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By AIME AIME

MEXICO embraces one of the great metal and petroleum producing provinces of the world. In this respect its history dates back to the overthrow of the Aztec empire by a Spanish force under Hernando Cortes between 1519 and 1.521. Even before then, its richness in silver and other minerals was not unknown. But it was a treasure house for the Spanish conquerors until the country became independent in 1821. It has been computed that in the 400 years following 1521, Mexico yielded 1.55,000 metric tons of silver, worth $3,000,000,000, two-thirds of the entire world production. In 1935 the country accounted for 36 per cent of the world's silver output, 14 per cent of its antimony (in 1934), 13 per cent of its lead, 3 per cent of its zinc and copper, and 21/2 per cent of its petroleum. Contrary to the impression of some, its gold output is now comparatively small, though important in the past. Its oil, as well, formerly hulked much larger than now, in 1921 being one-fourth of the world output.

Jan 1, 1936

By P. R. Ineson, D. W. James

For a criterion to be useful it must either demonstrate directly the role of exhalative processes in the formation of a deposit or describe a unique attribute of exhalative deposits. Few of those employed in previous investigations entirely satisfy either condition. The limitations of three of the most frequently employed criteria are illustrated by studies of the geology of the King Island Scheelite deposit in Tasmania.

Jan 12, 1993

By G. Merrington, B. J. Alloway

Tailings from three historical mining areas in the UK were leached in columns under a simulated weathering programme which was chosen to represent periods of 1 and 2 years at 3 different ambient temperatures. The total concentrations of Cd, Cu, Pb and Zn in the primary ore minerals present in the tailings showed only a limited correlation with metal concentrations in the leachate. The leachate from columns of tailings that were maintained at a temperature of 25 (+/-3) degrees C contained, on average, 50% more Pb and 75% more Cu than leachate from tailings that were maintained at a temperature of 10 (+/-3) degrees C. The pH values of leachates from all three types of tailings at 25 (+/-3) degrees C were 0.2 units lower than those from columns maintained at 10 (+/-3) degrees C. The concentration of Cd and Zn in the tailings leachates showed no marked difference at the different temperatures. The composition of the leachate was found to be dependent on the type of gangue mineral, the presence of other sulphide minerals and the formation of secondary iron minerals. A comparison of the concentrations of heavy metals in the leachates produced in the laboratory with those in leachates that were collected in the field over a similar period of time from two of the mine sites showed that concentrations were of a similar order.

Jan 8, 1993

By Irwan Halim, Seung Han Kim

This paper will describe design of precast segmental tunnel lining for the Pawtucket CSO Tunnel Project in Providence, Rhode Island. The tunnel is 11,700 LF long with 30-foot finished diameter to be constructed in complex sedimentary rocks. Special features of the segments include a large keystone and no connector used on radial joints. The typical segments will be steel fiber reinforced, and hybrid segments with additional steel rebars and shear bicones will be used around the adit openings without use of any structural framing. The important design considerations will be discussed, including special 3D segment to adit connection analyses performed.

Dec 1, 2022

By FREDERICK J. ALCOCK

THE high prices which lead and zinc have commanded during recent months have given a great impetus to search for workable deposits of these metals, and there has accordingly risen a demand for information about deposits which have been worked in the past and which might possibly be opened up anew under these more favorable conditions. Production of zinc and lead in Canada has been on the increase during the last few years. In 1924, 175,- 485,499 lb. of lead with a computed value of $14,221,- 345 were mined. Of this, 96 per cent. was produced in British Columbia, 3 per cent. in Ontario, while Quebec and the Mayo district of the Yukon accounted for the remaining one per cent. During the same year the production of zinc amounted to 98,909,077 lb.. valued at $6,274,791. Of this 96,000,069 lb. were produced in British Columbia and the remaining 2,909,008 in Quebec. The large producer of zinc and also of lead is the Sullivan Mine at Kimberley, B. C. In comparison with the Sullivan, the deposits which are known to occur in eastern Canada are relatively small. Two, however, the Kingdoll lead mine at Galetta, Ontario, and the Tetreault zinc property at Notre Dame des Anges, Quebec, are steady producers. The object of this paper is to describe briefly these and other deposits of eastern Canada, to show their relation to geological events and to point out what are the chances of any of those which are idle at present developing into active producers or what are the possibilities of new deposits being discovered.

