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By Qingyun Huang, Junyi Xiang, Xuewei Lv, Chenguang Bai

The extraction of vanadium from mechanically activated converter slag was studied in dilute sulfuric acid solution. The effects of roasting and leaching parameters were investigated. The results show that Ca/V mole ratio, roasting temperature, leaching temperature, liquid-solid ratio, and particle size all have significant effects on vanadium leaching efficiency from calcification-roasted converter slag.

Mar 1, 2017

By K. A. du Preez, P. J. van Staden, M. van Rooyen

Mine-impacted water, including acid mine drainage (AMD), is a global problem. While precipitation of dissolved metals and neutralization of acidity from mine-impacted water is accomplished relatively easily with lime addition, removal of sulphate to permissible discharge limits is challenging. This paper presents a high-level comparison of four sulphate removal technologies, namely reverse osmosis, ettringite precipitation, barium carbonate addition, and biological sulphate reduction. Primarily operating costs, based on reagent and utility consumptions, are compared. Each process is shown to be subject to a unique set of constraints which might favour one over another for a specific combination of location and AMD composition. Access to and cost of reagents would be a key cost component to any of the processes studied. The total cost calculated for each process also depends on the type of effluents that are allowed to be discharged.

Oct 1, 2021

By John Chapman, Daryl Hockley, Michael Paul, Silvia Jahn

As part of the waste characterisation program to address site reclamation, WISMUT GmbH initiated 56 columns operated as large-scale humidity cell tests. The columns were initiated to assess the acid generation characteristics of waste rock from 14 waste rock piles distributed around the site. Of the 56 tests, 11 are ongoing and have been operational in excess of 160 weeks. The results to date from these long-term tests are surnrnarised. In particular, the methods for, and importance of, establishing the availability of the carbonate neutralisation potential and acid generation potential respectively, are discussed. Geochemical controls on uranium, and the conformity between the geochemical models MINTEQA2 and EQ3/6 in assessing these controls are discussed. Testing indicates that waste rock with an MS-NP:AP ratio in excess of about 2.7 should result in net neutral pH conditions.

Jan 1, 2000

By J. B. McKenzie

Since connnencing underground prcxiuction in 1979, the Ruttan Mine has been prone to secon:iacy sulphide dust explosions. Al though infrequent during the early years of prcxiuction, these occurrences did result in major damage and lost time injuries. 'As the mine exparrled and developed to further depths, sulphide dust explosions occurred on a more frequent basis. Incomplete ventilation se:rvices, required to exhaust the affected areas, caused frequent delays resulting in lower prcxiuction rates due to the time required to ventilate the affected areas of the mine. CUrrent procedures to minimize the effects of secon:iacy dust explosions evolved from practical suggestions arrl examining methcx:ls other mines have developed to cope with the problem. Procedures and regulations to protect errployees from exposure to hazards of sulphur dioxide are time consuming, expensive and counter prcxiuctive in their present fonn. This paper describes the history of secon:iacy sulphide dust explosions at the Ruttan Mine and the methcx:ls and proced.ures currently in place to minimize and contain the effects of dust explosions.

May 11, 1988

By Steve Scott

Outline of Talk Seafloor Massive Sulfides (SMS) and Seafloor Sedimentary Sulfides (SSS) Ocean mining of SMS (Nautilus Minerals) Environmental issues Summary

May 1, 2013

By K. G. Wheeland, K. G. Byberg

The occurrence of a secondary, dust-fuelled explosion following blasting of sulphide ores has been reported in mines in many countries, including canada, the USA, Australia and South Africa. However there has been little effort to document the events and develop effective control technology. Following a detailed investigation of an incident at the Geco Di vision of Noranda Minerals Inc. , the company held a conference of interested parties in October 1986 to review the state-of-the-art and to agree on action. '!his paper outlines the causes and effects of such explosions, the key conference points and conclusions, and subsequent information-exchange and teclmology-developrnent activities.

May 11, 1988

By A. Consigny

New "clean technologies" to treat mining and metallurgical effluents containing dissolved metals have been successfully applied at mine sites in North America and Asia, treating water flows up to 24,000 m3/day. These clean technologies offer significant benefits compared to conventional alternatives and provide a sustainable solution that eliminates residual waste sludge, improves water conservation, generates revenues from wastewater, and delivers overall improvements to the environment. This paper will profile these technologies, and provide best practice case study examples of their application at mining operations, including data for water chemistry, flows, water quality, capital and operating costs, and life cycle costs of treatment.

