Search Documents

By S. Harshaw, C. Doyle, A. E. M. Warner, D. Stremlaw

"In the Utility Nickel furnaces, the hearth and sidewalls are lined with high-Al2O3 bricks. During charging and thermal cycling (more so as the linings on these reverberatory furnaces age), pieces of brick spall or abrade from the refractory and collect on the top of the bath. These pieces are removed using a non-corrosive slag toward the end of the heat when the bath temperature is ~1600°C.This benign liquid can be generated by two methods. First and most obvious, suitable ingredients can be pre-mixed so that the flux (flux A) is isochemical with the non-corrosive slag. All that is needed to produce this targetted slag is heat. Second, in other proportions (flux B), the pre-mixed ingredients generate a corrosive slag that melts completely at -1200 °C and corrodes some but not all of the brick particles on the bath surface. As the reaction progresses, the slag changes composition eventually attaining the targetted benign composition. Using this option, additions are monitored to avoid overfluxing. In both cases, the generated slag/brick mixture can then be rabbled from the furnace. This practice has been successfully used for over two years and has been a factor in extending Utility Nickel furnace life to its current levels (about25% increase)."

Jan 1, 1993

By A. Klingberg, M. Svensson, N. Smolko Schwarzmayr

"Removal of silicates and carbonates from sedimentary phosphate ores by the use of new synthetic collector/formulations was investigated in a comparative study with traditionally used collector systems as references. In the direct carbonate flotation the new formulations showed higher efficiency, contributed to an improved balance of P2O5 recovery and P2O5 enrichment in the recovered material. Efficiency of the new formulations containing synthetic surfactants was 1.5–2 times better than potassium salt of fatty acid sulfonate based formulations that are traditionally used for that purpose. The new formulations also provided up to 7% increase in P2O5 recovery at the same P2O5 grade. The new synthetic collectors for removal of silicates showed extremely good selectivity towards silica bearing minerals. The selectivity factor for the flotation tests when new formulations were used was 32–52 and for the flotation tests with the traditional collectors: 20–32. The ratio between distribution of an amount of silicates (as SiO2) and distribution of phosphate in the froth (waste) is defined as the selectivity factor. The new formulations provided more than 2% decrease of the amount of SiO2 at the same P2O5 recovery.INTRODUCTIONPopulation growth and decrease of arable land are the main reasons for constant increase of consumption of apatite (phosphate ore) in the fertilization field (Lannefors, Gorochovceva, Klingberg, Lima, & Gustafsson, 2015). Fertilizers play a key role for farmers to produce more with less land. The phosphate component of the fertilizer is vital for producing healthy and large amount of crop. As a result the demand for phosphate rock is growing.The largest producers of phosphate rock are the Unites States, Morocco, Tunisia, China, Russia, and Brazil. The term “phosphate ore” includes all phosphate-bearing minerals and rocks, but only two of them are of industrial interest: apatite (igneous origin) and sedimentary phosphate (Peres, Araujo, El-Shall, Zhang, & Abdel-Khalek, 2007). The majority of the world’s phosphate deposits are of the sedimentary type. There are two different types of sedimentary phosphates: siliceous and carbonaceous which are categorized based on gangue minerals (such as quartz, carbonates, mica, and clay)."