Jan 1, 1926

By William H. Shockley

THERE was an, extensive mining and industrial exploitation of Russia, about 20 years ago, by Belgian, French and British capitalists; but the results were discouraging. It is said that the Belgian and French public together lost approximately $400,000,000, chiefly in the coal and iron industry of southern Russia. This loss is largely accounted for by the fact that most of the companies were formed, as usual in " boom " times, to sell stock; and that thorough investigations were not made. In 1906, renewed interest was taken in Russian mines, especially in those of gold and copper, and a considerable literature is growing on this subject; but as yet I have seen no account of one of the large Russian mining estates. The following notes on such property, where the conditions are so different from those in the mining regions of the United States, should be of interest This inadequate and probably somewhat inaccurate account is made up, partly from my own notes made on the ground, in the summers of 1904 and 1905, and partly from a volume on the geology and resources of the estate issued several years ago, containing surface-and mine-maps, and from a pamphlet published in 1904, giving a general account of the condition and prospects of the property. This pamphlet includes a report made by Arthur L. Pearse, a member of this Institute, in 1899. Both these books are in Russian, and were prepared by the Bogoslovsk Mining Co., which owns and operates the property. Articles in many other languages have appeared dealing with various matters connected with the estate; but I know of no other general account of it. In numerous books and articles on the Urals and Siberia, however, localities are described in which somewhat similar conditions prevail. Recent papers by

Mar 1, 1908

By Yongsik Jeong, Kwangmin Kim

Conventional tailings slurry contains a significant amount of water, and water management is key to ensuring the stability of a tailings storage facility (TSF). Simply reducing the water content in the slurry before discharging it from the mill could be an effective way to improve TSF water management. This study investigated the potential for using an environmentally friendly polymer as a new drag reduction agent (DRA) to reduce frictional pressure loss and also conserve water. It entailed conducting pipe loop tests to assess the polymer’s effect on pressure loss in tailings flow and then applying the test results to validate a numerical model using computational fluid dynamics (CFD). The model was also used to determine the polymer’s optimal concentrations at given solid concentrations and flow rates, its effect on energy efficiency for tailings transportation, and its potential for saving water. A case study for a mid-sized, hard-rock mine with a throughput of 50,000 t/day found that the solid concentration could be increased from 30 to 45% with no pressure loss by applying 1996 m3 of the polymer per day. Adding the polymer also resulted in water savings of 57,552 m3/day. The results of this study demonstrated the potential for using the new DRA not only to improve TSF stability but also to save water.

Jun 29, 2020

By Y. Chen, D. He, J. H. Potgieter

The demand for rare earth elements (REE) is increasing rapidly owing to the emergence of new cleanenergy and defense-related technologies. China’s dominates the world production of REE. In this paper, we review the ore characteristics of four typical REE deposits in China and discuss the conventional beneficiation techniques, including gravity and magnetic separation, flotation, and hydrometallurgical processing of these ores. Some of the latest laboratory findings and industrial applications, as well as the development of novel reagents for REE processing in China are presented. The REE beneficiation technologies developed and employed in China could constitute a good case study for many other emerging projects being explored around the world.

Mar 2, 2022

By Juliana Gonçalves Pohlmann

A redução das emissões de CO2 pela substituição parcial de carvões por um combustível renovável como a biomassa é um assunto de crescente interesse na siderurgia. As emissões de CO2 na etapa de redução podem ser reduzidas pelo uso de biomassa como combustível ou pela queima em condições de oxi-combustão. Este trabalho visa investigar a combustibilidade de eucaliptos termicamente tratados em laboratório em atmosferas convencional (O2/N2) e de oxi-combustão (O2/CO2), comparando com uma moinha de carvão vegetal e carvões típicos do processo de injeção em altos-fornos (PCI). Os testes de combustibilidade foram conduzidos em um forno de queda livre (DTF) a 1.300°C com diferentes proporções de O2/N2 e O2/CO2. Os chars do DTF foram caracterizados quanto à aparência ao microscópio, área superficial e reatividade. Os eucaliptos termicamente tratados apresentaram as maiores combustibilidades, seguidos pela moinha e pelos carvões. Os chars das biomassas apresentaram estruturas mais reativas do que os chars dos carvões, e maiores áreas superficiais e reatividades. As poucas diferenças de combustibilidade e reatividade devido à atmosfera de oxi-combustão indicaram que, se aplicada ao alto-forno, esta tecnologia pode não ocasionar efeitos negativos no comportamento de carvões e biomassas.

