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By Paul McAnuff, Alastair Grogan

In Canada, the only vibration regulations which apply across the entire country are intended to protect fish spawning areas. The Provinces and Territories regulate mines and quarries, and are responsible for setting vibration and airblast regulations. Some Provinces have set specific regulations, while others leave these restrictions to the mines inspectors who can set limits on a case by case basis. For the most part, it is left to individual municipalities to regulate blast vibrations and airblast from other blasting activities, which differ from jurisdiction to jurisdiction, and in some cases are not enforced. Blasters working in different jurisdictions have to be aware of the applicable regulations for the area they are working.

Jan 1, 2005

By G N. Phillips

No new goldfields have been found in the Witwatersrand Basin for over 60 years, and one consequence of this is a long-term decline in gold production. Exploration throughout this period has been based on the placer model that infers alluvial transport of gold grains and then sedimentary sorting in the basin; however, there is no viable source for so much alluvial gold and no single sedimentary setting that hosts the gold.An alternative genetic model can now provide a quantified explanation for the source of the gold, and it does not rely on alluvial gold processes. The hydrothermal model can easily explain the source of the Witwatersrand gold as being derived from the background gold at parts per billion (ppb) level throughout the Kaapvaal craton of South Africa. This gold is involved in metamorphic processes, available for solution in metamorphic fluids, and hence may be transported whilst dissolved in fluid into the Witwatersrand Basin. The hydrothermal model warrants consideration as it can explain the source of gold, the large alteration halo in the goldfields, the mineralogy, and especially the gold-carbon association.Working on the premise that if one model (placer) is not giving the desired results (discovery of new goldfields), then it may be prudent to consider alternatives. Application of a hydrothermal model to guide exploration would place importance on large and small early structures in and around the Witwatersrand Basin; it would also emphasise the geochemical nature of potential host rocks (especially C and Fe) rather than their sedimentary origin.CITATION:Phillips, G N, 2013. Origin of Witwatersrand Gold - a viable source region and source process for gold, in Proceedings World Gold 2013 , pp 175-180 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By Milton Manrique

The thermal decomposition of zircon concentrates in a non-transferred arc thermal plasma flow reactor was investigated. The plasma torch was operated using argon-helium and argon-nitrogen mixtures as plasma gases. The effect of power, feed rate and zircon particle size was studied. Products were characterized by XRD, SEM, TEM and chemical analytical techniques. The average size of the product was in the submicron range. Free energy minimization plots were used to predict the behavior of the system under different operating conditions. A kinetic model to describe the different stages of the thermal decomposition process is proposed. The results of this investigation showed a significant segregation process where the zirconia-rich product is collected in the reactor while the silica-rich product is collected in the filter. TEM analysis indicated that silica vapor is condensed on the surface of the zirconia particles.

Jan 1, 1996

By Douglas A. Sloan

AN INCENTIVE or bonus system of payment is commonly used for mine labour. The incentive rates are usually based on the variable units of production, such as dollars per foot of drift advance or cents per ton of ore broken. Portions of the work that must be done to achieve the units of ?production are independent of the production unit and tend to be fixed work for the shift or for the job, irrespective of the production achieved. This fixed work has considerable influence on the equity of incentive rates. The effect of fixed work is to accelerate the loosening or tightening of rates if the production task is over-achieved or under-achieved, and of increasing the loosening of rates loosely set and the tightening of rates tightly set. This gearing of mine contract rates is the reason why changes in conditions, materials, equipment, or methods will change the incentive earnings to a greater degree than would normally be expected. Obviously, therefore, care should be taken in the setting of the task for incentive rates as the gearing makes an inequitable rate even more inequitable.

