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The deep seafloor in Papua New Guinea's proposed Exclusive Economic Zone appears to be a gold-rich province in the same sense as the territory above sea level. Two significant sites with polymetallic massive sulphide deposits forming today are known on neovolcanic ridges in the Manus Basin. Their high precious metal contents have led to renewed interest in the issue of exploiting seafloor mineral deposits. The prospects of finding other, possibly larger deposits in the region appear substantial. This paper reviews current data on seafloor deposits in Papua New Guinea (PNG) and raises some issues relating to future commercial exploration and mining of the sea floor. One of the known PNG deposits could become a prime candidate for the trials needed to develop technology, establish costs, and minimise environmental impact.

Jan 1, 1994

By J. J. Cai

The status of fossil fuel and secondary resource in metallurgy industry in China were reviewed, and conversion efficiency of fossil fuel, utilization technologies of secondary energy were studied. Fossil fuel, accounting for over 90% of energy structure in metallurgy industry, took in the highest flight in China, and a great deal of which was converted to secondary energy through the equipment of blast furnace and coke oven. These secondary energy which were mostly made of blast furnace gas(BFG), coke oven gas(COG) and Lindz Donawitz gas(LDG) occupied about 30% of total secondary energy. The way enhancing fossil fuel conversion efficiency, secondary resource recovery and the secondary energy such as BFG, COG, LDG utilization promoted to save fossil fuel was discussed in this paper. And efficient use of lower caloric value fuel was studied, such as preheating combustion air and fuel, generating electricity power etc. and regeneration purposes of high-caloric fuel was also researched, for producing hydrogen, methanol or direct reduction iron etc. The using model of secondary energy at iron and steel works was presented as fuel and chemical materials. The results suggest that utilization of these energy efficiently and reasonably could help to energy saving and environment protecting.

Jan 1, 2014

By S J. Neethling and, S J. R Simons

In this paper the effect of humic substances (natural surfactants), electrolytes and solid particles on bubble coalescence, and as a consequence on froth stability, have been investigated. In this study two bubbles of equal size were formed and forced to collide using a novel experimental apparatus. The interactions were recorded by a high-speed camera, the images of which helped to determine the coalescence frequency and the coalescence time, as well as the mechanisms of the interactions. Two types of humic substances were used, along with three different electrolytes. Humic substances appeared to have a considerable effect on bubble coalescence, while the effect of electrolytes was minimal. Moderate and high hydrophobic glass spheres were used between two bubbles. Very hydrophobic spheres promoted fast bubble coalescence, while moderate hydrophobic spheres had no effect. Data of coalescence frequency and time is presented, as well as images of the coalescence events. The coalescence frequency was used to validate a parameter, Pf, known as the film failure frequency, used in a simulation model to predict foam height in a gas-sparged vessel. Predictions determined using Pf were then validated by experimentation.

Jan 1, 2005

By Lendall P. Warriner, Blandford C. Burgess

Jasper County lies just north of the geographical center of Georgia, bounded on the west and north by the Ocmulgee River. The county seat, Monticello, is approximately 65 miles east-southeast of Atlanta and 40 miles north of Macon. It is served by the Macon-Athens branch of the Central of Georgia Railway Co. and by five paved highways converging from adjoining county seats. Farming and lumbering are the principal local occupations. About half the county is covered with pine and mixed hardwoods; a large part of the forested land is owned by the Soil Conservation Service of the Department of Agriculture in its Piedmont Land Utilization Project. The topography is one of gently rolling field and forest with occasional hills rising 100 ft or: more above the creek beds. Though annual rainfall is in the neighborhood of 60 in., most of it falls in torrential downpours of short duration which tend rapidly to erode the red soil and convert the country roads to greasy tracks of red mud.

Jan 1, 1949

By Walter E. Dean

Deep-sea manganese nodules are considered to be potential ores of manganese, nickel, cobalt, and copper. Considerable time, effort, and funds have been applied to the study of Se distribution of nodules on the sea floor and the location of economically important areas, but little effort has been spent in understanding the origin of nodules. Most theories that have been proposed to explain the origin of manganese nodules have been based on inorganic physicochemical processes. It is not by coincidence, however, that the area considered to be most economically feasible is in the zone of high biological productivity in the eastern equatorial Pacific Ocean and underlain by siliceous biogenic sediment. The genesis of manganese nodules and the concentration of many trace elements are intimately associated with biological processes.

