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By C. D. Anderson, C. G. Anderson, P. R. Taylor

"Rare Earths have become critical for our energy and materials driven society. While primary production must ramp up to fill growing demands, the recycle of these strategic elements must also be initiated. This paper will outline the potentials of and metallurgical technologies employed for Rare Earths recycle from various secondary sources.INTRODUCTIONWhen investigating the recovery of rare earths from secondary sources it is necessary to understand the nature of the sources to be processed. As of 2009, the USGS reports the distribution of rare earths by end use, in decreasing order, was: chemical catalysts 22%, metallurgical applications and alloys 21%, petroleum refining catalysts 14%, automotive catalytic converters 13%, glass polishing and ceramics 9%, rare earth phosphors for computer monitors, lighting, televisions 8%, permanent magnets 7%, electronics 3%, and others 3% (USGS, 2011). Additionally, it is reported that the amount of recycling was quite small and consisted primarily of rare earth magnet scrap, although with the sharp increase in the price of rare earths, and the potential shortage in supply, focus in this area is continually growing. Thus, the opportunities, whether realistic or not, are extremely vast in the recycling of rare earth containing materials. The following subsections will present methods proposed for the recycling of rare earths based on the feed material type.RECYCLING OF RARE EARTH MAGNETSCurrently, investigations are ongoing in the area of recycling production scrap and end-of-life materials in the rare earth magnet industry. The following techniques illustrate potential methods for the recovery of rare earths from secondary RE magnet sources.Recycling of Rare Earth Magnet Sludge by Selective ChlorinationDuring the production of neodymium magnets, a by-product of production is the so called “magnetic sludge”. This by-product contains high amounts of neodymium, thus a process for the recovery of Nd has been proposed. In this process the Nd present is selectively chlorinated/distilled by the addition FeCl2 via the following reactions."

Jan 1, 2012

By J. B. Kwon

For improvement in the productivity of tall building projects, table formwork is one of the main methods that have been adopted for slab formwork. Because the table formwork method is an equipment-oriented construction method, the type of lifting equipment and method of operation considerably affects the productivity and cost of the table formwork. It is also important to make an equipment input plan for completing the table formwork within the time given, according to the structural construction cycle. For performing the table formwork, a tower crane or an independent lifting system, and shifting trolleys, are required. However, if an inefficient equipment input plan is made, exorbitant cost may be incurred. Therefore, the purpose of this study is to analyze the productivity of a table formwork, considering the type and number of lifting equipment and the number of trolleys inputted, and to suggest quantitative data for making a cost-efficient equipment input plan within the construction duration given. It is expected that the results of this research will be utilized as a basis for cost-efficient equipment input planning.

Aug 1, 2013

By D. Atkinson

"Porphyry molybdenum-tungsten mineralization on the east flank of Hudson Bay Mountain crops out over 5 km2 and is intersected to depths of 2 km. Features such as a hornblende-biotite aureole, mineralogical zoning and dike, vein and fracture geometries within lithologies of the Middle to Lower Jurassic Hazelton Group and Cretaceous Skeena Group reflect an intrusive complex, the Upper Cretaceous to Early Tertiary Hudson Bay Mountain stock which has been intersected by drill holes. The stock is believed to be the mineralizing agent. A southeast-dipping granodiorite sill has been outlined by drilling within the Hazelton Group. Molybdenite and scheelite veins cut all rock types; however, the granodiorite sill hosts a higher density of fine-grained, banded, quartz-molybdenite and pegmatitic quartz-molybdenite veins reflecting a competency contrast between the intrusive sill and other country rock. Due to the relative abundance of these veins, grade is higher within areas of the sill. Above the 15000£ cross-cut 20.6 million tonnes grading 0.401% MoS2 and 0.041% W03 have been defined. During exploration of the deposit sampling procedures had to be adjusted because of the nugget effect attributed to drill intersections of banded and pegmatitic veins.IntroductionMolybdenite was discovered in outcrop at the foot of Kathlyn Glacier on Hudson Bay Mountain and first reported by the Geological Survey of Canada in 1944. The deposit has several names: Hudson Bay Mountain or Glacier Gulch, both after its location, and Yorke-Hardy after the original staker.The deposit is on the east flank of Hudson Bay Mountain, 9 km northwest of Smithers, west-central British Columbia, within NTS area 93L/14 (54° 49' North, 127° 18' West, Fig. 1). Hudson Bay Mountain, on the southern edge of the Bulkley Valley, is a dominant topographical feature reaching 2590 m elevation. Mineralization is partly overlain by the Kathyln Glacier which is visible from Highway 16. Access to the 3100 m of underground development is from a portal at 1066 m elevation on the east slope of Hudson Bay Mountain."

