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By M Revell, B Sainsbury, D Sainsbury

This paper extends the existing knowledge associated with the design and placement of prefabricated pastefill barricades through a consideration of asymmetric drive geometry and conditions. The load capacity of prefabricated barricades and their failure modes are considered in relation to abutment geology and barricade geometry that includes curvature and span and drive geometry that includes abutment angles, haunch angles and misalignment. Design charts are provided for typical barricade sizes to provide general guidance for design capacities and optimising location placement based on asymmetric drive geometry. A recent barricade failure is considered in relation to the drive geometry and the potential impact it had on the installed capacity.

Nov 29, 2022

By Justin Jensen, Luis Moya, Jose Carlos Durazo, William Szolga, Tyler McCallum, Tim Doubleday

Sulfuric acid mist is an undesired by-product of the copper electrowinning process, caused by oxygen evolution at the anode which entrains droplets of the acidic copper electrolyte solution. As the oxygen moves to the surface of the cell, these droplets become aerosolized resulting in acid mist. The addition of chemical anti-misting agents to the copper electrolyte is a common mitigation technique. This paper details Syensqo’s laboratory development of a new environmentally friendly acid mist suppressant, ACORGA® EW98. The product exhibits excellent acid mist suppression and it is fully compatible with the adjacent solvent extraction process. Lab and pilot test results are reviewed ahead of future planned industrial trial testing.

Feb 1, 2025

By AIME AIME

PRESIDENT Edwin Ludlow and Secretary Bradley Stoughton made their first-trip of the year 1921 to visit Local Sections of the Institute, and talk over Institute interests and policies, during the early part of April. The main purpose of the trip, as usual, was to bring back to headquarters suggestions or comments on the Institute's work on the part of, members. The trip was made a brief, one by the necessity of remaining in New Fork until Apr. 1, and of the attendance of President Ludlow at a meeting of American Engineering Council and. the organization of a Philadelphia Section of the Institute in Philadelphia on Apr. 16.

Jan 1, 1921

By Herbert Hoover

THERE is one problem of the new administration that has received the attention and thought of the organized engineers of America for many years past. This is the problem of the reorganization of the Federal Government. The, inadequacy, the wastefulness, and the inefficiency of our federal organization was evident, enough under pre-war conditions. These inadequacies, these inefficiencies, these wastes were exhibited to the country during the war at the cost of millions. Congress has placed the problem in the hands of a very able Congressional Joint Committee, but if this Joint Committee succeeds in securing the imminently necessary results it will only be by full insistent support to it by public opinion. Many attempts have been made at reorganization before but all, of them have gone to the same crematory-the interminable differences in opinion among the executive and legislative officials over details.

Jan 1, 1921

By Jon A. Hummer, Aleksandar D. Bugarski, Shawn Vanderslice, Teresa Barone

Reducing the contribution of heavy- and light-duty diesel-powered equipment to concentrations of aerosols and gases is essential to industry’s efforts to improve air quality in underground mining operations. The results of this study demonstrated a potential of control strategies based on retrofitting existing power packages with diesel oxidation catalyst (DOC) and diesel particulate filter (DPF) systems and repowering existing systems with advanced power packages to reduce contributions of diesel-powered vehicles to concentrations of diesel aerosols and criteria gases in underground mines. The implementation of viable exhaust aftertreatment systems and advanced diesel power packages could be instrumental in the underground mining industry securing a clean, economical and dependable source of power for mobile equipment.

By Glenio F. Daniel, Vinícius O. Barbosa, André R. Gomes, Sergio N. Monteiro, Victor B. de Souza, Frederico M. Margem

Nowadays notorious technological growth is encouraging research natural materials in substitution to more usual synthetic ones. One of those initiatives is the vegetable fibers that have been studied for the replacement of glass and carbon fibers. This research addresses broadly the study of the natural fibers mechanics properties, but none study have been made with natural fabrics, such as the pure jute fabric used in Brazil to make ropes and carpets. This work aim to evaluate the mechanical behavior of jute fabric strips with different dimensions to be used as reinforcement into polymeric composites Lots of those fabric strips were subjected to tensile tests in order to obtain the tensile resistance for each strip size. The results obtained during the tests were satisfactory and indicated that 160 × 160 × 1 mm correspond to the best result and the perfect fabric strip for the composite reinforcement.