Jan 1, 2011

By H. W. Manley

SULPHUR, like the minerals of coal, iron and petroleum, is one of the essential materials in our modern expanding industrial civilization. Before discussing the salient features of the production of sulphur from the Canadian sour gas, it seems appropriate to outline the historical past and probable future utilization of sulphur. The ancient Greek writer Homer spoke of its "pest-averting sulphur" and the "divine purifying fumigation". Ancient alchemists found sulphur to be a fascinating and baffling material. The discovery of gun powder in the year of 1250, and its application to the art of war a, century later, made sulphur an important commodity in the progress of mankind. The initial manufacture of sulphuric acid in the year of 1736 by the Englishman Joshua Ward, established the basis of a chemical industry that today utilizes 80 per cent of the consumption of elemental sulphur. Commercial production of the chemical soda ash ( N a2C03) discovered in 1787 by the famous Leblanc Process, in-creased international demand for the element sulphur and marks the birthday of the Sicilian sulphur industry.

Jan 1, 1961

By K. Loutet, A. Guenkel, K. Nikolaisen

"The INCO SO2/air process was patented by INCO in 1985. Well over 80 mining operations worldwide are using this process to oxidize cyanides to cyanates in the tailings from gold, silver and copper mining operations. The sulphur dioxide (SO2) for this process can be supplied either as liquid SO2, SO2 gas or as a sulphite-based salt. The majority of SO2/air operations have used sulphite-based salts as the ‘SO2’ equivalent probably due to low capital cost. Liquid SO2 has also been used frequently, but due to concerns with safety and availability, this option is often not preferred. The solid salt sodium meta-bisulphite (SMBS) is commonly employed, but its cost is an order of magnitude higher than that of sulphur. Due to the high cost of SMBS, the increased capital cost for a sulphur-burning SO2 gas plant (green field or retrofit) usually has a pay-back of less than three years. In addition, a SO2 gas plant offers potential for significant heat recovery from the sulphur burning process. In terms of safety, the SO2 gas plant only requires the storage of relatively benign sulphur and the site inventory of SO2 will be limited to the plant gas volume. Therefore, a SO2 gas plant will not trigger the Canadian Environmental Protection Act (CEPA) E2 Regulations or the US Clean Air Act Section 112(r) accident prevention regulations, as may be the case for liquid SO2.Most existing mining operations using ‘SO2’ are gold operations, but in recent years there has been an increased interest in larger sulphur dioxide gas plants for hydrometallurgical facilities that employ leaching of cobalt/manganese minerals or precipitation of manganese/iron (e.g. Tenke Fungurume and El Boleo).This paper focuses on the production of sulphur dioxide gas generated on site and on demand for the use in hydrometallurgical processes. The capital and operational costs of a SO2 gas plant is compared to conventional process alternatives using sulphite-based salts or liquid SO2."

Jan 1, 2016

By Alfred Guenkel, Kyle Marte, K. Nikolaisen

"The INCO SO2/air process was patented by INCO in 1985 (Borbely, Devuyst, Ettel, Mosoiu & Schitka, 1985). Well over 80 mining operations worldwide are using this process to oxidize cyanides to cyanates in the tailings from gold, silver and copper mining operations. Though it is possible to supply sulphur dioxide (SO2) in either gas or liquid form, the majority of these SO2/air operations use sulphite-based salts as the ‘SO2’ equivalent reducing agent. This is probably due to the lower capital cost, safety concerns with, and availability of liquid SO2. Sodium metabisulphite (SMBS) is commonly employed, and its cost is an order of magnitude higher than that of sulphur. The increased capital expenditures (CAPEX) for a sulphur-burning SO2 gas plant could have a pay-back of less than two years. In addition, a SO2 gas plant offers potential for significant heat recovery from the sulphur burning process. In terms of safety, the SO2 gas plant only requires the storage of relatively benign sulphur and the site inventory of SO2 will be limited to the plant gas inventory. Furthermore, a SO2 gas plant will not trigger the US Clean Air Act Section 112(r) accident prevention regulations, as may be the case for liquid SO2.Most existing mining operations using ‘SO2’ are gold operations, but in recent years there has been an increased interest in larger sulphur dioxide gas plants for hydrometallurgical facilities that employ leaching of cobalt/manganese minerals or precipitation of manganese/iron (e.g. Tenke Fungurume and Boleo).This paper discusses the different processes which require SO2 as a reducing agent and compares the capital and operational costs of a SO2 gas plant to conventional process alternatives using sulphite-based salts or liquid SO2.The heart of the SO2 gas plant is the sulphur furnace. The most economical way to produce SO2 is by combustion of sulphur in air producing up to 19.5 vol% SO2. Examples of large and small sulphur furnaces are discussed in terms of design, operation, and impacts on operational costs.The SO2 gas produced in a sulphur-burning plant has to be contacted with the liquor to be reduced. The choice of gas-liquid contacting device is important, and two contacting devices are discussed: 1) Gas sparging into the bottom of leach tanks (high, nearly constant, back pressure due to liquid head) and 2) absorption columns (low gas-side pressure drop)."