Jan 1, 1995

By Luke Meers

Roadway development rates in Australian underground coal mines are failing to keep pace with modern longwall systems and are unlikely to sustain further improvements in longwall productivity into the future unless step change improvements to roadway development equipment and practices are made. Bottlenecks which limit and constrain improved production and impact the safety of operators have been identified through a series of industry surveys, with the manual installation of strata support materials, consumables delivery, coal haulage and monorail installation being highlighted as major areas to improve development performance. This paper looks at research being carried out at the University of Wollongong in designing an integrated system approach for the fully automated handling and installing of development consumables, and the systems required to support these activities. A series of hard automation manipulation devices have been demonstrated in surface trials and the results indicate that rapid roadway development can be achieved.

Aug 1, 2013

By Ming’an Wei, Qifu Duan, Jianmin Wu, Lusheng Zhou, HMR Group Limited / HMR Technology Canada Ltd., Wenjian Wu

"The development and industrial applications of magnetic liners have been around for decades. A Swedish company Skega first introduced rubber magnetic liners, and then followed by the Chinese invention of metal magnetic liners. Traditionally, both liners were used in secondary ball mills and regrind ball mills for industrial applications, especially for ores containing magnetic materials. Mostly steel balls or equivalent forged steel balls, usually below 60 mm in diameter, were used as grinding media. With the development of mineral resources over the years, SAG mills and larger ball mills have become the dominating components for comminution circuit design. Due to the development of larger diameter ball mills and thus larger ball charge diameter (up to 80mm) especially in non-ferrous metal mining operations, the application of magnetic liners have been very limited. Based on “Magnetism theory” and the development of new materials, the HMR Group Limited has been conducting researches on examining the structures of magnetic liners, associated materials and magnetic circuits which led to the invention of the Nano Alloy Steel Magnetic Liner (NSML). Recently, NSML had a successful application in a 5.5 m diameter × 6.5 m ball mill at the Erdenet Copper Mine in Mongolia. The NSML successfully handled a ball size up of to 80 mm, while achieving a service life of nearly 24 months, which is almost 3 times wear life of the original manganese steel liners.INTRODUCTIONDuring the development and utilization of mineral resources, mineral processing is an indispensably operation. The effective separation of various useful minerals depends on sufficient monomer dissociation of minerals in the ores. The crushing and grinding operation is prior operation of mineral processing. Ball mills are used in different concentrators. As the main consumption parts of mill, liners have been studied constantly. As a new kind of liners, magnetic liners besides can meet the requirement of production, and also have characteristics with maintenance-free, saving energy and increasing efficiency. So the magnetic liners are worth to be spread and applied world widely."

Jan 1, 2016

By M. Narita, S. Nakayama, M. Fujihara

Hibi Kyodo Smelting Co., Ltd. was founded in 1968 and celebrated its 50th anniversary in 2018. In 1972, we started producing copper cathode with a production capacity of 84 KTPY. Since the company founding, we have undertaken seven expansion projects, and our current copper-cathode production capacity is 290 KTPY. To increase our production efficiency, two tank houses were converted from Conventional process to ISA process in 2006 and 2014. In another investment, we equipped a continuous glue dosing system, which allowed for strict additive-concentration control, yielded quality improvements and reduced the power-consumption rate. Along with an increase in the production of copper cathode, the amount of impurities eluted from the anode increases. To solve this problem, the chelate-resin purification process that was introduced in 1983 was renovated, and impurities could be recovered more efficiently. In this paper, we report various improvements that have been implemented at the refinery since 2000. INTRODUCTION Tamano Smelter and Refinery of Hibi Kyodo Smelting Co., Ltd., founded in 1968, celebrated the 50th anniversary of its founding in 2018. The Tamano Smelter opened its No. 1 tankhouse in 1972, and began operating No. 2 tankhouse in 1984. Thereafter, with continuous production increases and technical improvements, electrolytic copper production was increased from 84 KTPY to 290 KTPY as shown in Figure 1. Table 1 shows the major operating facilities and operation data in 2017.In this paper, details of equipment introduced to continuously dissolve and add glue, various improvements made to the chelate resin process, enhancements made to the crude Ni sulfate process, and another vibrating screen introduced to the copper slime processing flow in accordance with the expansion of copper production capacity since 2000 are reported.