Mar 1, 2017

By Thomas P. Goslin

T e mechanization of industry to reduce labor costs and to improve product quality is affecting he scale industry as it has affected many other industries. With increased emphasis on higher production rates many operators are experiencing difficulty in overcoming production problems where weight is a factor. Unfortunately, the scale industry has not shown the development over the last twenty-five years that other instrument industries have. For centuries the balance scale has been the standard and the workhorse of most weighing operations. In recent years considerable effort has been applied to designs to make balance scales more acceptable to industries employing automatic or semi-automatic processes. For the most part the designers have not attempted to replace the basic scale but toautomate functions of material handling and human judgement. Modern dump scales, for example, will accept material from a conveyor until a preset amount of material is on the scale, At this time the scale turns off the conveyor, dumps the load of material and repeats the operation with any desired timing. These improvements have helped industry. Even the scale observer has been replaced with devices which observe the scale reading and operate on weighed objects according to their weights. In spite of' the application of automation to the material handling, the balance scale has not been completely satisfactory. One reason for this is fairly evident when one considers the construction of the scales. Inherently, they are slow devices because of the inertia of the beams. The beam scale, primarily a static measuring device, is at the best limited to slow dynamic measurements.

Jan 1, 1958

By P Mikula, B Darlington, J Graham, P Young

In underground mines experiencing dynamic events, there is an ever-present challenge to design and maintain a capable ground support system. One key component of ground support systems is surface support, which serves the essential roles of retaining failed rock and transferring forces generated by surface displacement to rock bolts or other support elements. Observations underground show that in many instances, standard mesh panels alone do not provide sufficient dynamic support to retain substantial bulking failures imposing displacement onto mesh, and in such cases Mesh straps and W-straps may be employed. Determining the performance of surface support elements proves to be difficult, with a multitude of variables at play in the underground environment. Quite comprehensive work has been completed on laboratory testing of surface support systems; however, very little work has been conducted on in situ dynamic testing of Mesh straps and W-straps. In 2019 in Western Area’s Flying Fox Mine, in situ dynamic testing was conducted on a series of Mesh straps and W-straps using Sandvik’s in situ Dynamic Test Rig (DTR). The testing regime applied impact energies from 5.1 to 15.3 kJ to Mesh straps and W-straps. The performance of the straps that did not fail was a maximum absorbed energy of 9.3 kJ and 14.2 kJ for the Mesh straps and W-straps respectively. The testing successfully demonstrated the ability of Sandvik’s DTR to test not only rock bolts, but also surface support elements, creating new testing and research possibilities. The testing also provided important design guidance data that is not practicable to obtain using laboratory dynamic testing facilities.

Nov 29, 2022

By A. J. Vietti

"Drought conditions and the possible lack of sufficient raw water supply are a constant reminder to the Southern African diamond miner of the need to minimize raw (new) water input while maintaining or expanding mine throughput.Since water input volume is directly related to water output (loss) volume, mainly to the tailings, it is obviously beneficial to dewater the tailings as much as possible. However, this may not always be as easily achieved as first thought. Owing to the unique mineralogy of each kimberlite deposit and the unique chemical profile of each raw water source, dewatering of the slurry is not a standard process that can be applied equally across the entire diamond industry.This paper presents a first-step strategy that kimberlite diamond mine operators should consider and apply to meet and exceed their watersaving targets. Introduction A common metric for measuring water use efficiency in a metallurgical plant is the amount of raw water used per ton of head feed treated (m3/t). The metric includes all water recycled from the dewatering process and from the tailings storage facility (TSF), and the only inputs are tons of ROM ore and cubic metres of raw water make-up to replace water lost to evaporation, seepage, and lock-up at the TSF (Figure 1).The volume of new raw water available to the process is not unlimited and a maximum monthly allowance is typically set during the mine permitting process. Consequently, if the volume of water lost exceeds the volume of new water available or alternatively, in times of drought where the allowable volume is unavailable, the plant has no other option but to reduce throughput.However, if the plant operator is able reduce the volume of water lost to the TSF, the plant will have additional capacity to either increase tonnage throughput or sustain nameplate capacity during periods of severe drought. The obvious conclusion, therefore, is to reduce the volume of water lost to the tailings by improving the efficiency of the dewatering process (typically gravity thickening) simply by increasing the density of the tailings being discharged. In practice, however, the unique mineralogy of each kimberlite deposit and the chemical profile of the raw water source used imply that at some mine sites, solid/liquid separation (or settling) of tailings slurries at the dewatering process is more easily achieved than at others. In these cases, simple practical steps such as firstly improving the flocculant reagent make-up and dosing control, and secondly focusing on thickener discharge control, are the only requirements for enhancing water recovery at the dewatering circuit. At other mine sites however, solid/liquid separation of the tailings may not be achieved at all, in which case efforts to increase water recovery by improving reagent dosage and thickener control would be fruitless unless the colloidal properties of the thickener feed slurry are modified."

