Search Documents

By Shuan-cheng Gu

Roof bed separation often occurred due to the deformation incoordination of surrounding rock following the excavation of mine roadway. Bed separation has effect on the bolts, and the estimation of the influence will directly affect the safety of support systems. In this paper, the hyperbolic function model to analyze the load transfer mechanism on the bolts was simplified as the exponential function form for easy calculation. An elastic-plastic analysis model of the bolt loading occurred by the bed separation was established. And the development low that the bed separation affected to the bolt loading was discussed. According to the parameters analysis of different separation values and locations, the influence law of the bolt loading caused by roof bed separation was summarized. Finally, the effects of bed separation were considered for the bolting design, it was able to provide a reference to the anchorage design of stratified rock.

Aug 1, 2013

By F. Dubuc

"The Adams Mine of Jones & Laughlin Steel Corporation is situated on the Boston Township iron range near Kirkland Lake, Ontario. Eight different orebodies have been outlined, with a total open-pit crude tonnage of. about 100,000,000 tons or the equivalent of 30,000,000 tons of concentrate. The ore consists of fine-grained, well-bedded Early Precambrian iron-formation composed essentially of alternating layers of chert and magnetite. Grade averages about 22 per cent magnetic Fe.The iron range varies in width from 3,000 to 4,000 feet and is made up of several horizons of iron-formation, cherty ""quartzite"" and volcanic rocks. The latter consist mostly of basic lava flows and minor amounts of tuff. Dips are rarely Jess than 50 degrees, and the range is believed to represent an overturned limb of a major synclinal structure. Dykes of syenite and lam prophyre, along with local younger diabase, intrude the rocks of the iron range."

Jan 1, 1966

By Z. B. Karshigina, Ye. G. Bochevskaya, E. A. Sargelova, Z. S. Abisheva

At the present time of depletion of reserves of high grade rare earth deposits, it has become necessary to involve low grade raw materials in the production. Among the rare-earth deposits in Kazakhstan, the most advanced one is Kundybai. The mineralogical composition of ore is represented by the minerals: a-quartz SiO2, kaolinite Al2(Si2O5)(OH)4, muscovite KAl2(AlSi3)O10(OH, F)2, albite Na(AlSi3O8), rutile TiO2, and hematite Fe2O3. It contains: 59.1–68.5% SiO2, 19.1–28.4% Al2O3, 7.2–10.3% Fe2O3, 0.51–0.84% TiO2, 0.10–2.32% CaO, 0.39–2.10% MgO, and some other elements. Rare earths are located in the clay part (kaolinite, goethite) in the ion-adsorbing form, and they are represented by the main ore mineral churchite - YPO4·2H2O. In the ore the amount of rare-earth elements (total REEs) varies from 210 to 600 ppm. Elements of the cerium group predominate (La, Nd, Ce, Sm, Pr) and the yttrium group is represented by Y, Gd and Dy. Extremely thin intergrowth and accumulation of REEs in clay minerals cause difficulties in their recovery using flotation and gravitation beneficiating methods. The purpose of this work is the development of an extraction method for the main mineral components of ore with transfer of the total REEs into the solution with high extractive efficiency. Results of the experimental work into high-temperature processing (hereinafter referred to as sulphatization) of ore by sulphuric acid with subsequent dual-mode water leaching of the sulphate product (sinter) are presented in this manuscript. The influence on the ore sulphatization process of some physical and chemical parameters: liquid-to-solid (L/S) ratio (0.36–0.86 cm3/g), temperature (100 – 500°?), concentration of sulphuric acid (3.0–18.62 mol/L) and duration (0.5–2.5 h) was studied. Optimal technological parameters of the process were determined to be: L/S ratio 0.36–0.46 cm3/g; temperature 500°?; concentration of H2SO4 9.0 mol/L; soaking time 1.5 h. Under these conditions it is possible to obtain extractions of ~ 85% REE, as well as 58% aluminium and 10% iron. XRD and IR-spectroscopy analyses were used to determine the material constitution of sulphated cakes obtained under optimal conditions. It was found that the primary minerals are quartz and muscovite; however different sodium aluminium silicates and albite minerals are present as well. In the future, it is proposed that the leach residue cakes are processed into precipitated silica (“white soot”).

