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By A. R. Naderian

Laboratory strength and deformation testing of freshly blasted sandstone and claystone overburden from Jeebropilly colliery in Queensland and in-situ plate-bearing tests on four backfills of different ages showed that the bearing capacity of backfill is a function mainly of compaction, not of age. The modulus or stiffness of the backfill is significantly increased by previous loading, in some cases up to threefold. Backfill material experiences some compaction through the passage of mining vehicles, likely to provide a bearing capacity that will support normal construction activities; the limited testing performed suggested that completed backfills are capable of supporting loads of up to 200 kN/m2 while sustaining displacements acceptable for a wide range of residential and industrial uses, but may be susceptible to collapse settlements due to saturation in the long term

Jun 19, 1905

By Alex Matheson, Nick W. D. Massey, Peter T. Bobrowsky

Crowing pressures on aggregate resources include diminishing reserves, high transportation costs, sterilization and land use conflicts. In the absence of detailed resource knowledge for a particular region, aggregate resource potential maps provide the best "first approximation" regarding the surficial distribution of sand and gravel. The 1:50 000 scale Level Ill aggregate potential map integrates several important factors which influence the management of sand and gravel. Data used to generate this type of thematic map is readily available in most areas, fieldwork required is minimal, there is a logical quantitative evaluation of the data layers and integration is easily accomplished on a desktop PC-based platform. Also the aggregate potential map, with its focus on identifying areas of potential future aggregate exploitation as well as present inventory, provides a useful tool for the aggregate explorationist.

Jan 1, 2001

By William W. Adams

Reports for the calendar year 1923 that have been transmitted to the Bureau of Mines of the Department of the Interior by mine officials of the various coal-producing States show that accidents in and around the coal mines resulted in the death of 2,452 men. The output of coal during the year, as reported to the United States Geo- logical Survey, was 641,476,000 tons; hence the fatality rate per million tons was 3.82 as compared with 4.15 for 1922, a decline of about 8 per cent. The average rate for the decade ending with 1922 was 4.11. This reduction of 8 per cent in the fatal-accident rate per million tons is equivalent to the saving of 210 lives--that is, had the fatality rate of 1922 continued through 1923 the number of lives lost would have been 210 more than they actually were. Not only was there a net reduction in the fatality rate from all causes combined, but each of the main causes of coal-mine fatalities also showed a decline. Falls of roof and coal, which generally account for nearly half of all deaths in coal mines, were responsible for 1,158 fatalities in 1923, which represents a rate of 1.81 per million tons as compared with 1.90 in 1922. (See Table 2.) Haulage accidents underground usually cause about 17 per cent of all fatalities, and the reports for 1923 show that 413 deaths were due to this cause, indi- cating a rate of 0.64 per million tons, as against 0.71 for the previous year. Gas and dust explosions killed 372 men, the fatality rate being 0.58; the rate for 1922 was 0.65. Seventy-five deaths were due to electricity, for which class of accidents the fatality rate per million tons was 0.12 as compared with 0.16 the year before. Powder and other explosives caused 114 deaths, representing a rate of 0.18 as compared with 0.19 for 1922. Of the 2,452 fatal accidents during the year, 2,249 occurred under- ground, 46 in shafts, and 157 on the surface. At bituminous coal mines the number of deaths was 1,943, of which 1,816 were under- ground, 31 in shafts, and 96 on the surface. At the anthracite mines

Jan 1, 1923

It cannot be said that accurate and reliable ore reserve estimation is the fundamental of any mining operation success. Estimation techniques which are used to estimate the grade distribution of an orebody together with the assessment of uncertainty and risk have a vital influence on the success of any optimisation algorithm. Traditional estimation techniques such as kriging or inverse distance weighting are frequently used for assigning grade values to blocks. Various attempts have been made in order to compare geostatistical estimated methods for ore reserve estimation. This paper aims to evaluate the sensitivity of different estimation methods over changing the block dimension. For this reason, several block models with different dimensions were derived in Chador Malu iron ore mine which is located in 180 km northeast of Yazd in the centre of Iran. Each block model was estimated by different estimation methods such as nearest neighbours (NN), inverse distance (ID) and ordinary kriging (OK). The results of each estimation methods were compared against a control block file created by using the assay results of all blastholes drilled in the ore over four benches of the pit. The results signify that by estimating the large block size, no significant improvement occurred due to the employment of different estimation techniques. Furthermore, the grades estimated based on ID method is more reliable, but OK methods estimated more accurate tonnage.

