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By M. P. Sinha, Rashmi, Tata Steel Ltd., S. Jaiswal, A. Bhatnagar, P. Garg

Reagents form a crucial part of flotation process as they have the power to control the surface properties of minerals. In case of coal flotation, collectors and frothers are two the important and commonly used reagents. But other types of reagents such as promoters, modifiers and depressants are also finding wide applications because of their availability to improve selectivity and increase recovery. Because of these chemicals the scenario has changed from flotation being used mostly for high rank hydrophobic coals to low rank, oxidised or inferior coals. In the present work a case is presented in which two non-ionic surfactants (abbreviated as A & B) known to act as emulsifier have been studied to get a better flotation performance for a preparation plant with varying feed characteristics. Laboratory flotation tests were conducted with both the surfactants using three feed samples of the plant by varying the dosage at three different levels. The highest combustible matter recovery (more than 80%) was obtained for surfactant B at a dosage of 75 ppm (parts per million) for feed 1. But at the same dosage the recovery decreased by 21% and 10.2 % respectively for feed 2 and 3. On the other hand surfactant A showed a consistent result for all the three feed samples giving the highest value at a dosage of 50 ppm followed by a decrease beyond this point. The tests were complemented by contact angle measurements that demonstrated the same trend. In addition to this the reproducibility of data for Surfactant A was checked and found that the standard deviations for both separation efficiency and combustible matter recovery were within the permissible range (less than 5%). Finally an in-plant process optimization study to evaluate the performance and applicability of surfactant A at industrial level was done and has been discussed.

Jan 1, 2016

By D. Raicevic

Interest has recently been revived in the recovery of tantalum from the Bernie Lake pegmatite deposit. A gravity concentration process was developed to give satisfactory recovery and concentrate grade. The application of high-intensity magnetic separation was also stud1ed. A pilot-plant investigation that confirmed the laboratory testing and provided a commercial-grade concentrate 1s described.

Jan 1, 1968

By D. A. Livingstone

Abstract Golden Manitou Mines, Limited, nine miles east of the town of Val d'Or in northwestern Quebec, are presently milling, at the rate of 1,000 tons daily, a relatively complex 3.11-phide ore and producing, in decreasing order of value, zinc, silver, gold, lead, and copper. The products are a zinc concentrate, a silver-lead-copper concentrate, and a silver-gold precipitate from cyanidation. Although several independent pre-production metallurgical investigations into the treatment of the ore were carried out, current practice is different from any of the recommended methods and, while still leaving room for improvement, is considerably more effective than earlier performance. Flow-sheet developments from the commencement of operations in 1942 are dealt with briefly, showing the reasons for making numerous changes, the shortcomings of the various schemes tried, and, finally, covering data pertinent to present-day practice. From the recovery standpoint, silver has presented the greatest difficulty. The writer's association with the Company coincided with the start of production. Characteristics of the Ore The predominant metallic minerals present in the ore, in decreasing order of their abundance, are: pyrite, sphalerite, galena and chalcopyrite, with lesser amounts of argentiferous tennantite-tetrahedrite, arsenopyrite, covellite, bornite, and chalcocite. The sphalerite is mostly light in colour, sometimes colourless, and practically free from combined iron. Some of the sphalerite is very closely associated with minor amounts of pyrite, chalcopyrite, and galena. Pyrie is abundantly disseminated as medium to fine grains; more rarely it is massive and contains occasional grains of sphalerite, galena, and chalcopyrite.

Jan 1, 1952

By K. Jomoto, H. Majima

"Experimental work has been attempted to find a useful criterion of comminution which can be determined simply in a laboratory. The suitability of the ratio of the square of tensile strength to Young's modulus, St2/E, previously derived from the theory of elasticity as a criterion of comminution, was examined measuring tensile strength, Young's modulus and critical height for drop-weight impact of five different rocks. However, satisfactory correlation between St2 /E and critical height has not been obtained, suggesting the necessity of further experimental verification of the representative value of Young's modulus of rocks. The plot of St2 vs. critical height, however, shows one-to-one correspondence, and this finding suggests that St• may be a useful criterion of impact crushing. Also, a close relationship was observed between st• and the energy index for tumbling mill grinding of •the sample rocks. It is confirmed from these findings that the quantity St• is a useful criterion of comminution of rocks, not only for impact crushing but also for tumbling mill grinding. As shown in the experimental part of this paper, the determination ol St with irregularly shaped specimens is simple."

