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By R. Butar-Butar, J. Mosher, G. Banini, J. Hollow, A. Villanueva

The effect of High Pressure Grinding Rolls (HPGR), as a preceding stage to a conventional ball mill circuit at PT Freeport Indonesia’s C1/C2 concentrators, has been studied in terms of downstream grinding efficiency and circuit performance. When milling the product from the HPGR, mill capacity increased by 21% for the same product grind size, when compared to processing similar ore from a conventional crushing circuit. This achievement is a result of several reasons, among them: reduction in feed size (F80), fines generation beyond the proportional reduction in F80, reduction in ore hardness induced by HPGR comminution mechanism, optimization of the recycle system of the HPGR and ball string optimization in the ball mill circuit given the new feed to the mill.

Jan 1, 2012

By R M. Ennis, J. C. Botham

This paper is one of a series pre-pared to study the role of fuels and reductants in metallurgical processes, especially from the viewpoint of Canadian requirements. The object of these studies is to provide a reason-ably authoritative interpretation on the interrelation of fuels in light of the considerable changes that have taken place in the Canadian energy field during the past few years. Previous papers in this group have dealt with the problem generally, and specifically in terms of the development of the iron and steel industry of Western Canada. These latter papers, presented at the Symposium on Iron and Steel in Western Canada held in Edmonton, Alberta, on September 8-9, 1959, surveyed the ferrous processes of interest for use in Wes tern Canada, especially with regard to solid fuel requirements. At that time it was evident that there was a need for a similar study of the fuels aspect of the non-ferrous metals industry.

Jan 1, 1961

By John G. Ayttes

"The following is a review of the advance of raise boring and its current position. The viewpoint presented is that the mining industry, through its worldwide acceptance of raise boring, has acknowledged the success of the method in general. Acceptance, however, does not imply complete satisfaction with either the equipment or current operating costs. Therefore, a brief review of how boring costs are being r educed is presented, citing examples. Recent raise borer applications of special interest are presented to show adaptability of current equipment, and some special projects in the planning stage are highlighted."

Jan 1, 1972

By G. M. Behrend

"The mining and processing of mineral ores is a very old industry which is steeped in tradition. Rising demand for metals has recently forced the exploitation of lower-grade orebodies which require extensive beneficiation. The high capital expenditures involved, together with market pressures for high-quality concentrates and pellets, have forced the development of new process technologies which are heavily dependent on automatic process control. Development of suitable instrumentation has been rapid and it is being applied to mining processes today with a high degree of sophistication. The drive for higher efficiency and profitability goes on and has reached a level at which modern digital computers appear to be the only answer. However, the efficient application of a digital process computer is extremely complicated and is therefore approached by the mining industry with considerable hesitation.Some of the benefits promised by the digital computer can be obtained today by other means, which are more manageable and can provide immediate payoff. The result would be a building-block system which would utilize the digital process computer as its final component, to perform true plant optimization, free from routine chores."

Jan 1, 1971

By K. Morin, C. -Y. Hon, G. Lachapelle

"Air-sampling results suggest drill operators working inside environmental drilling cabs at an open-pit gold mine in Nunavut, Canada, are at risk of exposure to asbestos and silica (quartz). The authors installed RESPA® CF Vortex HyperFLOW® units, which showed promising results under laboratory conditions. The goal was to evaluate the effectiveness of these units under actual working conditions. Personal and area air sampling was conducted in drilling cabs with and without the unit and a Wilcoxon rank-sum test was performed to compare the results. Particulate concentrations were significantly lower in drill cabs with a unit installed than in those without.RÉSUMÉ Selon les résultats d’une campagne d’échantillonnage de l’air, les foreurs travaillant dans des cabines de forage environnemental dans une mine d’or à ciel ouvert du Nunavut, au Canada, risquent d’être exposés à l’amiante et la silice (sous forme de quartz). Les auteurs ont installé des unités RESPA® CF Vortex HyperFLOW®, lesquelles of frent des résultats prometteurs en laboratoire. L’objectif est d’évaluer l’efficacité de ces unités dans des conditions de travail réelles. Des échantillons de l’air inhalé par le personnel et dans les aires de travail ont été évalués dans des cabines de foreuses équipées ou non de cette unité ; un test de Wilcoxon (également appelé test de la somme des rangs de Wilcoxon) a été mené afin de comparer les résultats. Les concentrations particulaires étaient considérablement plus faibles dans les cabines de foreuses équipées d’une unité que dans celles en étant dépourvues.INTRODUCTIONGenerally, mining operations are associated with a variety of occupational hazards. In an open-pit gold mine in Nunavut, Canada, drill operators are routinely exposed to asbestos (primarily amosite) and silica (quartz)—two naturally occurring substances in the ore that is to be drilled (Table 1). Inhalation is the primary route of exposure for these two hazards, which are associated with respiratory health effects such as asbestosis and silicosis, respectively. In addition, asbestos and silica are classified as human carcinogens by the International Agency for Research in Cancer (2001, 2011). Given the toxicity of these two agents, it is imperative that precautions be taken to minimize the risk of exposure of the mine’s workforce. To address this matter, the mine has an exposure-control plan, which includes the provision of personal protective equipment, personal hygiene facilities, training, and a medical surveillance program. Furthermore, the mine performs occupational exposure assessments or air sampling on a regular basis because the morphology of the ore changes rapidly with respect to asbestos and silica content."