Feb 1, 2019

By Edward I. Renouard

"THE mineral industry is constantly undergoing changes and facing challenges, and today we are in the midst of another serious one -namely, manpower requirement at every level in the mines, shops and plants. In the not too distant past we had a situation where labour was plentiful, although the equipment, by present-day standards, was quite inadequate, and that's easily understandable when you look back at the primitive methods by which our Western mines were first developed and operated, and then improved by the inventiveness and ingenuity of man.I'd like to show you a few slides from drawings made by Buck O'-Donnell which illustrate some of yesterday's methods of mining. Some of you probably had first-hand experience with some of these so you know they were tedious, time-consuming and involved a lot of heavy labour.Taking the Anaconda Company operations at Butte as an example, we can see what has happened in just the past ten years. In August of 1956, the Butte mines had 5,516 day's-pay employees and 976 salaried employees, for a total payroll of 6,492. In August of this year, there were 3,645 day's-pay employees and 605 on the salaried roll, for a total of 4,250. The number of contract miners had gone from 1,347 in 1956 to 606 in 1966 and that of other underground miners from 2,893 ten years ago to 1,149 this year. Along with these changes, however, another change of special significance has taken place, and that is in the number of skilled craftsmen, surface engineers and so on required for our operations. In 1966, we had 1,890 of these people, 600 more than in 1956 and nearly three times as many as just twenty years ago."

Jan 1, 1967

By George F. McIntyre

The subject of this paper is mineral processing chemicals - how they work and where they end up environmentally. First of all, it is necessary to recognize that water is the most universally and widely used chemical used by the mining industry to separate desirable minerals from unwanted wastes, sands, and slimes. Of the total world's water supply, over 97 percent is found in the oceans. Another two percent is tied up in the ice caps, leaving roughly only one percent for us to work with. This one percent is distributed either as ground or surface water and makes up the bulk of all water used industrially. Even with such a small proportion available for immediate use, there appears to be enough fresh water to meet our needs for at least another hundred years. This availability, however, depends heavily on how we handle our waste waters, how we process them, and how we plan for their reuse. Certain governmental agencies have been charged with the task of setting up standards of water quality which must be met prior to environmental discharge. There is even discussion of zero discharge from industrial operations. Due to limited supply and availability, the mining industry has always been forced to reuse its process water or to treat it prior to discharge. Consequently, we are in an enviable position and are presently able to live with the environmentalists demands. To stay on top of the situation, it is necessary to continually concern ourselves with the .effects of changing orebodies and reagents on the final mill effluent. From a process standpoint, it is also important to recognize the impurities of plant recycle water and how they might tend to influence overall operations

Jan 1, 1974

By B Cook, M Karakus, J Light, E K. Chanda

The aim of this research is to develop a model through which the appropriate paste recipe parameters, for example solid content and cement content, can be derived given the stope specific requirements such as stope dimensions, required strength and curing time. A large number of samples and uniaxial compressive strength (UCS) tests were conducted at the Angas Zinc Mine (AZM) paste plant and testing facility. Samples were varied in tailings solids content, cement content and sand content. The results of this testing were modelled to determine the UCS relationship to each of the parameters. The output of this modelling was an easy-to-use program that outputs the design mixture given the stope dimensions and required stope backfill-curing time. This allowed flexibility within the mining schedule for curing times of cemented paste backfill stopes. The optimised schedule using the stope specific mix design, when compared to the standard 14-day curing time used previously, resulted in a smoother weekly mine production schedule. For the modelled 12-week period (one quarter) the 14-day curing time would result in an eight-day shutdown of the mill. The cost for each shutdown is in the order of $125 000/d. Due to the unique nature of each mine’s tailings, this exact outcome would not be directly applicable to another paste fill site. However, the process in this report could be followed for another site to achieve a system similar to the output of this project. This would ultimately lead to a more optimised backfill and stoping cycle and a more optimised mine.CITATION:Chanda, E K, Karakus, M, Light, J, Cook, B and Harris, A, 2014. Optimisation of the paste fill cycle at Angas Zinc Mine, Strathalbyn, South Australia, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 259–264 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By I. Gaballah