Jan 1, 1958

By A. V. Bogdanovich

In diamond ores processing, final waste tailings size, rejected to dump, is one of the most important parameters. On one side, it is necessary to minimize losses of diamonds, whose size exceeds 1 mm, on the other side ? to provide for the plant high throughput and sufficiently low capital and energy costs, which is in greater part connected with disintegration process. Extensive laboratory, pilot-scale and commercial-scale dressability studies of different types of diamond ores have been performed at JSC ?Mekhanobr Engineering? in recent years. With that, special consideration was given to determination of the required ores? disintegration size that would provide for a high recovery of diamonds. In diamond ores processing, in order to exclude breaking of large diamonds, stage disintegration is used with regrinding of light fractions and heavy fraction X-ray fluorescent separation tailings. On account of rather weak bonds of diamonds with enclosing minerals, in crushing and grinding of diamond ores, selective disintegration takes place, with aggregates? breakup along plane surfaces of least bonding, which facilitates liberation of diamonds and their transition to free state. Heavy components losses with different sizes of final dump tailings were studied in processing of large samples. It was established, that in order to almost completely exclude losses of heavy components over 1 mm size, light fractions had to be ground to 2.5-3 mm size, while X-ray fluorescent separation heavy tailings of -15+3 mm size do not contain diamonds larger 1 mm in aggregates, and their regrinding does not increase total recovery of diamonds. On the basis of the conducted studies, relationships regarding heavy components and diamonds losses with respect to diamond ores final disintegration size were obtained, providing for more rational organization of the ores disintegration and processing flow sheet. Keywords: diamond, waste tailings size, disintegration process, recovery of diamonds

Sep 1, 2012

By Frederick B. Kuhnow

Harmonic energetic delamination of T2 building is being considered for demolition at a formerly known atomic lab. The T2 building is within a containment structure that is under a negative pressure of -49 Pa (-0.2 inches of WC) so that no remaining radioactive material is leaked out. The T2 containment enclosure is a portal frame-type system that spans east/west over 35.05 m (114’-11 7/8”) and spaced 2.9 m (9’-6”) apart. The west side of the portal frames is supported by a 64 cm (2’-1”)thick concrete wall which is backfilled to the west and open to the T2 basement to the east. The east side of the portal frames is supported by a 61 cm (2’-0”) thick concrete wall that is backfilled to the east and open to the tank farm vaults to the west. A concrete slab-type footing supports both the east and west walls. Transverse walls provide lateral support for the walls as part of the original design. The west wall has an elevated slab that provides further stiffening of the concrete wall between the transverse walls.

Jan 1, 2017

By H. M. Woodrooffe

IT IS WELL KNOWN that chrysotile asbestos from various occurrences exhibits varied physical properties and certain differences in chemical corn position, both of which conditions may have an important bearing on the industrial utilization of the fibre. The usefulness of a harsh fibre in the manufacture of asbestos cement products and of low-iron fibre for certain electrical uses are examples. It is also .possible to obtain a fibre with a texture too harsh and brittle to be of economic value. Much research into the structure of the mineral and to a lesser degree observations relating the water of combination to certain physical properties have ?been reported. This paper is an attempt to show that the pyrolysis of ?chrysotile takes place in three stages and that the conditions of pyrolysis are peculiar to the fibre and may afford some clue to the variations in physical properties of asbestos fibres which affect their utilization.

Jan 1, 1956

By L. Bratek, K. Jaworek, M. Czaplicka

Methods for arsenic compound removal from aqueous solutions include processes such as: coagulation, adsorption, membrane techniques, electrochemical and biotechnology techniques. Advanced oxidation using both UV radiation and strong oxidizing agents such as ozone and hydrogen peroxide may also decompose these compounds. It is known that effluents from metallurgical processes contain inorganic arsenic compounds in addition to the organic compounds such as: dimethylarsinic acid and phenylarsonic acid. This paper presents the conditions that lead to the formation of deposits containing mainly arsenic, such as pH, the wavelength of the radiation and the type of oxidant, for this type of effluent.

Jan 1, 2014

By L. Kilburn

"A survey of 281 mineral exploration agreements examines the ratios among three ways that may be used to purchase an interest in a mineral property, viz: pay cash, pay shares and make future expenditures on the property.The dollar value of the future expenditures exceeds that of cash or shares by about nine times in most of the 110 agreements that contain cash-expenditure or share-expenditure components. Results suggest that cash and shares are treated about the same in terms of value.Buyers and sellers have opposing priorities for the way that they prefer to purchase a mineral property. These opposing priorities should give rise to a perceived 50:50 balance between cash/share payment and future expenditures to satisfy the idealized situation described by most definitions of fair market value (FMV). This balance between cash/share payments and future expenditures appears to be rationalized in negotiations to a FMV when expenditures are nine times greater than cash and/or payments.On this basis, it is proposed that the FMV of a property may be determined by aggregating the dollar amount of the cash/share payments plus one-ninth the dollar value of future expenditures, as set forth in the respective purchase agreement, and proportionately applying such aggregate to full property value."