Jan 1, 1972

By H. H. Bleakney

The merit of reduction-in-area as a criterion of quality in metals is shown to lie in its influence on breaking stress, but the virtue of elongation is not easy to find. In order to assess the value of elongation, either as a measure of quality or as a guide to design, it will be necessary to separate the overall de-formation occurring in tension tests from the localized deformation associated with localized reduction in area. The obstacles to a successful solution of this problem have been shown to be more formidable than is generally appreciated, and a new solution to the problem has been suggested. This solution involves a de-vice by which an electric circuit is broken when the particular value of strain is reached that is to be taken as the point of separation between general and localized deformation. The report presents results from a number of tests on both low-carbon and alloy steels. These results indicate that the selected criterion of separation is accurately identified by the proposed method; that it

Jan 1, 1962

By J. Edwin Van Buskirk

For a country that is as important a gold producer as Canada, the return to the gold standard of the major commercial countries of the world during the past five years is of particular significance. To the Canadian gold mining industry, the advantages of the gold standard are a matter of more than theoretical importance. According to economic theory, prices are determined by the relation between the demand for, and the supply of, money. The demand consists of the offering of goods for money; the more goods offered, the greater the demand. The supply consists of the total money available for the purchase of goods. The total supply of goods to be exchanged through the instrumentality of money remaining the same, an increase in the supply of money will, according to this theory, raise prices; conversely, a decrease in the supply of money will lower prices. Let us imagine that everyone in the world suddenly had twice as much money, and that the sum total of all goods remained the same. Is it not obvious that we would pay just double the price for these goods? In Canada today, most people have approximately 50 per cent grea.ter income than in 1913, and the average price for all articles sold in Canada is 50 per cent above those in 1913.

Jan 1, 1928

By F. A. Auld

"During the period 1958-1980 seven deep shafts were sunk from the surface in the UK. From 1977 until 1989 sixteen deep shafts were sunk in the UK, all concrete lined. Subsequently from 1989 up to the present day no deep shafts have been sunk in the UK, a period of 30 years. Developments in the design and construction of deep shaft linings in the UK therefore were predominantly carried out throughout the period 1977–1989. This knowledge is recorded in several published papers by the author over that period which will be referred to in the paper. INTRODUCTION The paper includes a review of past precedent for the design of deep shaft concrete linings in the UK and sets out the principles for future designs, including the design load to be adopted and Factors of Safety (SFs) to be used in the design. Hydrostatic pressure increases with depth from the surface and therefore the concrete lining must increase in thickness and strength throughout its depth to resist the pressure. High strength concrete mixes were developed to enable economic linings to reach greater depths and these will be detailed. The ground conditions to sink through in the UK consist of predominantly competent (self-standing when excavated) rock, which can be water bearing, and hence a hydrostatic pressure resisting lining is required. The paper describes the construction measures needed to produce a dry shaft by way of pour length, joint detail, backwall grouting and joint sealing details. PAST PRECEDENT FOR UK DEEP SHAFT SINKING AND LINING Seven deep shafts were sunk from the surface in the UK from 1957–1977 over a 20-year period (Auld, 1987). These are listed in Table 1. Three shafts were for British Coal, two were for Cleveland Potash Ltd and two were for the Central Electricity Generating Board. The British Coal shafts were 5.486 m and 7.315 m internal diameter to depths of 550 m and 780 m, respectively. At 5.5 m internal diameter and a depth of 1150 m, the two Boulby Mine shafts for Cleveland Potash Ltd are currently the deepest shafts in the UK. The two Central Electricity Generating Board shafts of 5 m and 10 m internal diameter, to depths of 255 m and 440 m, respectively, were ventilation shafts for a pumped storage scheme. Six of the shafts were sunk by Thyssen (GB) Ltd and one by Cementation Mining Ltd."

