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By G McCullough, J Bassan, d P. Knights, C T. Farrelly

By 2045, carbon-neutral mines will be economically producing products that are vital for the world’s transition to renewable energy. After overcoming significant technical challenges (and the investment of significant capital), leaders have successfully eliminated the use of diesel and other fossil fuels by introducing a wide range of new decarbonisation technologies. These leaders will be reaping the benefits of lower production costs (resulting from elimination of diesel), stable and predictable operations, and easier access to capital for their future projects. This paper describes a future scenario of how a net zero carbon and zero-entry mine could operate by taking maximum advantage of technologies in development or already proven in other industries. Some miners have been unsuccessful in their efforts to reach decarbonisation targets. Instead, they have been forced to close or offload their assets to be acquired by operators with better sustainability credentials, or, in some cases, to indigenous or community-based enterprises with vested interest in making operations viable and sustainable. Regardless of ownership structure, all successful mining operations will have fostered strong and positive community relations that bring education, health, security and economic development opportunities to the communities while respecting their traditions, land-uses and culture. As shallow, easy to mine deposits have become scarce, the majority of new mines are underground. Advancements in electric underground technology and the feasibility of ‘zero entry mining’ (with no personnel in active mining zones) has made it increasingly possible to economically operate underground mines, even at shallow depths. The newest mines have a near zero footprint on the surface, produce no harmful by-products, and are employing in-place or in situ methods of extraction that are efficient and low impact. Surface land-uses, such as agriculture and renewable energy generation, continue in the immediate vicinity of the mine, with no significant ground disturbance, community impact or environmental footprint.

Sep 1, 2024

Smelter operating and environmental requirements demand high on-stream time (high reliability) from the primary smelter sulfur retention device - the sulfuric acid plant. The key to reliable smelter sulfuric acid plant operation is the gas cooling and cleaning system. Problems in the gas cleaning system cause corrosion, plugging, equipment failure, etc - plant down time, in the contact section of the plant. The last fifteen years have seen major changes in gas cleaning system design to the current standard of brick lined venturi scrubber, packed gas cooling tower with plate type liquor coolers and lead or plastic tube precipitators. The current-design offers improved impurity scrubbing along with increased reliability. In addition, a number of alternate gas cleaning systems have been offered. Chematics LAB System: Monsanto DuPont Dynawave System; Lurgi venturi scrubber with lead star gas cooler. This paper will review the design and operating advantages, disadvantages, and risk of the standard gas cleaning system and compare it to the alternate systems.

Jan 1, 1992

By Oliver C. Ralston

The Nonmetals Division studies problems relating to the use of minerals, many of which are important to national defence for purposes other than the extraction of metals. In fact, virtually all of the work of the division has been diverted to investigations pertaining to better use of the Nation's natural nonmetallic is resources as weapons of defense. The experiment stations of the division are at Norris, Tenn.; Tuscaloosa, Ala.; Seattle, Wash.; and College Park, Md. Studies involving the application of electric power to the nonmetallic minerals are conducted at the Electrotechnical Laboratory at Norris, and investigations on mineral-dressing treatment are conducted mainly at the Southern Experiment Station at Tuscaloosa. The cleaning and preparation of coal are studied at both Tuscaloosa and the Northwest Experiment Station Lit Seattle (other projects relating to utilization of coal are conducted by the Coal Division of the Bureau of Mines). Problems covering the use of minerals and fundamental problems as to their properties are studied at College Park.

Jan 1, 1941

By H E. S Moorcroft, D Scott

The increasing mining depths of South African gold mine deposits are resulting in ever-increasing heat loads associated with depth and the geothermal gradient. Together with changes in the mining horizons brought about by the depletion of older, shallower, high-grade reserves, this leads to the need for the continuous review and redesign of cooling requirements. Traditionally, cooling requirements were met by using a combination of cooling strategies, including bulk air cooling on surface and underground. If this proved to be insufficient, chilled service water and secondary remote air-cooling systems were introduced. This paper reviews these practices in order to provide a cost-effective means of catering for the introduction of hydropower at the Gold Fields Ltd South African operations. Some of the equipment that has been developed to meet the requirements of both hydropower and refrigeration includes hydropower fans, cooling coils and in-stope venturis. These are individually described and discussed, together with their roles within the greater strategy. The planned change in the cooling strategy and the employment of these technologies have effectively doubled the cooling available, from 10 MW to more than 20 MW, extracted from the hydropower water used to drive the mining equipment. In conclusion, the cooling strategy described allows a total heat load of approximately 52 MW to be successfully ventilated and cooled through the use of combined surface and underground refrigeration installations, and through the use of hydropower-chilled water.

