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Like it or not, CPD is upon us. As from 1 January 2006, all registered engineering professionals, i.e. professional engineers, professional engineering technologists, professional certificated engineers and professional engineering technicians, were required to undertake CPD in order to keep their professional registration current. The rules regarding CPD have been gazetted under Government Gazette No. 28328, Board Notice 131 on 23 December 2005, and they also appear on the ECSA website?www.ecsa.co.za. For the convenience of our members they are reproduced in full in this issue of the SAIMM Journal.

Jan 1, 2006

By M Quinteiro, Å Sundqvist

What is special about being a female mine manager? We do not believe that the challenge is greater for women in managing a mine compared to managerial positions in other male-dominated businesses. The challenge lies in the fact that it is a male-dominated business. Being a leader belonging to a minority creates a situation where competence not only lies in having technical knowledge or general leadership characteristics, but also in acquiring an understanding of the male norm and being able to behave and communicate effectively in the organisation.In order to move towards a better gender balance at senior levels it is important to set measurable objectives on desirable proportions between women and men at management levels within the company. Focus and action are required to achieve this goal. At LKAB, the current target is to reach 25 per cent women in the total workforce by 2020. To date, LKAB has reached 19.4 per cent women in the total workforce, and the number of women in management positions is 19.9 per cent.It is of vital importance to create a non-discriminating working environment to achieve equal opportunities at the workplace, to be able to use the whole workforce as a resource for recruitment of professionals and managers, thereby improving decision-making, productivity, efficiency and profitability.Women as mine managers is not a utopia, but rather an effect of long-term investments in actions that result in equal opportunities for all employees.CITATION:Quinteiro, M and Sundqvist, Å, 2016. Women as mine managers – a utopia?, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016) , pp 43–48 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Karl Zipf

In highwall mining, once a sufficient number of web pillars are developed, they can fail catastrophically in a domino-type failure, posing a safety hazard to highwall miners and sterilizing mineable reserves. Three recent case histories of catastrophic web pillar failure in U.S. and Australian mines are documented and analyzed with two design approaches. The conventional design approach uses only a strength criterion, while the postfailure design approach uses both strength and stability criteria to insure an acceptable failure mode should strength failure occur. Catastrophic highwall web pillar failures can cost money through equipment losses, production losses, coal reserve sterilization and lost opportunity costs. Coal recovery may be higher. but the benefits of higher recovery must balance the potential costs of failure. Application of the conventional or postfailure design approach will decrease coal recovery and revenues, but the risk of potentially costly failure is much less.

Jan 1, 1999

By L. W. Vigrass

Porous and permeable rocks deeply buried in sedimentary basins contain immense volumes of hot water with the potential to supply low-grade heat energy. A part of Canada with sizeable potential for low-grade geothermal energy is the northern Williston Basin of southern Saskatchewan. In this region, the University of Regina has conducted a geological study investigating the feasibility of producing large quantities of warm water suitable for space heating in the Regina - Moose Jaw area. The study has shown that the most favourable geothermal reservoirs are in the Basal Clastic Unit (Cambrian Ordovician), which, at an approximate depth of 2,000 metres has predicted temperatures of 71°C to 74°C. We anticipate sustainable flow rates from these reservoirs of 100 to 300 ms/hr. The water contains about 150,000ppm of total dissolved solids, mostly sodium chloride. It is anticipated that the sulphate content will be 3,000 to 6,000 ppm, that the dissolved oxygen and hydrogen sulphide content will be small, and that the waters will be neutral to slightly alkaline. It is anticipated that the piezometric level will be 46 m below the ground surface for reservoirs in the upper part of the Basal Clastic Unit and 141m below the ground surface for the lower reservoirs of the unit. Plans are to build a low-grade geothermal research, testing and demonstration facility at the University of Regina. To be a practical demonstration, the facility will have to handle very large volumes of water. Because of high salinity, the water will be re injected into a subsurface reservoir. We do not anticipate insurmountable problems because of salinities or as a result of corrosion provided that the waters are not aerated during handling

