this protected watershed area flow streams which give the Pacific coast states the largest single share of the potential water-power resources of the country. Something over 40 per cent. of the total estimated horsepower of the United States is to be found in the Pacific states, and British Columbia has 15 per cent. of the total for Canada; but of this total less than 10 per cent. has been developed.

Jan 1, 1924

By S. Deonarain, L. S. Schultz

"This paper details the process and methodology followed to rehabilitate a rectangular ventilation shaft, situated in the Free State region of the Witwatersrand Gold Fields in South Africa. The shaft consists of seven compartments where self-mining of the sidewalls had taken place and damage to the decayed steel work in the shaft had taken place, thus limiting access down the shaft. The paper will provide some insight into the successes and challenges encountered during the project and may provide some learnings for future projects of a similar nature. INTRODUCTION The ventilation shaft forms part of the Phakisa Mine, situated in the Welkom area of the Free State province of South Africa, and is located in the Southern part of the Witwatersrand Basin, one of the world’s largest known and richest gold deposits (Figure 1).As is typical in South African gold mines situated in the Witwatersrand basin, the shaft is 1 770 metres deep (below collar). The shaft was sunk during the early 1940’s and comprised a rectangular shape with 7 compartments, used for both rock hoisting and men and material winding, respectively, with a single lift “Mary-Anne” compartment. Early in 2003, the mine decided to change the shaft from a downcast hoisting shaft to an up-cast ventilation shaft. The conveyances, ropes, winders and headgear (head frame) were removed and replaced with a high volume fan delivering 323m³/s of air at a pressure of 4.2Pa on surface. The up-cast velocity in the shaft was 6.5m/s, however this reduced significantly with the scaling of the shaft and the restrictions at shaft bottom. Although Harmony had converted the shaft from a downcast service shaft to an up-cast ventilation shaft some years back, the shaft steel work in the barrel of the shaft was left intact. Over the years, the steelwork in the shaft had decayed (rust and grime) and portions of this steelwork fell down the shaft. Concurrent with the decaying steel work, portions of the shaft lining had collapsed and it was getting progressively worse."

Jan 1, 2019

By G. A. Frame, J. G. Patterson

The 24,000-tpd Frood-Stobie mill grinding circuit operation and control are described. Changes implemented during the past three years to improve grinding efficiency and capacity are discussed.

Jan 1, 1971

By S. Ross, M. Mayhew

"Kirkland Lake Gold introduced battery equipped vehicles (BEVs) at the Macassa Mine in 2011. The fleet of underground BEV haulage trucks and loaders has grown over the years to over 30 units, the world’s largest, currently handling approximately 80% of the daily production tonnage. The inflow and outflow of air occur through a limited number of relatively small openings, which limits the air volume delivered to the underground workings. In addition to improving air quality, the reduced heat load generated by the BEV (when compared to diesel equipment) had a significant positive impact in the workplace. The use of BEV for material handling has enabled increases in production that would not have been possible using diesel equipment.INTRODUCTIONMacassa mine was developed as a track-drift access mine, with the most recent shaft (#3) sunk in 1986. A new mining complex, the South Mine Complex (SMC) was discovered below the 5025 foot elevation south of traditional mining areas, and the majority of mining now occurs in the SMC. The discovery of that zone has led to an internal ramp which is used to access the SMC and haul ore to #3 shaft.The amount of airflow that can be moved through the mine is limited by the existing infrastructure to surface. This amount was recently increased to near its practical maximum from 118 CMS (250 kCFM) to 151 CMS (320 kCFM).Both diesel and electric equipment are used at Macassa. Tethered Load-Haul-Dump Machines (LHDs) have been replaced with Battery Electric LHDs, due to their increased mobility and depth of the mine. Battery trucks continue to replace locomotives to transport both ore and waste to the shaft, as mining has transitioned from tracked levels to trackless level and haulage has transitioned from horizontal levels to an inclined ramp.EQUIPMENT FLEET AT MACASSAMost of the primary material movers utilized at Macassa Mine are battery operated. As the mine goes deeper the battery technology will continue to be critical to the success of the operations. With over 300,000 hours of proven operation success, the battery technology and equipment will continue to be a major part of Macassa’s future."