Jan 1, 2005

By C. G. Maier

Relatively infrequent use by metallurgists of the term "sponge chromium" as contrasted to more than occasional reference to "sponge iron" may be ascribed to the fact that the former material is not a commercial product, while the latter has been known and used, at least in one form (Swedish sponge iron), for several decades. It is doubtful whether a true sponge chromium ever has been prepared heretofore in the laboratory by more than one or two investigators. Nature presents a much. more difficult problem to the investigator endeavoring to make sponge chromium than pertains to the production of more easily reducible elements such as iron or nickel. Recent widespread interest among metallurgists in the possibilities of powder metallurgy is ample incentive to explore the feasibility of producing pure chromium metal in finely divided form. The shift in terminology of this statement from "sponge" to the "finely divided form" is deliberate in emphasis of distinction between terms that occasionally have been used loosely. It would seem desirable that a uniform usage descriptive of finely divided metals be adopted. While to some it might seem preferable that the terra "powdered" metal be reserved for a finely divided form produced by mechanical means, as, for example, chromium produced by the mechanical comminution of electrolytic sheets or flakes, current usage of the term "powder metallurgy' involves no distinction as to source type of material. It is usually accepted, however, that a sponge metal is one reduced from oxide or other combined form at temperatures below the melting point of metal or oxide so that the particles of metal are pseudomorphic, at least macroscopically, with the source material, and, in consequence of the loss of material without change of external shape of the particles necessarily have an open, porous, or "spongy" structure.

Jan 1, 1942

By A. Uiga

The U.S. Bureau of Mines funded a project which addressed objectives concerning irrigation of native plants and inoculation of native plants with vesicular-arbuscular mycorrhizal (VAM) fungi. The specific irrigation objectives were 1) to demonstrate the performance capabilities of solid-set irrigation for reclaimed mineland conditions, and 2) to demonstrate and evaluate three irrigation concepts under two separate water supply conditions. The VAM inoculations were to assess irrigation benefits in establishing VAM relationships for transplanted native species. Following the seasonal demonstration (May to September 1983) at 3 separate mine sites, conclusions were made that apply to the 6 state Western mining industry. The demonstration sites were located in Montana, Wyoming, and New Mexico. Positive conclusions were reached for 1) the use of soil moisture sampling with or without irrigation, and 2) the selection of solid-set sprinklers as the irrigation method. The conclusions about the irrigation concepts and strategy were mixed, due to the short-term (1 season) nature of the project. No conclusions could be reached for the VAM inoculations because the study time was too short.

Jan 1, 1984

By Donn W. Leva

In North America, pipelines move more material than any other form of transportation. 1 Pipelines have been used principally for the transportation of liquids and gases; however, slurry pipelines have made notable gains in recent years enabling solid materials to be moved efficiently by pipelines. The obvious advantages of pipe-lines --low maintenance, low operating costs, minimal impact on the environment, greater land use, low labor intensity, safety and high operating factor --have stimulated researchers in England, West Germany, Japan, USSR and the USA during the past ten years to develop pneumatic capsule pipelines for the movement of bulk materials in large quantities. As a result of this work, pneumatic capsule pipelines are now available for the movement of dense bulk materials. Through these pneumatic capsule pipelines, material is moved in wheeled capsules which are pushed through the pipeline by flowing air. In this paper, a capsule pipeline system developed by the Georgia Institute of Technology and Tubexpress Systems, Inc. of Houston, Texas is discussed. The Tubexpress System Major Components The pipe used for a Tubexpress capsule system is standard thin wall welded steel pipe. Since pressures in the system generally do not exceed one atmosphere, the controlling design criteria for wall thickness of the pipeline is pressure from the overburden of the backfill if the line is buried or the structural requirements for supporting itself and the load if it is suspended or supported on piers. The air pumping system for Tubexpress is a combination of