Aug 16, 2017

By L. Roux

This review was initially motivated by the author’s own experience in attempting to reconcile run-of mine production tons with the Coal Resource and Reserve estimation of mineable, in-situ tonnages. The primary scientific measurements and observations that are collected during exploration at the beginning of the value chain will have a profound effect on the future of the mining operation. Due diligence must be exercised during the planning of a new mine and during the life of an existing mine. The comments provided by the technical and economic assessment group of Venmyn Deloitte confirmed the need for this critical review. They found the reporting of Coal Resources in South Africa to be inconsistent. This was particularly problematic in the Waterberg Coalfield in Limpopo Province. In this coalfield there are two types of coal deposit present. The first is comprised of the thick intercalated, cyclic coal and shale/mudstone sequences of the Volksrust Formation. This overlies multiple coal seams within the Vryheid Formation, each of which is thick enough to be extracted as an individual raw coal unit. On the other hand, the interbedded coal and shale seams of the Volksrust Formation require beneficiation to separate the coal from the shale. The review examines practices and methods, investigates alternatives, provides checks and balances, and tests these against actual production reconciliations. In conclusion, the best estimates of the mineable, in-situ tonnage will be obtained from the air-dry raw material density. These estimates should be adjusted afterwards to allow for free moisture content. The adjustments are derived from reconciliation data. The greatest contributing factor to the over-estimation of Reserve tonnages is the moisture content of the raw material. This fluctuates significantly under varying conditions in situ, as well as upon exposure to the natural environment. The air-dried density of the raw material includes inherent (structurally bound) moisture within the matrix. It provides credible tonnage estimations of raw material available while also providing an indication of voids within the volume of material being assessed. The calculated solids percentage can be used to adjust the specific gravity, which is determined via the Archimedes principle. This will supply a representative estimate of the material to be mined.

Nov 1, 2021

By R. E. Robinson

I shall present a concept for the development of the resources of this country and its neighbours that repre¬sents a fantastic challenge to our scientists and entre¬preneurs. This concept offers prospects of development that must make our previous achievements seem equivalent only to the first act in a drama enacted on the stage of Southern Africa. I hope to illustrate how, in Act Two, chemistry will play a dominant role, and chemists and chemical engineers will be among the principal actors.

Jan 1, 1980

By N M. Rana, A Take, N Ghahramani, S McDougall, S G. Evans

A critical issue associated with mining operations has been the stability of tailings impoundments. Some breach events have produced catastrophic tailings flows that have caused significant economic damage, mass casualties and long-lasting environmental impact in the downstream environment. This paper reports independently estimated values of runout distance, inundation area and fahrboschung of 16 tailings flows. The adopted methodology involves the geospatial analysis of satellite and aerial imagery to classify each tailings flow into a primary impact zone (Zone 1: main overland flow) and a secondary impact zone (Zone 2: along-creek diluted flow) to characterise runout. Only Zone 1 runout values are reported herein given the greater significance in relation to downstream impact. The fahrboschung is calculated using elevation data from global 30 m digital elevation models (DEMs) and source literature. The results show that all the selected tailings flows travelled long distances (2.4 km to 98.5 km) and inundated large areas (0.35 km2 to 27.0 km2) over very low fahrboschung values (0.04° to 4.8°). This indicates very high flow mobility that is largely governed by the high water content sourced from interstitial waters and, in many cases, supernatant ponds. Scatter plots display poor correlations owing to the complexity and variability in travel path characteristics (confinement, slope angle and obstructions) and the inherent properties of the flowing mass. The slope angle of the travel path exerts a strong control over the flow velocity which has implications on kinetic energy and downstream geomorphological impact. Mean tailings flow velocities may range from ~6 m/s on near-flat, open terrain to over 30 m/s in relatively steeper, channelised travel paths, indicating that tailings flows fall within the extremely rapid and high mobility spectrum of global mass movements. The presented work forms an inceptive part of the CanBreach tailings project, a major component of which is to develop a comprehensive database of case histories to examine the role of geotechnics, failure modes and downstream terrains in influencing tailings flow behaviour.