Jan 1, 2017

By Roger J. Goodman, Don Riva

"IntroductionCrows Nest Resources Limited (CNRL), a wholly-owned subsidiary of Shell Canada Resources Limited, is nearing completion of its first coal project, located in southeastern British Columbia. CNRL shipped over 700,000 tonnes of thermal coal to foreign markets in 1982. With the completion of the metallurgical coal plant in December, 1982, shipments of both thermal and metallurgical coal will increase substantially in 1983 and will approach the anticipated operating capacity of 3.0 million tonnes in 1985. The Line Creek Mine lies some 25 kilometres north of Sparwood in southeast British Columbia (Fig. 1). The open-pit mine is located on top of Line Creek Ridge, with coal being hauled 16 km to the thermal and metallurgical coal preparation plants, situated adjacent to the already existing Canadian Pacific Railway. Most of the coal is moved by 108 car unit trains by CP Rail to coal ports in Vancouver, where it is loaded onto vessels destined for overseas markets. Some smaller scale car load shipments are moved by rail to contiguous markets in the Pacific Northwest. History The southeastern British Columbia area, known as the East Kootenays, is steeped in a rich coal mining heritage, dating back to the latter part of the nineteenth century. Predecessors of Crows Nest Resources Limited were instrumental in developing the rich coal reserves in the area. In 1887, William Fernie, a pioneer-cum-prospector recognized the potential of coal deposits in the East Kootenays. Spurred by the relentless push west of the Canadian Pacific Railway through the Crows Nest Pass area, Fernie recognized that it was just a matter of time before the steam locomotives provided him with his required market. That time arrived in 1897 when Fernie helped to form the Crows Nest Pass Coal Company and coal mining commenced at Coal Creek, near his namesake town of Fernie. During its almost 70-year history, this company produced over 48 million tonnes of steam coal and 8 million tonnes of coking coal. In 1965, the Crows Nest Pass Coal Company was re-named Crows Nest Industries, to better reflect its expanded interests into forest products, and it is the latter company which Shell Canada Resources Limited acquired in 1978. The extensive coal resources of Shell, in both Alberta and British Columbia, were rationalized into one group with the birth of Crows Nest Resources Limited to manage and develop the coal holdings."

Jan 1, 1985

By Yu. V. Ponomarenko, A. I. Meka, P. A. Witherspoon, Yu. I. Volkov, J. E. Gale

"The mining of iron ore in the Kursk Magnetic Anomaly (KMA) region of the U.S.S.R. is done mostly by the open-cut method. An assembly of open pits capable of producing about 100 million tons of ore per year makes KMA the largest iron ore field in the world. Three gigantic open pits are currently in operation: Lebedinsky, Mikhailovsky and Stoilensky. These pits are as large as 13 km2 on the surface and as deep as 230 m. The mining operations are constantly faced with the problem of flooding from aquifers that overlie the orebodies; the magnitude of the problem is evident from the fact that the present groundwater inflow to these three pits is about 110 million mt /yr.Under such conditions, safe operations and pit wall stability are of great importance, and this has been accomplished very effectively by the appropriate use of seepage barriers and drainage systems. At KMA, the most important items used in the system of groundwater control are standard pumping wells, raise wells that drain into a 20 km to 30 km long underground drift located just outside the perimeter of the pit, horizontal wells driven through the pit walls, and horizontal drains. This paper describes the mining and engineering technology that have been developed at KMA to control the groundwater systems and protect the mines from flooding."