Jan 1, 2019

By R. R. Rogers

Abstract The degree of cathodic protection of steel and the anode corrosion rate were determined when anodes and waters of different compositions were used at temperatures similar to those in domestic hot water tanks. Twenty different anode materials, sixteen of them magnesium-zinc-aluminium alloys, were immersed in six different synthetic waters resembling those to be found in various parts of Canada. The results showed that (1) both the degree of cathode protection and the average anode corrosion rate are affected materially by the composition of the anode material and of the water; (2) poor cathode protection is associated with low anode corrosion rate; (3) when the cathode is fully protected, the anode corrosion rate may be comparatively low or comparatively high, depending upon the composttion of the water; (4) an important relationship exists between the magnesium content of the preferred anode and the composition of the water; (5) the degree of protection is increased as the SO4 + Cl concentration of the water is increased and thus as its specific resistance is decreased. Introduction Fairly recently, the use of the active metal magnesium for the cathodic protection of less active metals has received a considerable amount of attention. This interest has been stimulated by the fact that the wartime demand for magnesium was greatly in excess of the present peacetime demand and there is a natural desire to continue operating the large magnesium plants which were built during the war. Information regarding the use of zinc and aluminium for this purpose also has been published. There is a great demand for domestic hot-water tanks which will resist corrosion satisfactorily. This problem is rather complex in view of the fact that the composition of the water used in such tanks varies greatly and depends upon the locality. The present investigation deals with the effect of water composition and anode composition on the cathodic protection of steel under conditions approaching those which exist in hot water tanks.

Jan 1, 1948

By H. G. Stephenson, C. W. Gregory

"This article describes the methods used for pillar extraction in the Wilson Seam at Canmore Mines, Alberta. The Wilson Seam is extremely gassy and varies in thickness between 7 and 30 ft, with an average of 12 ft. The gradient varies from 5 to 30 degrees, with an average of 15 degrees. The seam was developed using Lee Norse miners to form pillars which the company intended to extract using the same machines. Before pillar extraction commenced, an abandoned and inaccessible mine 160 ft above the Wilson had to be drained of 360 million gallons of water. When this was done pillar extraction commenced. Conditions in the mine slowly deteriorated and after 6 months the decision to withdraw the continuous miners was taken. Slusher hoists were installed to replace the continuous miners, with the result that roof conditions and safety steadily improved."

Jan 1, 1972

By V. A. Preto

The Rexspar uranium deposit is located approximately 5 kilometres south of Birch Island, B.C. Three separate zones of commercial-grade uranium mineralization mineable by open pit have been outlined. Uranium and fluorite-celestite mineralization occur in a trachytic member of alkali-feldspar porphyry, lithic tuff, tuff breccias and pyritic schist conformably interlayered with a succession of strongly deformed greenschists and fragmental rocks that are, in large part at least, of volcanic origin. The age of these strata is not precisely known, but they are considered as part of the possibly Mississippian Eagle Bay Formation. Commercial-grade uranium mineralization is always associated with fluorphlogopite-pyrite replacement of the trachytic unit and is contiguous to, but separate from , a zone of ore-grade fluorite mineralization. In all zones, ore occurs in lenses of variable thickness and lateral extent, which lie parallel to the schistosity of the trachytic rocks and surrounding greenschists. The principal radioactive minerals at Rexspar have been identified by other workers as uraninite, uranothorite, bastnaesite, torbernite and metatorbernite. Considerable amounts of thorium oxide and widespread rare earths have been reported from all three radioactive zones. The geology of the deposit suggests that the trachytic rocks represent a highly differentiated intrusive-extrusive system in which fluorphlogopite, pyrite, fluorite and uranium-bearing minerals were deposited late in the evolution of the system by deuteric, volatile-rich fluids. The considerable amounts of thorium and widespread rare earths associated with the uranium tend to support the thesis that this element is of primary origin rather than secondary.

Jan 1, 1978

By M. S. Badollet, W. C. Streib

"AbstractA commercial method .has been developed for controlling the texture of chrysotile asbestos fibers so that they may possess properties comparable with natural sem1-harsh fibers for use in wet •processes.The physical properties of the soft, silky and slimy fibers are partially altered by a flash-heating process which removes a portion of the molecular water.The heat-treated fibers show an improvement in filterability, an increase in bulk, absorption, and surface area and better electrical properties, such as volume resistivity.IntroductionCHRYSOTILE ASBESTOS fibers are found in nature having varying degrees of texture, referred to as soft, semi-harsh, and harsh. Fibers of each type of texture have inherent characteristics which directly affect their usefulness to industry. Visual differences are apparent under a microscope where it is seen that the soft-textured fibers have a silky, serpentine or wavy appearance, whereas the harsh-textured fibers are coarser and spicular. Semi-harsh fibers, of course, have properties intermediate between these extremes.Fankuchen and Schneider ( l) have shown by the use of low-angle X-ray scattering that the diameter of the harsh type of chrysotile fiber is somewhat greater than tha of the soft variety. Surface area measurements on various chrysotiles of different textures tend to confirm their findings. By nitrogen adsorption methods, it was found that the surface areas of soft types of chrysotile asbestos are approximately 23M2 / g whereas for the harsh types they are as low as 11M2/g."