Jan 1, 1982

By K. V. K. Prasad

Stochastic simulation has been routinely used for performing risk and sensitivity analyses in a variety of fields. The commonly used means of generating the simulations has been the Monte Carlo approach which usually employs a Simple Random Sampling (SRS) scheme of the variable distributions. This method is prone to sample clustering and requires a large number of samples to represent the distribution faith-fully. This can become problematic for simulating complex processes where it is impossible to run an arbitrarily large number of replicate simulations. The Latin Hypercube Sampling (LHS) method uses a stratified sampling approach which assures representation of the input distributions for any given number of samples. In this paper the LHS and SRS approaches are compared using a petroleum resource estimation example.

Jan 1, 1993

By D. J. Parker

This report is based on data collected in and about the Liberty mine of the Liberty Fuel Co. by D. J. Parker and W. W. Kessler on December 13 and 14, 1933. An important phase of an examination to determine the general condition of a mine with respect to safety is the collection of dust samples from rock- dusted areas. Definite conclusions, based on intelligent interpretation of the analyses of such samples, can be reached only when the general condition of the mine is known. A similar examination and report were made on this property in January 1930 by D. J. Parker and R. I. C. Manning. Since that time much has been done by the management to improve safety conditions in this mine. The changes made will be noted in the course of this report. The mine is in Spring Canyon at Latuda, Carbon County, Utah, and is served by a branch line of the Denver & Rio Grande Western Railroad about 7 miles long and connecting to the main line near Helper, Utah. The writer desires to express his sincere appreciation for the many courtesies and helpful cooperation extended by Superintendent George Schultz and Mine Foreman F. W. Koelling.

Nov 1, 1934

By M. H. Forester, John D. Cooner

ANTHRACITE ALTHOUGH the unmined anthracite will last for approximately 150 years, most of the thicker and cleaner coal beds have been almost entirely first-mined and pretty well robbed, leaving much of the present and future production to come from thin and dirtier beds. Herewith is a section of one of the dirty beds being mined in the Wyoming region [ ] This section shows that 45.8 per cent of the bed is made up of impurities and that the 45 in. of coal in the bed is in five benches, the thickest of which is 19 inches. In some localities of the anthracite region there are 14 beds of minable coal. Orderly and proper mining of the coal makes it necessary to rob or second-mine-almost all beds have already been first-mined-in sequence from the top downward. Therefore the robbing of the few remaining portions of the thicker and cleaner beds is in many instances being held up by the mining of the overlying thin and dirtier coal beds. Impurities Impurities consist of fire clay, slate, rock, and bone. The latter, which is black, contains 40 to 60 per cent carbon and often resembles good coal. In some beds there are also bands of "blue" coal, which, as the name implies, is of a bluish slaty color. Although much of this "blue" coal has a carbon content almost as high as the good anthracite, it is not

Jan 1, 1943

By W. S. Landers

This report presents a study by the Federal Bureau of Mines of technical factors related to the production of special carbon and tar from selected Wyoming coals. Certain Wyoming high-volatile bituminous and subbituminous coals were processed in bench-scale apparatus to determine potential carbonization yields and in pilot plant retorts to produce sufficient char and tar for testing. These tests have shown that a critical selection of coal is necessary when the coal is processed for a specialized carbon. Generally high yields of tar are obtained from low-temperature carbonization of Wyoming high-volatile bituminous and subbituminous coals, and the yield of tar usually increases with increase in rank within this range of coals. The production and evaluation of industrial carbons from Wyoming coals by using pilot plant and bench-scale techniques is part of the continuous program of upgrading western coals. It has been found that: 1. Most Wyoming coals are nonagglomerating and may be carbonized in fluidized systems. Chars produced in pilot plant retorts at low temperatures contain about 17 to 23 pct, residual volatile matter and are easily ignited. These chars appear suitable as power plant fuel. The tar-plus-light-oil yields range from 14 to 40 gal./ton of raw coal processed. 2. Wyoming high-volatile coals produce a slightly smaller and somewhat weaker coke than currently mined Western United States high-volatile coals used commercially as blending stock in metallurgical coke production.