Jan 1, 2016

By D. E. M. Plaumann, B. S. Fee, R. D. Hansen, R. R. Klimpel

"This paper briefly summaries the status of a recent program aimed at identifying new chemistry for use as sulfide mineral frothers and collectors. The background motivation and planning behind this work is given along with the general families of chemical structures synthesied and studied in detail followed by typical flotation application results in various laboratory and plant scale tests. Flotation testing to date has been very encouraging with often improved recoveries of certain minerals and improved pyrite selectivity being observed over commercially available reagents. In addition, in some cases, the dosage and lime requirements of these new collectors are significantly less than that associated with standard sulfide mineral collectors. INTRODUCTIONFroth flotation is one of the most widely used and economic means of concentrating metal sulfide ores. There are numerous reference books that have been published on the chemical aspects of flotation [e.g., ref. 1-7] which are based on studying the influence on selected minerals of chemical structures that have been used commercially for many years. In fact, almost 98% of the volume of flotation collector and frother reagents used at the industrial level today were known and manufactured in some form 25 years ago [8]. There are many reasons for this lack of significant new flotation reagent development [9] including the general utility and relative cheapness of existing collectors such as xanthates and existing frothers such as the alcohols and glycol ethers. Another reason is the inherent complexity of the flotation process itself coupled with highly variable and difficult to standardize feed materials. This environment makes reliable reagent comparisons difficult and seriously limits the use of theoretically based chemical structure studies to predict new or optimal reagents. In addition, the higher cost of specialty flotation reagents demands that their performance attributes be significantly greater than that achieved with existing all-purpose commercial reagents - something often difficult to prove in practice."

Jan 1, 1988

By G. Kallfa P. Geo

Exploration at both Greenfields and Brownfields stages entails business risks of different nature and success rates. Greenfields exploration is exceedingly assumptive and the success rate of exploration or return on investment is low because exploration is an inherently risky business. Brownfields exploration on the other hand is less risky, as the geology is better understood, but generally speaking since the larger ore bodies close to surface have already been found the return is lower. In addition, most exploration at the Brownfields stage is generally more expensive due to extensive use of drilling. Surface geology mapping and expensive drilling have been key technical contributors to most exploration programs over the last two decades. However, as client expectations, logistics, target depths and complexity of exploration programs increase, there has been a growing emphasis on using geophysical techniques to complement other methods. Integration and optimization of various geoscientific disciplines is becoming more important in successful exploration programs of the future to reduce exploration risks, successful integrated exploration requires putting reliable geophysical parameters and correspondent petrophysical property contrasts into an assumed or conceptual geological model. This paper discusses a new multi-parameter geophysical methodology finalized in a unique conceptual geologic model which can be used either as a root model in grassroots exploration or as an efficient tool in Brownfields exploration to successfully find satellite orebodies of almost any size. The application of a new multi-parametric geophysical approach to Brownfields exploration is illustrated with examples from Manitoba, including a past producing nickel sulphide deposit in Lynn Lake and the Reed Copper deposit, currently in development.

May 1, 2013

By Earl T. Hayes

This paper briefly reviews the laws enacted in the United States governing the coal miner. It discusses amendments to the Coal Mine Safety Act and describes the provisions of the Metal and Non-Metallic Mine Safety Act.

Jan 1, 1969

By S. C. Cohen, A. F. Mikkelsen

"This paper describes the improvements made to the operation of a liquid phase, 300°C, heat transfer system in the paste plant of an aluminum smelter. These improvements were achieved by replacing the original heat transfer fluid, a synthetic aromatic, with a new technology, petroleum-based product. This new fluid, Calflo HTF, provided better thermal stability, with lower toxicity, and improved plant working conditions.The procedures for fluid selection, changeout and performance monitoring are described along with a summary of control analysis over the last three years."

Jan 1, 1993

By Frank Mucciardi, Zhongsen Yuan

A new heat transfer technology --- termed Thermopump technology has been developed. This technology originates from conventional heat pipe configurations but has now evolved into its own class of heat transfer units, which we refer to as `Thermopumps (TP)'. A key feature is that Thermopump technology can be applied to high temperature / high heat flux environments where conventional heat pipe technology fails. Moreover, when implemented in less demanding applications where heat pipes appear to operate, Thermopump units have been found to function more smoothly and reliably. This paper will introduce Thermopump technology and several applications of this technology in steelmaking and refining will also be discussed. In addition, this paper will focus on three classes of applications: 1) waterless, non-consumable, high efficiency Thermopump oxygen lance and/or burner for EAF's, 2) Thermopump ladle lance for the desulfurization process, and 3) Thermopump cooling panels for furnace walls and roofs. Facilities equipped with Thermopump technology are expected to he better than the current corresponding ones in terms of increasing productivity and energy efficiency while at the same time lowering operating costs.

