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By Hunsaker R. D

The description, characteristics, advantages and application of a new bulk explosive for medium to large diameter dry blasthole conditions is described. A brief outline of the delivery system for the product is also included. This explosive has been designed to provide an alternative to ANFO, currently the most common bulk dry hole product available to the mining and quarrying industry. The selection of the optimum explosive for any blasting operation is of prime importance. It is a major factor contributing to the production of the desired results in terms of muckpile fragmentation, shape and diggability. The optimum explosive can be defined as the most cost-effective in producing satisfactory breakage and displacement of the material. ANFO satisfies this prerequisite for a significant proportion of dry hole applications. This unique, low density and low velocity of detonation explosive has been developed to provide the industry with a cost competitive alternative to ANFO. Typical loading or average inhole densities nominally range between 0.40 g/cc to 0.70 g/cc, depending on the application. Characteristics of this explosive allow for specific and common applications in open cut coal and metalliferous operations. These include ore/waste control operations, prestripping and presplitting applications, sites confronting cap rock problems, and large hole diameter quarries.

Jan 1, 1995

By O N. Antzutkin, A V. Ivanov, W Forsl

Polycrystalline and surface complexes (at synthetic sphalerite, ZnS, and galena, PbS) of zinc(II) and lead(II) ions with eight different O,OÆ-dialkyldithiophosphate (Dtph) substances have been prepared and comparatively studied by means of 31P CP/MAS NMR spectroscopy. The 31P resonances have been assigned to dithiophosphate groups with terminal S,SÆ-chelating or bridging coordinations in the mono-, bi-, tetra- and polynuclear complexes respectively. The bridging coordination of two neighbouring zinc(II) ions by O,OÆ-dialkyldithio-phosphate ligands was established at the surface of synthetic sphalerite.The adsorption mechanism of dialkyldithiophosphate on synthetic galena includes formation of a surface complex as well as surface precipitation. Principally different coordination modes of the reagent were discovered at the surfaces of galena and sphalerite (ie terminal S,SÆ-chelating coordination to the lead atom).Derivatives of monothiophosphoric and phosphoric acids were displayed as hydrolysis products of dialkyldithiophosphates at synthetic PbS.

Jan 1, 2005

By Richards JR, Herbert HK

A basic question in preparing this review was how to define sulphur mineral occurrences as being associated with the Pacific Rim. This question will be reconsidered later. The isotope composition of sulphur- containing minerals may be considered in terms of two primary sources - 1. deep- seated sulphur, devoid of crustal contam- ination with a 634S value near 00/0o and 2. oceanic sulphate which fluctuated in value between +10 and +300/00 over geological time (Claypool et al., 1980). However, minerals have seldom been directly derived from these primary sources as even evaporites have been dissolved and reprecipitated. The marine source is differentiated biochemically and isotopically in recent sediments where sulphide from bacterial sulphate reduction may be significantly depleted in 31S. The question of chemical interaction of ascend- ing magma with upper crustal rocks has become one of degree rather than whether or not it occurs. Mineral deposition is considered increasingly in terms of mixing of fluids and their chemical reactions with rocks rather than direct precipitation from magmas or hydrothermal fluids derived from them.

Jan 1, 1987

The development of the Moura Coal Preparation Plant is described, commencing with the first'stage of the plant commissioned in 1963. The subsequent expansion stages are traced through to October, 1973. The plant has undergone frequent stages of expansion and modification and this process is continuing. The development programme for 1974 is described as proposed in late 1973. The characteristics of the Moura and Kianga field coal seams with respect to washability are summarised and some comment is made on the blending of these coals prior to washing, to ensure production of export grade coal within specification.

Jan 1, 1974

The present stage of economic development of the Broken Hill lode, attained after 40 years of active exploitation, leaves little opportunity for the study of the zone of secondary sulphides.Little remains of the oxidised zone, and the observations of the secondary sulphides of copper and silver can rarely be made on specimens collected in situ. A few specimens containing secondary...

Jan 1, 1927

By I Gipps

The mining industry has come through a period of major change in community expectations regarding safety and environmental impact and these changes can be expected to continue in the future. These changes are ultimately reflected in Government regulations and industry safety standards and form the basis of the ælicense to operateÆ. Equally, advances in technology have made possible new equipment and processes either available now, or close to completion, that will allow mines to meet these more stringent expectations if properly introduced. Changes in technology provide opportunities for mine management to introduce new systems that will remove people from hazardous areas and lead to improvements in the ætriple bottom lineÆ. In a longer time frame of five to ten years, novel and advanced technologies that are currently being developed will deliver new mining methods and conversion of presently uneconomic resources to ore. This is consistent with the time frame required to develop a new mine from discovery. Strategic decisions can be taken now by mine designers to enable the introduction of these major technology changes. Examples of both practical and strategic opportunities are drawn from the integration of rock cutting/blasting, automation, electronic communications and new mining methods. This paper discusses emerging industry trends, changes to legislative framework and some practical choices for existing and imminent technology.