Jan 1, 1992

By C. Lara-Valenzuela, R. Perez-Garibay, F. López-Saucedo, A. Uribe-Salas, L. Magallanes-Hernandez

A relationship between gas dispersion parameters, namely gas rate (Jg), gas holdup (Eg), average bubble size (db) and bubble surface area flux (Sb), with the metallurgical performance (e.g., grade and recovery) has been established.. Results of eleven columns operating at five concentrators of Grupo Pefioles (Mexico), ranging between 1.52 to 3.35 min diameter and performing in the cleaning stages of lead and zinc circuits, are presented and discussed. The results showed that the effect of gas dispersion parameters was consistent and that both, Sb and Eg, correlate well with recovery particularly when the influence of feed pulp density is also considered.

Jan 1, 2009

By Vincent Doyon

For several years, the GDD SSW EM Probe is being used in nickel?s mines in Canada and Brazil to define ore limits, reduce dilution and predict nickel grades. It is used with success to test most if not all percussion blast holes at all Falconbridge Mines in Sudbury and Raglan and all Inco?s Thompson mines. However, after testing the SSW Probe in other metal mines, we realized that EM conductivity does not define ore limits by testing blast holes for copper, zinc or gold. For non-conductive ores, no instrumentation is yet available on the market to reduce dilution, by outlining quickly and inexpensively the real shape of an orebody. To that effect, Instrumentation GDD Inc has developed a new revolutionary photonic probe that will make the reduction of dilution possible by probing blast holes. Once surveyed with the probe, a computer draws graphs of the ore grade as a function of depth for each blast hole. A contribution by Canada Economic Development made possible the development of this new technology. Canmet and Soredem also cautioned this technology developed by Instrumentation GDD Inc. This new photonic probe will allow: 1) to better understand the shape of the orebody 2) to raise the grade of the ore fed to the mill 3) a more complete extraction of the ore 4) to raise the competitiveness of mines

Oct 1, 2004

By G. A. Gross

Nearly 90 per cent of the iron ore produced in Canada is derived from iron-formation or bedded iron deposits. About 70 per cent of this consists of concentrates obtained fom iron-formation; another 20 per cent was formed by natural enrichment processes. Four principal varieties of iron-formation are recognized -the Algoma, Superior, Clinton and Minette types. Differences in their geology, mineralogy, chemical composition and environment of deposition are of special significance in their evaluation as ore.

Feb 1, 1966

By A. S. Romaniuk

More than a decade ago, CANMET management recognized the need to make better use of existing technological information in mining and extractive metallurgy-two fields basic to the economic well-being of Canada. There were at that time no indexes or files dedicated to disseminating technical information for the many minerals mined and processed in Canada, including coal. CANMET, with the nation's largest research and library resources in the minerals field, was in a unique position to fill this need. Initial efforts were concentrated on building a mining file, beginning with identification of world sources of published information, development of a special thesaurus of terms for language control and adoption of a manual indexing/retrieval system. By early 1973, this file held 8,300 references, with source, abstract and keywords given for each reference. In mid-1973, operations were computerized. Software for indexing and retrieval by batch mode was written by CANMET staff to utilize the hardware facilities of EMR's Computer Science Centre. The resulting MINTEC file-one of the few files of technological information produced in Canada-is the basis for the national literature search service in mining offered by CANMET. Attention is now focussed on building a sister-file in extractive metallurgy using the system already developed. Published information sources have been identified and a thesaurus of terms is being compiled and tested. The software developed for CANMET's file-building operations has several features, including the selective dissemination of information and production from magnetic tape of photo ready copy for publication, as in a bi-monthly abstracts journal.

Jan 1, 1979

By H. M. Woodrooffe

This paper deals with the laboratory facilities at the Mines Branch for carrying out research in the industrial minerals field, and also reviews current programs in ceramics and construction materials, in non-metallic minerals and in the milling of industrial minerals. It then discusses the application of these pro-grams to industrial problems.