Jul 1, 2021

By S Maritsa, E K. Chiwandika, S M. Masuka

The iron and steel industry is experiencing an increase in the use of iron and steel commodities within societies, decarbonisation pressures, depletion of high iron ore grades and high energy consumption. This necessitates scrap metal recycling, low-grade ore utilisation using the induction or electric arc furnace to achieve the global target of net zero CO2 emission. The available highquality scrap metal cannot sustain the steel industry but the world has unused hematite-goethite ores. It is the aim of this research that this resource be utilised using the induction furnace to sustain the steel industry in an environmentally friendly manner. Indurated pellets prepared from the hematite-goethite ore, 5 wt per cent limestone and 5 wt per cent coal addition were smelted in the induction furnace at 1350 ± 50°C with 25 mins holding time. The effects of basicity and carbon content were also investigated to optimise the smelting parameters. The results showed that the careful control of the basicity, and iron-to-carbon ratio maximised total metal recovery. The optimal basicity ratio was determined to be 1.3 and a carbon to iron ratio of 1.4 achieved a total metal recovery of 73 per cent. The metal recovery was closely related to the estimated slag melting temperature. The basicity ratio of 1.3 achieved the lowest slag melting temperature estimated to be around 1380°C based on the CaO-SiO2-Al2O3 phase diagram. The recovered metal had a comparable chemical composition and microstructure to that products from an ITmk3 furnace.

Jun 19, 2024

By M S. Henderson, R D. Alorro, L G. Dyer

An alternative leaching system for rare earth element recovery from monazite is under development. The initial stage utilises oxalic acid to convert the rare earth phosphate into an oxalate salt through dissolution and reprecipitation and it is the efficiency of this stage that governs the overall recovery achieved. It has previously been proposed that lixiviant consumption is the primary limitation in this process. This work further investigates a range of conditions in an attempt to further elucidate the factors influencing the achievable conversion in this stage. It has been shown that the pH may be governed by multiple reactions both consuming and producing acid (thus the mild change over time). The importance of proper mixing and potential to operate at lower temperature with only moderate impact on kinetics has also been demonstrated. Staged/sequential leaching is more effective in fresh solution as opposed to restoring the lixiviant concentration with subsequent reagent addition, suggesting some impact of solution composition. However, contrary to previous findings, subjecting the leach residue to fresh solution resulted in significant decline in leach rate and overall dissolution. This may be because a greater proportion of conversion was achieved in stage 1 in this work than in previous investigation. This may indicate that eventual passivation or the presence of some more refractory REE minerals limits dissolution. Iron dissolution was relatively consistent upon exposure to fresh solution, displaying the ability of the solution to continue to leach the goethite component of the concentrate.

Aug 24, 2022

By I. James, R. J. Durrheim, M. S. D. Manzi, O. Valeshin, J. Lepine, L. V. Socco, C. Colombero, A. Malehmir, M. K. Rapetsoa, M. Sihoyiya

The FUTURE project aims to enhance seismic surveying in South African mining by integrating advanced acquisition technologies. In this paper, we detail surface and underground seismic surveys at the South Deep gold mine as part of the project. Surface seismic acquisition used co-located broadband micro-electromechanical sensors, one and three component recorders connected to geophones, distributed acoustic sensing using a straight fibre optic cable, along with a 6 ton broadband seismic vibrator operating with 4–180 Hz linear sweeps. In addition, underground surveys employed a combination of straight, and helically wound fibre optic cables, cabled-based and nodal sensors, along with a 500 kg drophammer mounted on a skid steer bobcat. The surface and underground seismic arrays were time synchronised using a GPS-time transmitter to allow for accurate seismic data recording in a GPS-denied environment. Results show the efficacy of these techniques in acquiring high-resolution seismic data, revealing detailed subsurface geological structures and mineralisation down to 3500 m below ground surface. Surface data revealed clear seismic reflections corresponding to the Black Reef and Ventersdorp Contact Reef. An underground P-wave velocity model exhibits low velocity anomalies that are associated with fracturing, while a P-wave reflection stack section shows significant reflections and a degree of faulting below the tunnel floor that was not observed on the surface reflection seismic data. We highlight the potential of these technologies to enhance safety, efficiency, and sustainability in mining. This study sets a benchmark for future reflection seismic surveys, paving the way for safer, more efficient, deep mineral exploration and extraction practices.

Jan 12, 2025

By Jack C. Haptonstall

Abstract-Minas de San Luis, S.A. operates the old Tayoltita mine located in the Sierra Madre Occidental in Durango, Mexico. Yearly production is 55 000 kg (1.7 million troy ox) of silver and 1000 kg (31,000 troy ox) of gold from milling 165 000 t/y (181,900 stpy) obtained from fissure veins. A 4.4 km (2.75 miles) adit, to intersect the veins below existing workings, was completed in 1974. The adit and ancillary projects facilitated extensive mechanization of the mine, ramp development of it, integration of duplicate facilities and elimination of obsolete facilities. It provided a deep-level access for exploration and development of the veins, and resulted in a 25% increase in production with the same labor force. The cost of the in-house financed project was $3.4 million.

