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By Stephen Birch

The Chitina mining district of Alaska is located at the headwaters of the Chitina and Copper Rivers. At present, the only producing mining properties are the mines of the Kennecott Copper Corpn. and the Mother Lode Coalition Co., which are situated 196 miles from Cordova, the port of entry. The first claims, later acquired by the Kennecott Mines Co. and afterwards transferred to the Kennecott Copper Corpn., were discovered in 1900. The Copper River & Northwestern Ry., which connects the mines with tide water at Cordova, was completed in the spring of 1911. Contemporary with the construction of the railroad, aerial tram equipment was brought to the mines by pack train and a tramway, 3 miles long, connecting Bonanza mine with the proposed railroad terminal, was finished, enabling shipments of high-grade ore to be made immediately the railroad was completed. A mill to treat the lower grade ore was begun the same year. The Kennecott company's holdings consist of 111 mineral claims. The Mother Lode Coalition Mines Co., which is controlled by the Kennecott Copper Corpn., owns 73 claims adjoining the Kennecott holdings. All data on operations and geology refer equally well to the Mother Lode property. Geology The general geology of the district has been covered by the U. S. Geological Survey1 and the geological features of the mines have been carefully studied by A. M. Bateman, in his capacity as consulting geologist to the company.2

Jan 1, 1925

By Jesús L. Valenzuela

The solvent extraction for gold from alkaline cyanide solutions has been investigated using LIX 79 guanidine-based extractant. Different variables that could affect the extraction system were evaluated: equilibrium time, aqueous pH and extractant and modifier concentrations. The extraction isotherms of the aurocyanide complex with respect to other cyanoanions were compared and the following order of selectivity Au>Ag>Cu>Zn>>Fe was observed. From the pH isotherms it was found that aurocyanide can be extracted in alkaline media and a better separation with respect to other cyanoaniones was obtained in the range of 10.5 < pH < 11.2. Better selectivity was observed when using LIX 79 and tridecanol at 10% and 5% vol, respectively. Stripping gold from loaded organic was carried out at pH>12, using NaOH and NaCN solutions.

Jan 1, 2003

By P. van Niekerk, V. J. Solomon

Improvements in the drilling and blasting techniques used in the stopes of narrow reefs have caused the clearing of broken rock to become the major cause of delay in the achievement of a regular cyclic operation. This paper discusses the development of a scoop in accordance with a predetermined set of performance parameters. The test results obtained to date have shown that the basic objectives have been achieved within tolerable limits of variation.

Jan 1, 1979

By T Weaver, R Dick, R Sivakumar, C T. Aimone

A series of small-scale crater tests were performed in concrete and sand in an effort to understand the cratering process in large-scale field blasts. The surface orientation of these tests varied from flat to a 30° slope. In comparison to previous crater experiments in competent oil shale, the crater tests in concrete produced craters similar to those in oil shale after scaling the measurements for differences in the mass of explosives among the experiments. Material strengths and the degree of brittleness had a significant effect on the size and shape of the crater. The small-scale sand tests resulted in some crater features that were similar to large explosive tests in alluvium and soil.

Jan 1, 1986

By W. W. Weller

Heat capacity measurements of anhydrous cobalt sulfate (CoSO4), copper sulfate (CuSO4), nickel sulfate (NiSO4), and zinc sulfate (ZnSO4) were conducted over the temperature range 51° to 298° K. The results were used to evaluate the following entropies at 298.15° K (cal/deg mole): CoSO4, 28.1; CuSO4, 26.8; NiSO4, 24.8; and ZnSO4, 26.4. Entropies were combined with heats of formation to give free energies of formation.

Jan 1, 1965

By R. F. Favreau, Patrice Favreau

"Ever since we have started to assist those responsible for blasting with blast simulation studies, we havebecome aware of an interesting aspect, namely that in 90 % of cases we are asked ‘‘Can you seek ablasting method which gives better fragmentation than the method which we use now’’. But after a visit to the site, and the evaluation of the fragmentation obtained with their present blasting method, it very often becomes evident that it is the ease of mucking and not the fragmentation which requires improvement. Hence we then proceed to do a simulation study the results of which are improved mucking rather then more fragmentation, and those responsible for the blasting always become very satisfied."

Jan 1, 2017

Four data sets are required to put constraints on the tectonic evolution of the southern rim of the Pacific Ocean basinI . data bearing on the dispersal of the major Gondwanaland continental fragments and the birth of the Southern Ocean,2. data bearing on the interaction of the Pacific Ocean basin lithosphere with the South American, Antarctic, and Australasian continental masses,3. data bearing on.the evolution of the Scotia Sea floor, and 4. data bearing on the evolution of the various continents, microcontinents. and volcanic arcs.

