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The New Technology of Enrichment of a Fine Low-Grade Tungsten from Complex Multi-Metallic Ore

Sep 13, 2010

By V L. Los, G J. Abramson

The paper examines three types of polar zoning of ore-forming and associated elements that can be detected from geochemical data. Polar zoning is mapped in the form of geochemical ore systems of various ranks. Various types of polar zoning can be found in some systems, which present a general geochemical model of the ore object. The genetic basis of zoning is examined from the perspective of the conception of geoelectrochemical redistribution of matter, including ore-forming elements. The volume of the geochemical ore system may be used in the prognosis of resources for every rank.

Jan 1, 1999

By Claudia Castillo, Katja Freitag, Jan Cilliers, Diana Drinkwater, Robert Seitz

The talent gap in mining is not a new challenge. Mining companies continue to seek innovative ways to attract, develop and retain talent, and younger workers are looking for opportunities to develop their professional careers. Training provides a key value proposition for both employees and employers as it helps build a talent pipeline while offering opportunities for learning and growth and value creation. In 2020, Metcelerate launched its 20-month program for early career mineral processing engineers. The program helps develop critical technical skills in the workplace and is a tool to identify motivated engineers and change culture within teams. Learners cap their skills development by executing a technical investigation. This generates immediate value—a win-win outcome for learner and company.

Feb 1, 2025

By J. Seo

We propose a dynamic biomechanical simulation method that uses motion capture to evaluate the risk of Work-related Musculoskeletal Disorders (WMSDs). Statistics show that WMSDs accounted for 33% of all non-fatal occupational injuries and illness in construction in 2009, and were a leading cause of temporary and permanent disability. Present methods rely largely on self-reports from workers, observational techniques, and direct measurements of motion and muscle activity to assess awkward postures, physical loads, repetitiveness, and the duration of exposure. While these methods have helped to prevent WMSDs in construction work, they may not be suitable for estimating the internal tissue loads associated with WMSDs. We propose a dynamic biomechanical simulation method to estimate internal forces and moments at each body joint of construction workers with motion capture data. Particularly, we explore the biomechanical loads by simulating active 3D musculoskeletal models based on measured postures and movements. To demonstrate the feasibility of this approach, we studied a ladder climbing task using a portable ladder under controlled laboratory conditions. Postures and motions were determined with a commercial motion capture system (e.g., VICON). The results were analyzed to investigate the feasibility of identifying risk factors based on biomechanical simulation. The results show that the proposed approach allows us to determine the biomechanical basis for WMSDs, and to identify postures and movements associated with excessive physical demands on each body joint. When combined with marker-less motion capture which is our ongoing work, the proposed approach has the potential to assess an individual?s motions and to provide personalized feedback for the purpose of reducing biomechanical loads and WMSD risk in real workplaces.

Aug 1, 2013

By E. R. Bauer

Noise-induced hearing loss (NIHL) continues to be a concern of the mining industry. A new noise standard (30 CFR, Part 62) is aimed at reducing NIHL in mining through engineering and administrative noise controls. However, the difficulty and expense of implementing engineering controls can make administrative controls an attractive alternative for reducing worker noise exposure. Over the last three years, the National Institute for Occupational Safety and Health (NIOSH) has conducted worker noise exposure surveys in underground and surface coal mines and in coal preparation plants. The surveys revealed numerous possible administrative controls and an approach to implementation and analysis. The surveys have shown that worker dosimetry, time-motion studies and equipment noise profiling are important aspects of effectively utilizing administrative controls. A description of the approach for selecting, implementing and evaluating administrative controls and a list of possible administrative controls are reported.

Jan 1, 2007

By A. D. Garman

The mining ordinance of Costa Rica dates from 1830. In spite of the numerous attempts to enact a new ordinance , it has been so much amended and reamended during the hundred years of its existence either expressly or , more often , by implication , and sometimes by Executive Decrees of which the validity has been called in question - that in most cases no one but a lawyer thoroughly conversant with Costa Rican mining practice could properly advise with reference to it . The present attempt at a digest of these laws is based on the 1929 edition of Bolandi and Johanning - the only source available in Washington . Apparently this edition has no official character , and the editors themselves often made surmises although one would think that definite facts would be available in Costa Rica where it was published .

