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By G. Vouille, P. Bérest

Residual stresses observed in rocks often result from non-compatible initial strains. These stresses can be determined when the incompatibility tensor associated with the initial strain tensor is known. The residual stresses in a cylindrical rock sample can be computed the sample is considered small enough for its incompatibility tensor to be constant. Les contraintes résiduelles, dont on observe couramment les manifestations dans les roches, résultent souvent de l’existence de déformations initiales non-compatibles. Ces contraintes peuvent être calculées lorsque le tenseur d’incompatibilité associé aux déformations initiales est connu. Les contraintes résiduelles dans une éprouvette cylindrique sont données dans le cas où le tenseur d’incompatibilité est constant. Eigenspannungen, die man haeufig in Steinen beobachtet, sind oft Ergebnis einer inkompatiblen Deformation des Anfangszustandes. Diese Spannungen koennen berechnet werden, wenn der Inkompatibilitaets-Tensor der Anfangsdeformation bekannt ist. Die Eigenspannungen einer zylindrischen Probe werden fuer Fall eines konstanten Inkompatibilitaets-Tensor bestimmt.

Jan 1, 2003

By L. Hacini, N. Van L ê, P. Bacher, D. Thibault

Manufacturer welded components may suffer from high level of residual stresses which can cause premature cracking and decrease the life of the components if they reach values close to the yield strength of the material. In the present work, a robotized hammer peening technique is simulated by an impact machine and the residual stresses generated by the indentation are measured. To better understand phenomena behind residual stresses relaxation by hammer peening, the impact energy level was changed. 304L steel plates were hammer peened with 10 impacts. The contact between the hammer and sample surface was always at the same location. The strains on the surface close to the impact location were recorded during the test using strain gauges to follow residual stresses variations. At the end of the test residual stresses were measured indepth using hole drilling technique at 8mm from the impact center. The micro-hardness was monitored to evaluate the affected zone by the hammer peening. This approach gave a good estimation of the energy and number of blows to be used for efficient relaxation of the manufactured parts.

Jan 1, 2006

By D Langberg, R Taylor

Many metallurgical operations produce fine residues and dusts as by-products which can be difficult to handle and offer little direct financial incentive to treat. There is a growing imperative to deal with these materials particularly since land fill is fast becoming an uncertain long term solution. One possible means of treatment is to extract the valuable metals while fusing the remainder into a slag. In this way valuable metal components of the material can be recovered and the less valuable components be converted into useful products, eg cements and inorganic polymers which have a high environmental stability and a growing market. The aim of this project is to establish solids injection and fusion in a slag bath as a viable method of treating industrial wastes and residues. The benefits of this approach are expected to be: the ability to treat a wide range of organic and inorganic residue materials, ease of recovery of volatile and valuable elements and the production of final materials which could be used in other industries. In ongoing experimental work at the CSIRO Minerals a 250 kg slag bath reactor has been used to test the injection of Paragoethite residue into an iron silicate based slag. An experimental apparatus has been designed and commissioned to pneumatically inject solid material at feed rates of up to 80 kg/hour. The capture efficiency of injected solids by the slag bath was calculated by monitoring the composition of the slag. Using this method of treatment, the zinc contained in the residue can be recovered as a fume by varying the oxidation state of the slag. Other valuable elements could be recovered by creating a matte or metal phase in the reactor with the final material being used in the production of cement. A capture efficiency of injected solid paragoethite particles in the slag bath of up to 97 per cent was achieved. Under the conditions of the experimental work capture efficiency was found to be independent of injection velocity and slag depth. The rate of fuming during injection was found to increase slightly with injection velocity and was independent of slag depth.

Jan 1, 2002

By Garrigan J. S, Oakes I

Current operating practice in a plant commissioned some five years ago to treat ferritic zinc plant residue by the "Jarosite" process is described. Major problems overcome include obtaining reliable pH measurements at 100¦C, prevention of scale build up in spent electrolyte heaters, blinding of jarosite filter cloths and the deposition of gypsum in filter presses.

Jan 1, 1977

By Juergen Antrekowitsch, Stefan Steinlechner

"Within the last decades, mainly the base metals, like zinc, copper and lead were recycled from different industrial residues without taking into account that accompanied minor side-elements are often also present. A high supply risk for critical raw materials derives mainly due to the high share of the worldwide production in a limited number of countries. Examples include indium and germanium in China, PGM in South Africa and Russia or cobalt and tungsten in the Democratic Republic of Congo. By taking the market of critical metals into account, the recycling of potential residues does not only contribute to an economic treatment but also to the European strategy to decrease the supply risk of certain metals. Depending on the metal discussed, political unrest, decreasing primary resources leading to supply risks in different countries or also simply economic interests moved these mentioned side elements and with this the residues where they are present in, into the focus of the recycling industry.Because of this, the typical routes of lead, zinc and copper production are evaluated concerning generated residues and their typical contents of contained minor elements. Finally, the paper tries to answer the questions how a possible treatment of these wastes could contribute to the overall supply of for example silver but also other minor elements."