Jan 1, 2019

By Jun Dai

Based upon research findings from several countries, the combination of microwave and mechanical means to break hard rock holds promise for the future. To achieve this goal, it is essential to understand the laws governing strength reduction of hard rock, such as granite, induced by microwave irradiation. Two aspects to consider are: 1) laws associated with the tensile strength of hard rock after microwave irradiation and 2) the sensitivity of different types of rock strengths to microwave energy. In this study, granite with a range of tensile strengths was exposed to microwaves for various time periods to compare the response of rocks with different strength values exposed to the same microwave irradiation. In addition, a method based on hotspots is presented to explain the mechanism by which granite strength is reduced by microwave irradiation. Granite extracted from Qinling Mountain in Shaanxi Province, China is used in the research. ?50 × 50 mm cylindrical granite specimens were exposed to microwaves at a specific power level. The strength values of the heated granite specimens were compared with those of unheated specimens. Through the comparison and analyses, relationships were determined between 1) reduction in granite strength and microwave irradiation time period, and 2) granite strength and sensitivity to a given energy of microwave irradiation. Finally, a mechanism to explain the experimental results is proposed. Research findings will aid in the design of a microwave + machine rock-breaking system for use in rock breakage in underground mines at depth and for future mine applications on earth and other planets. In addition, the experimental approach could be used to test other rock types to further our understanding of rock damage induced by microwave irradiation.

Aug 1, 2013

By Norman R. Ball

"Many people in the mining and metallurgical industries were brought up to embrace Henry Ford's pronouncement that ""History is bunk"" but it is not generally known that the same Henry Ford created and paid for one of the finest technological museums in the Western World. I am aware that many people feel that industry history is something you ask aging executives to do or that history is a clip-andpaste compendium of pictures re-discovered every 25 years or on the occasion of issuing a press release on plant expansion. Moreover, there are many who fear historians as somewhat deranged individuals interested only in corruption, injustice and sensational labour strife. Good history lies somewhere between the controlled P.R. handout and the hysterical attack. Writing good history is a difficult creative act based on the application of experience, insight, wide knowledge and careful reasoning to available evidence. To date, the Canadian mining and metallurgical industries have achieved a great deal but left too little evidence and it is this lack of evidence which must be corrected before it is too late. It is the purpose of this article to stimulate thoughts with regard to archives, one of the more important vehicles for the preservation of such evidence."

Jan 1, 1999

By T. H. Wilson

In 1901, the Crow's Nest Pass Coal Company, Limited, began producing industrial coke in 212 beehive ovens at Michel colliery. By 1908, 486 ovens had been installed and in that year 147,623 tons of coke were produced. Coke manufacture has been continuous from 1901 until the present time (1946), with total production of 2,795,402 tons. At present writing, only 100 beehive ovens are operating and production is reduced to 1,800 tons per month, due to the shortage of suitable labour. These ovens are drawn by hand, on contract, and the workmen are exposed to considerable heat. A man draws three ovens in eight hours, thereby producing approximately 1072 tons of coke per day. In addition to the inefficient and costly method of drawing coke in beehive ovens, tremendous losses are experienced in the wastage of gas and tar, which are driven off into the atmosphere. Also, the yield of coke per ton of coal fed to the ovens is low as part 9f the carbon is utilized in producing heat to carbonize the remainder of the coal. A recovery of only 55 per cent of the carbon, as coke, is obtained. The coking process takes place from the top of the charge, which is 21/2 feet deep, downward to the floor. Six and a half tons of coal are charged and 3.6 tons of coke are drawn from the oven after 72 hours' carbonization. The beehive ovens using Michel coal produce a very hard and tough coke, large in size and of silvery appearance, which has served the requirements of both foundry and smelter for many years. In 1938, the Company made a careful study of coking processes with a view to introducing a more economical method than beehive ovens and one that would be less dependent on skilled labour, the supply of which was rapidly diminishing at that time. Various methods of by-product coking were investigated, and it was decided that the Curran-Knowles process offered the greatest possibilities because of the low capital investment in relation to output and also because the horizontal oven design was suitable for an expanding coal. Consequently, a test on Michel B seam coal, supervised by Mr. E. Burrough, of the Fuel Research Department, Ottawa, was run in the Curran-Knowles plant at West Frankfurt, III. The results of this test led to the construction of a ten-oven battery of 32 ft. 6 in. by 8 ft. 3 in. Curran-Knowles ovens at Michel, which were completed in November, 1939. This battery was built as an experimental unit, with provision for an additional ten ovens if the coke proved satisfactory for the market. In 1942, an expanding coke market led to the construction of a second battery of ten ovens, which were completed in April, 1943.