Jan 1, 2004

By T. L. Tanton

"The New Helen mine is 12 miles east of Michipicoten harbour on lake Superior. It is 2 miles east of Wawa station, on the Algoma Central railway, with which it is connected by a spur line railway and a highway.The mine was discovered by Ben Boyer in 1898 during the gold rush near Wawa lake, Ontario. The original discovery was of solid hematite ore extending to a height of 100 feet on a hill rising abruptly on the east side of Boyer lake. The property was acquired by the Algoma Steel Corporation and mining was commenced in 1899. The first iron ore was shipped in 1900. The mine was operated until 1918 when the hematite became exhausted at a depth of 800 feet below Boyer Lake level.Drilling at the Helen mine, after 1910, revealed a large body of siderite both below and to the east of the hematite. By 1913, the body was known to be about 200 feet wide, 3,000 feet long, and at least 2,200 feet deep. In this there was estimated to be 100,000,000 tons of proved and probable siderite ore. An adit was driven into this body in 1917, and in 1918 work was suspended. In 1937 the Algoma Steel Corporation proceeded with the development of the New Helen mine by open-cut mining, and the beneficiation of the ore by sintering. Production commenced in 1939 and has since been maintained at the rate of approximately 500,000 tons a year.From 1900 to 1918, inclusive, the total production from the Helen mine was 2,823,369 tons of hematite ore and 51,930 tons of pyrite. From 1939 to the end of 1945 the total production from the New Helen mine was 3,921,455 gross tons of siderite ore.GEOLOGYThe Helen property is underlain by rocks of Precambrian age. For general description, and a statement on the structure of the iron deposits, the map-units are those shown in Fig. 1.The oldest rocks occur in a complex that lies north and south of an east-west trending zone, 1 ½ miles long and ¼ mile wide, in which the iron deposits occur. That part of the complex lying south of the iron deposits includes small masses of altered conglomerate and slate, and greenstones and pyroclastics. Other fairly abundant rocks are sericitic, chloritic, ottrelitic, and carbonatized schists of doubtful origin, and almost massive metamorphic rocks in which a development of carbonate, ottrelite, quartz, and other minerals has obscured a pre-existing schistose structure. Felsite and quartz porphyry are· prominently exposed south of the iron deposits."

Jan 1, 1954

By Bo R. Arvidson

"New permanent magnetic alloys have recently opened up possibilities for development of unique mineral separators. These are now making several new applications feasible. In many cases where conventional electromagnetic-induced roll separators have traditionally been used, the new permanent magnetic roll separators may reduce both over-all capital costs and operation costs.The development of the next generation of extremely powerful permanent magnets, i.e. neodymium-iron alloys, is progressing rapidly and will affect the roll separator as well as another type of magnetic separator. Permanent Magnet Roll SeparatorDesign and FeaturesDiscs of permanent magnets interleaved with soft iron discs constitute the basic magnetic roll design (Fig. I). By enveloping the magnetic roll with a thin abrasive resistant belt (Fig. 2), even highly magnetic particles are removed.The first prototype roll utilizing the new magnets was shown to have approximately equal strength as induced magnetic roll (IMR) separators. Since the initial test roll, the new separator, called the PERMROLL® , has been made twice as strong with regard to magnetic force, that is, the magnetic flux density is determined to exceed 1.7 tesla (17 kilogauss), while the magnetic field gradient is more than twice the gradient than can be practically achieved with IMR."