Jan 1, 1977

By Shawn P. Coughlin, Michael A. Schimmenti, Juan Leonardo Tello del Pino

"The Sistema de Potabilización Área Norte project (Northern Area Purification System) was a major expansion of the potable water system in Buenos Aires Province, Argentina. The aim of the project was to transport and purify raw water from the Paraná River to provide potable water for five communities in the northern part of the province, benefitting up to two million people. The project was constructed by a joint venture (JV) of four South American contractors and consisted of the following key components:• Treatment plant: A 16-ha (39-acre) area was cleared for the construction of a treatment plant to purify 900,000 m3/day (1.2 million cu ft/d) of raw water from the Paraná River and distribute it to the surrounding communities.• Bored tunnel: Nearly 15 km (9 miles) of 3.6 m (12 ft) inner diameter tunnel, ranging from 18 to 22 m (59 ft to 72 ft) below grade, was bored with two earth pressure balance (EPB) tunnel boring machines (TBM) to draw the raw water from the river. The TBMs started from a central launch shaft and proceeded in opposite directions. Cristina advanced northbound to the Paraná River Intake System, and Liliana advanced southbound to the new treatment plant.• Access and ventilation shafts: Five access shafts and eight ventilation shafts were installed along the length of the tunnel. The access shafts were designed to provide entry points for inspection and maintenance of the final tunnel. The five shafts consisted of one central launch shaft in the middle of the tunnel alignment, one retrieval shaft at each end of the tunnel (intake and treatment plant, respectively) and two intermediate shafts. The intermediate shafts were installed before the TBM passed, with a final liner to be installedafterward."

Sep 1, 2016

By M Brady

"It has long been recognised that the barometer infl uences areas of underground coal mines that havebeen sealed off from the current, or active, mine workings but it appears litt le formal research hasbeen done on how the barometer aff ects the goafstream sample point. Based on statistical analysis of samples from a number of mines from Queensland and New South Wales it can be concluded that there is a direct correlation between the barometer and oxygen concentration at a goafstream sample point. To help mitigate some of the high consequence hazards within the underground coal industry and protect the health and safety of the persons within that environment, many monitoring tools are utilised. A control recognised in management plans prescribed under New South Wales and Queensland legislation is the need to conduct monitoring to identify the early warning signs of spontaneous combustion. One of the monitoring tools utilised involves a bagsample being collected from a goafstream sample point then returned to the surface for analysis.When the sample is incorrectly collected, the resultant analysis from a gas chromatograph provides litt le value to the persons charged with the obligation of operating the coal mine at an acceptable level of risk. This, therefore, increases the probability of spontaneous combustion leading to a loss of equipment, mine and in the worst case, life. When the sample is collected correctly, the analysis presents early warning signs of low level oxidation allowing corrective action to be taken, to prevent the oxidation accelerating to spontaneous combustion. The eff ect the barometer has on this sample point should be recognised and the knowledge imparted to persons who conduct sampling to remove a variable in the bag sample collection process. This will ensure the persons operating the mine have a bett er understanding of what is happening within their longwall goaf."

