Search Documents

By Jerome E. Grader

Special-purpose analog computers are being profitably applied in the process industries to perform miscellaneoas online computing functions in situations where conventional measurement and/or control hardware cannot perform a required task satisfactorily. This paper will discuss the application of such equipment in the mining industry. It is divided into two parts, beginning with a description of operation of the hardware, followed by a discussion of several applications of the computers to mining industry control problems.

Jan 1, 1969

By Kevin Andrews, Zach Agioutantis

Analysis of Coal Pillar Stability (ACPS) software, released in 2018, integrates numerous empirical pillar design techniques. The ACPS program incorporates methodologies originally available as design tools from the National Institute for Occupational Safety & Health (NIOSH), including Analysis of Longwall Pillar Stability (ALPS), Analysis of Retreat Mining Pillar Stability (ARMPS), Analysis of Multiple Seam Stability (AMSS), and concepts including Coal Mine Roof Rating (CMRR), the Mark-Bieniawski pillar formula, and pressure arch loading. The design methodologies that are the basis of ACPS were developed via analysis of significant amounts of real-world data and have been standards of the United States coal industry for decades. While there are empirical factors built into ACPS, making it ideal for use in U.S. coalfields, the concepts in the program have proven to be applicable in variable mine settings, and the software was developed to allow for user-based, site-specific modifications of key design inputs. Application of ACPS to cases outside the regions for which it was developed must be approached carefully, and continuous development of site-specific data is mandatory. A case study is presented involving the application of ACPS to assess pillar stability and assist future design for an underground lignite mine in Eastern Europe. Assessment of in-mine observations, review of the geology of the lignite mine, and evaluation of specific conditions associated with a failure event resulted in “calibration” of key input factors to ACPS. Scenarios evaluated with ACPS suggest that pillar strength and overburden depth are key factors for the determination of pillar stability and design in future areas.

Jun 25, 2024

By A. D. Ajak

A complete mining cycle involves digging, loading, hauling and dumping of the materials. Moving the ore from the pit to the crusher or to the waste dump requires access routes, which are termed haul roads. These roads have to be designed, constructed and maintained. A review of the literature indicates a common consensus among researchers that there should be a balance between haul road economics and safety of the road users. However, there is no universally accepted theory on the design of haul road geometry and, in particular, road dimensions. The current industry practice is based on empirical data and rules of thumb developed by engineers. Therefore, this paper will use the overlooked and less valued branch of mathematics, arithmetic progression, to derive a road width equation. It is beyond the scope of this paper to discuss all road design components. The focus will be on the geometric aspects, which more often have a direct impact on road safety. In this paper, the current design practices and techniques for haul road geometrics design will be explored, using arithmetic progression to formulate road width equations, case examples to apply the equation and then validating the results with conventional techniques that have confirmed the reliability of road width equations, thus eliminating use of tables during design.

Jan 1, 2012

By L. Archambeault

This paper describes preliminary research on the application of Markov Decision Processes (MDP) to Real Option Valuation (ROV) and the optimisation of mine scheduling. The MDP framework is a novel approach to option valuation and scheduling in mining operations. A learning agent is introduced into the valuation process of an open pit, where prices and block ore grades have probabilistic values. The prices are modelled using a mean reverting diffusion process and the block grades using sequential Gaussian simulation. The agent is asked to learn which production parameters should be used in order to maximise the overall value of the project. The introduction of the agent permits a real option approach to mine valuation, such that the value associated with the robustness of a design to uncertainty can be measured. A simulated example is used in which there are ten blocks to be extracted under conditions of grade and price uncertainty. Using policy iteration, an optimal policy is generated and the value of production options is found. The potential financial gains from applying MDPs to mine valuation and optimisation are substantial and warrant further investigation.

Jan 1, 2007

By Gupta A, Fung C. C

The hydrocyclone parameter d5Oc is estimated by the application of Artificial Neural Network (ANN). Results indicate that ANN performs equally well as compared to statically derived analytical formulae. Results also show that ANN will also be convenient in the on-line control of hydrocyclones.