Jan 1, 2016

By Maurice Morton

THE use of organic and inorganic stains has found wide application as a means of detection and estimation of organic fibres. Such stains have enabled the analyst to distinguish between organic fibres of different type and even between wood fibres produced by different processes. Among these stains, aqueous iodine solutions have figured prominently, as in the case of the well-known Sutermeister and Herzberg stains. At the Johns-Manville laboratories, the idea of applying a stain to asbestos fibres was first considered solely as a visual aid in the microscopic examination of such fibres. The staining medium used in this work consisted of a 1 per cent solution of iodine in C.P. glycerine, the latter being used extensively here as a dispersing and mounting liquid for asbestos fibre. This iodine solution was found to have distinct staining properties when used on the local chrysotile fibres, and to improve greatly their visibility under the microscope. It was soon revealed, however, that this staining is apparently limited to the chrysotile variety of asbestos, as against other varieties. It can be readily seen that, if such were the case, the staining test would become a very useful tool in differentiating between chrysotile fibre and the other mineral fibres, without recourse to a lengthy chemical analysis. Hence this investigation was launched, with the purpose of obtaining more information as to the selectivity of this stain as well as its mechanism. The only previous work of this nature that could be found in the literature was that of Van Winsen and Graham (1, 2, 3) on the adsorption of erioviolet dye by serpentine and related magnesia minerals. However, these authors did not refer to any specific behaviour of chrysotile as against other types of asbestos fibre.

Jan 1, 1941

By lchimura. R. .

Japan Oil, Gas and Metals National Corporation (JOGMEC) and Centro de Investigation Minera y Metalurgica (CIMM) commenced a five year project from 2001 to modify the treatment of the furnace dust from Teniente converter containing harmful elements like arsenic and lead. The project was supported by Japanese and Chilean governments, and a demonstration plant was installed and operated at Las Ventanas Smelter and Refinery (Division Ventanas CODELCO). The basic and detailed engineering was made by Mitsui Mining and Smelting Co., Ltd (MMS) based on the joint study among JOGMEC, CIMM and Division Ventanas CODELCO. Arsenic in flue dust is lixiviated by sulfuric acid and fixed as crystalline ferric arsenate, where leachability of arsenic will be lower enough than the regulation, 5mg/I by TCLP (Toxicity Charactaristic Leaching Procedure) of USEPA. On the other hand, the recovered copper from the dust will be fed to the copper production process at Las Ventanas Smelter and Refinery, while zinc will be recovered as the exportable product. As introducing the crystallization and growing stage, the stable crystalline ferric arsenate formation can be achieved under the normal pressure.

Jan 1, 2007

By A. Tabereaux

The reduction of perfluorocarbon (PFC) emissions from aluminum electrolytic cells is a key issue in reducing greenhouse gases at all aluminum smelters, The emission of tetrafluoromethane (CF4) and hexafluoroethane (C2F6) gases during anode effects at smelters can be calculated using two different methods; anode effect-minutes slope and anode effect overvoltage, This work demonstrates that the optimum method depends to a large extent on the type of anode effect kill algorithm utilized at each smelter, CF4 emissions vary widely from aluminum cells depending on the type of anode effect kill method utilized; fast, aggressive anode bridge movements vs. slower, moderate anode bridge movements.

Jan 1, 2005

By R. Q. Honaker

It has been shown that naturally hydrophobic carbonaceous materials such as coal and graphite can be selectively coagulated and separated from hydrophilic impurities without using oily agglomerants, flocculants or electrolytes. The coagulation occurs at C-potentials significantly higher than those predicted by the classical DLVO theory, suggesting that it is driven by the hydrophobic interaction. In the present work, the energy barriers for the coagulation of a hydrophobic coal sample have been calculated using the extended DLVO theory which incorporates the hydrophobic interaction energy in addition to the dispersion and the electrostatic energies. For the coagulation of minerals present in the coal, the classical DLVO theory has been used for the energy barrier calculation. The results of these calculations provide an excellent correlation with the results of a series of Selective Hydrophobic Coagulation (SHC) tests conducted with run-of-mine coal and graphite samples.

Jan 1, 2004

In the flotation of a copper ore, entrainment of fine silicate and iron sulfide gangue minerals resulted in poor copper concentrate grade. In the cleaning stage, rejection of these gangue minerals was particularly difficult due to severe mechanical entrainment when the rougher concentrate was ground to 10 µm. To reduce gangue entrainment, polymeric depressants were tested. The rationale being that with the use of such polymeric depressants that also possess flocculation power, not only minerals-to-be-depressed can be made hydrophilic, but their particle size can also be enlarged. In this manner both the "genuine" flotation and the mechanical entrainment can be reduced. An effective polymer to reduce entrainment of silicate gangue mineral in sulfide flotation was identified from bench flotation tests conducted on single minerals. It was then applied to the flotation of a copper-gold ore confirming the beneficial role of the polymeric depressant in the reduction of fine gangue entrainment.