Jun 1, 2012

By J. Jerome MacDonald, Stephen B. Flewelling

"In the base metals industry of today, operations required to continuously improve productivity and reduce unit production costs. Consistent with these goals is the improvement of the muck haulage cycle from open stopes with the No. 12 Mine.Existing haulage from open stopes occurs with LHD units experience at Brunswick indicates that LHD units have a higher unit cost per tonne mucked than loader-truck combinations when the haulage exceeds approximately 150 m.The reintroduction of open stoping at Brunswick made existing loader-truck combinations unsuitable. It was recognized that application of recent continuous loading technology could potentially result in significant unit cost savings and productivity increases.A review of the technology resulted in the testing of the Voest Alpine AL60 loader in the open stopes located on the 1000m Le vel. Testing began in January 1988 and finished in late November 1988. The test will provide experience as well as quantified production and maintenenace parameters f or the purpose of quantifying production unit costs and system productivity, ultimately resulting in a decision to further utilize or not utilize the loader as a primarymucking unit at Brunswick .INTRODUCTIONBrunswick Mining and Smelting Corporation Ltd. produces approximately 10500 tonnes per day from the No. 12Mine located 35 km southwest of Bathurst, New Brunswick Mining is the largest (single mine) producer of zinc in the world having mined over 52 million tonnes since 1964. Many years of production still remain with proven and probable reserves in excess of 90 million tonnes. Reserves grade at an average of 3.65% Pb. 8.99070 Zn, 99g/mt Ag and 0.32% Cu . The operation employs 1446 people with approximately 800underground including operations and maintenance staff.In the No. 12 Mine two major mining methods are presently utilized . The primary method is Mechanized Cut and Fill (MCF) accounting for approximately 6500 tonnes per day from four major areas. The remaining 4000 tonnes per day is produced from open stopes with the majority of 2800 tonnes per day being produced by the 1000 level.The 1000Level contains 30 million tonnes segmented into open stope blocks 30 m high, 15m and 30 m on strike , with a transverse width of 10m to 50 m (Fig. I). Stopes are organized on a primary secondary stope arrangement along strike. Primary stopes are undercut and overcut full size with the back fully cablebolted. All stope and lateral development is driven 4.0 m high. All stopes to date are flat bottom (Fig. 2). Primary stopes are filled with cemented rock- fill , secondaries with conventional rockfill, Haulage from the stopes is primarily with 8-yard LHD units ; mucking is approximately 50% conventional and 50% remote. Haul distance to date has averaged approximately 150m with current stope haul distances of approximately 300m. Haulage is presently to a small jaw crusher situated on the 1000 Level. From August 1989on, haulage will be to a set of ore passes feeding to a large gyratory crusher situated on the 1200 Level. Start up of the gyratory crusher corresponds to an increase in tonnage from 1000 Level to 4100 tonnes per day."

Jan 1, 1989

By Michael K. Phang

The use of explosives to fragment rock generates ground vibrations which may have a detrimental effect on contiguous underground coal mine openings. Increased surface blasting by a burgeoning number of surface coal mines and quarries has caused considerable concern among underground mine operators. Ground vibration effects generated from surface mine blasting are also causing public concern. In response to this concern, the U.S. Bureau of Mines (Stagg and Engler, 1980) has measured and analyzed ground vibrations and their effects on underground and surface structures. Some of the complaints registered against the mining industry are claims of substantial material damage from vibrations generated by the blasting; others are nuisance complaints of minor damage or annoyance. In general, allegations of damage from surface blasting have been sufficiently numerous to constitute a major problem for mine operators engaged in blasting operations. They have recognized the need for more technological data to evaluate the vibration problems associated with blasting. Both the operators and the general public need adequate safeguards based upon factual data to protect their specific interests. The coal mine industry needs reliable information from which to change blasting operations to reduce the number and severity of major damage claims and eliminate the growing number of nuisance complaints. The problem is of major concern not only to coal mine operators and nearby property owners, but also to federal, state and local governments. At the same time, environmental control agencies responsible for blasting and explosives use require reasonable and appropriate guidelines to protect the miners' lives.