Jan 1, 1967

By T. H. Chuang, Y. Y. Shiue

"Rapid whisker growth was significantly alleviated in a Sn-58Bi alloy doped with 0.5 wt.% La. Experimental results showed that many thin, plate-form intermetallic phases appeared in the solder matrix. The absence of tin whiskers was correlated to the shape effect of RE-containing intermetallic plates. After reflowing, Cu6Sn5 intermetallic compounds appeared at the solder/pad interfaces of Sn-58Bi and Sn-58Bi- 0.5La packages with OSP pads, which grow linearly during the aging at 75 and 100? for various times ranging from 100 to 1000 h. In addition, the interfacial intermetallics layers in Sn-58Bi-0.5La solder joints were also observed thinner than those in undoped Sn-58Bi joints. However, RE-containing interfacial intermetallic compounds in Sn-58Bi-0.5La solder joints led to lower bonding strengths in both ball shear tests (0.4 mm/s) and high speed ball shear tests (2000 mm/s). All the reflowed and aged solder joints of both packages were ruptured through the solder balls indicating brittle characteristic INTRODUCTIONIt has been widely reported that solder alloys doped with rare earth (RE) elements reveal many beneficial effects, such as higher strength, lower melting point, improved wettability, and longer creep life (Wu et al., 2004; Ma et al., 2002; Chen et al., 2002). In addition, Dudek et al. reported that the alloying with 0.5 wt.% La in Sn-3.8Ag-0.7Cu solders resulted in an increase of rupture strain, up to 150% over undoped solders (Dudek et al., 2006). However, Chuang and Yen observed that a large amount of long, fiber-shaped tin whiskers were extruded out of the oxidized CeSn3 intermetallic clusters in the matrix of a Sn-3Ag-0.5Cu-0.5Ce solder air-stored at room temperature for several days (Chuang & Yen, 2006). Furthermore, many coarse hillocks appeared around the CeSn3 clusters in the RE-doped alloy after storage in an air furnace at 150? for several minutes. Chuang proposed a mechanism for the phenomenon of rapid whisker growth, which the predominate oxidation of CeSn3 intermetallics in Sn-3Ag-0.5Cu-0.5Ce solders induced compressive stress and extruded the tin atoms out of the specimen in the form of tin whiskers (Chuang, 2007). However, further investigation showed that Sn-9Zn-0.5Ce solders, after long term exposure at room temperature and 150?, were immune to the whisker growth; the immunity was attributed to the refining of the CeSn3 intermetallic phase in the alloy (Chuang & Lin, 2008). The inhibition of tin whiskers through the refining of rare earth containing intermetallics was further observed in Sn-3Ag- 0.5Cu-0.5Ce solders doped with 0.5 wt. Zn (Chuang & Lin, 2009). In addition to the size effect, the thin plate shape of intermetallic compounds was also shown in this study to inhibit the whisker growth on the surface of Sn-58Bi-0.5La solders."

Jan 1, 2012

By J. L. Chakravarty, S. K. Dutta, S. Banerjee, D. Putatunda

"General purpose uniprocessor systems used in control applications, however fast they may be, at a certain stage attain saturation, forcing the user or designer to consider other avenues for solving the problem. This paper gives a broad overview of multiprocessing with special reference to transputers. Virtually all aspects, from parallel systems real-time control to artificial intelligence (AI) and expert systems, have been highlighted. The application of transpurters in unilayer and multilayer control are discussed in detail, with specific attention to sensor integration. Two case studies describe at length the utilization of transputers. IntroductionIn conformance with the high level taxonomy of parallel computer architectures as given by Ralph Duncan(l) (an improvement to Flynn's classification, which maintains the essential elements of useful taxonomy based on instructions and data streams), the MlMD architectures are categorized into two groups: (I) shared memory, and (2) distributed memory type. While the shared memory multiprocessors are more popular than the message-passing multiprocessors because they can be programmed in a conventional sequential fashion, their aspect of the architecture creates a perfonnance bottleneck. In contrast, message-passing multiprocessors (MPM) suffer from no such limitation and can attain linear speed increases that are directly proportional to the number of processors put into use. The MPM implementation also has its own advantages and disadvantages. Because the performance of the system is heavily dependent on it, the interconnection strategy in a distributed memory MIMD machine is of paramount importance. The transputer(2.J), a multiprocessor node of the distributed memory type, is becoming very popular. The advantages offered by the transputer make its application in the mining and processing industries very promising."