Jan 1, 1985

By Songgen He, Jianchun Guo

With the development of complex, unconventional and deep reservoirs, it shows that many rocks behave plastically with the influence of clay and confining pressure. Traditional linear elastic hydraulic fracturing initiation models are not good predictors for elastic-plastic reservoirs. With the deformation theory of plasticity, a power hardening constitutive equation was developed in piecewise approximation method. Based on the nonlinear constitutive equation, a model of the stress field around the wellbore was developed considering fracturing fluid penetrating effect and in-situ stress anisotropy. At last, coupled with the maximum tensile strength criterion and Mohr-Coulomb criterion, a new elastic-plastic hydraulic fracturing initiation model was built. The following conclusions were summarized in the paper: (1)The piecewise power hardening constitutive equation based on the deformation theory of plasticity can accurately describe the nonlinearity of elastic-plastic deformation. (2)Whether the rock is yielded or not is determined by in-situ stress, yield stress, Biot coefficient and pore pressure. (3)Plastic yield has little influence on radial stress but significant impact on circumferential stress. The radius of the plastic zone is positively correlated with in-situ stress but negatively correlated with yield stress, power hardening index, pore pressure and Biot coefficient. (4)Initiation modes include tensile failure and shear failure when rock is yielded. (5) For elastic-plastic reservoir, the initiation pressure predicted by linear elastic model is much lower if the rock is yielded.

Jan 1, 2015

By ByongPil Lee, Changkyu Lee, Jin Gyun Park, Hyung Sub Eom, Sung-Koo Jo, Jae-Young Lee, Gilsoo Han

"A new hydrometallurgical process for nickel extraction from a low grade laterite ore such as limonite has been developed by RIST and POSCO. This POSCO Nickel Extraction Process (PosNEP) consists of five main processes: ore reduction using hydrogen as a reductant; acid leaching at atmospheric pressure and temperature; cementation by the use of reduced-ore seed; production of the main product such as ferronickel or a high purity nickel compound; and production of by-products such as cobalt and iron in the forms of cobalt sulfate and iron oxide. In addition, hydrogen produced in acid leaching and hydrochloric acid regenerated in pyrohydrolysis for iron oxide production can be reused in the process, which makes PosNEP more cost-effective. The performance of PosNEP has been proven through pilot tests, showing that this process is economically and technically viable. In this paper, basic concepts and detailed test results of PosNEP are shown.INTRODUCTIONNickel has been extracted from two types of ore, sulfide and oxide ore. Nickel and cobalt usually occur together in the ores. The principal ore mineral of the sulfide is pentlandite, (Ni,Fe)9S8, which is easily beneficiated to produce sulfide concentrates(Moats & Davenport, 2014). These concentrates are usually treated by smelting and converting to make a matte. The produced matte is then purified through either hydrometallurgical or pyrometallurgical processes to produce high-purity nickel. In general, this process for sulfide ore has been known as a more cost-effective process than that for oxide ore.The oxide ore is laterite comprised of two different ore types, saprolite and limonite. The main nickel-bearing mineral of saprolite is nickeliferrous garnierite,(Mg,Ni)6Si4O10(OH)8, and that of limonite is nickeliferrous goethite (Fe,Ni)O·OH ore (Moats & Davenport, 2014). Since the saprolite has high contents of nickel and slag formers (MgO and SiO2) and a low content of iron, it tends to be treated by a pyrometallurgical smelting process such as calcination and electric furnace techniques to produce ferronickel for use in stainless steel. In this process, the cobalt in the ferronickel does not have any economic value."

Jan 1, 2017

By T. Boiselle, C. Gielen, P. Henry, J. M. Bier

"Hydrometal is specialized in the production of zinc sulphate from complex secondary raw materials. Electric Arc Furnace (EAF) dust is one of the more interesting potential sources to produce zinc sulphate. In order to minimize waste quantities generated from EAF dust treatment, our R&D team has developed and patented a new process to recover the Fe contained in the dust as iron oxide product to be used and sold into the pigment market. The process is based on a specific reductive leaching step of the zinc ferrite contained in EAF dust, followed by a purification step to remove impurities (Ni, Cr, Cu...) and finally the controlled precipitation of the iron oxide. The aim of the iron precipitation step is to obtain the right shape and length of crystals in order to guarantee the right color and tinting strength of the pigment. The innovative aspects of the process results in the controlled oxidation of the iron to get the right crystal size and good purity material. The iron product can be valorized as red or yellow pigment often produced by the Penniman-Zoph process.INTRODUCTION A Few Words about HYDROMETAL Hydrometal SA (Engis, Belgium) is a subsidiary of Jean Goldschmidt International SA (JGI) in Brussels. JGI is mainly involved in metal trading activities (Goldschmidt, 1995). In 1985, JGI acquired the leaching circuit of a Belgian electrolytic zinc producer located in Engis, a few kilometers south of Liège, near the river Meuse and it was decided to name this plant: SA HYDROMETAL. Hydrometal is well connected by water, rail and road from its central location in the industrial region of Liege, in the heart of Europe. The company received in 1997 an additional license to process and recycle toxic and hazardous waste. Figure 1 shows a picture of the plant."