Jan 1, 1984

By S. W. Swerson

25.1-THE PURCHASING FUNCTION The word "purchase" means "to obtain by paying money or its equivalent; to buy for a price." This definition is all too simple to properly describe the word "purchase." One should consider the basic objectives of purchasing-to procure the right material, of the right quality, in the right quantity, at the right time, from the right source at the right price. Here it should be noted that in purchasing it is recognized that the best quality or grade of materials may be the only grade to purchase for a specific job. However. there are other jobs where the medium, standard or poor grade of materials is the right quality, as the lesser grade will perform adequately. In some companies the purchasing department makes the decision as to the right quality, while in others this function is shared with other departments. Years ago in business the owners controlled the purchase of required materials and services by performing the task themselves. The owners obtained the type materials and services they needed and paid the price demanded. This function was performed along with all the other duties requisite to the owner of a business, namely, clerical, hiring and firing of personnel, financial management, etc. As companies grew in size, clerical duties were assigned to other personnel and the owner usually retained the purchasing authority. This same division exists today in many small companies. However, in the larger companies, the purchasing function has been assigned to a separate department. Importance of the Purchasing Function-The larger the company the greater the need for a separate department to perform the purchasing function. Today the purchasing agent for most larger progressive companies has policy-making authority. Therefore, it is reasonable for him to report to the president or vice president of his company. Studies of several hundred companies show the purchasing department head reporting to top management 87.5% of the time. This fact in itself is indicative of the importance of recognizing that effective purchasing requires a department staffed with specialists in the field of procurement with knowledge and experience sufficient to perform in today's complicated business atmosphere. In the manufacturing field it is a common axiom that usually half of the company's dollar expenditures are for materials. If a purchasing department functions properly and the right product or service is purchased and a savings accomplished, the contribution to the net profit of the company is much greater, as opposed to sale dollars, where only a small portion is carried forward to net profit. Thus, the importance of the purchasing department and the contribution it can make to the success of the company are obvious. 25.1.1-THE PURCHASING FUNCTION 1. Responsibilities of the Purchasing Function-The purchasing agent in performing his function is acting as an agent for the company and others in the company requiring materials and services. Accordingly, he is committing the company for materials and services subject to certain limitations which the board of directors may stipulate. In view of this, the purchasing agent,'^ position must of necessity he

Jan 1, 1973

By Cristian Castro, Patricio Gomez, Jason Furtney, Augusto Lucarelli

Understanding the effect of blast-induced damage on wall stability is critical to safe and economical operation of a large open pit mine. In this paper, a numerical modeling methodology is used to investigate damage to rock at distances of greater than 10 m (30 ft) from a blast. Two applications of the model are demonstrated. First, the method is applied at a zinc mine to investigate the effects of pit blasting on underground stopes. The model predictions are compared with the scaled distance formula. Next, the model is used to investigate a common problem in which unfavorable jointing creates a rock wedge on the bench above a blast. The numerical predictions of wedge stability are compared to the wedge energy model described by Wong & Pang (1992).

By Cristian Castro, Patricio Gomez, Jason Furtney, Augusto Lucarelli

Understanding the effect of blast-induced damage on wall stability is critical to safe and economical operation of a large open pit mine. In this paper, a numerical modeling methodology is used to investigate damage to rock at distances of greater than 10 m (30 ft) from a blast. Two applications of the model are demonstrated. First, the method is applied at a zinc mine to investigate the effects of pit blasting on underground stopes. The model predictions are compared with the scaled distance formula. Next, the model is used to investigate a common problem in which unfavorable jointing creates a rock wedge on the bench above a blast. The numerical predictions of wedge stability are compared to the wedge energy model described by Wong & Pang (1992).

Feb 1, 2020

By Alfred Petrick

This report analyzes the byproducts systems of lead, zinc, uranium, rare earths, iron, aluminum, titanium, and lithium. Specific byproduct metals covered are cadmium, germanium, indium, and thallium from the zinc system; antimony and bismuth from the lead system; vanadium, radium, and scandium from the uranium system; rare-earth oxides from the rare-earth system; and cobalt, gallium hafnium, and rubidium from other systems. The report discusses various metallurgical systems, marginal and incremental production costs of byproduct subsystems, industry structure and organization, and historical data on price, consumption, and supply.