Jul 1, 1930

By D. Harrington

"Up to the last 10 or 15 years, responsibility for accidents in mines was generally, though not universally, placed upon the person or persons immediately involved. Present-day thought is rapidly veering toward holding the industry responsible for accidents, with ultimate payment of the bill by the consumer, if financial expenditure should be necessary. While it is undoubtedly correct in principle that responsibility for accidents in and around mines should be shouldered by the employer and while it is probable that as time passes the burden will become even more definitely than now that of the mining companies, on the other hand it is an undeniable fact that large numbers of accidents occur through acts of omission or of commission of some person, very frequently the victim of the accident being the offender.Out of about 3,000 persons killed every rear in our -mines and quarries, nearly half or approximately 1,500 of the fatalities are due to falls of overlying material or of persons, about 500 to haulage, about 350 to fires and explosions, about 125 to explosives, approximately the same number to electricity, and about 300 to various miscellaneous accidents.Generally the accidents from falls involve but one or two persons at a time, and the tendency is now as it always has been to charge the victim or possibly a coworker with the responsibility. Usually this sort of accident occurs at or near a working face (statistics indicate that about 80 per cent of fatalities from falls of roof or rib occur near the face), and as it is Generally agreed that it is the duty of the worker to keep his working place safe, the worker and especially the face worker is given the blame in case of accident."

Apr 1, 1930

Continuous pH and Pulp Potential Measurements During Complex Sulfide Ore Flotation

Sep 13, 2010

By V. L., McCutchan

FORM of ore bodies, strength of wall rock, and quantity of water that must be handled differ so greatly in the various districts in which the Corporation operates that a variety of mining methods have to be employed. All are underground, however, with the exception of glory holes at Cerro de Pasco from which siliceous silver pacos ore is obtained. In general, the ors is in many relatively small bodies unsuitable for hulk mining, such as caving or top slicing. The strength of the rock and ore rarely permit open stopes, though shrinkage is successfully used on various veins with strong walls, particularly in, Casapalca. Horizontal cut and-fill and square-set stoping with careful filling are the principal methods employed, with the necessarily higher cost for supplies and labor offset as much as possible by care in the avoidance of dilution. The mines at both Morococha and Casapalca are notoriously wet, and even at Cerro de Pasco the quantity of water was enough to retard deep development until the perfection of electric pumps. In Morococha particularly, the extension of successive levels, first from adits of moderate length, then from shafts and heavy pumping installations on the 750 and 1000 levels, and finally by the 30,564-ft. Kingsmill tunnel, was one of the most difficult and long continued fights against water and resulting heavy ground that is recorded in mining history.

Jan 1, 1945

By K. Mayhew, K. Murray

The CESL Copper Process was developed as a hydrometallurgical alternative to smelting and refining for copper sulphide concentrates. As the majority of such concentrates contain appreciable gold and silver values, effective recovery of these metals is essential to the economics of this technology. Unfortunately, conventional cyanide processing cannot be used on the residue from the copper process, clue to its unusual characteristics when compared with naturally occurring gold and silver ores. An abundance of elemental sulphur, as well as the presence of cyanide soluble copper, leads to the formation of both thiocyanate and copper cyanide which is detrimental to process economics clue to excessive cyanide consumption. This, however, can be reduced to acceptable levels by process innovations such as pressure cyanidation and cyanide recovery. This paper outlines the successful application of the CESL Gold Process to various gold-bearing copper concentrates from bench to demonstration scale.

Jan 1, 2011

By G. C. Hambleton

"The author has had wide experience in the reclamation of coal from coal mine waste dumps in the United Kingdom.The paper includes such topics as the processing decision and factors affecting processability; method of testing and appraisal; test data interpretation; historical influences in apppraisal; special contaminants and processing difficulties; methods of treatment; review of systems in use and their comparative economics; over-all system economics including excavation, handling methods, recovery system and shale disposal; effluent treatment; environmental considerations; alternatives to processing for coal recovery; light aggregate and cement usage; burned shale heaps; land reclamation; shale deposition for encouragement of vegetation by natural or artificial means; use of tailings fines; the environmental argument for action."

Jan 1, 1972

In high stress mining environments, production drill rigs are often employed for rapid drilling of boreholes for systematic cable bolting. One outcome of this drilling method is the need for larger boreholes than would normally be drilled using customised bolting machines, such as the Tamrock Cabolter. Past laboratory studies indicate that, under ideal grouting conditions, borehole diameter has little effect on the pull-out strength of cable bolts with high bulb densities. However, the sensitivity of pull-out strength to large boreholes and less ideal variations of grout strength have not been investigated. To explore these sensitivities, industry standard single embedment tests were conducted on large boreholes simulated using steel pipes. Four borehole diameters were tested, namely: 42 mm, 52 mm, 81 mm and 106 mm. In each case the grout water to cement ratio was varied from 0.35 to 0.45 and two cable bolt bulb spacings were considered, namely: one and three bulbs per metre. The results indicate that, across the range of parameters tested, variations in peak axial load at failure corresponding to changes in hole diameter were statistically insignificant.