Jan 1, 1994

By K. Konigsman

"Representatives of various industries and the Canadian coast Guard formed a Bulk Cargoes Committee three years ago. In 1976 and 1978, I have attended the meeting which take place once per year here in Ottawa as representative of the Canadian Mineral Processors, Dave Hendricks from Granisle accepted the charge in 1977. Our Secretary, Bob Bruce, has suggested repeatedly that I report to the Membership on the deliberations to this group. Twice I found good excuses; this year I did not. I was reluctant to address you since the Committee's deliberation proceeded at a pace which might be identified as Government squared. The Committee advises a Government agency which in turn negotiates with foreign Government agencies.At the outset, I will describe the developments which led to the formation of the Committee and its purpose.The Canadian Mining Industry ships annually millions of tons of products to overseas customers; be it iron ore, coal, fertilizer, or base metal concentrates. Most loadings are in vessels of foreign registry and all will be directly affected by Canadian or International regulations of the transport of such bulk commodities. The major shipping nations are members of an Intergovernmental Maritime Consultative Organization (IMCO). This organization elaborates regulations which govern shipment of all cargo, bulk materials and concentrates included. At IMCO'S deliberations, Canada has one vote, one voice on the Consultative Committee and is represented by our Coast Guard. The Coast Guard has over the years been in contact with industries when discussions concerned shipment of bulk cargoes. In the early sixties, a ""Concentrate Committee"" did exist. It consisted of metallurgists from a number of mining companies and Government representatives. This committee was instrumental in the development of what became known as the ""Concentrate Code"", legislation which has evolved into the Canadian Bulk Cargoes Code as it is known today. The concepts of the flow moisture point and transportable moisture limit originated from its work. Incidentally, both criteria are widely accepted and utilized world-wide. The Concentrate Committee faded away once the Concentrate Code has been adopted."

Jan 1, 1979

By J. M. Whatley

"IntroductionIN UNDERGROUND mining operations, the mine hoist has become one of the most important and one of the most expensive single pieces of equipment. As the means of transporting men and materials to the face, broken ore to the mill, and waste to the dump, it is often the very lifeline of a mine and must operate with dependability and efficiency or the whole operation will suffer. The mine hoist has become synonymous with safety. In few other types of mechanical equipment do so many men so frequently and completely place their lives. In Canada, more has probably been done to assure safe hoisting than in most other countries, but, unfortunately, this has resulted, in many cases, in the mines having to pay a high price for equipment. Hoist manufacturers have carried out much research in recent years in the endeavour to keep down these costs and at the same time maintain or improve the efficiency and safety of their products. Broadly classified, the bases for design research are dependability, efficiency, safety, and first cost.Probably the greatest single factor influencing the design of mine hoists was the introduction of electric motor drives. It was not until about 1905 that an effective start was made in the development of electric mine hoists, and then only with machines of small size. From that time on, however, progress was rapid, as may be gauged from the fact that by 1910 one large group of mines in Johannesburg had in use, or on order, fifty-four three-phase hoists and four Ward-Leonard. type hoists."

Jan 1, 1953

By Thomas C. Poulter

Abstract The Poulter seismic method of geophysical exploration is an attempt to obtain an increased efficiency in the conversion of the energy of an m~pl06ion into useful energy which has directive properties and which contains a minimum of random frequency and random phase relations. Very little effort has been made in the past to simplify OT even control the uniformity of the seismic energy being introduced into the ground. The Poulter seismic method is also an attempt to improve the signal-to-noise ratio not merely by trying to complete the impartial filtering done by the earth on ,the continuous spectrum of primarily high-frequency energy radiated from a shot point but by applying a frequency control at the point of origin of the seismic wave. The energy from a shot-hole charge is peaked in a frequency which is much higher than will be transmitted through the ground, and its absorption introduces background interference. Only 10 to 20 per cent of the seismic energy of a shot-hole charge .is directed downward in a 90-degree vertical cone, whereas, from a pattern of charges detonated above the surface of the ground, 85 per cent of the seismic energy is included in a 90-degree cone and in some cases it is even confined to as small as a 30-degree cone. This greatly reduces the horizontally distributed energy, thereby producing a marked improvement in the signal-to-noise ratio. The frequency of the signal energy may be peaked in a rather narrow range by the proper application of two or more impulses upon the surface of the ground controlled as to direction, magnitude, and timing. These impulses may be controlled by the reflection shock wave technique, the pressure pulse technique, and the sequence firing technique, using the primary controls as outlined. The information obtained from the study of directivity of seismic energy in a high velocity, uniform material such as the ice on Taku glacier, in the Juneau ice field in Alaska, has been of great assistance in the application of the method to oilfield and mining problems.