Jan 1, 1955

By R. A. McGuire

THE recorded production of the Sheep Creek camp from 1900, when the Yellowstone Mining Company first put its mill into operation, to the present day is in excess of $17,500,000. Of this total, $2,500,000 can be attributed to the early period from 1900 to 1916, at which time increased costs of labour and material due to the Great War forced abandonment of any operations on a large scale for a number of years. Since the camp was revived in 1929, at which time the Reno mine started large-scale operations, and the early 'thirties', when the increased price of gold induced the commencement of operations on other properties in the district, total gross production has been in excess of $15,000,000. In addition to the above totals, intermittent shipments were made by lessees and small operators, principally during the period of inactivity from 1916 to 1929, but no records of this production are available. The Sheep Creek camp would rank fifth in the Province-behind Rossland, Portland Canal, Bridge River, and Hedley-in gross gold production, but, because of relatively inexpensive mining and milling costs, would occupy a more prominent position in regard to total dividends paid. Operating mines at the present time include Reno Gold Mines, Gold Belt Mining Company, Kootenay Belle Gold Mines, and Sheep Creek Gold Mines. Each one of these companies, with the exception of Kootenay Belle, represents a consolidation of several smaller properties, all of which were in existence for a number of years prior to 1929. These four companies, at the present time, own, or hold options on, practically all the important claims in the district with the exception of a very few claims and fractions still held by private owners.

Jan 1, 1942

By N. Melnyk, H W. Habgood

The conventional low temperature process for extracting' helium from natural gas involves liquefying the whole gas stream in order to remove the relatively small fraction of helium. A process based on the selective diffusion of helium through a semi-permeable barrier is, in principle, more economical and flexible, particularly for the treatment of small re-serves and low concentrations. The well-known permeability of glass to helium offers the possibility of such a diffusion process and McAfee of the Bell telephone Laboratories showed in 1958 that practical separations could be achieved by passing natural gas over bundles of fine capillary glass tubing. Developmental studies have been carried out involving larger units and more extended field tests than those of McAfee. Fine capillary tubing of Pyrex glass 0.0035 in. diameter was prepared by drawing ordinary 6 mm. laboratory tubing in a furnace. Extraction units were pre-pared containing about 10,000 such tubes, 4 ft. long and cemented inside

Jan 1, 1961

"The Hardy Cross algorithm offers a reliable method of solving network systems of fluid flow and has become widely used for solving water and ventilation flow networks. A limitation is that computational iterations and time to solve a network rises rapidly with the size of the model and modern detailed ventilation networks have typically grown to thousands of airways. Non-linear matrix solving methods can offer improved performance, however these are more complex and may be unstable if initial estimates are poor. This paper presents improvements that can be applied to the traditional Hardy Cross algorithm to greatly reduce iterations and solving time for large ventilation models. INTRODUCTION The Hardy Cross algorithm (Cross, 1936), was originally developed to solve water flow in city and urban pipe networks. Using principles of Kirchhoff’s electricity current laws, Hardy Cross developed an iterative algorithm for solving non-linear equations associated with network water flow. Traditional network analysis research refers to the various members of system networks as branches, nodes and meshes. This terminology has been changed in this paper to airways, junctions and loops respectively which are terms more familiar to engineers in mine ventilation. When Kirchhoff’s laws are applied to fluid networks, the following assumptions can be made: •The sum of fluid flows into a junction must equal the sum of fluid flows out of the junction.•The sum of pressure losses around any loop through a network system must be equal to zero.An iterative solution can therefore be achieved by initially guessing flow in a network, calculatingthe pressure losses around the network loops (Figure 1), and applying flow corrections using Newton’s method for each loop if the sum of the pressure losses does not equal zero. To solve the system, a loop must be defined for every segment or series of segments between a junction of 3 or more airways.The Hardy Cross algorithm has been used extensively for ventilation network analysis since the introduction of the first electronic computers (Tien, 1997), however numerous other variations and methods have since been developed through the use of matrices to solve the required system of nonlinear equations. Commonly used algorithms such as the Newton Raphson method (Brown, 1969), the Gradient method (Todini & Pilati, 1988), the Linear Theory method (Gupta & Prasad, 2000), and Coupled Network Solver (G. Danko, 2008) have found general use in fluid flow network solvers (Rossman, 2000). Despite poor and sometimes unpredictable convergence performance however, the Hardy Cross algorithm still has unique properties that make it attractive for ventilation models. Some benefits are:"