Jan 1, 2019

By Cindy Schiewek

Industrial injury occurrences are an ongoing concern for Mine Operators. Along with the personal suffering of injured workers comes an increase in compensation and productivity costs. Growing recognition of repetitive stress and bodily injuries, accompanied by recent studies, validates the assumption that a relationship exists between ergonomic injuries and machine design. Intuitively, there is a belief that an ergonomically designed machine will reduce repetitive stress injuries through design and education however; quantifying this belief has been a challenge for Mine Operators. Sandvik Tamrock has undertaken a project aimed at developing a business model to assist in quantifying the benefits of ergonomic intervention. This model focuses on distinguishing and quantifying this method of intervention to allow for a better evaluation of the machine. For simplicity, the project initially focused on the Face Drill Jumbos. The target of the project was three fold: !" Recognition of the cost drivers for compensation; ergonomic injuries !" Identification of the relationship between ergonomic machine design, and the decrease of the negative effects associated with the cost drivers !" Systematic prioritization for ?prevention by design? The project findings substantiate the expected reduction in injuries and compensation claims. Based on all ergonomic intervention studies conducted, each case showed a reduction in compensation cost; through prevention by design, one can reduce the amount of potential risk. The paper addresses the resources and methodology used, along with the findings and its relevance to the issues that face the Mining industry.

May 1, 2003

By Yuyong Li, Liangman Zhang, Zhaolian Wang, Shun Wang, Ltd. Shandong Huate Magnet Technology Co., Fengliang Liu

"Introduce a newly revolutionary magnetic separator - Raising Concentrate Grade and Decreasing Dregs Content Magnetic Separator Series JCTN (i.e. RCG&DDC MS JCTN). HUATE® JCTN is designed for rinsing, purification, desliming and thickening of the magnetic minerals as per different requirements. Adopting 240°-270° larger magnetic element with multi-poles and magnetic pulsation, and combining the devices of multi-channel rinsing water and top flushing water and new style tank, HUATE® JCTN can improve another 2%-10% concentrate mFe% than the traditional MS without lowering the concentrate recovery rate. Thereby, it solves the uneasy concentrate upgradation problem of the traditional MS resulting from the magnetic aggregation. Now, JCTN has been successfully applied in more than 30 mines in Australia, China and Russia, e.g. Sino Iron of CITIC PACIFIC MINING MANAGERMENT PTY LTD. HUATE® JCTN can optimize the industrial processing line by: 1) improving the discarding rate before milling to discard the necessary tailing ASAP; 2) getting in advance the final concentrate after milling. One JCTN can replace many traditional MS in series. In some way, it can also replace the anti-flotation separation process.INTRODUCTIONWe’re writing to introduce a newly revolutionary magnetic separator - Raising Concentrate Grade and Decreasing Dregs Content Magnetic Separator Series JCTN (i.e. RCG&DDC MS JCTN). HUATE® JCTN is designed for rinsing, purification, desliming and thickening of the magnetic minerals as per different requirements."

Jan 1, 2016

By J. Hedderson, J. Starkey, S. Reeves, B. Hilscher

"As ore sorting becomes more common, it is important to quantify its impact on comminution circuits in order to precisely predict its effect on throughput, grind, and mill operating conditions. Since sulphides and other valuable minerals are often softer then the surrounding waste rock, the ore kept by a sorting system is typically softer than the average ore. In order to accurately forecast production, new measurements of hardness need to be performed on the new concentrated mill feed. This paper proposes a methodology to examine this effect quantitatively at an early stage of project development using the SAGDesign test.INTRODUCTION The application of ore sorting in the mining industry is one of the most promising recent technologies with the potential to cause step change in the way concentrators are designed. Most typically, ore sorters are used to sort a given ore flow for grade, either to reject waste from the mill feed, or rescue ore from the waste pile. Ore sorting technologies have been successfully applied at many mining properties in various forms and while the technology has reached or is reaching maturity in other industries, it is still in development in the mining sector. As a result, there is not yet a general consensus on the considerations that need to be made when designing a plant with ore sorting from a feasibility level above and beyond what is commonly performed as best practice. This paper will discuss those considerations and propose a methodology for integrating ore sorting into a comminution circuit at the design phase. Due to the linearly additive nature of the SAGDesign Test results, a “hardness balance” can be developed to estimate the ore hardness which would be measured in any sorting mass split using only two data points. This will allow a design engineer to make more informed decisions as to the most appropriate mass split to select in relation to the incurred operating costs and grinding circuit sizing."

Jan 1, 2019

By J. F. Henderson

Stable mining operations commenced in the Northwest Territories in 1933. Pitchblende from Great Bear lake and gold from the Yellowknife district are the main minerals produced. The value of pitchblende products produced from 1933 to 1941 was nearly $6; 000; 000; data on subsequent production are not available. The first gold was produced from the Con mine at Yellowknife in 1938. Other properties that later came into production include the Negus; Slave Lake; Thompson Lundmark; and Ptarmigan mines. The annual gold production reached $3; 862; 000 in 1942 but due to the war and consequent labour shortage fell to $333; 218 in 1945. The only producing mines at present (May; 1947) are the Con and Negus; but several promising properties are under development; including that of Giant Yellowknife Gold Mines where large tonnages of ore are being blocked out. With the reopening of former producing mines and new production from properties now being developed; gold production should rapidly increase and exceed its former peak within the next few years.

Jan 1, 1954