Jan 1, 1979

By Edwin Berry

THE consideration of the present value of a mine is of great importance when planning for the operation of a property,, and it is particularly so in the case of mines that have large ore reserves. At various times during the past 15 years, the writer has had occasion to make rather thorough studies of the subject, and has been greatly impressed by certain important points which these studies have brought out, points which, though they may be well known, are often lost track of in the rush to obtain low mining costs and high daily tonnage output. . It is the object of this paper to present briefly, and in a general way, some of these points, and especially those which have to do with the relationship which (1) ore reserves and plant capacity, (2) grade of ore mined, and (3) ore losses in mining, bear to the present value. Present value, sometimes called present worth or actuarial value, means the value today of the future earnings of an enterprise. Great industrial, manu-facturing or railroad enterprises, if properly handled, go on indefinitely and their value is directly dependent on their estimated annual earnings. Mines, or oil properties, on the other hand, have an earning capacity only until the ore or oil is exhausted, and their present value is dependent not only on their annual earnings but also on their life, which is the length of the period over which they can produce at a profit. A mine, or an oil property, is a "wasting asset," while an estab-lished manufacturing business is not, or should not be. In other words, the present value of a mining property. represents a sum of money on which there could be paid from operating profits a determined rate of interest, say 8 per cent., and in addition an amount which, if invested at compound interest as received, would at the end of the life of the mine pay back the present value. In his "Wealth and Income of the American People," Walter Renton Ingalls says: "The fundamental principle of mine valuation is the present worth of an annual dividend accruing during the period of years corresponding to the life of the mine."

Jan 7, 1922

By Rudolph Emmel

THE mines operated by the South American Development Co. are located in the Zaruma mining district of southwestern Ecuador. They are near the old mining town of Zaruma, which is the only important city in the canton of the same name. The district is situated in the upper end of a valley lying between two spurs of the Cordillera, one of which may be considered the Coast Range and the other an intermediate range. The mining camp proper, known as Portovelo, and the plant are 2.4 km. south of Zaruma, on the north bank of the Amarillo River, a tributary of the Tumbes River, which flows southwestward through Peru to the Pacific. Portovelo is difficult of access; it is reached from Guayaquil by means of river steamers and muleback. Embarking at Guayaquil, the route is down the Guayas River, across the Jambeli Canal, and up the Santa Rosa River to Santa Rosa, a distance of 177 km. From Santa Rosa, the road or trail follows the Santa Rosa River, then across the summit of the Coast Range into Portovelo, a distance of 74 km.-a two-day trip on muleback. The mining property of the South American Development Co. comprises 297 lode claims and 142 placer claims. The combined lode claims cover an area, roughly rectangular in shape, 9000 m. long from north to south by 4000 m. wide; the northern edge of the rectangle is about 3000 m. north of the central plaza of Zaruma. Mineral lands in Ecuador are held by virtue of an annual tax per claim paid to the central government, no surface rights being included.

Jan 1, 1925

By Luis Alberto Martinez Tipe

The paper show how the inclusion of the uncertainty of the geology of the orebody into the mine planning and design process can be of great help, for the mine planner, in both assessing and quantifying the existing risk in the key project indicators such as DCF, and ore tonnage. This is achieved by using conditional simulation and Monte Carlo techniques which provide equally probable models of the original orebody model of the deposit. In this fashion, it is possible to assess the sensitivity of the pit design and related long-term production scheduling (cutbacks) to grade uncertainty.

Sep 12, 2005

This publication summarizes the in-house and contract research and development projects programed for fiscal pear 1980 by the Bureau of Mines under its Minerals Environmental Research activity. The document provides a mechanism for interested parties, including potential contractors, to gain insight into ongoing and projected work of the Bureau's environmental research efforts. Research to identify and correct environmental problems associated with mining and metallurgical operations has long been an integral part of the Bureau's mission. Through the years, efforts of various Bureau programs have yielded valuable information on the origin and control of many of these problems. With the reorganization of the Bureau of Mines in 1979, the Minerals Environmental Technology program was structured to consolidate these efforts into a single program that will systematically investigate al aspects of mining- and processing-related environmental pollution and damage-from initial discovery of the mineral resource to ultimate return of the land to productive use. In fiscal year 1980, the Bureau received an appropriation of about $21 million to conduct research and development work on these problems.