Jan 1, 2005

By Jaeheon Lee, Junmo Ahn, Isabel F. Barton

"Newmont’s Mike prospect, currently undeveloped, is a blind Cu-Au(-Zn) deposit on the Carlin Trend, containing >8.5 M oz. Au, 1027 M lbs. Cu, and 809 M lbs. Zn as Carlin-type gold and polymetallic Cu-Zn minerals in Paleozoic lower-plate carbonates and shales. This project was undertaken 1) to examine the effectiveness of different lixiviants for leaching the Mike supergene Cu-Au ores via bottle roll tests, and 2) to determine what ore minerals resist dissolution in each leaching agent by comparing the mineralogy and chemistry of head and tail samples. Sulfuric and sulfurous acids were used to leach copper and cyanide was used to leach gold. Thiourea, glycine, and other lixiviants were used to leach both base metals and precious metal. QEMSCAN and SEM study of six samples of different ore types and grades indicate that the Au occurs as varieties of native gold, including auricupride and electrum. Major Cu minerals are native Cu, cuprite, malachite, chrysocolla, and conichalcite (Ca-Cu arsenate), with locally significant Cu in jarosite and goethite. Gangue mineralogy is dominated by quartz, sericite, chlorite, alunite, smectite and kaolinite, K-feldspar, and iron oxides (sensu lato). Results of bottle roll tests and leach residue mineralogy will be presented and discussed at the conference.INTRODUCTION Resource and Geologic Setting The Mike deposit is a large, blind Cu-Au(-Zn) deposit in the Maggie Creek district of the Carlin Trend of Nevada, USA, near the Gold Quarry mine (Figure 1). The mineral inventory, based on drilling, is 8.568 Moz. Au, 1027 M lbs. Cu, and 809 M lbs. Zn at average grades of 0.72 g/t Au, 0.34 wt% Cu, and 2.13 wt% Zn (inventory for a cone at $400/oz Au and $0.80/lb Cu by Norby and Orobona, 2002)."

Jan 1, 2017

By Stephen A. Hare, O&apos

Powder metallurgy processing of commercial Raney nickel powders was examined. The typical angular particle shape, in conjuction with aluminum present in a eutectic phase, facilitated interlocking leading to excellent green strength after compaction. Density and porosity as influenced by the compacting pressure were studied over the range of 37.5 to 207 meganewton per square meter (MN/m2). Sintering in an inert atmosphere from 575° to 850° C caused a volume increase which is attributed to a solid state reaction between Al and Ni2Al3 phases. The reaction is 3Al + Ni2Al3 ? 2NiA13. A thermal pretreatment of 70 hours at 700° C was required to prevent this reaction from occurring during sintering. Density and porosity as a function of compacting pressure and sintering temperature were determined after a thermal pretreatment of the powder.

Jan 1, 1976

By I. A. Agapov, I. S. Anisimov, N. V. Rylov, A. M. Sagitova

"The smelter slags represented silicate crystalline rock with medium to coarse-grained structure with spinifex skeletal network of olivine in hedenbergite matrix. Accessory magnetite, pyrrhotite and copper sulfides chalcopyrite, bornite, covellite, chalcocite and digenite occurred in dissemination in silicate matrix. The sample was studied by optical and electron microscopy with support of quantitative XRD. Modal mineralogical composition included olivine, pyroxene, magnetite, chalcopyrite, quartz, pyrrhotite. Copper deportment showed copper distributed in chalcopyrite (40 %), cuprite (22 %), covellite (21 %), bornite, chalcocite, digenite (5 %), Cu-bearing pyrrhotite (4 %) and spinel (2%). Liberation of copper minerals in the material ground to P80=71 µm was good with over 90 % sulfides in free grains and floatable binaries. The results showed theoretical possibility of 65 % copper recovery by flotation. Conclusion based on mineralogical data was precisely confirmed with flotation tests studies that proved to recover around 60 % of copper to commercial grade concentrate. INTRODUCTION Annual world copper matte smelter slags production is estimated to be millions of tones and contain thousands tones of unrecovered Cu, Zn and significant amounts of Ag and Au. Mineralogical study of one large processing sample of material of historical piles of Cu matte smelter slag was carried out to find possibility to recover copper and define theoretical recovery by flotation. The study of the slag material was aimed to determine possibility of upgrading the material on existing copper flotation plant to develop additional mineral resources. The objectives for mineralogical investigation were to target for best liberation fineness, determine theoretical recovery and possible concentrate quality for sulfide flotation tests. MATERIALS AND METHODS Large representative processing sample was collected by mixing of 120 t of slag material representatively excavated from historical piles of Cu matte smelter slag. The sample was used to define the processing technology to recover copper and gold from the material."