Jan 1, 2003

Many volcanoes in western Melanesia have tectonic settings and rock compositions that do not conform to conventional models of arc- trench systems. Part of the reason for this may be that in an environment of rapid tectonic change mantle source regions bear the imprint of former subduction even though subduction has now ceased. Results bearing on this concept and on other important aspects of Plelit nesian v ican ism and tectonics, were obtained in 1982-1986 from >e,:eral marine - geoscience studies in the re,,ii n

Jan 1, 1987

By Chen Z, Dong H

This paper describes the autogenous carrier flotation of 0 - 20 ¦m ilmenite using 40 -- 80 }tm ilmenite as carrier. Investigation is made of the influence of main technological parameters on autogenous carrier flotation. The mechanism of autogenous carrier flotation is discussed using extended DLVO theory. The main conclusions are as follows: 1. the smaller the fine particles the more easily they adhere.to carriers; 2. the selectivity of autogenous carrier flotation depends on the selectivity of adsorption of collector. In the autogenous carrier flotation of ilmenite/plagioclase mixture assaying 15.35 per cent TiO2, a concentrate containing 47.17 per cent Ti02 can be obtained by primary separation with a recovery of 93.05 per cent. KEYWORDS: Autogenous carrier flotation, extended DLVO theory, ilmenite, styrylphosphonic acid.

Jan 1, 1993

Mine reconciliation is the practice of comparing the tonnage and grade of material processed by the mill with the tonnage and grade of ore in the reserve model of a deposit, and with the tonnage and grade in the grade control models used to de

Jan 1, 1998

By T Peglas, A de Aboitiz

The Queensland Government, via the special purpose company vehicle û City North Infrastructure Pty Ltd û is currently developing BrisbaneÆs Airport Link underground toll road and Northern Busway (Windsor to Kedron).Airport Link is a predominantly underground toll road planned between BrisbaneÆs northern suburbs, the airport and the Brisbane Central Business District (CBD) frame. The Northern Busway forms part of BrisbaneÆs expanding busway network, sections of which will be jointly delivered with Airport Link. Airport Link will connect the North-South Bypass Tunnel, Inner City Bypass and local road network at Bowen Hills to the northern arterials of Gympie Road and Stafford Road at Kedron and Sandgate Road and the East-West Arterial in the cityÆs north-east. The Northern Busway is a two-lane, two-way bus-only roadway proposed to connect the existing Inner Northern Busway at Herston with Windsor, Lutwyche, Kedron, Chermside, Aspley and Bracken Ridge. Airport Link and Northern Busway (Windsor to Kedron) is one of the largest infrastructure projects planned in the first phase of the State GovernmentÆs South East Queensland Infrastructure Plan and Program. The paper will provide an overview of the projects, including a discussion on the technical and environmental aspects as well as the procurement of the Airport Link as a public private partnership.

Jan 1, 2008

By Whiting AN

Major changes in the world in recent years are changing the criteria for selection of future developments. Oil prices soared during the 1970's while commodity prices including metals and minerals fell. Many new independent nations, have been created and now control the resources in areas which were once part of great colonial Empires.

Jan 1, 1983

By Belton G. R

The kinetics of the interfacial reaction of H2O on liquid silica-saturated iron silicates has been studied by means of measurement of the HDO-H2 isotope exchange reaction. The apparent first order rate constant, ka, was found to be inversely proportional to the H20/H2 ratio, consistent with two electron (melt to adsorbed/dissociating molecule) transfer mechanism and can be given by the expression In ka = -1.97 x 104/T + 1.57 - ln(pH2O/pH2), where the units for ka are mol cm -2 s-1 atm 1. The results of the current study are shown to be consistent with the indirect measurements of earlier work.

Jan 1, 1987

By A K. Bayer

When the human eye fails in the evaluation of quality parameters in the extraction of minerals the use of laser-induced fluorescence analysis (LIF) can supply more detailed information on the composition of rocks. On the basis of measurements of selected raw materials engineering concepts for the use of this method in the mining industry as an innovative system for horizon control of mining machines will be described and the most important analysis parameters, influencing factors and interference variables are presented.

Jan 1, 2003

By Heath E, van Calsteren P, Turner S, McDermott F

U-Th isotope studies of recent volcanic rocks may be used to evaluate the depths and rates of melt generation beneath mid- ocean ridges and ocean islands. Island arc rocks exhibit a similar range in Th isotopes to that seen in both MORB and OIB, but while those with high (230Th/232Th) tend to have excess 238U, many of those with low (230Th/232Th) are in isotope equilibrium. The excess 238U is attributed to the preferential mobilisation of U in hydrous fluids from the subducted slab within the last 100,000 years, whereas the low Th isotope ratios in the higher-K arcs are primarily due to the introduction of subducted sediment. Preliminary results from mineral separates from lavas on Soufriere on the island of St. Vincent indicate that some of the minerals crystallised up to 50,000 years prior to eruption.