Jan 1, 1990

By R. D. H. Wigmore

"The title of this paper probably sounds quite simple and self-explanatory. The problem, however, was not a simple one, and proved somewhat baffling and expensive over a period of years. After outlining the problem, and the methods which were used to overcome it, we will present our solution, or perhaps it would be more accurate to say the partial solution which we reached.We have in the cyanide circuit at Upper Canada two Dorr Single Tray Thickeners with 30 ft. diameter wood stave tanks 12 ft 4 1/ 2 in. deep. In the years prior to 1948, when the tonnage was 250 to 280 tons per day, two stage thickening was practised. As the tonnage was increased to 450, 500, and finally 560-600 the thickeners were used in parallel.Some settling problems were encountered, and in those days the means to combat these problems were very few. The only remedy was to dump in pounds and pounds of lime. Then along came a few reagents, and the writer remembers one in particular, - 11 Carboxel11 (carboxymethlycellulose). When water or solution was added to this reagent, the result was a gooey mass somewhat resembling tapioca. One drawback was that it stayed in this state, and didn't go anywhere. A method was finally developed of containing the mass (or mess) on a fine screen, and dissolving some of it was a fine spray of solution. The only thing the writer recalls was that it was not a very effective settling agent.Shortly after this time, along came the new flocculents, first a few, and then many, and our settling problems were over.But when the settling problem was solved at Upper Canada, some other problems were creeping up on us."

Jan 1, 1965

By R. D. Stewart

Abstract. Induced fluorescent sorting is a means of beneficiating an ore by selective labeling with a reagent combination which fluoresces when activated by ultraviolet light The reagent combination normally consists of a surface active compound and a fluorescent dye. The surfactant adheres selectively to a specific surface and carries the dye with it. Upon activation with ultraviolet light, the labeled pieces, in the size range 1.27 cm to 20 cm (0.5 to 8 in.), are detected during free fall by photosensitive cells and ejected by water jets. Either ore or gangue may be labeled.

Jan 1, 1980

Elimination of zinc by the reduction of iron works dusts is examined. The process consists of blending, filtration, drying, balling, preheating and reduction in the rotary kiln. Dust slurries and dry dusts are mixed and stored in slurry basins and the blended slurry is filtered. In the balling process it is important to make green pellets which will withstand Thermal shock in the preheater and rotary kiln. Preheating to about 2000C is preferred to ensure effective use of coke fines in the blast furnace dust. The coke retained in the pellets accelerates the reduction rate. However, at the initial stage of the reduction the pellets become weakened and have to be heated slowly to prevent ring formation. In order to ensure zinc vaporization, pellets should be heated to a temperature of 1100-11500C in the kiln with injection of l ignite fines from the discharge end. Pellets having a degree of metallization of more than 90% and containing less than 0. 1% zinc have been obtained using a test kiln. The final pellet product is intended for use as blast furnace feed. A new plant with a capacity of 20, 000 tonne of dust per month is now under construct- ion and will be in operation next year.

Jan 1, 1974

By J. H. Hodgson

"Those of us who have been concerned with the problem of geophysical exploration in southwestern Ontario have followed the development of the Poulter method with much interest. I have much appreciated the opportunity of reading an advance copy of Dr. Poulter's clear exposition and of preparing the following brief remarks on the probable applicability of the method to the Palaeozoic area of southwestern Ontario.During the years 1944 to 1946, the Ontario Department of Mines, in co-operation with the Union Gas Company and the Dominion Natural Gas Company, operated an experimental party in the hope of establishing a seismic technique appropriate to the •area. The results were completely negative. During two summers' field work, no reflections whatever were obtained except in one area near Windsor. It is the •purpose of these remarks to inquire whether Dr. Poulter's techniques might yield favourable results.It was the conclusion of the report on our work that two principal causes contributed to the failure of the method. In the first place, the geological column possesses few elastic discontinuities and those that exist appear to have low reflection coefficients. In the second place, the area is drift-covered in general. This drift complicates the situation by absorbing seismic energy and by giving rise to groups of complicating refracted phases which obscure the entire interesting section of the record. The situation is further complicated by the high reflection velocities and the relative shortness of the Palaeozoic section, these factors combining to bring in a reflection from the basement in about half a second."

