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By Mishra BK, Agrawala S

The traditional method of scale-up uses the population-balance model. In particular, the selection function values for a material are determined in a laboratory mill and a variety of correlations are used to scale these values to plant scale mills. For example, the factor D2-5L (D-mill diameter, L-mill length) appears in many power correlations. The number of collisions is proportional to the number of balls (aD2L), the frequency of mill rotation ((x 1/4D-) and effectiveness of impact ((XD), which gives rise to the 'D2.5L' expression. However, what is lacking in this expression is that it does not throw light on the intensities of collisions. In other words, the collision intensities in both laboratory and plant scale mills are implied to be identical. This fact has been very limiting. Alternatively, the collision frequencies and intensity of impacts can be computed with the discrete element code. This code computes the motion and collision of each individual ball in the ball charge. Therefore the number of collisions and the fraction of collisions in the energy range Et, E2.òòE. (collision energy density) are calculated for a given mill size and operating conditions. Then, using the breakage function determined in drop-weight experiments, the evolution of size distribution is computed for a lab mill. The collision frequency and energy density for larger mill sizes are shown. The fundamental theory outlined for the calculation of size distribution is equally applicable for the large mill, which is the basis for scale-up.

Jan 1, 1993

The impact of moves to introduce Abori- ginal land rights was felt in the Northern Territory as early as 1972 when the Federal Government froze the processing of all appli- cations for mining interests over vacant Crown land. The Aboriginal Land Rights (Northern Territory) Act was finally proclaimed on Aust- ralia Day 1977 and since that date the mining industry and the Territory legislature have struggled to make the Act work. Despite these efforts long delays have been experienced by those required to negotiate mining and explor- ation agreements under the Act. In fact explor- ation on Aboriginal land has been effectively stiffled since the introduction of the Abori- ginal Land Rights Act. The Northern Territory government and the mining industry have both sought amendment to the Act to remedy some of its more onerous problems. These efforts have generally been fruitless. Some of the recommendations put forward by Mr Justice Toohey following his recent review of the Act would provide relief in some important areas. However, any such improvements are more than offset by a number of Mr Justice Toohey's recommendations which would severely disadvantage the vast majority of Territorians. A recent survey of mining companies seeking exploration licences over Aboriginal land indicates that many of the existing diffi- culties could be overcome without significant amendment to the Act but rather by the adoption of a positive administrative approach by the Land Councils. It is now up to the Commonwealth and the Land Councils to demonstrate that their Act can work without crippling the Northern Territory economy and its mining industry.

Jan 1, 1984

Urban railway systems need high invest- ments, especially if their routes and stations have to be placed in the subsurface. In the FRG the construction and equipment cost of urban underground railway systems are in the range of 60 to 100 Mill DM per km tunnel. For this reason, track sections on the surface and on elevated structures are used as far as that is possible. Considering whole systems, the costs are in a range from to 45 Mill DM per km length for a metro system with about 80 % of its tracks and stations in tunnels and from 20 to 25 Mill DM per km for a light railway system with about 25 % subsurface infra= structure. The amount of route lengths in tunnels depends on the size of a city, the situation regarding above ground structure and free space on the surface, the level of service quality which has to be achieved with the railway system etc. Despite of the urgent needs to improve the transport conditions there very often arise doubts if an urban railway system is really necessary and can be justified in an economic sense. The experience from many cities around the world shows, that there arise a lot of benefits from urban railway systems, especially with larger sections placed under- ground. They are to be found in the interests of the operator (f.e. operating costs), the user (travel time, quality of service etc.) and regarding social aspects (environmental protection, accidents, consumption of energy Etc.).

Jan 1, 1987

By Adhikari G. R, Raju N. M

The breaking of rock by explosives occurs so rapidly that the details of the phenomenon cannot he observed by the unaided eye. High resolution cameras and VCRs offer a means of slowing down the blasting action. A high resolution super video camera with digital zoom and a variable shutter speed was imported and used for the first time in India as a tool for blast optimisation studies at Malanjkhand Copper Project. Slow motion play-back revealed that the gases vented out through the fissures. The crest moved prior to the lower portion of the bench when initiated with detonating cord. The delay timing between the rows was not enough to provide sufficient relief and rock movement. This inadequate delay timing resulted in flyrock from the back rows. Stemming ejection was observed from practically all the holes. The muck profile was not satisfactory. A trial was carried out using 450 ms in hole delays and 25 nis surface delays. The front row holes were drilled based on the observations made from the laser profiling survey system. The video of the monitored blast showed that the rock started moving prior to the stemming ejection. It could be clearly seen that the entire block was completely initiated through the surface delays before the onset of the burden movement, thus eliminating any chance of misfires. Viewing blasts in high quality slow motion was useful to arrive at modified design parameters, resulting in uniform fragment size distribution and controlled rock movement.