Jan 1, 2018

By Peter Woodall, Paul Telford, Pengfu Tan

"Arsenic enters the Mount Isa copper circuit in the form of arsenic rich minerals in concentrates from both the Mount Isa and Ernest Henry copper mines. Arsenic is a volatile metal, and will partition in the copper smelter between smelter off gases, slag and anode. Most of the volatile arsenic will report to Isasmelt Electrostatic Precipitator (ESP) or Waste Heat Boiler dusts where it will form a re-circulating load within the smelter. ESP dust is produced at a rate of 15,000 - 20,000 t/y and is currently removed from the precipitator and leached in the new ESP Dust Recovery Plant to separate copper and arsenic from the ESP dust. This paper describes the laboratory test works of ESP dust leaching, neutralisation and cementation processes. The planttrial, commissioning and operation have been presented as well.1. IntroductionThe flue dusts generated in the process of copper smelting contain appreciable amounts of copper and other valuable metals including precious metals. These flue dusts also contain appreciable amounts of arsenic trioxide where arsenic occurs in the ore body. The copper smelters processing concentrates generate residuals, such as ESP dust, containing arsenic trioxide. ESP dust contains impurities such as arsenic and bismuth which are harmful to the copper refining process if they report to anode. These impurities are fumed off in the smelting process and report to the dust as arsenic and bismuth oxides.The content of arsenic in the feed of Mount Isa copper smelter is about 0.1 % to 0.4%. Arsenic is a volatile metal, and will partition in the copper smelter between off gases and anode. Most of the volatile arsenic reports to Electrostatic Precipitator (ESP) and Waste Heat Boiler dusts where it will form a re-circulating load within Mount Isa Copper Smelter. Unless arsenic is bled from the smelter circuit, it will build up to a point where both anode quality and smelter hygiene are adversely impacted."

Jan 1, 2011

By L. P. Chrismas

"IN 1975, Nova Scotia produced 1.8 million tons of coal with a FOB mine value of $47.6 million. Of this total, about 30 per cent or 600,000 tons was coking coal and the remainder was steam and industrial-grade coal. The Nova Scotia Power Corporation consumed 630,000 tons in three generating stations and 570,000 tons were sold to Sydney Steel for making coke for its steel operations. Exports, principally to Great Britain, comprised 370,000 tons in 1975 in addition to the 300,- 000 tons shipped to other provinces for use by cement and pulp and paper companies. In 1975, just over 100,000 tons of coking coal were imported into the province from Alberta. Before 1975, low-volatile coking coal was traditionally obtained from the United States. In 1975, production came from seven individual mines and one project involving reclamation from mine dumps in Pictou County. Of the seven producers, four are owned by the Cape Breton Development Corporation, a federal Crown corporation; the remaining three are small independent mines, but, even though small, they are sizeable contributors to the economies of their local areas. After 101 years of continuous operation, Devco's Princess mine was closed in 1975. The Nova Scotia coal industry, in terms of value, accounted for about half of total mineral production in 1975. The industry provides jobs for 3,000 men and women. It is also significant that in 1975 Nova Scotia produced about 6.5 per cent of Canada's total coal production of 28.3 million tons. Detailed statistics on Nova Scotia's coal industry appear in the Appendix."

Jan 1, 1976

By C Rothfuss, X Wang, S J. Herbert, K Prasad

The extraction of groundwater to produce gas from coal seam gas (CSG) reservoirs has highlighted the opportunity for beneficial uses of groundwater in Australia. This paper presents an assessment of alternate groundwater modelling approaches that can be used for assessment of one beneficial use option, that of injection. This assessment examines the outcome of the use of different simulation methods on predictions of hydrodynamic behaviour.In this paper, a simplified hydraulic concept of a multi-aquifer system within the hypothetical injection field was used to investigate the hydrodynamic behaviour of injection into the Precipice Sandstone. Comparisons were made through the analysis of a Theis 3D analytical solution with 2D and 3D numerical solutions. The paper discusses the different solution methods and the impact of these on predictions of pressure and flux. Differences in 2D and 3D solutions result in implications if planning injection as a beneficial use of water. For example, the 2D solution resulted in faster and higher injection pressure build-up when compared to the 3D solutions. The 2D modelling could result in either plans that require higher capital expenditure for a greater number of wells in order to spread the pressure effect and remain below the maximum injection pressure or a reduced injection rate. Meanwhile, the 3D modelling with sensitivity analysis could result in planning for lower capital expenditure for fewer wells required to spread the pressure effect and remain below the maximum injection pressure. CITATION:Wang, X, Herbert, S J,?Rothfuss, C and Prasad, K, 2013. Assessment of effectiveness of artificial recharge for coal seam gas water management based on numerical modelling, in Proceedings Water in Mining 2013 , pp 67-72 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By Charles A. Beasley