Jan 1, 1950

By M. Sakata, H. Hata, K. Haiki

"Most of the secondary ZnO contains fluorine (F) in large quantities. Serious troubles at the zinc electrowinning are occurred by the cathode corrosion caused by F, therefore we developed iron compounds as F-adsorbents used in zinc sulfate solution. The iron compounds can be reused repeatedly as F-adsorbents because they can adsorb/desorb F alternatively depending on the pH. Moreover, if the adsorptive capacity decreases, we can dissolve and re-synthesize them easily. In this paper, results of the experimental process which consists of five steps (leaching, F removal, Cl removal, purification and electrowinning) to produce high purity electrolytic zinc from the secondary ZnO are reported. INTRODUCTIONThe recycle material for zinc, secondary ZnO, contains large amounts of fluorine (F) and chlorine (Cl) which are halogen elements, compared with calcine obtained by roasting of zinc sulfide concentrate. The halogen elements cause adverse effects in the zinc electrowinning process and particularly F causes corrosion of aluminum cathode plates and eventually sticking of electrodeposited zinc and therefore, F concentration in the electrolyte is controlled to less than approximately 20 mg/L. There are several methods to remove F from secondary ZnO, such as leaching with Na2CO3 or NaOH solution [1-2], vaporizing in a rotary kiln by roasting at 1000 to 1200 degrees C [3-4]. However, up to the moment, there has been no effective method for the removal of F from zinc electrolyte and it has been a big obstacle in treatment of secondary ZnO in electrowining of zinc.The authors, therefore, developed an iron compound used as an adsorbent of F in the zinc sulfate solution [5-8]. This iron compound is Akaganeite that has a crystalline structure of ß-FeOOH. Akaganeite is synthesized by neutralization of FeCl3 solution containing a small amount of SO4 2- with Na2CO3. When this iron compound is immersed into weak acidified zinc sulfate solution, F in the solution is adsorbed. F adsorbed in the iron compound is removed by immersing in weak alkaline solution and the iron compound can be reused as F adsorbent."

Jan 1, 2012

By A. F. Sirianni

The Peace River iron ore deposit represents the sole source of raw material for an integrated steel industry in Alberta. The ore has proved refractory to beneficiation by a number of techniques. A selective oil-phase agglomeration technique is described. Medium-grade concentrates, analyzing 48-53% Fe and 10-14% SiO2 were obtained with recoveries of about 75% of the total iron. These results appear to represent the optimum possible for this ore body.

Jan 1, 1977

By W C. Brukle

Our title for this presentation could be taken in many ways. One course would be terrifying and that would be to cite incredibly bad practices. All of our votes/efforts should be for the reverse direction in which everyone does his/her best to keep their pit or working place free from hazards.

Jan 1, 1983

By Chris G. Dobson

Introduction The Britannia mine is at Britannia Beach, on Howe sound, approximately thirty miles from Vancouver. The first claims were staked in 1898, and a local company was formed at that time to develop them. In 1904, Mr. Grant B. Schley became actively interested in the property and in the following year the Britannia Mining and Smelting Company, Limited, was incorporated to operate it. This Company was taken over a few years later by the Howe Sound Company, Limited. The mine comprises five more or less separate ore-bodies, which have produced approximately 20,000,000 tons of ore to date. The East Bluff ore-body, with which the present paper deals, is well suited to large-scale mining by means of carefully placed powder blasts. It covers approximately an acre and lies in the slate footwall, in a bay produced by a fault. The hanging-wall side, on the west, forms the face of the Bluff glory-hole, which extends to the 1,200 level. A portion of this ore was available for breaking into this old glory-hole, below which four bulldoze chambers could quickly be built. Mining of this block is complicated by a very soft footwall, which &apos;runs&apos; badly when broken. In stoping, care is taken to guard against the hazard of dilution by deliberately leaving a small portion of ore on the footwall. Some of this will undoubtedly be lost, but it is hoped to recover a fair amount of it after the major drawing is completed. The deposit occurs in a greenstone which has been highly silicified following brecciation. The chief minerals are chalcopyrite, sphalerite, and pyrite. Concentrates of copper, zinc, and pyrite are made at the mill. The average grade of ore runs 0.7 per cent copper, 1.5 per cent zinc, and 0.03 oz. gold per ton. The rock, which is practically a chert, is extremely hard, but shatters well. Both in stoping and drifting, holes must be closely spaced and powder used generously. Development When development work started in the East Bluff, there were no raises and only one drift on each level in this section of the mine. After blocking out the ore by thorough diamond drilling, a production of two thousand tons per day was set as a goal. To obtain this tonnage from so small an area required a great deal of carefully planned and well timed development work.

Jan 1, 1935

By Jean Fortin

In order to remain competitive, the search for excellence has been and will remain the only viable option facing the Mount-Wright operations. Safety and environment, process and technology as well as cost performance have been the focus points on which the operations have concentrated their efforts in order to meet and exceed our company&apos;s "Vision 2000" plan. Some of our mine&apos;s accomplishments have been a new work organization, a world class maintenance and a new collective agreement. The concentrator, maintenance and production departments have evaluated their processes and implemented various improvements in areas such as power supply, dewatering, blasting, implementation of service centers for large and small vehicles, fleet standardization, crusher, mills and silos improvements... etc. Safety and work environment for personnel have been our driving force in order to achieve this plan.