Jan 1, 1995

The paper deals with the taking of soundings in connection with coal mining operations under part of the Pacific Ocean adjoining John Darling Colliery.INTRODUCTIONIn the early days of mining in the Newcastle District there did not appear to be any definite law specifying the limits to which mine workings, other than certain borings, could extend under tidal waters.As time went on, a figure of 120 ft. was fixed as the minimum thickness of strata between the roof of the seam and the sea bottom; beyond this mining operations are disallowed. The laws relating to working coal under tidal waters are as follow:-The minimum width of pillars to be left shall be eight (8) yards and the maximum width of bords or other excavations shall be six (6) yards, but the lessee may at his discretion increase the minimum width of the pillars or decrease the maximum width of the bordsor other excavations so as to increase the general safety.The eight (8) yard pillars shall be left unwrought.In on-road of every pair of Winning-off or leading headings, a bore shall be kept going ten (10) feet in advance for the purpose of foretelling the presence of any fissure, wash-out, open joint, fault, dyke, or otherwise, and all winning-off headings shall be driven atleast one hundred (100) yards in advance of the working bords.The most accurate and trustworthy information shall be obtained by the lessee not only' of the depth and character of the ocean bed, river, lake, or estuary deposit, but also of the strata overlying the coal seam.When working under the ocean, strata shall be bored through and proved a minimum thickness of thirty (30) feet at the face of the leading headings or levels immediately such headings or levels are under the ocean, and...

Jan 1, 1947

By Aspinall T. O

Draglines have found wide application in strip mining coal seams down to 60m depth. A research Project funded through NERDDC has been underway during the past two years investigating the application of large draglines loading overburden into hoppers feeding into conveyor systems or off-highway trucks. This paper presents the preliminary results of these investigations and covers overburden characteristics, bucket spotting con- trol, bucket design, conceptual hopper systems, system application at representative mine sites, and broad process comparison. The studies have initiated new concepts in the extended use of draglines at deeper strip- ping depths. Alternate arrangements for dragline bucket rigging and bucket control aspects of dragline stripping operations offer productivity improvements. Extended use of existing draglines includes, draglines dumping into hoppers which feed large trucks or conveyors, trigger dump buckets rigging arrangements, and rear dump dragline buckets with integral grizzly bars. The paper details these suggestions, and points to specific areas where the most productive applied research is anticipated. Mine planning considerations detail the factors involved in selecting dragline bench heights in association with hopper operations.

Jan 1, 1989

Australis Mining N.L. operates a continuous mode carbon-in-pulp (CIP) gold plant, processing sand and slime tailings from previous gold mining operations in the Norseman area. Plant design is that of conventional countercurrent contact between pregnant pulp and activated carbon. Gold desorption is achieved by the Zadra process using near boiling tempera- tures and atmospheric pressure. Process water is drawn from nearby Lake Cowan (saline). The plant operates at, or above, design specification of 400 dry tonnes per day. This paper describes the plant design and operating processes utilised in optimising throughput and gold recovery. TNTDnPTTnmTnM Favourable world gold prices and substantial reserves of sand and slime tailings prompted Australis Mining N.L. to construct a gold extraction plant during 1981. The projected plant throughput was set so as to complete treatment of available tailings over a three year period. Metal- lurgical tests indicated that, with a regrind facility satisfactory gold recovery could be achieved using a countercurrent CIP process. Reflecting the entry of Australis Mining N.L. into its first large scale treatment operation, the plant design emphasised simplicity but effectiveness of Operation.