Dec 6, 2010

With the employment of a system of ore pillars to support the hanging wall during the mining operations at the North Mine, it was found that, when the stopes were worked out and the pillars remained intact, the main footwall drives developed an undulating longitudinal section due to the shrinkage of the filling in the worked out stopes.These depressions collected water, which made the footwall drives very wet under foot, and everitually worked its way into the pillar workings and the levels below.Water was also finding its way into the shafts because of the silting-up of the level drainage systems and, as both the shafts are down-cast, this tended to increase the humidity of the air entering the mine.To overcome these troubles it was decided to try a system of siphons as a method of subsidiary drainage.SYSTEM AT PRESENT IN USE.All drainage water is collected as near to its source as possible, run into a sump in an adjacent low lying part of the level, and continuously removed from these sumps by a siphon system.Each level has its own system. Water is collected from the sumps by a 1-in. pipe and delivered to a pipe running the length of the level along the back of the footwall drive. At the shaft the pipe is increased to...

Jan 1, 1938

By D. S. Pye, J. P. Gallus

Successful hydraulic pressure treatment of oil and gas wells that have long producing intervals, multiple pay zones, fluid thief zones, or natural or induced fractures has long been a serious problem plaguing the petroleum industry. High fluid-injection rates, straddle packers, ball sealers, and either liquid or solid additives to the treating fluids are being used to cope with this difficult and costly problem.l-6 The use of ball sealers and straddle packers is limited, in practice, to wells that have been completed with perforated cemented casings or liners. Well stimulation with ball sealers and straddle packers is usually successful as long as the cement remains competent. The other techniques of diverting are used with all types of completions. However, there are two significant disadvantages of the high rate method: excessive horsepower requirements, and the need of large treating-fluid volume. Consequently, most well stimulation techniques that involve diverting depend upon ball sealers or granular materials. Liquid diverting agents, and some of the solid ones in use today, frequently will cause formation damage. On the other hand, the most popular particulate diverting agents often are so soluble in the treating fluid that they become largely ineffective; their particle size is severely reduced as they dissolve while being transported through thousands of feet of pipe to the formation face down hole. In our attempts to deal with the shortcomings of these diverting agents, we experimented with a large variety of potentially suitable deformable materials the solubility of which could be controlled. Following are the criteria for the diverting agent sought: 1. The material must be effective in reducing fluid loss to thief zones, including existing fractures and very high permeability layers in the formation to be pressure treated. 2. The material must have enough strength to bridge under the treating pressure. 3. The material must be insoluble or slowly soluble in the treating fluids so that the particles retain sufficient size to be effective after they reach the formation face. 4. The material must be completely soluble in the produced oil or condensate liquid so that it can be removed readily; it must not cause formation damage. A number of products consisting of various polymers blended with waxes and other solid hydrocarbons were examined. All these materials satisfied the criteria for a diverting agent and also exhibited some degree of plastic deformability. On the basis of initial tests of strength and hardness, several blends of wax and polymer were selected for extensive testing in the laboratory and the field. These compounds have congealing temperatures ranging from 140 to 190F; they are insoluble in water and soluble in oil. They conformed, therefore, to the criteria specified for a theoretically superior diverting agent. Laboratory and field tests were conducted using these wax-polymer materials to demonstrate that the use of a deformable diverting agent can significantly improve fluid diverting performance. Data in this