Jan 1, 1996

In Mount Isa voltage and frequency fluctuations caused. by haulage shaft operation gave considerable difficulties with the initial application of Atomic Absorption Spectro-photometry.The methods used to stabilise the various units ' have been described.- Some other difficulties and the means used to eliminate or reduce them together with a-modified burner design are also discussed.

Jan 1, 1963

By Willie M. NeSmith

Conventional augered, cast-in-place (ACIP) piles were introduced into the New York City area as a result of the damage to existing structures caused by pile driving operations. ACIP piles are often specified where deep foundations are to be installed adjacent to transit facilities, sensitive underground utilities or in close proximity to existing structures. However, loss-of-ground issues associated with the installation of ACIP piles have prevented the wide-scale use of these systems. Beginning in 2002, Berkel & Company Contractors, Inc. began using its augered, cast-in-place displacement (ACIPD) system in the New York City area. Like conventional ACIP piles, this system produces almost no vibration. Also, as almost no material is brought to the surface, there is no opportunity for loss of ground. This paper presents a description of Berkel's displacement pile system and a brief discussion of six projects in the New York City area that have been executed with this system over the past two years.

Jan 1, 2004

By Robert Matusewicz

Ausmelt Technology has been applied to the recycling of spent pot liner (SPL) generated from primary alnminum production. The process is centered on the Ausmelt furnace, in which the SPL is converted under high temperature, oxidizing conditions to an HF containing gas stream and inert slag. fluorine is recovered from the SPL as HF gas and is concentrated and used to manufacture AIF) for recycle to the aluminum smelters. Approximately 87% of the fluorine can be recovered and converted to AIF), with the remainder being effectively tied up in the by product slag. Cost projections show that the recycling process will be competitive with other processes for SPL. The production and recycling of AIF) provides available credit that significantly offsets the operating cost of the facility. Ausmelt Technology for recycling of SPL is currently being marketed in North America by Ausmelt Technology Corporation in Denver, Colorado, and in the rest of the world by Ausmelt Limited of Dandenong, Australia.

Jan 1, 1996

By Paul H. Atkinson

"Sampling in the mineral processing industry has always been a subject which has received considerable discussion. There have been many volumes written on theory, techniques and practical application of sampling. However, until recently, the companies were not completely aware of the potential savings available with properly designed sampling systems both to assist in pieces: control and final product values.Definition In our discussion today, we will define sampling as the operation of removing a part, convenient in quantity for analysis, from a whole, which is of much greater hulk, and removing it in such a way that the proportion and distribution of the quality to be tested, i.e. size of particle, moisture content, specific gravity content, mineral and chemical composition, are the same in both the sample and the whole.Application It has been well established that undetected errors can result in large economic losses, thus most firms depend upon some type of sampling and sample analysis as a control in their continuous processing of materials. Despite the large investment in facilities and personnel the ""analysis"" of a sample can be no more accurate or reliable than the sample on which it is being based. The importance of sampling is recognized by a great many but it is appreciated by only a few, largely because it is sometimes one of the items which is taken for granted."

Jan 1, 1976

The schlieren technique describes an optical analysis method designed to enhance light distortions caused by air movement. The ability to visualize air flow has significant implications for analyzing underground mine ventilation systems, including the enhancement of surveys and models. Currently, traditional schlieren methods are impractical underground. Background oriented schlieren (BOS) provides a solution to this problem. BOS requires two primary components, a professional quality digital camera and a schlieren background. A schlieren background is composed of a varying contrast repetitive pattern, such as black and white stripes. This background allows the camera?s sensor to capture minor light diffractions, such as those caused by air flow. Although BOS shows great potential for ventilation analysis, sensitivity is an issue. This paper seeks to validate the BOS technique for imaging flow through a regulator by comparing BOS images with traditional schlieren images. This paper also outlines initial experimental efforts used for the validation.