Jan 1, 1995

By Prakash AJ, Singh PK, Dhar BB

Safety and stability of underground mine openings, coal pillars and water dams in the near vicinity of operating surface mines are endangered from excessive blast induced vibrations. This paper deals with the investigations carried out in four coal mines. Simultaneous measurements at equal distances from the source indicated higher level of vibration on the surface than those produced in the underground workings. The values of peak particle velocity (PPV) measured on coal pillars, body of water dam were lower than those measured on roof and junctions of the roadways. The parting of coal (3-4.5 m) between two sections vibrated with higher PPV compared to the roof of top section and floor of bottom section. In one case the influence of total charge fired in a round was significant in generation of vibration compared to the maximum charge/delay where monitoring was done vertically below the source.

Jan 1, 1995

By D Cohen, A Wurster

Many Southern African mining operations produce mine water which is beneficially and productively utilised on the mine sites and to support other water uses. Mine water treatment typically takes place within the context of integrated mine water management involving pollution prevention, waste minimisation, recycling and reuse as well as river discharges. Development of new and improved mine water treatment has focused on the neutralisation of metals removal, desalination of high sulfate waters and passive treatment. Mine water neutralisation processes now incorporate a combination of natural limestone and lime treatment, as well as features to maximise gypsum precipitation. The South African CSIR developed a suite of limestone-based neutralisation processes, which include reuse of CO2 and CaCO3 generated in the process. Desalination of high sulfate mine water is typically done using one of the following technologies:biological sulfate removal with different approaches to the handling of the sulfide generated in the process, and ultrafiltration (UF)/reverse osmosis (RO) treatment with different approaches to the handling and disposal of the brine. The current research and development focus is the separation and recovery of saleable products from the treatment residues and brine streams.

Jan 1, 2006

By Smith I. T

Mine operators have long recognised that the results achieved in primary blasting are critical to subsequent mining activities. With the introduction of "in the hole" drills under- ground and the advantages offered by the use of water gels in conjunction with ammonium nitrate-fuel oil (ANFO) explosives, new mining methods have been developed and enabled improvements in older methods. Pumpable water gels have been used with varying success underground. These gels allow a high loading density even in ragged bore- holes. The problems encountered with slumping in upholes is recognised so the current trend is to use these gels in downholes where wet holes are prevalent. Cartridged water gel technology has advanced to the point where it has allowed the replacement of nitroglycerin (NG) based explosives and pumpable water gels. Today, gels can be made as a tampable product for use in development headings or as a slump- ing product for downholes to give an effective coupling. With the introduction of the Tovex« pneumatic loaders, the problems associated with a pumpable gel were eliminated and gave the user the ability to alter his loading density.

Jan 1, 1977

By A Bonani, R Molina, H Constanzo

With conventional undercutting sequence the infrastructure on the production level often has a short serviceable life before major rehabilitation is necessary and is characterised by high maintenance costs. The abutment stress zone is the main cause of this situation. The application of the pre-undercut caving method variant can increase the availability and utilisation of the production level When a pre-undercut is used development and construction are carried out underneath a previously undercut area, far away from the abutment stress zone, under more favourable stress conditions. This paper describes the design principles and the relevant results from the application of the pre-undercut variant over three years to the Esmeralda sector of El Teniente mine. The aspects described are the undercut-extraction, the undercut-development and construction distances, the geometry and drawbells opening, cave extraction rates, and the rate and height of undercutting.

Jan 1, 2000

P.IISTRACTThe Pacific Rim is advantaged by the uniqueness and diversity of its geological features. Why then is geology given so little regard in the education systems of the countries of this region? Not that these countries differ greatly from those in other parts of the world. Papers presented during the Precollege Geoscience Education session at the 28th International Geological Congress (28th IGC) held in Washington, July, 1989, indicated strongly that the problem is universal. There is a marked decline in interest in the Earth sciences and many nations are looking towards methods that might change this trend. Problems affecting geological education include the lack of purpose and direction, its obsolete curricula and the difficulty in attracting gifted students.The world-wide plight of geology comes at the very time when it should be fundamental to a public understanding of the global effect of human population pressure. There is a universal awareness of "the environment" but very little awareness of the science that has supplied most of the data. Geology, as the science of the Earth, is of paramount importance to an understanding of our life on this planet, particularly in its role as the source of our every need.

Jan 1, 1990

By Pollard DM, Willis GM

The removal of bismuth from liquid copper in a vacuum furnace was studied over a range of pressures. The rate determining step changes from diffusion in the gas at pressures above 0.2 Torr to approach the Langmuir evaporation rate at pressures of 10-2 Torr. Oxygen and sulphur were found to have a negligible effect on the rate. Bismuth removal from copper sulphide was found to be considerably slower than from copper. This is consistent with the known thermodynamic properties of ternary sulphide melts.

Jan 1, 1980