Jan 1, 1970

By C. J. Farrow, M. J. Smith

"Bechtel has managed a number of test programs to establish autogenous grinding circuits and size mills for a variety of ores.This paper outlines the procedures whereby bench scale and pilot plant tests are used to select the most efficient circuit to grind the range of ore types likely in the mill feed.Five examples are given. One example traces the development of a pilot plant program; it shows how bench scale Work Indices provide a target for the grinding power requirement of an ore and relates how pilot circuits are changed as a result of interpreting the results from preceding tests. The other four examples relate the interpretation of the test results to provide design data; they illustrate a number of phenomena which have been observed.INTRODUCTIONConventional crushing and grinding circuits can be specified from bench scale test data such as Bond Work Indices. Bond Indices have been correlated to a large number of rod and ball mills and by applying appropriate factors, mills can be sized from the Work Index.For autogenous or semi-autogenous grinding circuits, bench scale tests are not sufficient to be able to specify the circuit and size of the mills for a commercial plant. It is necessary to run a series of pilot plant tests to determine how the ore behaves."

Jan 1, 1982

By Takashi Sasaoka, Hiroshi Takamoto, Akihiro Hamanaka, Pongpanya Phnthoudeth, Hideki Shimada, Jiro Oya

"Indonesia is the second largest coal exporter to Japan, accounting for about 30 Mt annually. They produced over 400 Mt in 2015, over 99% of which is from open-cut mines. However, the conditions of surface mining are becoming worse year by year: the stripping ratio is increasing, the economy is worsening, and the infrastructure for coal transportation from inland mining areas is not being maintained. To meet the demand for coal in Indonesia and the rest of the world, underground mines have to be developed. In consideration of growing need, our research program is conducting a study on the potential for an underground coal mine in Indonesia. This research is being done through the roadway heading research program, which is looking into developing an underground coal mine from an open pit highwall. The greatest challenge for underground coal mine development in Indonesia is the maintaining the safety of the mine roadway during heading because the roof rock is exceptionally weaker. There is a potential for heading below mobile, unconsolidated soft sediment, and instead mining a deep area. This increases the likelihood for problems in the stability of the support system due to increasing ground pressure. The ground behavior around the roadway was measured using telltales, extensometers, and convergence measurements. Moreover, rock property tests were also conducted on exploration drilling cores. Based on the geological dates and monitoring data, a series of numerical analyses were conducted in order to assess support needs in the main roadway under different depths. Results of numerical analyses indicate that the current arch support design is effective when the mining depth is lower than 100m. However, if the mining depth is larger than 100m, the current arch support design should be changed to include the application of higher yield strength material, shorter spacing, etc. Moreover, bolting may also be useful if ground pressure is high locally. Based on a series of measurement data of ground and support behavior, a control criterion for main roadways under weak geological conditions is proposed in this paper."

Jan 1, 2017

By L Langer, R Simcock, M Davis

Rehabilitation of mining sites helps to achieve the purpose 5(2c) of The Resource Management Act 1991 û æavoiding, remedying, or mitigating any adverse effects of activities on the environmentÆ. The environmental outcomes for recent and current mining operations on the West Coast are variable. There are some exemplary mining operations which are restoring or even improving land use and environmental factors in the region, particularly those operated by the larger mining companies. There are also examples of an exploitative mentality where the environment and land have been severely degraded by mining activities. Technology has been developed to prevent a repetition of the historical destruction of the environment through mining. Failure to rehabilitate mined land is no longer acceptable to the New Zealand public in the 1990s and damages the credibility of the mining industry. Examples of successful mine site rehabilitation to pastoral farming and to production or plantation forestry are illustrated from the alluvial gold mining industry. Planning, sequencing of operations, the utilization of sailor plant growth materials, and aftercare are key factors in successful land rehabilitation to these productive uses. There is also a recent focus on restoring indigenous forests and wetlands at both coal and gold mining sites, particularly for mines on or adjacent to the conservation estate. The results of scientific research and efforts by the industry on techniques for rehabilitating rainforest and pakihi wetland after mining are presented, particularly from the Giles Creek Dunoille Coal Mine. There is a need for further research and trials to apply and extend rehabilitation techniques to other geological and environmental situations, particularly to mines in mountainous areas and to difficult environments like the coal measures ecosystems of the plateaux above Westport.