May 1, 2003

By S Planeta

The use of explosives in underground mining has its drawbacks, particularly in the case of thin or narrow vein type deposits. Due to that, there is a need to develop more discriminative and safe rock-breaking technologies. Mechanical rock splitting seems to be one of the most promising avenues in this respect. This paper describes briefly principles and features of radial-axial splitters. It reviews a feasibility study done to evaluate a potential of this technology in selective mining. It was intended to compare productivity and cost of ædrill-splitÆ mining with conventional cut-and-fill method. Hypotheses and assumptions adopted, methodology used and the obtained results are presented and discussed. The study has confirmed an interesting potential of radial-axial splitters in mining thin and narrow vein deposits. In conclusion, it is stressed however, that it will take more R&D work to corroborate the results obtained. Some suggestions concerning future research in this field are also given.

Jan 1, 2003

By W. Warscheid

Coppernico fue evidenciado inicialmente como sistema tipo pórfido de cobre en el año 2008 por Quippu Exploraciones en virtud a un reconocimiento de cateos con mineralización oxidada de cobre en el valle de la quebrada de Choque, afluente del río Fortaleza. Dicha mineralización se desarrollaba en vetas de cuarzo hospedadas en granodiorita plutónica. El proEXPLO 2017 246 seguimiento de las mismas junto con el reconocimiento general del área permitió identificar un estilo de fracturamiento en enrejillado con relleno de cuarzo, óxidos de hierro y cobre en menor grado alojado en el cuerpo intrusivo.

May 1, 2008

By Veronica Escobar

This paper presents results from a two month pilot evaluation of EMEW® technology at CODELCO Radomiro Tomic, in Chile. A prime focus in the test programme was to assess the technology?s capabilities to recover high quality copper from the Radomiro Tomic electrowinning tank house bleed stream. The EMEW® cell developed by Electrometals Technologies Ltd. tolerates substantially higher levels of contaminants than those found in conventional tankhouse, operating at high current densities while maintaining high cathode copper quality all the way down to low copper concentrations. To maintain high copper purity in a copper electrowinning (or electro-refining) tank house, a continuous bleed of solution must be taken from the tank house inventory to prevent build-up of contaminants, and resulting degradation in cathode quality. In an SX-EW operation, this bleed stream is normally recycled back to the solvent extraction circuit, but is occasionally sent to the raffinate pond to re-enter the leach circuit. Return of the bleed stream to the solvent extraction circuit creates a continually recycling load of copper in solution, which may reduce overall plant capacity and expansion potential. Return to the leach circuit has a similar effect, and methods to reduce its impact are always under consideration. The use of the EMEW® technology allows for direct and efficient recovery of near 100% of the contained copper instead of recycling. Tests were run at ambient temperature on bleed electrolyte using current densities which varied between 250 and 1100 amps per square meter, with copper concentrations between 38 and 1 g/l. A profile of maximum allowable current density with respect to concentration was developed, showing that high grade copper can be obtained at all levels of concentrations tested, by choosing an appropriate current density and electrolyte flow rate. The results of this programme show that the recirculating bleed electrolyte from an SX-EW operation can be converted into an expansion in copper production at a comparatively low investment cost.

Jan 1, 2003

By M. W. Hayward

THE object of this paper is to record and tabulate the data and field observations obtained by the writers and their associates during 10 years of intensive study of lead-zinc deposits in the Cretaceous limestone areas in Northern Mexico, particularly in mines owned by the Cia Minera de Peñoles, S. A. At the El Paso meeting of the Institute in October, 1930, J. G. Barry made the suggestion that a committee be appointed to correlate the ideas and theories which have been put forth by the numerous engineers and geologists who, during recent years, have made a study of the ore deposits in the area under consideration. The first step in a work of this nature would be to record all of the observed facts, and these facts would have to be accepted by those who attempted to formulate a theory of ore deposition. It is with this idea in mind that the writers have described as accurately as possible the actual, observed facts pertaining to the occurrence of the lead-zinc ores in dolomites or dolomitic horizons. By most writers the term "dolomite" is loosely used to designate magnesium-bearing limestones, regardless of the percentage of MgO present. Since no true dolomites exist in the areas to be described, we shall also loosely use the terms dolomite or dolomitic limestone to desig-nate those beds having a magnesia content of 5 per cent MgO or more. For a number of years the writers have been impressed with the fact that in areas where dolomite beds occur a large percentage of the lead ore is found in these beds, in spite of the fact that such beds may be overlain or underlain by pure limestone, which one would assume to be just as favorable for replacement as the dolomite, if not more so on account of its being more soluble in acid solutions than the dolomite. It is true that in some limestone areas, such as the Erupcion-Ahumada districts, Chihuahua, and Providencia, Zacatecas, where no dolomite beds have been found, large tonnages of lead ores have been mined. We venture to predict, however, that had there been dolomitic beds in these areas, the

Jan 1, 1932