Jan 1, 2014

By Thomas P. Mucho, Dennis Dolinar, Christopher Mark

During the 1990s, the former U.S. Bureau of Mines conducted a number of field studies in which the performance of different types of roof bolts were evaluated in different geologic environments. The studies used a standard suite of measurements, including multipoint extensometers, strain-gauged roof bolts, and roof bolt load cells. The sites were chosen to investigate the effect of a variety of parameters, including installed tension, bolt capacity, grout annulus, and horizontal stress orientation. Although not fully successful, the measurements provided valuable insights into each of these issues. They also showed that instrumentation and monitoring have important advantages over observational methods for comparing the performance of different roof bolting systems.

Jan 10, 2000

By W. N. Hamilton

Industrial minerals are plentiful in Alberta. Although exi ting in variety and in quantity, they constitute a minor segment of the province's mineral industry, which is based on oil and gas. In 1983 Alberta led all the other provinces in value of mineral production with a total of $22,2 18 million, 62 per cent of the total for Canada. Of Alberta's total, $22 million or about 3 per cent came from the indu trial minerals. Nearly two-third of this production is accounted for by sulphur, which is actually a by-product of the oil and ga industry. Alberta ranked third among the province in industrial minerals production for 1983, with about 20 per cent of the national total.

Jan 1, 1984

By PAUL L. DEAN

Industrial mineral deposits are widespread in Newfoundland and Labrador and a variety of commodities are produced. The province has the only pyrophyllite mine in Canada and also produces asbestos, gypsum, silica, barite, limestone, gemstones, cement and other structural materials. Large reserves of these and other industrial minerals are known and several deposits are likely future producers. Most producers are wellestablished and have large tonnages of ore reserves.

Jan 1, 1984

By John H. Fowler

Nova Scotia has been mining and exporting industrial minerals for over two hundred years. As an industrial mineral producer, this province continues to rank as the number one gypsum mining and exporting region in North America. Mining of many other commodities is ongoing, supplying many local and export markets. In all, excluding aggregate producers, there are nineteen industrial mineral producers operating at thirty sites producing nine commodities including anhydrite, barite, clay and shale, dolomite, gypsum, limestone, salt, silica sand and stone (Fig. I). Numerous aggregate producing operations supply all the province's aggregate requirements and export some of these materials to other regions of Atlantic Canada and as far away as Bermuda (Fig. 2) . Production value of industrial mineral commodities in Nova Scotia for 1982 was $105 million , representing 39% of the total value for all mineral production for the year. Because of the general improvement in the economy, indications are that the 1983 value of production will be higher.

Jan 1, 1984

By D. G. Minnes

Many non-metallic minerals and structural materials are produced in Ontario to serve the needs of domestic manufacturers and export markets. In 1982 production was estimated to have a value of $765 million. Approximately 81 per cent of this was represented by structural materials, nearly 12.8 per cent by salt, and the remainder was other industrial minerals. Total mineral production in Ontario in 1982 was estimated at $3 .16 billion, down nearly $1.5 billion from 1980's high of $4.58 billion.

Jan 1, 1984

By R. B. King

This document was prepared by the DFI International Grouting Committee with the intent to provide a summary of main Standards and Guidelines available for the North America and Europe grouting industry. This document highlights the different approaches, methods and tools used internationally. The DFI International Grouting Committee comprises all parties involved on a grouting project: Owners, regulators, engineers, contractors, and manufacturers (equipment and materials). This document is not intended to cover every conceivable application or requirement of grouting. However, it does provide standard practice requirements for qualifications, materials, equipment, testing, and production procedures for the professional engineer to incorporate into their project specific requirements.

Jan 1, 2021

By Francis D. Leathers

Four friction pile load test programs, including 23 tension tests and 9 compression tests, have been performed as part of the Central Artery/Tunnel Project in Boston, Massachusetts. The tests, performed on both precast, prestressed concrete (PPC) piles and steel piles, yielded the following adhesion values: [Soil Type Clay Clay Glacial Till Interbedded Sand and Clay Interbedded Sand and Clay Pile Type PPC Steel Steel Steel PPC Adhesion (psf) 610 to 1,200 230 to 900 220 to 550 680 1,280 ] The adhesion appears to be affected by differences in pile material type, with PPC piles having higher adhesion than steel piles. However, part of the apparent difference for the clay may be due to differences in time between driving and testing. The significant range of test data means that the need for site specific testing to determine or verify design values of adhesion should be considered during design. Creep rates at loads near failure ranged from about 0.02 to 0.18 inches per log cycle of time, with most values in the range of about 0.04 to 0.08 inches per log cycle of time.