Jan 1, 2011

By K. R. Griffin, K. D. Luxbacher, E. C. Jong

The schlieren technique describes an optical analysis method designed to enhance light distortions caused by air movement. The ability to visualize air flow has significant implications for analyzing underground mine ventilation systems, including the enhancement of surveys and models. Currently, traditional schlieren methods are impractical underground. Background-oriented schlieren (BOS) provides a solution to this problem. BOS requires two primary components, a professional quality digital camera and a schlieren background. A schlieren background is composed of a varying contrast repetitive pattern, such as black and white stripes. This background allows the camera’s sensor to capture minor light diffractions, such as those caused by air flow. Although BOS shows great potential for ventilation analysis, sensitivity is an issue. This paper seeks to validate the BOS technique for imaging flow through a regulator by comparing BOS images with traditional schlieren images. This paper also outlines initial experimental efforts used for the validation.

Jan 1, 2011

By P. Fecko

The objective of the paper was application of bacterial leaching on two brown coal samples from locality Mine Druzba, seams Antonin and Josef (Sokolov brown coal basin, Czech republic). Based on the results of bacterial leaching and petrologic analyses of the given samples, it is possible to say that application of bacterial leaching gived good results. Applying bacterial leaching it is possible to remove from 34% to 47% of total sulphur and from 45% to 64% of pyritic sulphur from the coal.

Jan 1, 2014

By Lewis Delano

IT HAS been generally recognized that, owing to the extreme friability of, galena, fine grinding has a tendency to cause excessive sliming of the mineral, so operators of lead mills have attempted to avoid this condition by commencing concentration at as coarse sizes as any mineral is freed. Jigging has been the basis of the milling process, making a clean coarse concentrate and a large amount of tailing, which was considered sufficiently low-grade to be rejected. However, developments and improvements in concentration processes are everywhere changing the low-grade tailing of yesterday into material worth retreating today. Investigations of the work of the Hancock jig on the Bonne Terre ore- have shown that the best results to be expected will give a tailing assaying 0.75 per cent. lead; the average over all conditions and grades of ore will be between .0.80 and 0.90 per cent. By crushing the jig tailings in ball-mills and retreating by tables and flotation, a tailing of considerably lower grade can be made; the problem then becomes an economic one of increased crushing costs versus higher recovery. In considering the entire elimination of jigging, the increased smelting charges; due to a greater amount of slime galena will be counterbalanced by the lower operating cost, in-creased recovery, and the many advantages of a simpler flow sheet. In developing these problems in the Bonne Terre mill of the' St. Joseph Lead Co., a long series of tests has been carried out covering every stage of crushing and concentration, and a large number of possible flow sheets were considered and tried. Only the final results and a few comparisons will be given here. At the same time, a careful and detailed cost-keeping system has enabled us to compare milling costs with the various flow sheets, and to calculate the economics of the problem' with great accuracy. .

Jan 8, 1920

By J. Hanna

Four Ca-bentonitic clays from Alabama were evaluated for use in Diammonium Phosphate (DAP) or Urea Ammonium Nitrate (UAN) fertilizer suspensions. The viscosity and gel strength of suspensions prepared with different proportions of a Western bentonite clay and sodium exchanged Alabama clays, were measured as a function of clay content and dispersant concentration. The results obtained suggested that three of the Alabama Ca-bentonites would replace about 40% of the more expensive Western bentonite in UAN and DAP fertilizer suspensions. The performance of the Na-modified clays, prepared according to the TVA soda ash method, was as good or even better than those observed for the Mg-, Na/Mg-or K-modified clays. The TVA clay modification procedure appears to be reliable and cost effective.