Jan 1, 2016

By William F. Caley, A. MacKinnon, P. W. Kingston

"The purpose of this paper is to identify a number of currently available opportunities for exploration and/or mine development in the industrial minerals field in southeastern Ontario. The paper is not intended as a complete review of the industrial minerals industry in southeastern Ontario, but highlights what are seen by the authors as areas where there are immediate opportunities for investment and growth.Traditional exploration targets in the Grenville Supergroup in southeastern Ontario have been vein-hosted gold deposits, industrial minerals, and base metals. In recent years, emphasis has increasingly shifted to industrial minerals, in response to changing technologies in the minerals-consuming manufacturing industries, and to an increasing awareness of the industrial mineral potential in this area.This paper examines the resurgence of interest in exploring for and developing a wide variety of industrial minerals, and it examines the work the Ontario Ministry of Northern Development and Mines has done under the current Canada-Ontario Mineral Development Agreement. Specific development opportunities are identified in various commodity areas. Use oj the industrial minerals wollastonite and nepheline as substitutes for fluorspar in the formulation of synthetic steelmaking slags is also discussed."

Jan 1, 1990

By Göran Bäckblom

The Swedish mining companies LKAB and Boliden, the equipment supplier Atlas Copco, the general contractor NCC and the specialist company Reflex joined forces in 2005 to advance the field of rock technology for the purpose of mining and underground construction. The creation of the company Rock Tech Centre is part of the strategy developed by the Swedish mining industry to strengthen co-operation with industry, academia and society. This paper outlines the current R&D strategies developed for the industry in general, discusses what focus areas are selected and provides some details on the current RTC project portfolio, especially faster and better drifting.

May 1, 2006

By A. D. Yell

"Recovery of water is always a major factor in the Beneficiation process. As Preparation Plants become larger the recovery of water for reuse, is a critical cost consideration. Tema Isenmann Inc in conjunction with our sister Company Multotec Manufacturing, has over the years, developed numerous different Screen Panels, Sieve Bends and Static Screens for dewatering. This paper will focus on a new innovation, the TeePee™ Panel which has double the open area of conventional Screen Panels. This results in efficient dewatering (reduced filter cake moistures) which allows for the use of smaller Vibrating Screens or increased capacity on existing Vibrating Screens. A major factor in the efficiency of any Screen Panel, including TeePee™ Panels, is the performance of the Vibrating Screen. If the Vibrating Screen does not have the required gravitational force or screen area to drain it will not dewater efficiently. Therefore a holistic approach has to be taken where the Vibrating Screen needs to operate at an optimal level, in conjunction with the correct Screen Panels, to achieve efficient dewatering. Key performance areas for Vibrating Screens are therefore detailed in this paper with an emphasis on important dewatering criteria. Case studies of different dewatering applications are included, where the use of TeePee™ Panels, has shown a marked improvement over conventional flat Screen Panels in reduction of filter cake moisture content.INTRODUCTION Dewatering can be done in a number of different ways and is largely dependent on the ore type, the particle size distribution and to what extent one needs to dewater will determine the method used. There are a number of different dewatering methods that can be used for particles above 200 micron, including Screen Bowl Centrifuges, Filter Presses, Static Screens, Static Sieve Bends and Vibrating Screens. This paper will focus primarily on Vibrating Dewatering Screens showing improved drainage and a reduction in the filter cake moisture content. KEY PERFORMANCE CRITERIAL FOR VIBRATING DEWATERING SCREENS For clarification the critical key performance criteria for Vibrating Dewatering Screens are set out in this paper. Dewatering Screens Vibrating Dewatering Screens are normally linear motion, either horizontal or inclined at 5 to 7° upwards with a vertical or back sloped plate at 45° to the rest of the screen deck. The back plate will often have screen panels in them to increase the dewatering capability, as shown in Figure 2 below."