Jan 1, 1980

By E. Gallestey, D. Groenveld, F. Kolb, M. Rozou

"Recent copper price evolution pushes modern mining industry even harder to achieve highest production with maximum efficiency. Operations are bound by numerous contractual and environmental conditions that bring a high degree of complexity to both the operators controlling the process and the plant managers assessing the circuit’s potential and setting the production goals.Advanced process control (APC) for grinding is one important tool to operate this most energy intense area in an optimal way, finding the optimal trade-offs between highest throughput, energy efficiency and product quality based on variable ore properties, production targets and management priorities.ABB’s state of the art control and optimization software platform enables user to design a controller based on model predictive control (MPC). The paper and the presentation show the technology used and the results achieved through an APC controller installed in a pilot project in Aitik (Boliden SA), Sweden. Furthermore, possibilities to interconnect grinding with other areas as stockpile management and flotation with various interconnected APC controllers will be shown. Finally, an example of the return on investment and the payback times based on the increased throughput and better product quality will be presented.INTRODUCTIONDepending on the ore characteristics and the targeted plant capacity, the design of the grinding circuit may vary significantly. Typically, the circuit consists of several mills (rod, ball, SAG, AG) in series and/or parallel with a number of classifiers and sumps at appropriate locations (see Figure 1).The main goal of the grinding section is to reduce the ore particle size to a level that enables efficient separation between gangue and precious metals in the subsiding processing step. The trade-off between quality and quantity has to be made. At the same time, it is also crucial to execute this process at the lowest possible energy and grinding media consumption."

Jan 1, 2015

By P. W. van Deventer

?Soil quality is the capacity of a soil to function, within ecosystem and land use boundaries, to sustain biological productivity, maintain environmental quality, and promote plant, animal and human health?. In the long-term, vegetative rehabilitation of mining wastes aims at, as far as possible, the proper ecological integration of the reclaimed area into the surrounding landscape, which is sustainable and requires minimal maintenance. A certain succession pattern is therefore needed. Recent ecological concepts recognize the role of the substrate?s quality and nutrients in affecting the rates and directions of succession patterns. Although pedogenesis and eventually soil quality in mine waste are not well known, monitoring of soil quality parameters in kimberlite mine tailings reveal a remarkable establishment and or improvement of specifics oil quality indicators. During the same time the vegetative cover?s total functionality as well as reproductive ability improved. Functions of soil, and thus soil quality, can be assessed at the field, farm, ecosystem, pedosphere, and global scale. It is recognized, however, that management of soil becomes increasingly difficult at larger scales, but for demarcated mine waste sites it is possible to ameliorate and manage and assess soil functions and quality. Therefore the significance of the study is the following: soil functions and quality become inseparable from the idea of system sustainability, and are considered as key indicators of ecosystem sustainability on rehabilitated mine tailings material.

Jan 1, 2008

By R. L. Xu

In this paper, the author would like to point out with figures that the building industry is one of the key industrial sectors of the national economy in China. And in the coming 15 years, the output of building construction will not in the least decrease, but increase. The requirements for building standards, quality, functions as well as physical environment will also be higher along with the incessant development of the national economy and the gradual raising of people's living standard. China is a country with a vast territory and a great, variety of physical characteristics. The topographic and engineering geotechnical conditions are complex and varies considerably from place to place. Although, in recent years, encouraging progress has been made in building construction, there still exist many problems unsolved or even not explored at all, which we have to tackle in the future design and construction of foundations. Also reviewed in this paper are the achievements attained in the past thirty odd years and the challenge we will face in the foundation engineering field in China.

Jan 1, 2010

By John H. Weigand, Stephen V. Crum

"VIBRONICS, INC. instrumented and monitored a residential structure for response to,blasting at aMidwestern surface coal operation. The residence was owned by the mining company and was extremely close to the operation. Blasting was conducted within 120 feet (36.5 meters) of the test structure. Up to seventeen (17), four (4)-channel seismographs were used during the monitoring period. The basement walls and floor were monitored. VIBRONICS, INC. also monitored a brick chimney in the basement and attic. Structural responses were then compared to outside vibration measurements taken in the soil near the foundation."