Jan 1, 1961

By R. J. Chase, C. Davies

"Abstract- The Merelani graphite-tanzanite deposit is located in northeast Tanzania, 14 kilometers south of Kilirnajaro International Airport and in close proximity to the towns of Moshi and Arusha . The graphite mineralization is hosted by relatively undeformed linear Proterowic metasedimentary gneisses, several of which have been subjected to hydrothermal alteration resulting in tanzanite mineralization. Exploration work comprised detailed geological mapping coupled with pit and trench channel sampling and a subsequent 1500 meters of diamond drilling. In addition, metallurgical tests have shown the graphite to be of unusually coarse flake size, crystallinity and high purity.Feasibility studies have shown the economic viability of a major coarse flake graphite deposit with the measured resource to 50 meters in excess of 9 million tonnes assaying over 8o/o graphitic carbon . Production is due to start by the end of the first quarter of 1994 with the processing plant design capacity initially set at 15 000 tonnes per annum.ln addition to graphite production, tanzanite will be produced through selective mining within the graphite open pit in the upper horizon and from underground workings within the lower horizon.The Merelani graphite-tanzanite deposit will be the first major orebody to be exploited through means of private funding since Tanzania gained independence."

Jan 1, 1994

By H. D. Dahl

In January, 1969, the Central Research Division of Continental Oil Company initiated a research program on roof control. The purpose of the research was to improve roof stability. Toward this end, it was necessary to determine which of the many geological and geometrical variables have a significant effect on roof stability. The isolation of these significant variables would allow research effort to be concentrated where it would be most effective in improving roof control. The research effort was directed toward two major objectives. One was to de-fine the geological and/or geometrical parameters that affect the severity of roof conditions in any particular area of the mine. This study was concerned with roof fall intensity. The second was to define why roof falls in Humphrey No. mine (and in northern West Virginia-south-western Pennsylvania coal mining areas) are oriented so that they occur primarily in north-south rooms or entries. This study was concerned with roof fall orientation. To provide a reference framework for further discussion, a geological description of the area is presented in Part II. In Parts III and IV, the procedures, methods, and 'results of the research applied toward the afore-mentioned major objectives are presented. Part V contains the conclusions and recommendations for-warded by this study.

Jan 1, 1971

By Mark K. Larson, Douglas R. Tesarik, Heather E. Lawson

"Load transfer distance (LTD) is simple in concept and usually evident in underground coal mines. Many people in the mining industry recognize LTD as the distance from the panel to where the mine ribs and pillars show evidence of renewed spalling, floor heave, or other effects of increased weight due to longwall mining or pillaring. Barrier pillars, in particular, are designed to shield mains and other relatively permanent facilities from this loading. LTD is also important in determining the extent and degree to which mining increases the load on pillars and ribs in the gate roads. Generally, a long LTD reduces loads in gate roads, but may require larger barrier pillar widths to protect mains or adjacent panels from excessive loads. Therefore, a long LTD may make it easy or difficult to meet various objectives of mine layout design . LTD reflects overburden geology in two ways: First, overburden that is weak and readily caves will limit both the amount and distance of load transfer. Second, stronger, stiffer, sandier, and more massive overburden increases both the amount and distance of load transfer. As such, LTD is central to coal mine layout design and calibration of numerical models that seek to anticipate these transfers of load during mining. However, the term does not have a consistent definition in the literature, and various instruments and observational techniques with varying sensitivities and thresholds have been used to indicate the onset of mining-induced stress increase and, subsequently, to determine an LTD. Consistency is important for meaningful comparison of ground response between mining sites and for accurate calibration of models.This paper adds to the body of observed and reported LTDs by presenting cases with relatively sandy and massive overburden at two western coal mines. These two cases include observation and measurement of LTD with multiple methods and provide insight into how distances reported relative to different criteria and instrumentation could be adjusted for comparison against a common base. This base is the criteria used by Peng and Chiang (1984) to determine their empirical equation. In one of these two cases, LTD was recently measured at a western U.S. coal mine (Mine A) to be approximately four times that calculated using the Peng and Chiang empirical equation. LTD measurements were examined using various instruments at Mine A and at adjacent Mine B. The measurements at Mine B showed that LTD was significantly greater than that calculated by the Peng and Chiang equation. Difficulties with BPC installation and fittings at Mine B permitted only ranges of LTD to be determined from some BPCs. Even so, the LTDs and ranges of LTDs determined were consistent with the LTDs determined at Mine A."

Jan 1, 2015

By Sean Masse

New Gold?s New Afton Mine, located 8 km (5 miles) west of Kamloops, British Columbia, is a 4.5-Mt/a (5-million stpy) block cave mine, making it the highest tonnage underground hard rock mine in Canada. The reserve is estimated at 52.5 Mt (55.9 million st) with grades of 0.65 g/t (0.02 oz/st) gold and 0.93 percent copper (2012). Commercial production was achieved in July 2012 and nameplate production was achieved ahead of schedule in September 2012, with the cave breaching to surface in 2013. The mill has a SAG and a ball mill with a froth flotation circuit.