Jan 1, 1982

By Hawes GW

Until 1980 copper, lead and zinc sulphide slurries have been success- fully dewatered for rail and sea transport for many years at the Rose- bery site of North Broken Hill Holdings Ltd. utilizing conventional vacuum disc filtration systems. An upgrading and mill expansion program completed in 1981, which also permitted the introduction of ore streams changes, had resulted in difficulties dewatering copper and lead sulphide slurries to comply with transportable moisture limits. Following an extensive investigation which included both laboratory and pilot plant testing a program was commenced to replace the 2 vacuum disc filtration systems with 2 pressure filtration systems for use on copper and lead slurry dewatering and also to retain other existing vacuum disc filters as standby. An analysis of mill operations performance resulted in slurry storage tanks with a capacity equivalent to 20 hours of normal production being incorporated into the project. The pressure filters are mounted above the concentrate stock- piles. A sealed sloping floor incorporating launders is used to prevent any accidental contamination of the concentrate from pipe leakages, spillage, or from water hoses used for clean up purposes around the area. The project was completed in 1985 and operating performance has been better than that predicted from testwork. Equipment availability at 95076 together with the slurry storage capacity provided results in minimal requirement for the standby vacuum filtration system. Some typical operating results are given.

Jan 1, 1988

By D A. Collins

The floatability methodology developed by the AMIRA P9 project through research contributions by the Julius Kruttschnitt Minerals Research Centre (JKMRC, Brisbane, Australia), University of Cape Town (UCT, Cape Town, South Africa) and McGill University (Montreal, Canada) has been successfully commercialised through JKTech. The methodology involves detailed flotation plant campaigns which require large quantities of data to fit models that can be used in JKSimFloat (a steady state simulator for the flotation process). The methodology to date, although widely accepted as the best flotation optimisation technology available, is limited to existing circuit optimisation and requires full plant or pilot plant data to calibrate new models. The floatability of new ore types cannot be characterised using this method unless a pilot campaign is undertaken. After reviewing a large database of existing industrial floatability data, a new methodology is proposed that involves a laboratory based flotation test procedure and review of the floatability database to characterise the floatability of new ores. The full methodology is labelled the floatability index test procedure (JKFIT). This paper outlines the JKFIT procedure and the results of applying this methodology to pilot plant data from a copper ore. JKFIT was applied to two different feed sizes (namely a P80 of 180 microns and 212 microns) of this copper ore. The results of applying JKFIT to this case showed that the metallurgical response (in terms of grade and recovery) from the full pilot plant survey data could be predicted well. Further validation of this methodology was conducted on a separate copper ore. The results from this validation also showed that the JKFIT test was able to be used to predict the full plant performance. The JKFIT test has the potential to become the 'drop weight' test of flotation which will improve the confidence in plant design flow sheet layouts, allow full orebody characterisation and prediction of key grades and recoveries before the ore enters the plant, and will provide an improved methodology for chemistry impact analysis on different ores.

Jan 1, 2008

By M Castle, D Mendelawitz

The Marra Mamba iron ore in FortescueÆs Chichester Range project area occurs as a very flat dipping series of waste shale and iron ore beddings. These beddings vary from millimetre thickness to several metres. The ore material generally exhibits a moderate degree of competence when subjected to ultimate compressive strength (UCS) tests, normally failing at up to 60 Mpa. However, the strength of the beddings is markedly less when subjected to the tensile forces imposed by the cutting action of the surface miner. Two surface miners of differing age and sizes were tested over a period of almost three months. These machines produced a product that had not been subjected to dilution by blasting and of such a size that primary crushing is not required. The machines were able to cut all ferrous material presented to them with varying degrees of success. Material containing higher quantities of manganese were broken but caused catastrophic wearing of the picks. During the trial the volume of material produced by the two machines in various strength materials very closely matched the manufacturerÆs estimates. The major impact on costs per tonne related to the wear on bits, which in turn varied with the bit design and composition. Bit design and composition testing is continuing.

Jan 1, 2007

By Doxford CI, Perry AJ

Mining Lease 908, situated on Gorge Creek near its confluence with the present Cape River system, has been subjected to intensive recent exploration for alluvial gold.The gold is hosted by a buried palaeochannel, the Gorge Creek Lead and by an overlying remnant meander of the Cape River. The principal, if not sole, sources of gold within the Gorge Creek Lead are the northwest trending Great Australian Reef and Green's Specimen Reef systems which are situated on adjacent high ground. Lower grade gold bearing eluvial ground separates the reefs from the Gorge Creek Lead. The sources for gold within the old Cape River system channel (Canton Lead) are thought to be situated some distance upstream, one source perhaps being the Lolworth Diggings located 30 kilometres to the northwest.Exploration of previously "heavily dug" ground on both leads consisted of detailed geological mapping followed by the collection and treatment of bulk samples from eight costeans. The wash samples varied in size from 120 to 396 cubic metres. Treatment was undertaken through a commercial sized conventional wet screen and jig plant.