Jan 1, 2017

By David G. Dixon, Ahmad Ghahremaninezhad, Edouard Asselin

"Atmospheric leaching of chalcopyrite in sulfuric acid solutions is a slow process due to the mineral’s passivation. We have investigated the nature of the passive film in this work. Electrochemical reduction and oxidation of chalcopyrite over the potential range of -0.5 to 1.2 VSHE were investigated in 0.5 M sulfuric acid solution (pH 0.3) at 25 ºC by multicyclic voltammetry and open circuit potential measurement. The influence of scan limits on the evolution of current peaks was studied with both stationary and rotating electrodes. It was observed that the anodic oxidation of chalcopyrite begins at potentials above 0.6 VSHE, most likely by preferential dissolution of iron atoms over copper atoms. The selective electro-dissolution process results in formation of a metal-deficient sulfide passive film (i.e. Cu1- xFe1-yS2, y > x). The passive film dissolves at 0.9 VSHE. Elemental sulfur is one of the products of chalcopyrite dissolution above 1.0 VSHE. Cathodic reactions within the potential region of 0.1 to 0.6 VSHE and anodic reactions at potentials lower that 0.5 VSHE are associated with at least one soluble species from solution. The soluble species involved in the cathodic reactions are likely ferric and cupric, while the soluble species involved in the anodic reactions is likely H2Saq."

Jan 1, 2014

By Julie Hunt

Rimfire Minerals Corporation: early stage precious metal exploration specialists with discovery opportunities in partnership with major and mid-tier gold producers or prominent junior exploration firms. Mike Roberts, Senior Geologist

May 1, 2006

By Somchet Vongpaisal

This paper presents the R&D results on the development of a new knowledge-based system for predicting stope instability and associated unplanned dilution in deep underground mining operations. A new prototype was developed based on databases generated from 3D non-linear elasto-plastic finite element stress analysis, heuristic rules, and case histories. This prototype aims to assist mine operators to make decisions on strategic mine planning and feasibility in a quick and efficient manner thereby minimizing risk on ground failure and optimizing mining costs.

Jun 1, 2012

By H De Beer

The 14MW SAG mill at Tarkwa, Ghana, experienced a frozen drop charge incident on 10 February 2010. This caused downtime of 112 hours, a repair cost of $200k and production loss of 162,000 tons, corresponding to a loss of $8.9M. A new locked charge protection system was installed on the two Tarkwa mills on 30 July 2010, mitigating this risk. This system calculates the ore angle in real time while the mill is starting up and trips the mill if the ore angle exceeds a trip angle setting. The calculation of the ore angle is derived from the mill motor rotor currents only - no mechanical transducers are required. The head of Gold Fields West Africa, Peter Turner, says of the new system: "This is excellent work and the type of technology that has had and will continue to have, major opportunity cost impacts on our business."

Nov 1, 2011

By P. van Zyl, M. Lombaard

The 14MW SAG mill at Tarkwa, Ghana, experienced a frozen drop charge incident on 10 February 2010. This caused downtime of 112 hours, a repair cost of $200k and production loss of 162,000 tons, corresponding to a loss of $8.9M. A new locked charge protection system was installed on the two Tarkwa mills on 30 July 2010, mitigating this risk. This system calculates the ore angle in real time while the mill is starting up and trips the mill if the ore angle exceeds a trip angle setting. The calculation of the ore angle is derived from the mill motor rotor currents only - no mechanical transducers are required. The head of Gold Fields West Africa, Peter Turner, says of the new system: "This is excellent work and the type of technology that has had and will continue to have, major opportunity cost impacts on our business."

Jan 1, 2012