Jan 1, 2014

Note this date. This will be the biggest meeting we have ever held. It is arranged so as to permit you to go immediately afterwards to Salt Lake. City to attend the meeting of the American Institute of Mining and Metallurgical Engineers there on August 31, September 1, 2 and 3. Notify the Secretary of any change in your address.

Jan 1, 1925

By R. P. King

"A model of the flotation process can be used effectively for design and control. For design purposes it can be used to predict the performance of a large plant from laboratory and pilot plant data. It can be used for control purposes to assess the utility of any proposed operating modification to an existing plant, and it can also be used to determine optimal control settings for best operating performance.A model has been developed that will allow for variations in feed properties and for variations in fineness of grind. The model can be used to assess the effects of reagent addition rate, aeration rate and pulp level on plant performance and these are the control variables that are used individually or together in all operating flotation plants. The model provides for a distribution in the values for flotation rate constants, particle size and mineral fraction, and, because of its complexity, requires a large computer when it is to be applied to a typical plant configuration. The computational method that is used to apply this model to such configurations is described in this paper, and particular attention is paid to the problem of allowing for feedback of tailings from cleaners and recleaners."

Jan 1, 2014

By Zhiyuan Ma, ZUI WANG, Xincheng Hu, Jianwei Cheng, Junhong Si, Yi Qin, Gao Ke

The harmfulness and destructiveness of mine gas explosion is quite serious, which is the first of all kinds of coal mine disasters. Once the gas explosion occurs, it could instantly generate explosion shock waves, high temperature airflows, and disaster gases, which cause the destruction of underground ventilation structures, disruption of airflow direction in a mine ventilation network, and miners’ deaths by asphyxiation. As an important barrier to prevent the spread of accidents caused by the gas explosion, the safety and reliability of the mine seal affects the mine’s production and the health of workers. Due to the demands of coal mine production and transportation, a large number of longitudinal and horizontal roadway networks have been developed underground. There are not only many flat and straight roadways in the complex roadway network structure, but also a large number of different types of bifurcations and bends. Once a gas explosion occurs, the impact of the blast waves on the mine seal after passing through the complex path is difficult to determine. Therefore, this paper establishes a numerical model of bifurcated and cornered roadways and studies how the impact of gas explosion shock waves on the structure of sandwich mine seal after passing through different types of bifurcated and cornered roadways. The damage state of sandwich mine seal is analyzed. The researching finding could prevent and manage the spread of gas explosion disaster, and improve the disaster mitigation of mine explosion accident.

Jul 11, 2023

By Mehdi Noori, Atefeh Azizitorghabeh, Fereshteh Rashchi, Ataollah Babakhani, Sarah Mahmoudi

The focus of this research was to evaluate the synergistic effect of bis(2,4,4-trimethylpentyl) phosphinic acid (CYANEX 272) and di-(2-ethylhexyl) phosphoric acid (D2EHPA), diluted in kerosene, on the extraction and separation of Co(II) and Li(I) from synthetic sulfate solution. The results indicated that using a mixture of CYANEX 272 and D2EHPA was efficient in extracting and separating Co(II) from Li(I). The optimum ratio of CYANEX 272/D2EHPA was found to be 5:1, in which the highest separation factor was obtained (5973.23), and ΔpH0.5 was 4.10. Adding tributyl phosphate (TBP) as a modifier and increasing the temperature improved the metals’ separation rate and extraction efficiency. Thermodynamic studies were also carried out, and ΔH, ΔS, and ΔG values were computed, revealing the endothermic nature of Co(II) and Li(I) extraction by CYANEX 272/D2EHPA mixture. The conducted experiments for the McCabe–Thiele diagram showed the possibility of using two stages to extract over 99% of Co(II) and Li(I). Slope analysis and Fourier transform infrared spectroscopy (FT-IR) were employed to comprehend the Co(II) and Li(I) extraction mechanism using a mixture of CYANEX 272 and D2EHPA.