Jan 1, 2007

By R. E. Stewart

"Using the concept of economic life and marginal analysis, it can be shown that proper equipment replacement timing can save a mining company many thousands of dollars. To assist management with determining the economic life of mining equipment, a new computer package has been developed. The package, called ERG (equipment replacement guide), incorporates all important economic factors related to equipment usage, such as operating costs, maintenance costs, salvage values, depreciation, volume of work, tax credits, inflation rates, ROJ, etc. The information is used in a series of equations which balance the costs of new equipment against the total cost of old equipment. The solution of the equations determines economic life and the point in time when the old equipment should be replaced. IntroductionIn an operating mine, equipment must eventually be replaced or downgraded for a variety of reasons. Fleets of haul trucks, dozers and other major pieces of equipment deteriorate over time until the mounting costs of maintenance and repair force either a major overhaul or the ir replacement by new and more efficient pieces of equipment.The question of determining the best time to replace old equipment has been approached in many different ways. Various methods, ranging from operating experience, intuition and physical necessity to sophisticated computer models have been devised to help cope with equipment replacement decisions . The best of the se will incorporate the most important economic factors related to equipment usage, such as operating and maintenance costs, salvage values, depreciation, work delivered, the cost of capital, tax credits and, of course, the effects of inflation.Economic TheoryThe fundamentals of equipment replacement theory grew out of the interaction between economics, engineering and finance. The use of annual cost comparisons and rate-of return calculations were helpful in handling situations in which assets with different finite lives were being compared. Later developments bringing together the concept of economic life and marginal analysis helped provide additional refinements to the theory. Taylorui showed that the displacement of an aging asset with a similar, but newer, asset can be justified economically when the marginal cost of keeping the asset one more year exceeds the minimum uniform annual cost equivalent of the proposed replacement."

Jan 1, 1980

By Karl J. C. Harries

"6.1. INTRODUCTIONThis chapter comments on some of the more common types of agreements related to property examination and acquisition, other than the farm-in/joint venture agreement or common undertaking, which is dealt with in the next two chapters. Many of the comments made in Part IV of Chapter 4 apply equally to any such agreement. In addition, many of the comments in Chapter 8 and the examples in Volume II are most certainly relevant to many other types of agreement.6.2. RIGHTS OF FIRST REFUSAL1A right of first refusal is a right that obligates an owner to offer his property, or an interest therein, to the holder of the first right if the owner intends to sell or otherwise dispose of it. It may be triggered either by the owner wishing to offer his property for sale or by receipt of a bona fide offer to purchase his interest from an “outside” third party. The mechanics and procedures to implement a first right should be set out clearly in the agreement, and their basics are the same, whether the first right is a stand-alone document or is part of an acquisition agreement.2Rights of first refusal are common in agreements to permit some control over the disposition of an interest and there they can be a valuable provision. However, some explorationists feel that they are also a good stand-alone agreement to have while a property is being evaluated to decide whether or not it is worth optioning. The reasoning is that such an arrangement will tie up the property to allow a quick look and, if the property looks interesting, the balance of the term of the first right will give an ample exclusive period of time to negotiate with the owner and settle an acquisition agreement. In addition, the explorationist is protected by the first right if the owner decides to negotiate a deal with another party."

Jan 1, 2003

By D. A. MacLeod

DURING the past fourteen months, dust surveys have been made at thirty-six mines in the Province. These surveys are made to determine the concentration of dust in the mine atmosphere, the flow of air through the mine, the methods adopted to prevent the generation of dust, and the measures taken for its elimination. When high concentrations of dust are encountered, suggestions are given for its prevention ?and elimination wherever possible. Dust sampling is absolutely necessary to determine the effectiveness of any measure taken in the prevention and elimination of dust in the mine workings. Consequently, more time has been spent on this phase of the work than on any other. The apparatus used is the Devers circular konimeter and Zeiss microscope. At various mines, the Zeiss konimeter is used, and the dust counts taken by the two instruments have given results that are closely comparable; so much so that either instrument can be used with confidence and the results obtained will compare in accuracy with those obtained by the methods used in Ontario and South Africa. Before the Workmen's Compensation Act Amendment Act was passed in November, 1936, most of the mine operators were already keenly interested in the prevention of silicosis. This interest has been intensified at all the mines, and measures have been adopted to decrease the amount of dust in the mine atmosphere. Several operators have spent a large amount of time and money in bettering these conditions, and have met with decided success. Practically all others are adopting the known methods of prevention, suppression, and elimination of dust, that apply to their ?particular mines. To prevent the production of dust in underground workings should be the first, as it is the most important, aim, especially during the time the men are underground. An atmosphere free of dust cannot be obtained, but measures can be adopted to lower the concentration that is found? in the average mine.