Nov 25, 2010

By Sunil S. Gandhi

Magmatic-hydrothermal deposits rich in magnetite and/or hematite form a broad group that includes monometallic Fe deposits and polymetallic (mainly Cu and Au) deposits. They show a considerable variation in deposit characteristics, but share the genetic processes of magmatic differentiation and related hydrothermal activity in intermediate to felsic melts, and in some cases involve brines and/or meteoric waters during mineralization. They include several world-class deposits. They range in age from Proterozoic to Recent, and form important metallogenic districts in Scandinavian, Canadian, Brazilian and Australian Shields, Circum-Pacific regions, and in China, Iran and Turkey. Monometallic deposits have been important sources of iron in the past and still contain significant resources of the metal, e.g., the Kiirunavaara deposit in Sweden. The giant Olympic Dam Cu-Au-Ag-U-REE deposit was discovered in 1975, and since then explorationists have focussed on search for analogues worldwide. This has brought to light a number of economically important new deposits and prospects, including examples in Canada. The discoveries have in turn prompted considerable research on individual deposits and the group as a whole. This short paper is an attempt to summarize the main aspects of the group from the literature cited in Gandhi and Bell (1996), and from the papers published recently in two milestone volumes on these deposits, edited by Porter (2000 and 2002).

May 1, 2003

By L. E. Cardwell

This Bureau of Mines publication contains routine analyses and related source data for 495 natural gas samples from 21 States and three foreign countries. Of this total, 376 samples were collected during calendar year 1968. The remaining 119 analyses are of samples collected during previous years, but releases granting permission to publish the results Here not received until 1968. All samples were collected as a part of a continuous survey of the free world for occurrences of helium in natural gas. This survey has been conducted in the United States by the Bureau of Mines since 1917 and in late 1965 was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus which are described in Bureau of Mines Bulletins 4863 and 576.4 Ten previous publications have presented results of 8,165 gas analyses made by the Bureau of Hines Helium Activity prior to 1968. The first three, Bulletins 486, 576,6 and 617,7 contain analyses and related source data on

Jan 1, 1970

By Marc. A. Meyers

The analysis of the phenomena involved in the determination of the compressive strength of iron-ore agglomerates leads to the identification of the important parameters. It is shown mathematically that the pellet rupture strength is proportional to the cross-sectional area. Fracture is initiated at the center of the pellets by the tensile stresses developed by the compressive loads normally to the compression axis. The variation in strength between individual pellets of identical composition and subjected to identical treatments is due to internal voids of varying sizes, that act as stress-concentration sites. Two novel testing procedures are proposed. The first consists of testing the pellets between two plates having three steel spheres each. This configuration simulates much better the environment actually encountered by the pellets. The second procedure consists of a thick-walled cylinder in which a piston penetrates; a large group of pellets is tested simultaneously, as the stress versus strain plot is being recorded. This latter test presents significant advantages over the conventional testing procedure; the main one is that one single test is sufficient to characterize the mechanical response of the pellets.

Jan 1, 1981

Research on the Design and Processing Characteristics of 320 m3 Air-Forced Mechanical Flotation Cell

Sep 13, 2010

High-sulphidation (HS) gold, silver and/or copper deposits are generated in both the epithermal and the upper parts of the underlying porphyry environments over vertical intervals of up to 2 km. The HS deposits are generated in advanced argillic lithocaps, which are products of the absorption of acidic magmatic volatiles by voluminous groundwater systems. Mineralisation styles in HS systems reflect depth of formation as well as the interplay between structural, lithological and hydrothermal parameters. The deep parts of HS systems, at depths of >1000 m, are typified by disseminated copper¦gold mineralisation comprising digenite, chalcocite and covellite in pervasive advanced argillic as well as underlying sericitic alteration. In highly telescoped systems, such mineralisation may overprint porphyry stocks and associated quartz-veinlet stockworks. Intermediate levels of HS systems commonly contain fault-controlled copper-gold mineralisation, typically as enargite in bodies of vuggy residual quartz, silicification and/or massive pyritic sulphide. The shallow parts of HS systems, at depths of The exploration focus is on four principal HS mineralisation styles:copper (eg Chuquicamata, Monywa) or copper-gold (Wafi) in the deep porphyry-hosted parts of systems preferably, in the case of the latter, where supergene oxidation is limited and, hence, flotation may be used for metal recovery; copper¦gold-bearing replacement mantos and pipes hosted by carbonate wallrocks in the deep parts of systems (eg Bisbee); high-grade gold in late-stage veins or hydrothermal breccias that overprint the intermediate to shallow levels of systems (eg El Indio, Goldfield); and large, bulk-mineable gold deposits in the shallow parts of systems that were subjected to supergene oxidation, thereby permitting heap-leach treatment (eg Yanacocha, Pierina). To these preferred HS styles may be added the low-sulphidation vein or disseminated gold¦silver mineralisation that is commonplace alongside many HS systems (eg Victoria at Lepanto).