Decontamination of synthetic solutions of PbC12 containing 10, 100 and 1000 ppm of lead, using chemically treated barks had been studied. The percentage of !cad cations' removal from solutions depends upon the pH and the initial concentration. About 99 % of the initial lead content can be removed at pH of about 3.5, 5.5 and 6.5 for initial concentrations of 10, 100 and 1000 ppm respectively. The maximum retention capacity of the treated bark is about 83 mg of lead per gram of modified bark. Bark loaded with lead had been analyzed by Infra Red spectroscopy. It seems that lead reacts with hydroxyl groups of the phenolic constituents of the bark. On the other hand, the removal of a lead cation by the bark leads to the release of two H+. This seems to show that the removal of lead could be interpreted as an ion exchange with hydrogen belonging to the hydroxyl groups of the modified bark.

Jan 1, 1994

By W. W. Wen

Approximately 3 percent of the raw coal processed in U. S. Steel coal-preparation plants ultimately reports to slurry- tailing disposal. The usual disposal method is to pump the refuse slurry containing the minus-48 mesh (300 µm) refuse into dams or impoundments that are constructed of the coarse refuse. The failure of an impoundment at Buffalo Creek, Saunders, West Virginia and the sliding failure of a coarse refuse pile at Aberfan, Wales, England, resulted in an evaluation of refuse disposal methods by various regulatory agencies as well as coal producers. The result of this evaluation was the promulgation of Federal regulations dealing with the construction, operation, and final abandonment of coal refuse disposal areas. As a consequence of these regulations the use of the landfill/impoundment method of disposal became in some cases economically urlfeasible or technically impossible. U, S. Steel has studied a number of alternative methods of refuse disposal. During an investigation of mechanical dewatering with a pressure filter, Portland cement was added to the slurry to solidify the filter cake. Because of the success of the cement addition it was decided to study the stabilization of fine-coal-refuse slurry through use of cement-type additives.

Jan 1, 1979

By Byron M. Jones

The use of computers in system analysis is well established. Analog computers have been used for this purpose since about 1940. As the power of digital computers increased and their cost decreased, much of the analysis formerly done by analog computers has been diverted to digital computers. The mathematical foundation for system analysis was laid between the years 1700 and 1900. In the 1930?s, telephone repeater amplifiers were designed using systems analysis techniques. From 1940 to 1960 systems were analyzed using either direct simulation or LaPlace transforms. Since 1960 analytical methods have been expanded to include linear vector space theory. All of these methods are being used to analyze the dynamic behavior of mining machinery.

Jan 1, 1974

By G. H. Li

Preparation strontium carbonate with celestite concentrate by flotation is studied by agglomeration-reduction roasting process. It is shown that, the drop strength of green pellet is greater than 4 times?(0.5m) -1 under the balling conditions of moisture of 9% and time of 18~20min. Lignin xanthate obviously improves the ballability of the celestite concentrate due to the increase of surface hydrophilicity, therefore, the balling rate is increased, as well as green ball strength. The drop strength of 7 times?(0.5m) -1 can be obtained when the lignin xanthate dosage is 0.5%~1%. Reduction roasting with anthracite shows that the SrSO4 conversion is 82%~83% for celestite concentrate pellet, under the optimal conditions of roasting temperature of 1100~1150? and time of 30min, and it is 10% higher than conversion of celestite lump under the same conditions. The strontium carbonate are prepared after roasted pellets are leached, purified and carbonated, and the SrCO3 content is higher than 97% , while the content of CaCO3 is less than 0.3%.