Jan 1, 1939

By John Hansen

This paper has been written for presentation at the 103rd Annual General Meeting of the Canadian Institute of Mining, Metallurgy, and Petroleum, April 29 to May 02, 2000. The paper addresses blast pattern fragmentation and diggability versus the blasting technique used. RESUME The author is the Vice President for Thunderbird Mining Systems. In this capacity he manages the mine site installation of surface mining mobile equipment monitoring and navigation systems. These systems are onboard instrumentation and software systems designed to: ??measure and log mobile equipments? production and health; and ??direct the equipment operators via onboard displays that show comprehensive maps and engineering instructions. The author is a mining engineering graduate from the Royal School of Mines. His work experience includes front line supervisor and mining engineer for Hudson Bay Mining & Smelting, mining engineer for Teck Corporation, and mining consultant for PriceWaterhouseCoopers.

May 1, 2001

By Boris Yacksic, R. W. Bruce

"The flotation of a cassiterite ore with oleic acid will recover primary or rougher concentrates assaying over 10 per cent Sn, with a recovery of 80 to 90 per cent. These rougher concentrates cannot be up-graded to a marketable grade by normal reflotation. Experiments were conducted on low-grade tin ores, and a process was developed for up-grading the rougher flotation concentrates by a reverse flotation technique. The process was tested on a number of samples of ore from the Catavi mine in Bolivia. The results of these tests showed that a concentrate assaying 40 to 60 per cent Sn could be readily produced, with a recovery of 60 to 75 per cent of the tin in the ore."

Jan 1, 1967

By Matthew Novak, J. Brent Hiskey

It is well known that when chalcopyrite is put in direct contact with copper in an acidic medium a galvanic cell is created. Chalcopyrite is reduced to iron and sulfur deficient defect phases such as bornite, chalcocite, and at very low potentials to elemental copper. Galvanic conversion experiments were performed using three chalcopyrite concentrates. The first chalcopyrite contained less than 10% impurity phases. The second concentrate had a high concentration of pyrite, and the third concentrate had a high concentration of pyrrhotite. The effect of temperature, acid concentration, chalcopyrite grain size, copper grain size, and agitation on the rate of chalcopyrite conversion was studied.

Jan 1, 2014

By Graeme G. Strathdee

"IntroductionThis paper presents an overview of the industry status, describes current potash industry practices at three mills, and summarizes developments that have taken place since the previous review by Banks (1985).The commodity potash is produced in both New Brunswick and Saskatchewan from the evaporite ore sylvinite. This ore is a mixture of co-crystallized halite, NaCl, and sylvite, KCl, and a minor assortment of silica, carbonate, sulphate, and clay minerals. Carnallite, KMgCl3.6H20, is also dispersed throughout the bedded deposits and can affect the recovery of sylvite for fertilizer and industrial uses.Canada continues to be a principal source of supply of agricultural and industrial potash products. Figure 1 shows the sector performance between 1989 and 1997 in the context of the world supply and demand situation as reported by Prud'homme (1997) of Natural Resources Canada.Potash industry output is traditionally measured as the quantity of potassium nutrient and reported as tonnes ofK20. Mineralogically, the principal form of potash produced in Canada is sylvite, KCl, and 1 nutrient tonne K20 corresponds to approximately 1.64 tonnes of sylvite of agricultural grade, about 95% KCI. In 1997, the Canadian industry milling capacity was 13.4 million metric tons (Mt) ofK20 (22 Mt KCl) while the actual production was 9.0 Mt K20 (14.8 Mt KCl). Worldwide milling capacity in 1997 was 35.9 Mt K20 (58.8 Mt KCl) and global consumption was 25.3 Mt K20 (41.6 Mt KCl). Canadian producers can deliver about 35% of the global demand for potash commodities"

Jan 1, 2000

By W. Hunka

PACIFIC PETROLEUMS, Ltd. first discovered commercial quantities of gas in the Peace River area in 1952. Development of gas wells in this area is quite ex-pensive due to low penetration rates. To improve the economics, the potential of the wells in many cases had to be increased. At that time, well stimulation was still in its infancy in Canada and in this area, in particular, no treatment of any consequence had been attempted. Therefore, trial-and-error was the only means available to determine the stimulating technique that would give optimum results. Various fluid treatments were available and these were used wherever the application was warrant-ed. This paper covers acid fracture and explosive treatments as carried out on various gas-bearing horizons.