Jan 1, 1996

By Matthew I. G

A new process for leaching zinc sulphide concentrates with gaseous mixtures of SO2 and O2 in aqueous solution is described.The reaction of SO2/O2 with Rosebery, Mt. Isa, Broken Hill and Elura zinc concentrates yields zinc and iron sulphates, elemental sulphur and some sulphuric acid. Rates of zinc extraction are controlled by a surface chemical reaction without apparent interference from the elemental sulphur layer for SO2 concentrations up to 9 per cent in the gas phase. Pyrite in concentrate exerts an activating effect, possibly through galvanic interaction with the sphalerite. Metal extractions are dependent on SO2 and O2 tenors of the gas, particle size, and the acidity and zinc content of the solution, but are independent of the ferric ion level. Extractions also reach maxima at about 85°C.Generation of acid may be prevented by conducting the reaction in the presence of ferrous iron and at acidities of 40 g/l or greater. Zinc and iron levels in Elura lead concentrate may be reduced by leaching with SO2/O2.

Jan 1, 1981

By Hans Janzon, Ernst Buechi

INTRODUCTION The headrace tunnel in Amlach is part of a hydro electric power scheme near the city of Lienz in south west Austria. The project is owned and developed by Tiroler Wasserkraftwerke AG, the regional electrical supply utility. The construction work was divided into seven contracts for the entire scheme. The power output will be 60 MW, this being developed from a head of 370 m and water flows of 20 m3/s. The water will be tapped from the river Drau and lead through a 22 km long headrace on the south side of the Puster valley through the Lienzer Dolomiten mountain range. Contract No. 4, which is a joint venture between Mayreder, Züblin, Strabag, Rella and Innerebner, involves the construction of 13.5 km of the headrace. It was decided to bore this from one single adit, which probably makes it the longest pressure tunnel driven from one side by a TBM. (See Fig. 1.) For the tunnelling an Atlas Copco Jarva MK 12 TBM was chosen. The excavation diameter is 3.90 m, with the final lined diameter being in the range of 3.20 to 3.40 m. The back-up is a 145 m long single track rail system supplied by Mühlhäuser (Germany). Side-tipping cars with a capacity each of 8.2 m were used for removing the muck. One California switch was attached to the back-up after 3,000 m, and a second fixed switch was installed after 8,000 m of boring. 3 m long

Jan 1, 1987

By Richard Paul Seelig

THE following review covers published information on pressing of metal powders at room temperature. Only those operations are considered which occur between the time the powder is filled into the cavity and the compact is ejected from the die. Thus, this review does not concern hot pressing, coining or sizing feed or flow problems, commercial presses nor designs. It was also necessary to disregard to a large extent the effect of pressing on subsequent operations and on properties after sintering. The pressing operation is considered independently in its function to compact loose metal powder into useful shapes which can subsequently be handled. There are some comments by the writer in connection with a few of the findings quoted in the literature in order to stimulate thought and discussion. The selection of references quoted in the text is in some cases arbitrary although an attempt was made to favor papers containing novel ideas, techniques or results which may stimulate future research. In order to enable the reader to check further into the subjects mentioned, the original, rather extensive, bibliography is appended even though not all the references are touched on in the printed version of this review. EXPERIMENTAL APPROACH The equipment used by various workers, for example a die design created by Bridgman,22 is very interesting. The die insert has a conical external surface. The vertical pressure exerted on the punch transmits itself to the die which in turn is pushed harder into its tapered retainer. Thus, the higher the pressure exerted on the punch, the higher also the pressure exerted inwards on the die inserts. In as much as this pressure counteracts the internal pressure from the compact the two stresses balance each other so that it is possible to obtain tremendous pressures without breaking the die. The die collar was made from an oil hardening tool steel, heat treated to a tensile strength of some 300,000 psi. The die was closed at the bottom by a plug made from special tool steels. Bridgman found that there is no steel which will withstand a compressive stress of 700,000 psi without continuous slow flow or immediate fracture. Therefore, the only material suitable for use in the pressing punch was sintered carbide. In view of the ingenious design it was possible to use special tool steel as die material. Jones22 raises the question whether this method of pressing has practical application in powder metallurgy. Al- though these tremendous pressures cannot readily be utilized without many special precautions, the tapered die and retainer idea is believed to be useful even for lower pressures. Bridgman, himself,8 calls attention to the fact that the properties