Jan 1, 2014

By Vladimir I. Skorohodov

The technology for copper utilization from circuit boards etching is proposed. The technology is based on combination of electrochemical and sorption methods. The conditions of copper electroextraction from ammonia-chloride solutions with obtaining of cathode copper are defined. The stage of electrolysis is destined for copper recuperation from etching process. Due to the electrochemical processes are unacceptable for cathode precipitation of the copper from diluted solutions such as rinse waters, the concentration on the strong-based cationites are used. After filtration throw the sorption columns solution is directed to the stage of circuit boards washing. It allows organizing close loop water recirculation. After saturation. resin is 'regenerated by chloride ammonium solutions. Obtained eluate directed to the etching stage, Generally. the technology provides copper recuperation and minimize wastes amount.

Jan 1, 2001

By Groom P.

The wastage of timber in coal-mines that is caused by decay is very great; in fact, far greater in this country than is generally realized. Mr. E. W. Peters estimates that of the whole wastage of timber in mines in the United States of America, 50 per cent, is due to decay and insects; of this 50 per cent, an overwhelming part is due to decay. The most efficient methods of decreasing this grave loss can be devised only by co-operation of the mining engineer and the scientific expert, and it is partly in the hope of procuring such collaboration that this paper is written. It contains, therefore, a resume of our present knowledge of the decay of wood, and of the economic methods of checking this in mines; but, with a view to improving those methods, it also directs attention to the gaps in our knowledge and the means by which these can be filled by future investigation

Dec 1, 1916

By Bianca Foggiatto, Marcos Bueno, Rajiv Chandramohan, Eddie McLean, Greg Lane

"With the increasing depletion of high-grade ore deposits, smarter mineral processing solutions are required to achieve sustainable and economic methods for mining and processing low-grade deposits. In order to make the treatment of low-grade deposits economically viable, large quantities of rock need to be mined and processed. The associated infrastructure costs (power, water supply, accommodation and support services, waste storage) result in a substantial penalty on the project, from both capital and operating cost perspectives. As a consequence, the challenge for the mining industry is to overcome the associated rise in energy and water consumption as well as increased project complexity when processing large amounts of low grade ore. Ore sorting technologies have been used for many years, predominantly on small projects, enabling the upgrade of marginal ores. Several sorting methods based on characteristics including specific gravity, radiometry, colour, particle size, grade and other detectable physical characteristics have been employed. The challenge for large low-grade ore bodies is to crush and sort at coarser rock size in order to minimise specific energy consumption in comminution and to reduce waste disposal costs. For large projects, the understanding of the economic impact of ore sorting is limited. The economic drivers include plant head grade improvement; sorting infrastructure capital, operating and maintenance costs; waste material handling and other environmental costs related to waste disposal. This paper analyses the economic impact of ore sorting in a large mineral processing operation. The focus of the analysis is to compare NPVs for a circuit including screening and ore sorting stages. A project for processing an Australian copper sulphide ore is considered as an example for this study."

Jan 1, 2014

By Rakesh Kumar, S. Mehrotra, T. Alex

"This paper, an overview of our recent findings on mechanical activation (MA) of minerals/materials, emphasizes the importance of sample genesis, mechanically induced/altered porosity and surface area, mineral interactions, glassy inorganic materials, surface alteration and zeta potential changes and, mechanically induced reactivity of solids. Materials investigated include Al-oxyhydroxides (gibbsite and boehmite), fly ash and granulated blast furnace slag. Planetary, attrition, vibratory and conventional ball mills are used for MA. Genesis of boehmite has been found to have a bearing on its behavior during MA. For example, BET specific surface area (SSA) of boehmite prepared by thermal dehydroxylation of gibbsite has decreased from 265 to 65 m2/g during 240 min of MA; in contrast, the SSA of hydrothermal boehmite has increased from ~2 to 36 m2/g. Mechanisms of surface area changes in the two boehmite samples differing in their genesis is explored. MA of gibbsite and its mixture with hematite/quartz using attrition milling has indicated that the presence of the second phase promotes amorphisation. Amorphous materials show signs of change in nature of bonding during milling as illustrated by MA of fly ash. Physicochemical changes during MA are not restricted to the bulk phase. The genesis of zeta potential changes in MA solids can be many; for example texture induced zeta potential changes as observed for gibbsite, while zeta potential changes during the milling of granulated blast furnace slag occur due to enhanced (possibly non-congruent) dissolution. Interesting manifestations of mechanically induced reactivity and its correlation with physicochemical changes are illustrated in terms of alkali leaching of boehmite and, hydration of MA slag. New findings reported here are associated with several open questions and are highlighted in the paper."

Jan 1, 2014