Jan 1, 1986

By Boyle L. A

A positive displacement pump is being dev eloped for pipeline transportation of coking coal to a -50 mm export specification, at a con- centration and velocity which will allow trans- portation in the plug flow region, minimising degradation of the particle structure, and pipe= line friction losses which will be lower than with turbulent or laminar flow. Pump operation is by hydraulic powered free pistons in a rota- ting cylinder block, with cylinders overlapped by stationary inlet and discharge ports in a water lubricated and sealed rotary valve. Before this development coking coal was not considered suitable for transportation in slurry form, for the valves in the double act- ing duplex piston pumps used for slurry pipe- lines, cannot be divorced from the slurry and require that the solid material must be reduced to a fines'consistency before introduction into the pump suction. The hydraulic transportation of 10 million tonnes of -50 mm coking coal, 50 km from the Bargo area west of the escarpment to an offshore shiploader at Port Kembla is feasible. Study shows that economic factors alone would dictate that the development of a pumping system for long distance transportation of coking coal is necessary. The greatest impact from the slurry transportation of coking coal would be the

Jan 1, 1976

By M Stewart, J Vann, S Dunham

Geometallurgy is an emerging, cross-disciplinary field that integrates spatial models of rock properties with time-based outcomes of mining and treatment processes. Geometallurgical variables include any rock property that has a positive or negative effect on the business. Some of the more critical geometallurgical variables include recovery, grindability, throughput, power consumption, mineralogy and content of deleterious materials. These variables drive project costs and revenues in a fundamental way and thus geometallurgy has potential to positively impact on the value of strategic and tactical decisions across many mining organisations. Geometallurgical models, like traditional grade-only models are based on samples collected from the mineralised and non-mineralised regions of the deposit. The nature of some non-grade variables, particularly those that are dependent on the ore treatment processes, requires special consideration during sampling and subsequent spatial modelling. Failing to objectively consider the characteristics of variables may seriously compromise the validity of the sample selection, sample treatment, data models and the subsequent decisions. In addition to addressing the vexed question of collecting an æunbiased and representativeÆ sample, the sampling and modelling approach must consider issues of scale, both geostatistical support and also the relationship between bench-scale data and operational-scale mineral processing performance. This paper proposes a framework (the Primary-Response framework) for the classification of geometallurgical variables. This framework is designed to assist with developing sampling approaches and identifying the most appropriate spatial modelling approach. The proposed framework can also help identify the risks associated with designing, sampling and modelling of both types of geometallurgical variables. The Primary-Response framework divides variables into two categories; primary variables and response variables. How a variable is classified in this framework depends on the degree to which the variable reflects either an intrinsic attribute of the rock (æprimaryÆ) or its response to measurement processes (æresponseÆ). Depending on the classification in this framework, appropriate sampling and modelling decisions can be made to minimise the risk associated with the incorrect treatment of the variable. In particular, the authors argue that for response variables, the approach taken to building spatial models may need to be different to conventional linear averaging approaches (for example kriging).

Jan 1, 2009

By Y Yang

Despite the importance and usefulness of basicity in metallurgical slags, the optimum quantitative expression of it has remained elusive, partly due to the fact that the precise concept of basicity has not been properly clarified. The two basic approaches to the concept of basicity are the Lux-Flood, which perceives basicity in terms of the activity of the free oxide ion, aO2-, and the Lewis, which perceives basicity in terms of the ability to donate negative charge. The former has been almost universally adopted in the area of metallurgical slags, while the latter has been increasingly accepted in the field of glass chemistry. In this paper, some difficulties of the Lux-Flood approach are pointed out, including the need for indirect measures of aO2-, which have proliferated in recent years. Accordingly, it is suggested that the Lewis approach has a good deal to commend it, and that the quantification of it in terms of optical basicity is the best measure of basicity available, which should therefore be more widely applied in metallurgical slags than it currently is. The fact that there are intrinsic problems in evaluating the optical basicities for the transition metal oxides is acknowledged, and a new scale is recommended. The patterns of iso-optical basicity lines in ternary systems are shown to agree well with the pattern of iso-activity and iso-capacity lines under appropriate conditions.