Jan 1, 1947

By W. Lin, Z. Z. Dong, C. L. Zhou, Y. C. Kuang

The inversion of rock mechanical properties based on well-logging data is a common method to drillbit selection in petroleum engineering, the basic principle of which is to use deep-well logging data and experimental regression model to calculate rock mechanical properties. The profile of rock mechanical properties can be established. According to the profile, the type of drillbit can be selected in different formations, which will improve the economic benefit of bit use indicators. Compressive strength of rock is one of the most important parameters. Conventional method to establish regression models of acoustic velocity and uniaxial compressive strength is on the basis of rock core sonic experiments and uniaxial compressive experiments. However, with the increase of deep drilling operation, triaxial compressive strength prediction model will play a more vital role in drillbit optimization selection in deep wells and improving ROP (Rate of Penetration). Triaxial compressive strength is an important parameter to evaluate the formation strength property. In this paper, to the sandstone commonly encountered in oil drilling, combined the rock mechanical experimental results with the changing porosity experimental results under confining pressure, a new interpretation model of triaxial compressive strength based on well logging data is proposed. Firstly, three types of sandstone samples are collected. Then measured components, uniaxial compressive strength, triaxial compressive strength and porosity. Experimental results show that: confining pressure has a significant influence on sandstone strength, with the increase of confining pressure, triaxial compressive strength increase; furthermore, the triaxial compressive strength of different porosity sandstones have different change rules when confining pressures changes; sandstone porosity decreases with the increase of confining pressure and it obeys logarithmic function. According to the results, regression models of sandstone, in-situ uniaxial compressive strength model and uniaxial compressive strength model under normal pressure are generated. Meanwhile, using well logging data in the acoustic velocity, density and gamma value can derive in-situ rock formations uniaxial compressive strength and in-situ porosity. Eventually, a new model established in this paper, containing in porosity, uniaxial compressive strength, lateral pressure and power exponent of regression, can predict triaxial compressive strength which will guide drillbit selection.

Jan 1, 2015

By Roger Francis

There is increasing use of acid leach extraction methods at elevated temperatures and pressures by the mining industry. In many locations there are limited supplies of fresh water, and waters with higher chloride contents must be used, making conditions more corrosive. The fluids downstream of the main autoclave are hot, acidic, oxidizing and contain chlorides and present a challenge to the mining community to ensure reliable operation. Zeron 100 is a high strength superduplex stainless stee, that offers high corrosion resistance at a cost effective price. The paper presents a combination of laboratory data and service experience, particularly in the aggressive fluids found in downstream processing.

Jan 1, 2010

By Keith Haddock

"The Sheerness Mine, a new surface coal mine located near Hanna, Alberta, went into full production in mid-1995. The mine, which is operated by Luscar’s subsidiary Forestburg Collieries (1984) Ltd., has the design capacity to supply up to 2.1 million tonnes of sub-bituminous coal per year to the adjacent Sheerness Generating station under a 30-year contract. This paper documents the construction phase of this project and highlights the major equipment purchases as well as the construction of the mine facilities. The paper also focuses on some of the areas where cost savings have been achieved that have allowed the mine to come on stream six months ahead of schedule, and under budget. Project ReviewMine DescriptionThe Sheerness Mine is located 25 km southeast of the town of Hanna in southeastern Alberta (Fig. 1). The mining property occupies the western portion of the Sheerness CoalField and borders the Montgomery Mine, operated by Manalta Coal Ltd. in the east, and Highway 36 in the west. The Montgomery Mine and the Sheerness Mine exclusively supply the total coal requirement of the adjacent Sheerness Generating Station. The station is owned jointly by Alberta Power Limited (APL) and TransAlta Utilities Corporation (TAU). APL is the operator. Manalta’s Montgomery Mine has supplied coal to the Sheerness Station since its opening in 1986. Coal is shipped by truck from the mines over a network of haul roads to the coal receiving hoppers located on the east side of Highway 36."