Jan 1, 1994

By J. Michael Howard

Holes cored through the Prairie Creek lamproite volcanic complex at the Crater of Diamonds State Park by companies interested in the site's commercial diamond potential give an opportunity to redefine the size and shape of the Prairie Creek pipe. Relationships of cored rock sequences and the discovery of a previously unrecognized major rock type allow a reinterpretation of the sequence and type of intrusive activity. Trench sampling of diamondiferous rock units yielded a diamond content far below what was anticipated based on an estimate from historical records. Inadequacies of shallow bulk-testing methods for a diamondiferous pipe are examined.

Jan 1, 1999

By K. Delbeke

Within the framework of the EU Existing Substance (93/793/EEC) and REACH regulations EC/1907/2006), the copper industry initiated in 2000 a comprehensive Voluntary Risk Assessment of copper and several copper compounds. The Italian Government's Istituto Superiore di Sanità, reviewed the process and reports on behalf of the European Commission. Copper exposure levels to man and the environment from production of copper anodes and cathodes, copper powders and copper chemicals as well as fabrication and use of semi-fabrication products and down stream user products were collected across Europe. Environmental and human health effects data were obtained from literature as well as novel research programs and used to deduct safe threshold

Jan 1, 2007

By Dale R. Ralston, Roy E. Williams, Gerry V. Winter, George L. Bloomsburg

Ground water inflow into a mine and the re¬sultant impact on district hydrology can be pre¬dicted on a site specific basis once the ground water flow systems at the site are sufficiently well under¬stood so that a valid conceptual model can be de¬veloped. Ground water flow systems are controlled by the hydrogeologic properties of the materials at the, site, including hydraulic continuity along flow paths, and boundary conditions. Preliminary delin¬eation of hydrostratigraphic units for conceptual models frequently can be based on surface water data; specifically, spring locations and the gain-loss reaches of streams. Quantitative predictions of mine water inflow and its impact on regional hydrology require col¬lection and analysis of numerous types of data. Hydraulic conductivity must be defined quantita¬tively both parallel and perpendicular to bedding as well as areally for each hydrostratigraphic unit. The characteristics of the Davis shale in case his¬tory number 2 illustrate this concept very well. The storage characteristics also must be determined for each hydrostratigraphic unit and the potential or hydrostatic head should be quantified vertically and areally for each unit. The potentiometric measure¬ments in the Bonneterre Formation as discussed in case history number 2 illustrate this point. The data collection and data analysis techniques constitute the weak link in the analysis of mine inflow and district impact. The technology for char¬acterizing a mine site in the field has lagged behind the technology for mathematical simulation; we at¬tribute this development to the fact that computer modeling is relatively inexpensive compared to field data collection and analysis. On-site tests provide the best means of quan¬tifying hydraulic conductivity parallel to bedding and the storage characteristics of the unit. Pump tests with multiple observation wells provide the best information from on site tests. Hydrogeologie boundaries can be located from such multiple well tests. Multiport piezometers provide a means for determining the vertical potential in a single borehole. Borehole geophysics can facilitate the def¬inition of hydrostratigraphic units. Vertical hy¬draulic conductivity is difficult but not impossible to quantify with existing field test methods; labo¬ratory tests of cores fail to give a value represent¬ative of the field situation. The storage characteristics of a confined (artesian) hydro¬stratigraphic unit can be difficult to quantify when pumping changes the confined unit to an uncon¬fined (water table) case after depressurization and dewatering. Transmissivity and storage coefficient can be approximated to some extent for given field con¬ditions by computer modeling if enough is known about hydrogeologic boundaries. Modeling can be used in a trial-and-error approach to match transmissivity and storage coefficients to existing water level data corresponding to estimated discharge rates. A solution can also be obtained using a tech¬nique referred to as the inverse method. Unfortu¬nately, such a solution is seldom unique. Fracture flow models exist but practicality usu¬ally necessitates reversion to a basic Darcy flow model. Data requirements for fracture flow models could be difficult to fulfill where fracture aperture, spacing, orientation, and length are required. Ob¬taining such data at depth prior to mining would be impossible for any mine simulation in fractured media. We are of the opinion that most fractured media simulations can be accomplished using con¬ventional Darcy flow models by viewing the field problem on a macroscopic scale. The real challenge is to delineate hydrostratigraphic units properly in the field. The question of whether a broken-up fault zone is an aquifer or a barrier boundary is seldom simple. The fractures usually can be treated as an equivalent porous medium in either case. Only a few techniques exist for predicting un¬derground mine water inflow. These techniques fre¬quently are designed to evaluate shaft or tunnel inflow under steady-state head conditions in a sin¬gle layer rather than in multiple hydrostratigraphic units. Few computer programs exist that have the

Jan 1, 1986