Jan 1, 1947

By Botelho Junior, Amilton Barbosa, Denise C. R. Espinosa, David B. Dreisinger

Copper and cobalt can be found on nickel laterite ores, and cobalt can be found also on copper ores, and many contaminants such as iron, aluminum, and magnesium are associated with these ores. In hydrometallurgical process, a purification step is necessary after leaching due to the presence of these impurities. Chelating resins are more selective for some metals than others, making them more efficient than cationic resins. This overview discusses chelating resin applications to recover copper, nickel, and cobalt from mining process and mining tailings and the effect of contaminants in leach solution. Chelating resins with iminodiacetate functional group can be used for selective copper recovery, and both iminodiacetate and bis-picolylamine resins are highly selective for nickel and cobalt. Chelating resins with the same functional group can have different performances on the kinetics of loading, because of variations of structure, the density of functional group, and degree of cross-linking. This article reviews commercial chelating resins that can be applied in leach solutions with different compositions, and also possible innovations for uses of chelating resins to recover metals from mining process and mining tailings.

Alkaline leaching with sodium carbonate solution adjusted to pH 9·5 to 10·0 preferentially dissolves thorium from a mixture of rare earth and thorium hydroxides. Rare earth sodium carbonates form in the alkaline leaching stage.These are converted to rare earth oxides for use as optical and ophthalmic polishing agents. Quadrivalent cerium is extracted under similar alkaline leaching conditions.INTRODUCTIONAustralia has made significant contributions to mineral chemistry and mineral dressing. As often happens with an industrially immature country, research investigations often outstrip the ability or desire of commerce to exploit them. It is wrong to think exclusively in terms of export of raw materials. Imagination assists in developing world trends. The chemical utilization of mineral sands has interested a group of investigators, chiefly at the Commonwealth Scientific and Industrial Research Organization (C.S.I.R.O.) and, more recently, in the mining industry itself. From an international point of view the highlight of this work was Newnham's (1960) process for the separation of hafnium from zirconium. Earlier work at C.S.I.R.O. investigated the chlorination of rutile, zircon, and monazite. Assuming that titanium tetrachloride would be available in large quantities in the post war years, extensive work was done by Kraitzer, McTaggart, and Winter (1948) on organic compounds of titanium. This work led to the development of heat resistant paints, plastic compositions, and improved organic protective coatings that predated overseas work by up to seven years. (Post, Shiihara and Schwartz, 1961; Anon, 1955). Contributions were made to the production of refractory hard metals (Kraitzer, 1949; Kraitzer and Newnham, 1956). Pilkington and Wylie (1947) and Urie (1947) investigated the production of rare earths from monazite by an acid process.

Jan 1, 1963

By M. Kuchta, A. Newman

LKAB’s Kiruna Mine, located in northern Sweden, produces about 24 Mton of iron ore yearly using sublevel caving. For efficiency, the mine must deliver planned quantities of three ore products. We use mixed integer programming to schedule Kiruna’s operations, specifically, which production blocks should be mined, and when they should be mined to minimize deviations from planned production quantities while adhering to mining restrictions (e.g., sequencing). A new production block database and a well-formulated mixed integer programming model dramatically reduce the size of the original problem; in less than ten minutes we generate five-year schedules with time fidelity of months.