Jan 1, 1997

By S. Hosseinpour

Chromate conversion coatings (CCCs) are usually applied to these alloys to enhance their resistance to localized corrosion and to improve paint adhesion. The special properties of these coatings such as their low electrical contact resistance (ECR) make them suitable for satellites. This study is aimed to develop advanced CCCs with the proper appearance, morphologies and surface roughness and to evaluate their role on the ECR and thermo physical properties on hardened aluminium alloy of Alclad-7075-T6. Coating characterization was performed by means of scanning electron microscope (SEM) and atomic force microscope (AFM). ECR of coatings were measured by special laboratory designed instrument and a and c were measured by Emissometer and Reflectometer respectively. In addition, corrosion performance of the CCC-coated alloys was determined by 168 hr exposing to salt-spray testing in accordance with ASTM-B117. The results of accomplished experiments on the developed CCCs in this study have been agreeable concerning available acceptability criteria for satellite surfaces.

Jan 1, 2007

By Yan-Jun Shen

The rock mass classification system, BQ (basic quality), is the only national system that is suitable to most kinds of rock engineering in China. It uses two main aspects of the rock mass, the intact uniaxial compressive strength (UCS) and the rock intactness index (KV), to obtain the rock mass BQ. The index KV could be measured by the acoustic wave method. However, because this method is an indirect approach to characterize the rock mass structure, misfits often occur between the test results and the actual rock mass characteristics. Therefore, a new parameter KGSI expressed by the geological strength index is proposed to replace the original KV, and a new method is presented to express the value of BQ as a function of the UCS and the KGSI. Then, the underground excavations at five hydropower stations were chosen as examples to study the relationship between the revised BQ and the each of the international systems (RMR, Q or RMi). In addition, the applicability of the RMR, Q, or RMi system is discussed for China?s rock characteristics and geological conditions, and suggestions are given for improving the revised BQ system.

Aug 1, 2013

By J. H. Starkey

Large differences between macro and micro grindability relationships have been discovered for mill design measurements using the patented SAGDesign(TM) test. Crushing, Rod and Ball Mill Wi tests, and breakage parameter measurements have previously been used to design SAG mills but have not revealed the true magnitude of these differences. A SAGDesign(TM) test measures the SAG/Bond Wi Ratio (defined below) for every sample tested and gives a good design result because the F80 of the SAG stage test feed is 19 mm and because the test includes a Bond Ball Mill Work Index on SAG ground ore. Good flotation operation demands properly sized grinding mills and steady feed to the flotation circuit.

Jan 1, 2009

By S. Duvah Pentiah

The transformation of an open pit coal mine to a horizontal-punch underground mine is subject to a number of challenges. These include scheduling the operation of various sizes of trucks over a long period, as well as updating delivery routes and dump site locations as the mine transformation progresses. In this process, rock is excavated from a quarry through earthworks. The bulk earthwork and quarry material delivery were initially drawn from traditional planning and experienced issues in their early phases. As a result, a traffic simulator was developed in order to validate schedules and predict achievable throughput, likely delays or blockages in the long term. The dynamic traffic simulator was also used to provide traffic density and vehicle arrival data at selected intersections in order to identify possible safety and efficiency issues.

Aug 1, 2013

By W. L. Ott, C. L. Lewis

"AbstractA technique is described for preparation of palladium sponge and for spectrochemical analysis of the metal in this form. The precision and accuracy of the method are discussed. Analyses are compared with previous spectrochemical analyses of palladium in the black form. Good agreement was found in the two sets •of results and it is concluded that they are more reliable than wet chemical .analyses of the same material.IntroductionFOR SEVERAL YEARS the problem of platinum metal analysis by spectrochemical methods has been under investigation at the Spedtrographic Laboratory, Department of Geological Sciences, Queen's University. The problem, briefly -stated, is as follows: Samples of platinum, palladium,-rhodium, ruthenium, and iridium are received as fine metal powders, called sponge. Direct spectrographic analysis of this material has not been found satisfactory due to its heterogeneity •as regards contaminant metals, which may be present up to a total of one per •cent or more. Further-more, spectrographic standards are difficult to obtain and difficult to prepare accurately by adding weighed portions of contaminant metals to the sponge. The fact that •contaminant metals in original samples are probably alloyed with the major constituent is a further difficulty since complete fusion of these refractory metals proved impractical in the present case as a means of standard preparation. It •has, therefore, been found most satisfactory to dissolve the metals, prepare standards by addition of solutions of contaminant metals, and to reduce both standards and samples to a homogeneous form. A previous paper, by Hawley, Wark, Lewis and Ott (2) dealt with a method for spectrochemical analysis of platinum and palladium in their black form. Since completion of research on the black technique, the possibility of analyzing palladium accurately in its sponge form has• been investigated."