Jan 1, 1999

By Y. Mao, D. Xie

The viscosity of TiO2-containing blast furnace slags may increase rapidly (commonly referred to as thickening) under strong reducing conditions in the blast furnace. To elucidate the mechanisms for slag thickening, measurements have been made of changes in the composition and rheological properties of TiO2-CaO-SiO2-Al2O3-MgO slags during the reduction process. The slag composition covered the range of 17–33 wt% TiO2, 9–19% Al2O3, 8–16% MgO and theCaO/SiO2from 0.8 to 1.4. The viscosities were measured using the rotating cylinder method at temperatures up to 1550ºC and the fusibility temperatures were determined from ‘breaks’ in the viscosity-temperature curves. The reduction of the slag was carried out in graphite crucibles at1500ºC for 2–6 hours The rheological properties of the slags during reduction were predominantly influenced by the slag basicity (CaO/SiO2), and the effect of other components depended largely on basic or acidic behaviour of the oxide. The reduction of TiO2in the slag by carbon was initially fast to formTi2O3, followed by further reduction to TiO and TiC. Correspondingly, the viscosity showed initially a slight decrease, followed by a gradual and then rapid increase. The thickening was found to be accelerated by an increase in TiO2content and a decrease in the CaO/SiO2in the slag. In addition to the existence of 1~3 wt% TiC, the thickened slags also had a significant amount of TiO (3~7 wt%), suggesting that TiO may play an important role in the ‘thickening phenomena’ ,possibly by forming solid solutions with TiC to significantly increase the number of solid particles in the heterogeneous slag. Keywords: TiO2slags, viscosity

Jan 1, 2004

By A. Paulin, A. W. D. Hills

The work has shown that packed-bed behaviour can be predicted from the results of single-particle experiments, total reaction times being predicted somewhat more accurately than gas and solid temperatures and gas compositions. A small laboratory packed-bed reactor was built and used to study the decomposition of beds of specially prepared CaCO3 spheres, steps being taken to minimise the effects exerted by the walls of the bed on processes occurring within the bed. Gas and solid temperatures and gas compositions were measured at various points in the bed and compared with theoretical predictions based on kinetic data determined in previous single-particle experiments. The measured solid temperatures and total reaction times agreed remarkably well with the values predicted theoretically. Gas and solid temperatures measured after the reaction had finished at any point in the bed did not agree with the theory. This was because solid temperatures in the bed rose very rapidly once the reaction was completed and the walls of the bed could not be heated at a sufficient rate for their temperatures to rise as rapidly; thus some loss of heat from the bed to the walls was inevitable, and this could not be accounted for in the theory. In addition, the theory did not allow for the conduction of heat within the bed, and this resulted in some further slight discrepancy between the measured and predicted values, particularly after the reaction was completed. Gas compositions measured in the bed were rather scattered, but, even so, they agreed moderately well with the predictions of the theory.

Dec 1, 1971

By N. Dhawan

In the last decades, High Pressure Grinding Roll (HPGR) has gained significant importance in hard rock processing due to numerous metallurgical benefits such as energy savings, particle weakening, preferential damage of coarse particles, and preferential comminution-liberation. There are a limited numbers of lab-scale HPGR units throughout the world. The laboratory-scale HPGR machine at the University of Utah is first-ever lab-scale machine designed by late Dr Klaus Schönert, the inventor of HPGR. This HPGR is constructed with two counter-rotating hardened tool steel rolls, each 200 mm in diameter and 100 mm in width. The HPGR unit is equipped with eight sensors and a robust control system, which serves as an ideal system for fundamental studies and lab-scale testing. In HPGR operation, throughput, energy and product size distribution are intricately linked to specific grinding pressure, roll gap and rolls speed. The nip angle existing during the operation determines the volume of feed material above the rolls that is pulled into rolls without slip. In this paper, scale-up factors and some of the existing models have been reviewed. A number of experiments have been carried out with limestone and a slag material. The influence of operating variables and their complex relationship has been studied.

Sep 1, 2012