Jan 2, 1978

By S. B. V. Stewart, W. W. Forsyth

"Since the Mathew's method for open stope design was first proposed by Golder Associates in 1980 it has been applied at a number of mine sites in Canada. The initial hypothesis was based on a relatively small amount of data and the intervening period has allowed the collection of a significant amount of new data to test the validity of the method.This paper examines a brief history of the evolution of rock mass classification systems to provide background and emphasize their empirical and non-rigorous approach. It also presents the new data which appear to indicate that the initial hypothesis was reasonably good. The modification to the original graph proposed by Potvin is discussed as well as the applicability of the method to predicting the onset of caving. The original graph has been updated and has been subdivided into four zones described as ""stable""; ""potentially unstable""; ""potential major failure""; and ""potential caving"". The method is recommended as a useful open stoping design tool provided it is recognized that it is not a rigorous design method.Finally the paper proposes a recommended approach for application of the method by would-be users and addresses some typical pitfalls that may be encountered."

Jan 1, 1995

By Robert E. Sorenson

EXPLORATION for deep-seated orebodies in the Silver Belt area of the Coeur d'Alene mining district is complicated by meager surface expressions of diagnostic criteria, lack of knowledge of the significance of specific alteration phenomena, and the great expense involved in the exploration for ore shoots, the tops of which often occur near sea level elevation or below and as much as 4000 ft or more below the surface. Except for the early studies of Ransome and Calkins in 1903 and 1904,[1] little geological work was done in the Coeur d'Alene district for many years, and it is only during the last 15 to 20 years that complete and careful geological mapping has been applied to most of the mines in the area. Much early information, which now would prove invaluable, is lost in hundreds of miles of caved and inaccessible mine openings not mapped by mining geologists. In more recent years mining geology has become a tool of greater use in the district, and some measurable progress is being made in the accumulation of observations that are adding gradually to the knowledge of ore deposits in the district.

Jan 7, 1951

The æMountain Camp reefÆ at Alford's mine, Wakamarina,Marlborough, had no recorded gold production although assays of 5 - 26 g/t were reported, but it did produce c. l000 kg of scheelite. The lode consists of a lower massive quartz layer, and upper, cm-banded, ribboned quartz layers, and has a very low sulphide content. Within the massive layer, relict early fine-grained mosaic quartz with idioblastic scheelite is surrounded by recrystallised granoblastic coarse-grained quartz with calcite and plagioclase, in which an original ribbon banding texture is mimiced by strings of tiny inclusions. In both the banded and massive layers, rounded quartz grains, created by cataclastic milling of grain margins and along syn-vein fractures, have been partially annealed within later quartz overgrowths. Late fibrous quartz and calcite fill brittle cross fractures.   Deformation events D1 and D2 are associated with mid-late Jurassic metamorphism of the Pelorus Group, D2 producing the main regional schistosity (S2, and the earliest scheelite. D3 is an extensional mylonitic shear event that formed the dominant schistosity in Alford's mine (S3). The quartz lode was emplaced within the mylonite by a series of individual dilation pulses (D4). The D5 event caused crenulation of the S3 mylonite, kink banding and chevron folding of the S2 schist and S3 mylonite, and reverse faulting, rodding and cross-fracturing with late fibrous quartz-calcite veining of the D4 quartz lode.   Fluid influxes during successive dilations of D4 fractures progressively caused recrystallisation of earlier quartz bands on the footwall, annealing and recrystallisation of quartz along milled crystal margins and fractures, and deposition of minor sulphides. There was thus a dynamic interplay between fault dilation, lode fracture, fluid influx, lode band deposition, and lode recrystallisation. Illite-Kfeldspar al ¦ 2 Ma (K/Ar), c.30 Ma after metamorphism.

Jan 1, 1996

By R. S. Jurani

Sunshine Mining Co.'s Kellogg operation is the primary silver producer in the US. Maintaining a comfortable working environment in this deep underground mine historically has been a complex and costly problem. To improve the ventilation and cooling systems at a time of declining and un-certain silver markets, it was proposed to optimize the performance of existing facilities at minimum cost. This paper discusses a two-year, $400,000 optimization program that resulted in increased total mine airflow, cooler ambient temperatures, reduced compressed air usage, and lower energy consumption by primary fans, air compressors, and refrigeration plants. This saved the company about $650,000 per year.

Jan 1, 1988