Jan 1, 1989

By H. J. Hutson

BRS, Inc. has utilized Carlson's Natural RegradeTM software to design the reclamation and stabilization of abandoned open pit uranium mine spoils, AML Project 16N, located in the Gas Hills Uranium District in central Wyoming. This work was completed for the State of Wyoming's Abandoned Mine Land Program (AML) on preSMCRA (Surface Mining Reclamation and Control Act) sites for which no reclamation obligation existed. The project successfully stabilized an eroding spoil dump, enhanced the local view shed, created habitat diversity and provided a significant source of fill material for open pit highwall hazard mitigation efforts. Additionally, the project served to evaluate innovative reclamation design methods, engineering software and grade control technology. This project was nominated for a National Association of Abandoned Mine Land Programs award by the State of Wyoming. The results of this project will be presented as a case history of the Natural RegradeTM approach to surface mine reclamation. Based on the successful application of this new mine reclamation technology on the AML 16N Project, reclamation designs for spoils associated with planned underground uranium mine operations at the Velvet Mine in the Lisbon Valley Uranium District of Utah for Uranium One USA, Inc have been prepared and will be presented. Critical elements will be the encapsulation of unsuitable materials, long term hydrologic stability, and sequencing and staging of ore and mine waste for final reclamation surface construction. The goal of the Uranium One Velvet Project will be to apply best available technology to reclamation planning and fully integrate the reclamation design with the mine planning. Benefits of the approach should include improved public and regulatory perception of the project, facilitate mine permit approvals and the eventual timely release of reclamation bonds, as it is anticipated the stable landform created through this process will result in more rapid stabilization of the site to pre-mine geomorphic conditions. NATURAL REGRADETM CASE STUDY AML Project 16N, D-9 and K Pit Reclamation Project, is located in an intensely disturbed area of the West Gas Hills Uranium Mining District in Fremont County, Wyoming. The overall design calls for the placement of approximately 7 million cubic yards of backfill materials in the D9 and K Pits, imported from adjacent mine spoils including the Central Spoils, and from local highwall excavation. Figure 1 shows the location of the Central Spoils excavation area, as well as the D9 and K Pits fill area. The entire project is located on public lands administered by the Bureau of Land Management, Lander, Wyoming District Office. No access controls are in place at the abandoned mine sites. The public lands are administered under a multiple use land policy including grazing of range land, public recreation, active mining and exploration, and oil and gas. The project site is located along Fremont County Road No. 5, which is a moderately well traveled road. Reclamation of the numerous and large abandoned open pits in the Gas Hills Uranium District has reduced the risk of death or injury to the public. Site History and Background The Gas Hills Uranium District was mined by multiple companies during the period from 1955 to 1981. The uranium was hosted in the Wind River formation, a sequence of soft sedimentary layers of interbedded sandstone, clayey shales, and conglomerates. Uranium was precipitated out of ground water in classic roll front deposits, which are found from very near surface to depths greater than 400 feet. Prior to the enactment of the Surface Mining Control and Reclamation Act of 1977 (SMCRA), very little reclamation work was performed when mines were abandoned or closed. The State of Wyoming Abandoned Mine Lands Program has worked to mitigate hazards associated with large open pits, control migration of unsuitable materials and restore watershed functionality of lands in the district. Additional reclamation is being performed by mining companies on bonded lands. Figure 2, Gas Hills Uranium District aerial photograph, shows the extent of the mining disturbance in the district. [ ] Project Hazards and Concerns The purpose of AML Project 16N is to mitigate hazardous conditions and risk to the public associated with open pit highwalls and toxic, acid forming, and /or radioactive mine waste materials. The D9 and K Pits are contiguous open pits characterized by an 8,800 foot long hazardous highwall that averages over 200 feet tall. In addition to the physical hazard presented by the highwall, the project addresses

Jan 1, 2009

By P. Somasundaran

Treatment of mineral surfaces with appropriate surfactants plays an important role in mineral processing operations such as flotation, flocculation and dewatering. Recently biosurfactants, in particular, have received a considerable amount of attention because of their unique surface active properties and biodegradability. In this work we examined the performance of biosurfactants, sugar based alkyl glycosides and sophorolipid esters as reagents to control the hydrophobicity of minerals with selectivity of adsorption on mineral surfaces for flotation applications. It was discovered that n-dodecyl-ß-D-maltoside adsorbs on alumina, titania and hematite but, interestingly, not on silica. The hydrophobicity obtained is governed both by the surface coverage as well as the nanostructure of the adsorbed layer in terms of orientation of the adsorbed species. Surprisingly, even though the above surfactants are non-ionic, their adsorption was pH-dependent. We have correlated this pH dependence to the type of species on the mineral surface. Also it is shown that mixing of these surfactants with traditional ones can help reduce the carbon footprint due to synergy between the reagents and help selectivity due to antagonism. The experimental results were analyzed to get information on optimal pH and dosage conditions, for mineral surface modification. The study provides guidance for mineral treatments using biosurfactants and the potential use of these next generation reagents in mineral processing.