Jan 1, 1953

By Robert A. Bosschart, Harold O. Seigel

"Most electromagnetic methods presently used in mining exploration are of the moving source type; i.e., the primary field source is moved simultaneously and in a fixed configuration with the receiver. Of the fixed-source methods, which employ a stationary primary field and a moving receiver, the Turam method is the most effective and has marked advantages over alternative electromagnetic methods. The results are little affected by topographic relief, and a high degree of resolution can be obtained because of the constant relation between source field and investigation area. Another inherent advantage of the Turam configuration is that it provides more favourable dimensional relations. Thus, the primary field attenuates at a much lower rate than in moving-source configurations and, secondly, the method is size sensitive; i.e., conductor size affects the strength of the response, which is not the case with moving-source methods. These factors result in a considerably better potential depth penetration."

Jan 1, 1966

By D. J. Lloyd

"Bending is involved in the forming of many sheet parts and it is important to understand the phenomena involved. In this paper the basic equations describing bending on a global scale are compared with strain measurements of bent sheet. The development of strain on a local, microstructural scale is also investigated, as is the general aspects of plasticity and the failure process. It is shown that the global equations can be used to estimate the strains involved and the local strains can be attributed to various aspects of the plasticity. The bendability can be related to the fracture strain of the sheet and the ability of a sheet alloy to accommodate the necessary bending to form the part can be assessed.INTRODUCTION The ability of a sheet alloy to undergo bending without failure is an important capability in the forming of many parts and it is useful to be able to assess the bendability of an alloy during its development. The basic mechanics of bending were developed in the 1950s (Lubhan & Sachs, 1950; Hoffman & Sachs, 1953). When a sheet is bent the upper bend surface is in tension, the lower surface in compression and at some point within the sheet there is a plane of zero strain which is referred to as the neutral axis. For sheet exhibiting limited plasticity the neutral axis is static and occurs at the mid-point of the sheet thickness but for sheet exhibiting extensive plasticity the neutral axis progresses deeper in to the sheet as bending progresses. This results in two expressions for the maximum strain at the upper bend surface depending on the motion of the neutral axis. For Al alloys such as AA6111, AA6016 and the like extensive plasticity occurs and the neutral axis is expected to move during bending. However, very few studies have examined how the neutral axis motion and the strains develop, compared with the mechanics analysis. Geist and Parker (1984) used hardness measurements to investigate neutral axis motion but these experiments did not have the resolution necessary to compare the results with experiment but did indicate neutral axis motion. To understand the nature of plasticity and failure during bending it is important to know the extent of neutral axis motion, the scale of strain gradients developed through the sheet and the maximum strains occurring at the bend surface, finally comparing experimental results with the theoretical predictions. The influence of microstructure on the evolution of strain and failure can then be considered in the context of these parameters. Recently, bending in some automotive Al alloys has been reported mainly from the microstructural perspective (Lloyd, 2000, Lloyd et al., 2002, Mattei et al., 2013) and FEM studies have also investigated the development of plasticity under bending, demonstrating the tendency for strain localization (Becker, 1992, Shi et al., 2014)."

Jan 1, 2018

By E. Godfrey

The average man one meets on the street thinks of an explosive as a medium of death and destruction, something unstable which should be given a wide berth, because he knows little or nothing about its use or its stability. Briefly, explosives are compounds that develop very large quantities of heat and gas in an extremely short time and in a small space, thereby exerting enormous pressure upon surrounding bodies, and by the rapid expansion of this highly heated gas are able to perform a considerable amount of useful work. The amount of heat generated and the volume of gas produced by the decomposition of an explosive determines the amount of mechanical work it can do, and the time occupied by its change from solid or liquid condition to gaseous condition determines its shattering effect. Explosives manufactured by reputable people are not extremely dangerous, on the other hand they are quite safe if handled in a proper manner. Furthermore, before an explosive can be placed on the Canadian market a sample must be submitted to the Explosives Division of the Mines Department, who may condemn or permit its manufacture, according to their findings regarding its safety in handling and its stability during storage.

Jan 1, 1926