Jan 1, 1973

By P. T. Bissert, L. Yan, M. D. Klein

"Federal regulations require the installation of refuge alternatives (RAs) in underground coal mines. Mobile RAs have a limited ability to dissipate heat, and heat buildup can lead to a life-threatening condition as the RA internal air temperature and relative humidity increase. The National Institute for Occupational Safety and Health Office of Mine Safety and Health Research performed heat testing on a 10-person tent-type training RA and contracted ThermoAnalytics, Inc. to develop a validated thermal simulation model (TSM) of the tested RA. The TSM was used to examine the effects of the constant mine strata temperature assumption, initial mine air temperature (MAT), initial mine strata surface temperature (MSST), initial mine strata temperature at depth (MSTD), and mine strata thermal behavior on RA internal air temperature using 117 W of sensible heat input per simulated miner. For the studied RA, when the mine strata temperature was treated as a constant, the final predicted RA internal air temperature was 12.8°F lower than it was when the mine strata thermal behavior was included in the model. A 10°F increase in the initial MSST resulted in a 7.1°F increase in the final RA internal air temperature, whereas a 10°F increase in the initial MSTD yielded a 2.5°F increase in the final RA internal air temperature. INTRODUCTION Since 2008, the Mine Safety and Health Administration (MSHA) has required the installation of refuge alternatives (RAs) in underground coal mines (1). MSHA requires that RAs provide an environment with breathable air for entrapped miners for a 96-hour period. Heat buildup inside an occupied RA is a serious concern. Without a means to dissipate the heat and humidity generated by the occupants and the carbon dioxide scrubbing system, the temperature and humidity inside RAs could lead to severe discomfort or heat stress depending on the mine ambient temperature before and during occupation of the RA. NIOSH recommended an apparent temperature limit of 95°F in its 2007 report to Congress (2). In 30 CFR 7.504, MSHA has specified a maximum apparent temperature of 95°F inside an occupied RA (3). The apparent temperature is calculated using both air temperature and relative humidity (4). Calculations could be used to determine if the air within an occupied RA will reach the apparent temperature limit. In these calculations, in order to simplify the problem, the mine temperature could be assumed to remain constant. With this assumption, the effects of the mine strata thermal mass and thermal conductivity on the heat buildup in an RA are ignored. OMSHR research has shown that the mine air and strata temperatures surrounding an RA increase when subjected to the heat of an occupied RA (5). Thus, calculations performed with the assumption that the mine temperature is constant would under-predict the resulting dry-bulb temperature and apparent temperature for a given RA occupancy. The mine air temperature has been used as the basis for RA temperature calculations. However, research has not been used to confirm that the mine air temperature is the appropriate basis."

Jan 1, 2016

By G. J. Hundman

Control of respirable dust produced by auger type continuous mining machines is normally attempted by water sprays from fixed nozzles mounted on the frame of the machine. In tests conducted under this contract, a 'wet auger' system was used, where the spray nozzles were mounted on the rotating auger itself. The tests were conducted at the Hunter mine of Smith and Stover Coal Company using a Jeffrey 1.00L auger miner. Operating the mining machine in the wet auger mode, it was found to produce 47 pct less respirable dust than when the fixed conventional sprays were used. On section dust levels were reduced too 3.5 mg/m3 which is equivalent to approximately 2.0 mg/m3 for a full shift portal to portal sample. The major difficulty that had to be overcome was the development of a simple reliable water transfer mechanism to get the water into the rotating augers. This was successfully achieved by the development of a water-through-the-shaft water system. This system can be retrofitted to existing machines and is available in kit form.