Jan 1, 1998

The 108th Annual General Meeting of The South African Institute of Mining and Metallurgy was held at The Country Club, Johannesburg, Napier Road, Auckland Park on Thursday, 11 August, 2005. Welcome The President extended a special welcome to the guests and representatives of our sister institutes and other associations, also to recipients of awards, senior members of industry, Honorary Life Fellows, past-presidents, our members and other guests, among them the following: Dr Con Fauconnier, President, Chamber of Mines of South Africa Prof. Jay Barton, President, The Geological Society of South Africa V. Townshend, President, Institute of Certificated Mechanical and Electric Engineering, South Africa M. Livingstone-Blevins, President, Institute of Certificated Mechanical and Electrical Engineers, South Africa Prof. B. Lacquet, President, South African Institute of Electrical Engineers Dr F. Malan, President, South African National Institute of Rock Engineering

Jan 1, 2005

By D. Harry Chambers

The Bureau of Mines, through a memorandum of agreement with the Department of Defense, conducted research to recover silver from aircraft scrap. Silver was recovered by an electrolytic method from stainless steel honeycomb sections separated from the aircraft. These sections had been constructed by sandwiching a stainless steel honeycomb core between stainless steel sheets and then brazing the assembly with a silver alloy. Over 300 pounds of silver was used in the B-58 bomber, concentrated in certain honeycomb sections of the aircraft. Following shredding of the aircraft parts, an average of 95 percent (ranging 67 to 100 percent) of the silver was recovered in a single electro-refining step. After the electrorefined product was magnetically cleaned, purity of the recovered silver was greater than 99.3 percent.

Jan 1, 1980

By T. O. Llewellyn

The Bureau of Mines conducted batch-?scale tests on a sample of parphyry copper mill tailings as part of a study to determine the feasibility of rutile recovery from this source. The tailings that were tested contained 0.75 percent titanium dioxide (Ti02), with about two-thirds of the Ti02 values occurring as rutile. Mineralogical studies indicated that about one-half of the Ti02 content could be considered recoverable. Beneficiation studies of the tailings showed that best flotation results were obtained when sulfides and carbonates were removed by bulk flotation prior to rutile flotation. Rutile flotation was most effective when a petroleum sulfonate collector was used in an acid circuit. From this basic method of flotation, two alternative procedures were developed. The first procedure was to size and grind the tailings to minus 200 mesh; deslime the total pulp; and then float the sulfides, carbonates, and rutile. The second procedure was the same, except that it did not include sizing and grinding. Flotation of the sized and ground tailings yielded rutile concentrates containing 43.1 percent Ti02 and 75.7 percent of the recoverable Ti02. Rutile concentrates floated from the tailings that were deslimed but not ground contained only 34.7 percent Ti02 and 69.4 percent of the recoverable Ti02.

Jan 1, 1980

By Y. He

Early research showed that the separation of particles based upon their density was not possible in steadily rising air streams. The terminal velocities of moving spheres are determined by their aerodynamic characteristics. This prevents particle separation by density in standard air classifiers. Passive pulsing air classifiers have accelerated airflow in certain regions, which achieves density-dominant separation. Numerical simulation of airflow within passive pulsing air classifiers was done to estimate airflow patterns near a damper. Analysis of those results shows the significant acceleration of the airflow above the damper. Laboratory trial separations have shown that passive pulsing classifiers are superior to standard air classifiers. Keywords: pulsing airflow, passive, simulation of airflow models, acceleration effect, density

Jan 1, 2005

In this study, the effects of slag compositions, slag amount, temperature, and carbon content of steel on the manganese and phosphorus distribution ratios during converter steelmaking were analysed using the classical regular solution theory, and industrial tests were performed using two 80 t top-and-bottom combined blown converters (duplex melting process). The results indicate that the slag amount, temperature, and carbon content in steel are the main factors affecting the manganese yield when converter slag compositions remain constant. The FeO content of the slag has a strong impact on the manganese distribution ratio, while the slag basicity and MgO content have no obvious effect. The calculations and experimental results show that the phosphorus distribution ratio increases sharply with increasing slag basicity R, but then decreases with the increase of MgO and MnO contents in the slag. The final slag in converter steelmaking should have the following characteristics: 3.5 < R < 4.5, 15% < (FeO) < 20%, and 6% < (MgO) < 8%. The slag amount should be controlled appropriately at the same time. The results of this investigation would be useful in deciding on the application of manganese ore in alloying and identifying the slagging regime in converter steelmaking.