Increased technical and legislative analysis by all parties of interest could result in more efficientand better directed regulatory legislation in the mining industry. Efforts to forestall or frustrate legislation through massive lobbying and public relations efforts are seldom effective over time and often lead to more stringent and far reaching legislation than necessary. The Federal Coal Mine Health and Safety Act of 1969 is perhaps an outstanding example of such insufficiences; a future example may well be regulatory surface mine legislation. Although a lack of extensive hard data seldom enables rapid or sophisticated analysis early in the legislative process, even preliminary analysis may be sufficient. Simple statistical analyses of available data, assessment of the legislative rationale, and subjective appraisal of other non-quantifiable constraints to improved mine safety. An average of 115 underground fatalities at an exposure frequency rate of 0.67 can be reasonably expected in the immediate future, under existing levels of technology, degree of regulation, and economic conditions. If gross unrefined estimates of 6 preparation plant, 5 surface, and 30 strip mining fatalities are assumed, the total fatality industry level could be expected to approximate 156 Serious professional, economic, and technical constraints within the the industry probably preclude any major decrease of these accident levels within the near future

Jan 1, 1972

By Xie Hao

According to its raw materials orthogonal test scheme is designed and a large number of systemic experiments were carried out in order to study the sintering characteristics of three types of fine ores in Kunming Iron&Steel Co.Ltd(KISC). The effects of carbon mixture ratio and basicity on sintering time, agglomeration ratio, physical properties and utilize coefficient were researched via single factor analysis and range analysis. The experimental results show the best mixture ratio of each fine ore. Analysis found that the influence of the carbon mixture ratio is more significant than which of the basicity on the sintering process except agglomeration ratio of foreign ore.

Jan 1, 2009

By W. J. González

With the increasing demand for minerals and the decline in the quality of ore reserves, technologies to maximize recovery are critical to a mine?s economic success. Many mining waters exhibit the potential to form hardness-based inorganic scales, which inhibit effective mineral recovery. Often, a continuously-fed chemical deposit control program is implemented by the mine site to inhibit these scales. The use of retractable scale coupons is the current industry standard for monitoring these programs; however, a key drawback to their use is the limited, and sometimes untimely amount of information they provide. A proprietary fouling analyzer has been developed that can be used to continuously monitor the formation of inorganic scales in mining process streams. Consequently, it can be used to continually, and more effectively, communicate the efficacy of an antiscalant program, thereby providing the ability to compare different scale control programs and to optimize their feedrates. Case studies presented validate the applicability of this technology to help optimize mineral recovery.

Feb 23, 2014

By F. E. Joyce, Charles Prasky

This report describes the response to high- temperature sulfatization of a variety of manganese minerals and companion compounds which may occur either as a principal component or as a gangue material in low- grade manganese deposits . Fourteen manganese samples representing oxide , carbonate , and silicate minerals as well as seven compounds which might occur as gangue with manganese minerals were tested batchwise in a bench- scale apparatus under conditions which would be favorable for the sulfatization of manganese . The manganese minerals substantiated thermodynamic predictions and responded to sulfatization but to varying degrees . The gangue materials , MgO , MgCO,, CaO , and CaCO3 , were sulfatized readily in contrast to the iron oxides and the aluminacontaining material which were not .

Jan 1, 1964

By J. Hart, P. W. Conrad, S. Rosenthal, R. A. Hogan

The Mining Engineering Department at Montana Technological University (Montana Tech) has a new Mine Safety and Health Administration (MSHA) approved program for Part 46 and Part 48 mine health and safety training. The training program will utilize the facilities and faculty from Montana Tech’s Mining Engineering and Safety, Health, and Industrial Hygiene departments to provide superior mine health and safety training to the mining industry. The faculty of each department includes professionals with experience in safety training and the mining industry. The training program incorporates adult learning techniques and extensive hands-on activities in all training modules. The instruction will exceed MSHA requirements. The resources available on Montana Tech’s campus will be utilized to strengthen the training program providing the mining industry with a world class mine health and safety training program.

Feb 1, 2023