Jan 1, 2000

Valuers will often intuitively express the probability that property value will exceed a certain amount . . . 'I think the chances that the value will exceed $50 million are excellent. The chances that they will exceed $80 million are poor'. This paper shows how it is possible to combine the uncertainties of the value of several key items to provide an estimate of the probability of a certain overall value being achieved. The valuation of a large copper/gold deposit was naturally influenced by uncertainties in the base assumptions of costs and metal prices. Potential acquisition of the property through share purchase raised the issue of what was a reasonable intrinsic value for the shares. Market considerations could be used to appropriately adjust the intrinsic value. After a range of possible metal prices and operating costs were determined, estimates were made of their probable distributions. By combining these probabilities in a random selection, a range of property values was calculated. Each value had its respective probability of occurrence. This allowed a most likely value of shares to be calculated. This paper demonstrates how the valuer's intuition is complemented by numerical analysis.

Jan 1, 1994

By J C. Diaz, C R. Scherpenisse

Blasting represents one of the most relevant unit operations in the process of mineral extraction. The final objective of this operation is that of obtaining an adequate final fragment size distribution such that the combined costs of drilling, blasting, excavation and transport, and crushing/grinding, are minimised, while at the same time producing the minimum possible level of damage to the surrounding rock mass. The strong influence that drilling and blasting has over the subsequent processes involved in the operational cycle makes it imminently desirable to have access to experience and technology which make possible the evaluation and optimisation of this unit operation. The correct use of vibration monitoring techniques offers a number of benefits in terms of their ability to examine any blasting process in detail. In effect, the measurement of particle velocity levels that result from the detonation of each explosive charge offers a means by which it is possible to measure relative efficiency of each charge, interactions (productive and counterproductive) between adjacent charges, and a definitive indication of general performance of any given blast design and its implementation. In this way the monitoring of blast vibrations in rock due to the blast event, can be used as a diagnostic tool, given that the correct interpretation of the vibration traces allows the determination of the level of interaction between the design and operational variables of the blast event. This makes it possible to evaluate, for example, the presence of out of sequence detonations, statistical scatter in the detonation times of pyrotechnic delay detonators, deficient detonation of charges, instantaneous detonation of charges and sympathetic detonation of charges, as well as the general of vibration levels in terms of peak particle velocity, acceleration, and displacement. Another important use of such data is in the construction of a database relating vibration levels to charge weight, hole diameter, and distance, for any given rock type, enables the calibration of predictive vibration models which in turn make it possible to predict the damaging effects of blasting. Knowledge of both the vibration levels induced, combined with quantitative measures of the geomechanical competence of a rock mass make it possible to estimate the probability of producing blast induced damage. The high levels of vibration generated by some blast events may damage the rock mass, producing new fractures or extending and dilating existing fractures. The vibration in this context may be considered as a dynamic stress provoking strain in the rock mass. This paper describes the application of the vibration monitoring technique, particularly in the underground mining environment, and its importance in diagnosis, modelling, control, and optimisation of the development blasting process. The potential of the technique is assessed in the context of achieving substantial techno-economic improvements development blasting results, increasing output whilst minimising the operational costs of the mining process.