Jan 1, 1977

By S Casas Castellanos

"Tyres consumption is one of the costliest branches of the operation in a truck-based haulage mine. Off-the-road (OTR) tyres working within undesirable conditions have a considerable negative impact on the whole mine’s productivity. Only the rolling resistance due to underinflated tyres could increase truck fuel consumption by 15 per cent. The impact of other conditions such as road surface quality and temperature are difficult to estimate. Tyre management is a demanding activity that requires a high level of coordination between maintenance and production departments.The project is aimed to develop a smart decision tool to assist mine managers to optimise tyre resources. By identifying factors that have significant impact on tyres, managers are able to take timely action to mitigate undesirable working conditions.The proposed model utilises real-time tyre measurement of pressure, temperature, speed, load, deformation and surface profile to report tyre performance in terms of tonne-kilometre-per-hour (TKPH) and tyre longevity. Both indicators are permanently monitored in order to trigger a warning system designed to keep tyres under optimal working conditions.An interactive database ‘Octo-Mine’ wirelessly receives records from a programmable logic controller (PLC) deployed on the truck. PLC records are the integration of multiple sensor signals with a time stamp. Octo-Mine utilises real-time and historical tyre records to generate online performance and longevity reports, as well as preventative and corrective tyre maintenance scheduling, by comparing current tyre status with established standards.To validate the model, the prototype database was populated with hypothetical data to simulate ideal working conditions subject to comparison with real field observations. Additionally, a laser-based technology prototype device successfully measured a new 9 mm tyre tread and a 60 000 km rolled tyre tread in the laboratory.In conclusion, optimal tyre management contributes not only to reduction of tyre waste but also to truck energy efficiency. This project is a first step in proving these benefits under real field conditions. It suggests that further development of sensor equipment and its integration with a communication system is a worthwhile focus for future research.Citation:Casas Castellanos, S, 2016. Optimum Management of Truck Tyres in a Mine, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 212–228 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By R. H. Schutz

TO ASSIST users in the selection of reliable and satisfactory respiratory protective devices, the Bureau of Mines bas established five schedules of minimum performance requirements for the approval of respirators. The current revisions of these schedules include 130 for self-contained breathing apparatus, 141F for gas masks, 19B and the amendments to 19B for supplied- air respirators, 21B for dust, fume, and .mist respirators, and 23B for chemical cartridge respirators. Copies of these schedules may be obtained from the Bureau of Mines, Publications Distribution Section, 4800 Forbes Avenue, Pitts- burgh, Pa., 15213. Approval tests on respirators are performed only at the request of the manufacturer of the respirator and at his expense. If the deice meets the approval requirements, a certificate of approval is granted on the complete respirator. This certificate states that as long as the respirator is manufactured as originally approved, or in accordance with any changes covered by an extension of the original approval, the manufacturer may advertise and sell his respirator as being approved by the Bureau of Mines. Many industries and regulatory agencies require that respirators approved by the Bureau of Mines he used where respiratory protection is needed. The Bureau of Mines, however, has no regulatory power over the use of the respirators that it approves. It acts as an impartial testing agency to insure the availability of suitable and safe respirators.

Jan 1, 1966

By Selwyn G. Blaylock

There is no more important problem today than industrial relationship, and probably none that is receiving more thought. But in these days of Epie and Utopia, one has to be rather careful in speaking on this subject. Consequently, for fear that my plea for taking the working man into the family might be misconstrued, by some, as a step towards communism or socialism, I would like to say at the outset that I believe that, so long as we have human individualism, human ambitions, human hopes and fears, straight socialism is as far off as the Millennium. The same applies to communism, which only differs from socialism in that the communist realizes that his ideals can only be attained by massacring millions and destroying all that we hold sacred. Each still looks to Russia for inspiration and guidance, totally disregarding the Soviet swing-back to individual contract work and differential wage scales. They seem to be oblivious of the tyranny and repression in the present Russian system, and get very restless when reminded of it. In spite of the fact that the standard of living in civilized countries has improved tremendously and is still improving, we find that, every seven or eight years, production in many lines has outstripped consumption, and we have had panics or depressions of greater or less magnitude, accompanied by extensive unemployment. It is evident to every thinking person that there must be no little inefficiency in the control of industry. For four long years, governments and industrialists have striven to find the key to solve the present problem. Many countries are getting back to a position approaching normal-Canada probably more so than most. None, however, can feel assured that they have actually cured the situation. All kinds of schemes have been developed; tariff barriers have sprung up over-night where none existed before; currencies have been inflated to gain added security in the home markets and to try to gain advantage in export trade; and each country watches the movements of the others with fear and mistrust. I am not prepared to formulate a full solution of our troubles, but I hope to be able to demonstrate the feasibility and wisdom of the type of industrial relationship I advocate, and also that it may be a large, and possibly an essential, step towards the solution of our difficulties.

Jan 1, 1935