Jan 17, 2022

By Mary Ellen Bruce

Let me first address the issue of the wet grab samples. The wet grab samples that were attempted to take on the Central Artery were hindered by the fact that the way the mixing was being done was only by injecting grout on the way out, during withdrawal of the mixing tools. They would auger down to the required depth (usually with some water being injected), which took anywhere from 45 minutes to an hour, and then when coming out, the grout would be injected with grout. That was leaving a column of grout in the center where the shaft had been (i.e. inside of the blades of the mixing tools), which would end up being something like a foot in diameter because the pipe that was used for the drill shaft was a foot in diameter. So we had 10 inches to a foot of almost pure grout in the middle of our column and then we had 2 feet on either side that was mixed soil cement. So when they went down with the wet grab sampler not knowing where that was in the column sometimes they/we were getting strengths of 1500 psi, and sometimes they/we were getting strength of 500 psi or 100 psi. So what was it that we were taking into the wet grab sampler? In those cases you don't really know, but it wasn't representative of the core samples we were taking. We were purposely not coring in the center because we knew that was going to be high cement content, almost pure grout. So the issue of wet grab sampling particularly on this project, the Central Artery Project, was that we didn't really know what we were sampling. What becomes an issue with wet grab sampling in other projects is that you have to have another device (machine) in most cases, a cherry picker crane or something similar that can raise and lower with a beam that is used to forces the sampler down into the freshly mixed soil-cement. And regarding economics, is it more economical to have that crane standing by with its operator or to have a drill rig to come along later and do the coring and take the material out that's fairly identical to what you're finding in situ? The complaint of micro-fracturing in the core samples as you're taking the cores was raised by Seiko as causing large strength reductions. But, if you're doing it carefully, then I don't think that's much of an issue anymore, on research basis perhaps but not on a practical level.

Feb 10, 2003

By A. W. Fahrenwald

FLOTATION practice in Idaho is now about 13 years old. The advance has been steady during these 13 years. The operators have been alert to take advantage of the newest developments and they have themselves made a constant effort to improve their work. The metallurgical improvements are due to the development of (1) better equipment, (2) better reagents, and (3) better understanding and control of the process. During the eight years the writer has been in this district, there has been continuous experimentation by several companies to improve the ore dressing by flotation methods. Gravity concentration has fought hard to hold its place, and although it is true that gravity processes have been improved during this period, nevertheless, in several of the important mills of the district the few tables that managed to hang on have finally given way. On the straight-lead ores, tables and jigs are still used; and, due to better classification, their hold on this job has been strengthened. ORES OF THE DISTRICT The ores of the district are of two general classes: (1) clean lead ores, such as those from the Bunker Hill and Hecla mines, and (2) complex lead-zinc ores. The general impression prevails that the clean lead ores, class 1, are simple and that it is easy to obtain high recoveries and good grade products. This, in a way, is a false impression; there is quite a high percentage of locked middling in these ores at 100 and 150-mesh sizes. Improved classification preparatory to table treatment of this type of ore has made it possible to segregate effectively a high-grade middling which is further comminuted and floated. The complex lead-zinc ores of the district, of which the ore from the Morning mine of the Federal Mining & Smelting Co. is a typical example, always have presented a difficult problem. It always has been comparatively easy to make a clean lead concentrate, but it never has been possible to concentrate sphalerite with a-specific gravity of 4.10 from siderite of gravity 3.88. Also, a large percentage of the galena and sphalerite of this class of ore refuses to separate out until the crushing has been carried

Jan 1, 1928

By Li Zhang, Jing Zhao, Chuanwei Zang, Shuanlin Wang

The application of gob-side entry retaining (GER) in steeply pitching seam longwall mining with a hard roof has always been a difficult problem. Based on the simplified roof beam mechanical model, the traditional gob-side entry retaining by packing (GERP) roof structure evolution process and its problems with use in steeply pitching seams are analyzed. Therefore, based on the unique characteristics of the gangue rolling and accumulating in the steeply pitching seam, this contribution proposes an innovative method of gob-side entry retaining by roof cutting (GERRC) in steeply pitching seam and details its technical process. The roof structures of the GERRC and the GERP are compared. Taking the Chang Gouyu Coal Mine as a case study, field experiments were carried out. This research finds that the GERRC can both overcome the impact of rolling gangue on roadside support and make the rolling and stacking gangue become a roadside support. The roof structure of the GERRC is in a one-time statically indeterminate state, which is conducive to the stability of the roadway. In the field test, the total displacement of the roadway roof and floor is 97 mm, the supporting pressure of the serried single props is less than 28 MPa, and the props have no obvious bending phenomenon.

May 6, 2020