Jan 1, 2014

By W. D. Gould, A. Kapoor, K. Morin, P. Bédard

This paper presents the results of a research study that is being conducted by the Mine Effluents Program, Mining and Mineral Science Laboratory (MMSL), Natural Resources Canada aimed at evaluating biotechnology processes for the treatment of nitrogen compounds such as thiocyanide (CNS) and ammonia (NH4-N) which are present in gold mill effluents. A sequencing batch reactor (SBR) technology, commonly used for the biological treatment of municipal and industrial effluents, was used in this study. In the SBR process, the micro-organisms were able to degrade CNS to NH4-N and NH4-N to nitrate (NO3-N) at operating conditions of two 12 h treatment cycles per day, with pH maintained in the 7.4 to 7.6 range, and at room temperature (approximately 21°C) and also at 12 °C. The end products of CNS and NH4-N biological oxidation were NO3-N and sulphate (SO4) that are relatively non-toxic. Partial removal of NO3-N was achieved by biological denitrification reactions in the SBR process. The SBR process effluent was measured to be non-toxic to rainbow trout based on the 96 h acute toxicity test. The microbial consortium isolated from the SBR treating a simulated effluent was able to effectively oxidize CNS and NH4-N to NO3-N in water samples (under batch conditions) collected at three mine sites located in Quebec, the Northwest Territories, and Yukon.

Jan 1, 2004

Microorganisms have been used throughout history for the benefit of mankind with some of the earliest applications being in the production of fermented foods and beverages. Reactions involving inorganic substances such as metals, sulphur and sulphide compounds were hardly ever used until the early 1900s when it was discovered that Thiobacillus ferrooxidans was capable of promoting the oxidation of metal sulphides in ores. Today, it is widely recognised that biotechnology has great potential in the minerals industries, particularly in such areas as the leaching of low-grade ores of metals such as copper, gold and uranium; removal of heavy metal ions from process streams and from liquid process wastes; and in the desulphurisation of high-sulphur fuels. Although widespread commercialisation of mineral biotechnology has not yet been achieved, it is estimated that by the Year 2000 mineral biotechnology will have a significant impact on the minerals and metal industry and will probably account for tens of billions of dollars worth of annual production world-wide. This paper examines the actual and possible future applications of biotechnology in the minerals, metal refining and fossil-fuel processing industries. Firstly, the important chemical (and biochemical) principles involved in bio-dissolution of metals from ores and solid wastes, and in bio-accumulation of metals from process and waste solutions are reviewed, including leaching practices - past, present and future. Microbial desulphurisation of coal, and microbially-enhanced oil recovery are also discussed. The practical aspects of genetics and genetic engineering, the types and characteristics of those microorganisms important to mineral biotechnology, and the current research trends are reviewed as well. KEYWORDS: Biotechnology, microbial leaching, bioaccumulation, biosorption, bioleaching, biohydrometallurgy.

Jan 1, 1993

By Lynn Long

We have seen many new developments in the explosive and blasting accessory category, but one of the most useful items is the blast control plug. Blast control plugs are cone shaped units that are placed in the stemming just above the explosive load. They are placed about 8 to 12 inches up into the stemming material.

Jan 1, 1996

By Song Yongxue

During the design and operation stages of a block caving project, a large amount of research and development work has been undertaken in the Tongkuangyu Copper Mine. This paper presents the research achievements from these studies, including a rock mass quality evaluation method, cavability prediction, fragmentation evaluation, caving mechanisms, a computerised production scheduling model and the optimised draw control system. The main features of the block caving system in the Tongkuangyu Copper Mine are also discussed.

Jan 1, 2000