Jan 1, 2014

By L C. Taylor, H U. Lesiste

This is a preliminary study of the statistical variation of the pressures on a target above a buried explosion. The data were taken at various distances from the charge centerline for three heights of the target above the soil and one charge depth of burial. All tests were conducted in saturated sand. They show that peak pressures and times of peaks are neither repeatable from shot to shot nor rotationally symmetric within a single shot. The peak pressure and time of peak at each location can be represented by cumulative normal distributions. The paper describes the means and standard deviations of these distributions at eight distances from the charge center for each height of target. These are used to determine the change in standard deviation of the distribution with distance from the charge centerline and height of target. The effect of scale on the mean peak pressures and times of peaks and on their standard deviations at a single scaled distance from the centerline of the charge are explored using various charge weights.

Jan 1, 2010

By L. Chen, G. A. Brooks, S. A. Nightingale

The dissolution of alumina and magnesia has been investigated using laser scanning confocal microscopy (alumina) and a rotating finger apparatus (magnesia) to assess the effects of temperature, composition and forced convection on the rate of dissolution in CaO-SiO2-Al2O3based slags. The two techniques have differing strengths and limitations, and provide complementary methods for studying dissolution. Alumina dissolution was studied for temperatures from 1477 to 1577°C. Based upon the data, the rate controlling mechanism was thought to be mass transfer control in the slag. The diffusion coefficients for the alumina particles are estimated to be in the range 10-11to 10-10m2.s. MgO degradation for sample rotation speeds of 50 to 800 rpm at 1500 and 1530°C was studied for both congruent and incongruent dissolution. The results show that the rate of dissolution for this is primarily controlled by a diffusion mass transfer mechanism for congruent dissolution except at the highest rotation speed. For incongruent dissolution, the mechanism is much more complex, with the morphology and distribution of the spinel reaction product having a significant effect. At high speeds and prolonged times, mechanical forces played a major role in the degradation process. Keywords; kinetics, corrosion, refractories, dissolution rate, inclusions, mass transfer, slags, steelmaking

Jan 1, 2004

Comparison of Grinding and Liberation Processes for Stalky Biomass Materials as a Prerequisite for Production of Energy Pellets with High Calorific Value Pelletising biomass, especially straw and stalky materials, requires a product specific size reduction and liberation. However, moisture content plays an important role in palletising and also affects the energetic properties of the biomass. The paper illustrates the characteristics of the mentioned type of biomass and specifies the necessities for production of energy pellets. Defined requirements for biomass energy pellets will be shown based on relevant standards. The work focuses on a comparative investigation of the straw fibres after grinding with hammer/impact mill and after the liberation of the straw fibres with twin-screw extruder (two different communition units). A traditional hammer mill as well as an hydrothermal process taking place in a twin-screw extruder were utilised. Results of the grinding and liberation of rye and wheat straw fibres are discussed based on a detailed particle characterisation (particle size and shape distribution). Besides high calorific value the main pellet quality parameters are mechanical stability, abrasion resistance and further combustion technical characteristics. The particle size distribution displayed optimum characteristics for the combustion processes to be carried out in a furnace. The durability of the pellets produced from straw fibres liberated with twin-screw extruder was comparatively better then that prepared with the straw fibres after grinding with impact mill. Particle size distribution, abrasion values and the strength characteristics showed a good correlation with each. The high presence of N and S would result in high NOx and SOx emissions, where as the high concentrations of Cl would corrode the furnace. These chemical properties of the straw would restrict its usage in small scale furnaces.

Sep 13, 2010