Jan 1, 2002

By Bijan Taheri, Behrouz Maghsodi, Monireh Heshami, Reza Kohan

A common problem recently encountered with the increase in the rate of input feed at Enrichment Plant 2 of the Sarcheshmeh Copper Complex is the loss of value to the tails, translating to lower recoveries. The feasibility of the direct transfer of part of the high-grade concentrate from rougher stages to an appropriate position along the circuit was studied, and two positions were proposed for direct transfer of the concentrate. One position was the feed flow into cleaner cells, and the other was the feed flow into the recleaner cell. The results indicated that transferring the concentrate from the first unit of the rougher stage to the feed flow into the cleaner cells was feasible, with no limitations, while the second position required the installation of a set of hydrocyclones. It was found that the transfer of concentrate to the proposed positions not only addressed the problem of limited cell capacity, resulting in debottlenecking of the circuit, but also improved metallurgical separation efficiency up to 1.4%.

By Nageswararao K

A series of tests was carried out on one of the rock-pebble milling circuits treating complex nickel ores at Kambalda Nickel Operations of Western Mining Corporation. A mathematical model to describe the behaviour of a 508 mm hydrocyclone was developed from the data.A "flat" reduced efficiency curve was observed for the system. This was attributed to a marked difference in the specific gravity of different size fractions of the feed. A modified approach in describing the shape or the reduced efficiency curve resulted in accurate prediction of the hydrocyclone performance.

Jan 1, 1981

By A Jäger, J L. Lett, J Rachocki and B Mobilio

The Newcrest Mining Limited Cadia East Panel Cave mines near Orange, New South Wales, Australia commenced production 1200 m below the surface in May 2014. Understanding the mine-wide impact caving had on excavation stability was a primary objective to ensure a safe working environment as production ramped up in the Panel Cave 1 operation and establishment activities were implemented in Panel Cave 2. The impact of cave interaction between Panel Cave 1 and Panel Cave 2 and establishing monitoring systems to assist mine planning and production as both caves joined is explained in this paper. Monitoring tools such as a microseismic system, open holes, HI-cells, extensometers, fibre optic sensing, cave markers, closure monitoring, underground observations and damage mapping were used to characterise the performance and position of the cave back. The data and observations collected were compared to predictions from numerical and empirical methods and used to calibrate the numerical models for forward prediction and to develop site empirical design tools. The results and methodology for monitoring deep high-output caves are the key discussion points in this paper.CITATION:Lett, J L, Jäger, A, Thornhill, T, Rachocki, J and Mobilio, B, 2016. Geotechnical challenges in cave monitoring – a modern approach, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 203–216 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Valentine A. Chanturiya

The aim of this paper is basically to show progress in the study of nanosecond processes involved in the disintegration and breaking-up of mineral complexes with fine noble metals. We studied the influence of nanosecond High-Power Electromagnetic Pulses (HPEMP) on the physical and technological properties of refractory gold-containing ores and beneficiation products. Experimental data are presented to confirm the formation of breakdown channels and selective disintegration of mineral complexes as a result of pulse irradiation, which makes for efficient access of lixiviant solutions to precious metal grains and enhanced precious metal recovery into lixivia during leaching. Preliminary processing of gravity concentrate with a HPEMP resulted in significant increase of gold and silver extraction into lixivia during the cyanidation stage, with gold recovery increased by ~31% (from 51.2% in a blank test to 82.3% after irradiation). Gold recovery from stale gold-containing dressing tailings products increased after pulses-irradiation from 8-12% to 80-90%.

Jan 1, 2006

By Eti Purwaningsih, Widi Astuti, Erik Prasetyo

Selective-reductive leaching of manganese from low-grade manganese ore using tannic acid as a reductant in acidic media was demonstrated by XRD, SEM-EDX characterization, and batch leaching studies at room temperature. The pH change in the liquid phase before and after leaching revealed that selectivity of manganese over iron was due to the hydrolysis of iron. The acidity in the liquid phase during leaching was dictated by two mechanisms: proton-consuming reaction (manganese oxide reduction by tannic acid) and proton-producing reaction (ferric ion reduction by tannic acid to produce ferrous ion). Based on the leaching studies, the more prevalent reaction between these two was determined by initial leaching conditions: tannic acid concentration, sulfuric acid concentration, liquid-solid ratio, temperatures, and agitation time. Kinetic studies revealed that maximum recovery was attained within 6-h agitation, which indicated a product layer diffusion process.