Jan 1, 1950

Despite the claims of energy efficiency and the considerable development that has gone into dramatically extending rolls? life and facilitating rolls? change-out, in the six years since the last SAG conference, only a few HPGR operations have entered the realm of mineral processing. Risk barriers to the take-up of new equipment or processes are: a massive increase in materials handling issues as well as in the number of pieces of equipment required, low total circuit potential energy savings, and similar or higher capital costs. An alternative route is to make use of the complementary strengths of the HPGR and SAG in hybrid circuits. Minimising materials handling issues, providing an ideal balanced feed to the AG or SAG mill, and improving controllability through shifting grinding load as the RoM feed changes, are all potential major advantages to this approach. Conceptual circuit layouts, based on real measured ore and equipment data, are presented here to illustrate the potential production upside, the reduction in operating costs and the reduction in the physical and energy footprints.

Jan 1, 2012

By J. Lu, M. Mohammadi, C. Pelletier, B. Wassink

Chemical reduction of selenate by chromous ions is proposed as a novel method to remove selenate from sulfate-bearing solutions Chromous ions were generated by electrochemical reduction of chromic ions using an electrochemical cell. The investigation was conducted in sulfate medium and under various concentrations of chromous ions (0.0062 to 0.05M), pH 1 to 2.2 and temperature 10 to 60°C. Selenate ions were rapidly reduced by chromous ions to hydrogen selenide. The overall reaction at a chromous/selenate molar ratio of 8 or higher can be expressed by the following reaction. At an initial chromous/selenate molar ratio below 8, the products are hydrogen selenide and elemental selenium. At a lower chromous/selenate molar ratio and pH, more elemental selenium and less hydrogen selenide are produced. The reduction kinetics is controlled by both chromous ion and hydrogen ions concentrations. The reaction rate is first order with respect to selenate, hydrogen ion and chromous ion concentrations. It was found that the selenate reduction rate with chromous is independent of the concentration of sulfate present in the solution. The general rate equation was proposed and the rate constant was calculated as k= 0.38 M-2s-1. An activation energy of 58.7 kJ/mol was obtained in the temperature range from 10 to 50°C. Nearly 100% of selenate can be reduced to H2Se from solution containing 17 ppm selenate in less than 30 minutes at pH 2.2 and 60°C. Various strategies have been tested to remove the produced H2Se from solution. INTRODUCTION Selenium in nature is mostly associated with metal sulfide minerals such as copper, iron, zinc, and lead sulfides (Zingaro & Cooper, 1974). The extraction of metals from ores has the potential for selenium contamination of ground and surface water which can pose an environmental and health concern. Therefore, selenium contamination in the receiving environment is a key issue for many industries (specifically copper industry) and the treatment of wastewater contaminated with selenium is a growing challenge. The effective removal of selenium from contaminated water is very important to support sustainability in the copper industry and the other industries with selenium pollution issues.

Jan 1, 2019

By D. M. Baird

"Enormous deposits of gypsum of exceptionally high grade are readily accessible in southwestern Newfoundland. Coming large-scale production from one of these is resulting in renewed interest in deposits which have been known for more than a hundred and twenty years. General stratigraphy and structure of the Carboniferous rocks in which the gypsum occurs are de-scribed. The stratigraphic position of the basal gypsum-anhydrite zone is described. This massive evaporite horizon, which reaches a thickness of about 1,0001 feet, appears at Fishels-Heatherton, where it is largely undeveloped, and again on the nose of an anticline east of Flat bay, where a present production of 20,000 to 40,000 tons per annum is soon to be expanded to make it one of Canada's major producers. Detailed descriptions are given of the several types of gypsum, the relation of the gypsum and anhydrite, and the distribution of sodium chloride in the evaporite beds, and the bearing of all these on the origin of the gypsum are discussed. Brief reference is made to relation to world markets, mining and transportation, grade, and reserves."

Jan 1, 1959