Jan 1, 1958

By A. Demers, M. Chapman, N. Reynier, R. Lastra, M. Courchesne, C. Laviolette

Historic medical isotope production at Canadian Nuclear Laboratories (CNL) in Chalk River involved the dissolution of irradiated isotope targets prior to extraction of Mo-99. This process generated liquid waste that was cemented in 5-gallon containers and transferred to an outdoor waste-management facility for intermediate storage. Research was undertaken to develop an innovative method for uranium, mercury and cesium recovery from the radioactive cemented waste (RCW). Regulations prohibit the removal of active radioactive waste from the Chalk River facility. Thus, CanmetMINING produced surrogate material following the same procedures and conditions to those used at CNL. The selective recovery of the uranium from the surrogate radioactive cemented waste (SRCW) could offer CNL more disposition options for the resulting wastes. Leaching tests were performed using four different SRCW at 1 kg scale. Different conditions, operating parameters, and the presence of plastic and corrosion products were evaluated on solubilization. The research investigated the use of potassium iodide with the sulphuric acid leach to increase metals recovery. Iodine improves the solubilisation of metals and the U dissolution reached 99%. The increase of leaching time reduces the U solubilization due to silica gel formation. Therefore, it will be important to control leaching time to avoid the loss of U during the pilot scale experiments. For Hg, the solubilization ranged from 60 to 80% due to the presence of metallic mercury and mercury sulphide found in SRCW cured at 60°C and/or aged for 30 months. Ion exchange (IX) was found the best method to separate the uranium from the impurities and produce a purified and concentrated uranium solution suitable for yielding a uranium product (yellow cake).

Jan 1, 2020

By J. W. Gregg, P. M. Dranchuk, D. L. Flock

"From preliminary investigations it has been observed that although evaporation losses may be estimated by comparing single values of certain physical properties of crude oils and their evaporation residues, such techniques possess little accuracy unless both the evaporation process and the variation of the property as a function of the process are completely known. The accuracy of estimation may be increased somewhat through the comparison of property mid-per-cent curves. Further increases in accuracy are possible if bottoms yield •curves rather than mid-percent curves are used. The use of both the mid-percent and bottoms yield curves however involves a prohibitive amount of effort in most cases. Examinations of distillation bottoms from Hempel type distillations carried to end points just short of the cracking point have indicated that these bottoms are not appreciably affected by the evaporation process. It was further observed that bottoms of identical API gravity, obtained from a crude oil and its evaporation residues behave as if they were pure components which were unaffected by evaporation. Based on these observations Hempel distillation bottoms of equal API gravity were obtained for a crude oil and its various evaporation residues from API gravity bottoms yield curves. The volume percent of these bottoms in the crude oil and its residues were used to calculate the evaporation losses suffered by the crude in order to yield the various residues. The results indicate that, although further refinements in technique are required, it is possible to calculate evaporation losses with an accept-able degree of accuracy through the use of this method."

Jan 1, 1960

By David Stone

The Beal Mountain Mine near Anaconda, MT is an interesting case history of a mine that has continued operations despite several large pit wall failures over a period of about 10 years. The largest event involved some 3.9 million tons of rock that has moved steadily at a rate of about 0.05 ft/day since 1992. This paper documents the geotechnical instrumentation and monitoring programs implemented at Beal to provide the company with a comfortable baseline that supported ongoing operations. The success and failure of a variety of stabilization measures will be discussed, along with typical instrumentation responses for several significant events. The success of Beal Mountain serves as a good model for mines faced with serious geotechnical challenges.

May 1, 2001

By M. Maley, S. Burling, R. Ring

ABSTRACT The numerous global uranium deposits vary significantly in mineralogy, grade, and textural characteristics; therefore, information from traditional (or conventional) sources on the fundamentals of leaching uranium and gangue minerals is not always applicable when studying particular ores. Empirical studies can be effective in understanding leach systems and can lead to improvements in process design but there remains a lack of fundamental understanding necessary for ongoing process optimization as ore bodies continue to vary. ANSTO Minerals has undertaken a work program to address several fundamental questions about uranium leaching, including the unexpected impact for some ore types of leaching at high oxidation potential.

Jan 1, 2012