Jan 1, 2019

By A. A. McDonald

Anode casting has been in operation for two years in Hudson Bay Mining and Smelting's Flin Flon smelter. The new plant allows all casting to be done on one shift and so achieves considerable labour savings. The equipment and operations are described. Some important features are as follows: very consistent anode weights by the use of the load-cell controlled casting ladle; excellent mould life ; very low reject rate; and trouble-free take -off tower. Some of the start-up problems are described and an outline is given of the main operator functions. Data on labour, propane and maintenance costs are presented.

Jan 1, 1977

By Jun Wang, Bo Zhang, Wenqing Qin, Guanzhou Qiu, Xiaozhen Ma, Key Lab of Biohydrometallurgy of Ministry of Education, Fen Jiao, Central South University, Yansheng Zhang

"Arsenic contained in minerals sulphides such as enargite and tennantite can represent not only a significant penalty element in base metals production, but also a disadvantage to the environment through producing the toxic emissions to the atmosphere. The achieving separation of arsenic bearing minerals either at an early stage in floatation or from the floatation concentration is significantly beneficial to the economic. However, there was no feasible commercial method of separation at the flotation stage because of its similar flotation properties with many other copper sulphides. In this work, the selective floatation of enargite from copper sulphide concentrate containing maily covllite, chalcoctie, bornite and enargite was investigated. A low arsenic concentrate with As 0.2%, Cu 22% and a high arsenic bulk concentrate with As 7.65%,Cu 33.65% were obtained. It was indicated that Ca(ClO)2 is the effective depressor and the optimum floatation condition was obtained. Most enargite could be floated at pH 11 and controlling the pulp potential at 290 mV SHE. Furthermore, the arsenic removal from the high arsenic bulk concentrate by hydrometallurgy methods was study. The results showed that the reaction temperature and the concentrations of NaOH were the most important variables affecting the rate of arsenic removal. A low arsenic concentrate with As 0.24%, Cu 37.80% was obtained in the optimum leaching condition.INTRODUCTIONArsenic is mainly produced as a by-product of base metals smelting, in particular copper concentrate. China has imposed an upper limit of 0.50% arsenic for concentrates entering (Long et al., 2012). Arsenic amount of copper concentrate within 0.40% has also been imposed in China, and above which will be introduced about 50 RMB penalties per ton for each 0.10% increasing by smelters now. Therefore, it is necessary to remove arsenic from the copper concentrate.In copper concentrate, arsenic is mainly in the form of arsenopyrite (FeAsS), enargite (Cu3AsS4) or tennantite (Cu12As4S13). There are two types of arsenic in the separation of copper and arsenic: arsenopyrite and arsenic bearing copper mineral. It is easier to separate arsenopyrite from the copper sulphide by flotation in comparsion with the separation of enargite or tennantite from non-arsenic copper minerals (Pineda et al., 2015). The main difficulty in the separation of arsenic copper mineral from non-arsenic copper sulphides is their extremely similar floatability, which depends on the fact that tennantite and enargite contain high copper content (Pineda et al., 2015)."