Jan 1, 1999

By G Solly, P J. Leevers

Day-to-day operating practices at existing operations need provide high quality data for decisions that will impact directly on the potential value of the available resource, in addition to meeting standards of quality expected of data used in feasibility studies that will be completed to obtain additional capital required to finance operational improvements. Drill hole location, down hole survey and assay data standards of accuracy and precision have received considerable attention in recent years. The authors propose that geological descriptions of both cored and non-cored drilling warrant at least equal attention, considering their fundamental role in establishing the framework used for geological modeling and resource estimation. The iron ore deposits of the Middleback Ranges have been a major source of iron ore for almost a century. High-grade hematite-dominant ore is currently mined by OneSteel from three open pit operations supplying ore to the companyÆs integrated steelworks at Whyalla. A review of OneSteelÆs future iron ore resources, commenced in 2002, highlighted the need for more flexible and comprehensive management of all forms of geological data used in resource evaluation. Driving this program was the information needs of feasibility studies of the Iron Magnet deposit, located beneath the existing Iron Duke and Iron Duchess mines. Prior to the beginning of 2003, resource evaluation drilling data collected by OneSteel was managed using an in-house system based on industry standard relational database software. The system was demonstrably effective in ensuring the fundamental integrity of basic drilling data, but lacked necessary capabilities for the acquisition and management of geological descriptions, geotechnical and geophysical data obtained by down-hole logging. OneSteelÆs existing system for the management and interpretation of geological descriptions was restricted to storage of a single three digit code for each lithological description interval. The original logs for a large number of older drill holes could not be located, having been either poorly archived or culled from the database in the belief that they did not contribute to the understanding of the resources currently being mined. The three digit codes represented a combination of lithological and stratigraphic descriptions, including many subtle variations in iron ore colour and texture believed to be associated with variations in geochemistry, but subsequently demonstrated to be either incorrect or inconsistently applied. This resulted in the establishment of a plethora of codes for a relatively small number of distinct lithologies. Improvements implemented by OneSteel geologists addressed these shortcomings by ensuring the new data management system: facilitated the objective description of lithological characteristics; distinguished between obsevations and interpretations (eg lithology versus stratigraphy); promoted consistency between descriptions provided by different geologists; and helped to ensure data integrity by developing an audit trail for alterations made to data subsequent to its acquisition. The data used to develop interpretations of mineralisation distribution and characteristics are fundamental to the effective utilisation of a mineral resource: any mineÆs most important asset. Resource related risk is widely recognised as the principal source of technical risks affecting resource development projects, whether they are new mines or expansions of existing operations. A key lesson from this work is that most commercial or æin-houseÆ developed geological data management systems are able to handle basic data validation tasks effectively. Geologists, however, need to ensure that the data management system is appropriately structured to help promote the acquisition of objective and consistent data for interpretation.

Jan 1, 2003

By Smart RST C, Johnson NW, Ralston J, Griffin LF

At the Copper Concentrator of Mount Isa Mines, the largest diluent of the copper concentrate is liberated fine pyrite. Laboratory flotation tests carried out as a function of grind and flotation Eh in combination with surface analysis by X-ray photoelectron spectroscopy (XPS) have identified the major mechanisms of iron sulphide flotation. It was found that a significant proportion of the iron sulphide minerals had surface coverages of graphitic carbon, sufficient to impart moderate hydrophobicity in the absence of collector. A smaller, but economically significant proportion of chalcopyrite was also affected by the graphitic carbon coating. Two methods were tested to reduce the impact of the natural floatability of the iron sulphides on concentrate grades. 1. Depression through the use of organic depressants. 2. Preflotation to remove the "naturally hydrophobic" iron sulphides (flotation independant of Eh ) prior to chalcopyrite flotation. Preflotation was tested at the pilot plant scale. It was found that the amount of chalcopyrite reporting to the preflotation rougher concentrate could be minimised through flotation at a mildly reducing Eh by the use of nitrogen as the flotation gas to maintain the low Eh conditions resulting from grinding. The preflotation rougher concentrate was upgraded to an iron sulphide concentrate or a low grade copper concentrate.

Jan 1, 1991

By A E. C Peres, P R. M Viana

The role of flotation columns in comparison with conventional mechanical flotation cells is discussed under the scenario of Brazilian flotation technology. All iron ore concentrator circuits commissioned since 1990 incorporated column only flotation technology in rougher, cleaner, scavenger configuration. Columns were also added to existing circuits, especially at the cleaner stage. Columns were also incorporated to phosphate ore flotation circuits operating mechanical cells. In two phosphate concentrators, columns substituted for all mechanical cells. Columns perform the cleaning stage in a large sulfide copper concentrator, following rougher flotation in tank cells. Scavenger of the cleaner tailings is performed in tank cells at this plant. Other ores that are concentrated in flotation columns include graphite, talc, lead-zinc sulfide, and a zinc hydrometallurgical residue for silver recovery.

Jan 1, 2005

By Mutmansky J. M, Organiscak J, Qin J, Bhaskar R

The results of a two-year research study into the relationship between quartz dust levels in host material and in respirable dust in continuous mining sections are presented in this paper. The experimental design and sampling procedures for underground data collection are outlined. The sample analysis procedures for quartz determination, the analysis results and conclusions of the study are discussed.

Jan 1, 1988