Jan 1, 2016

By Jiuhua Xu, Shuiku Jia, Weiren Sun

"Abstract -The Jinqingding gold deposit, situated in the east Jiaodong Peninsula of Shandong province, is typical of the pyrite-quartz vein gold deposits in the Muping-Rushan gold belt of China . The gold deposit is controlled by a great NNE fracture zone and is composed of several lenticular orebodies within the fracture zone occurring in the Kunyushan granite massif. The Kunyushan granite massif was formed by the replacement of the Archean Jiaodong group.The main minerals associated with gold are pyrite, chalcopyrite, galena and sphalerite; the gangue minerals are dominated by quartz, sericite, microcline and calcite. The mineralizing event can be divided into four stages: (1) pyrite-quartz; (2) quartz-pyrite; (3) siderite-polymetallic sulfides; and (4) calcite-quartz. Gold occurs mainly as native gold and electrum in stage 1 and stage II. There are some evident differences between pyrite from major stages of gold mineralization and that from minor stages; these include differences in crystal forms, size and composition of fluid inclusions.Wallrock alterations consist of sericitization, silicification, pyritization and potash-feldspar alteration. Five alteration zones can be distinguished from unaltered granite (zone 0) to vein lodes (zone IV). Au and Ag increase rapidly from zone 0 to zone IV, Cu increases continuously, while Pb and Zn increase slowly. R-type geological factor analysis indicates that the Au, Ag, Cu, Pb and Zn bear a close relationship to wallrock alteration."

Jan 1, 1994

By K. Adham

Both the dry and the wet fluorination systems require hydrogen fluoride (HF) for the process of uranium conversion to uranium hexafluoride (UF6). The dry methods depend on the electrolysis of HF to generate the fluorine (F2) required for the high temperature pyro-fluorination. The wet methods require aqueous HF in water solutions for the low temperature hydro-fluorination (Argonne, 2019). This paper uses the available HF safety guidelines and industry information to discuss the issues of transportation, storage and utilization. Health effects and environmental considerations are reviewed. Safe practices for handling the HF (both as anhydrous and as aqueous) are considered. Proper selection of different materials of construction are discussed, for both the anhydrous and the aqueous HF.

Jan 1, 2020

By G. C. Mackenzie

At the last Annual Meeting of the Institute, Dr. C. V. Corless sketched the potential mineral wealth of Canada so clearly, graphically and with-all so entertainingly that one's imagination was fired with the promise held out to future generations for the tremendous expansion of the mining industry in the Dominion. Posterity will undoubtedly witness the fruit of much of the geographical search and survey that is now carried on by our government mining departments. Year after year the work advances, slowly but surely, new areas are . explored, older areas are surveyed in detail, the information being compiled in maps and reports of incalculable value to the prospector, the engineer and the general public. The immensity of the task of exploring, geologically, the outlying portions of the country, with the ultimate view of making valuable mineral discoveries, may be visualized from a study of Dr. Corless' paper and the subsequent discussion which took place and one becomes impressed with the fact that three-quarters or more of the problem can be included under the word "transportation". For instance Dr. Corless said, "The few geological explorers who have penetrated to these remoter regions . . . . . . have as a rule been compelled to stick closely to canoe routes,"; Dr. Goodwin remarked, "This barren Laurentian granite, which is put down on the maps as covering the greater part of this area, is the best guess the geologist could make from travelling along watercourses Within the next few years . . . . . . the Timiskaming and Northern Ontario railway will undoubtedly be extended to James Bay . . . . . . In order that we may be prepared for the probable influx of prospectors when transportation facilities to tidewater are provided, I think all available information on this district should be gathered together in handy form." All three-Corless, Goodwin and Cole-emphasize the well-known fact that explorers, geologists and prospectors working in new country must stick to the watercourses and that transportation by rail, road or water has always been the all-important deciding factor in facilitating the exploration and development of remote districts. Dr. Corless did, however, suggest other means of transportation in stating, "The aeroplane will be of assistance in future study of some parts of these remote areas."

Jan 1, 1924

By A. M. Ramadan

The composition of phosphate rocks, mainly used in manufacturing fertilizers, varies among deposits; therefore, phosphate rocks from different sources are expected to behave differently in acidulation processes. This paper examines the effect of preconcentration of phosphate ore from El-Sebaiya East, Egypt, using flotation on uranium leaching. A high-grade ore sample (27.3% P2O5, 168 mg/kg U) supplied by the Al-Nasr Mining Company, was subjected to reverse single-stage flotation to separate carbonate from the phosphate sample. Subsequently, P2O5 and U concentrations were 32.2% (92.1% recovery) and 225 mg/kg, respectively. After the leach process, the U concentration in the liquor was 319 mg/L.

Jan 1, 2014