Jan 1, 2016

By S. Steinlechner, S. Wegscheider

"In the past, the metallurgical industry was most of the time dedicated on their main commodity, recovering base metals like zinc, copper or lead but leaving other valuable side elements in the generated residues. As a result, these accompanying minor elements, like gold, silver, indium or also PGMs can be found in the dumps of the corresponding industry. Because of political unrest, strikes, economic reasons or decreasing primary resources leading to a high supply risk, also those mentioned minor elements moved into the focus of the recycling industry. Therefore, beside the base metals, first of all the recovery of those minor metals would be of high interest contributing to the economic viability of recycling processes, although they occur in much smaller quantities in materials. In this context, residues from zinc industry, like leaching residues or precipitation residues show high potential to carry silver as well as indium next to lead and zinc. Therefore, the paper summarizes carried out thermochemical calculations investigating a possible recovery of silver as well as indium by volatilization and the influence of zinc and lead on this process. Based on these theoretical investigations with HSC, trials in lab scale were done verifying the obtained results.INTRODUCTIONHuge amounts of iron precipitate, mainly jarosite get landfilled every year although there is a high content of valuable metals in this residue beside iron. Nevertheless, jarosite has to be dumped due to the presence of contaminating heavy metals. The accumulation of these residues takes up massive land on the one hand but also causes a series of environmental problems in ecosystems on the other. Moreover, some toxic ingredients such as arsenic and cadmium can be dissolved in rain water and are therefore harmful to the health of the aquatic systems. (Erdem & Özverdi, 2011; ÖzverdI & Erdem, 2010) Approximately 0.5 t of dry jarosite accumulate in the production of 1 t of zinc by the hydrometallurgical zinc-winning route (Svens, 2010). Jarosite is a precipitation residue formed during the iron removal. In general, the iron already exists in the zinc ore which is why zinc ferrite builds up during the roasting step of the zinc ore. Zinc ferrite is only soluble in strongly acidic solutions and during the hot acid leaching step it gets dissolved while zinc and iron enter the solution. It is necessary to get rid of the iron because otherwise it would deposit on the cathode first due to its precious character which would be harmful in the zinc-winning electrolysis. Nevertheless successful investigations were done by adding chlorine to the jarosite to recover silver. These findings leads to another residue which occurs in huge amounts – electric arc furnace dust (abbreviated with EAFD) from the iron and steel industry. In 2013 the annual electric steel production reached about 451 million tons. Around 15-20 kg of EAFD is produced per ton of steel in an electric arc furnace (EAF), creating approximately up to 9 million tons of dust per year. (Grabda, Oleszek, Shibata, & Nakamura, 2014; World Steel Association) Next to elements like zinc, lead and iron, chlorine and fluorine are present in this dust. While galvanized steel plates in the scrap act as a source for zinc, casting powders, flame retardants and synthetic coatings are responsible for the chlorine and fluorine contents in the dust."

Jan 1, 2016

By Karla Ticona, Anthony Saldaña, Lourdes Cacya

La aparición del virus SARS-CoV2-2 en la ciudad de Wuhan China y su propagación vertiginosa en el mundo (OMS, 2020), frenó e impactó severamente los sistemas económicos, entre ellos la actividad minera a escala global. Nuestras operaciones en Mina Toquepala de Southern Perú, Grupo México, no fueron la excepción, siendo nuestros compañeros de trabajo y sus familias nuestra mayor preocupación. Es así, que la Alta Dirección de SPCC lideró las acciones necesarias para mitigar el impacto en la salud de nuestros compañeros y sus familias como prioridad corporativa.

Sep 29, 2023

By S M. Arndt, D Tyler, F Reusch

Although significant advances have been made in understanding the mechanics of pit slopes, numerical modelling hasnÆt significantly impacted on the reliability of the design process. It is well known that legacy modelling approaches donÆt simulate large slopes well. In recent times, the emergence of very large finite element (FE) models with more than ten million degrees of freedom and the ability to simulate a large number of discrete structures, has allowed a step change in the simulation precision for slopes. The model size allows global and local effects to be realistically simulated in one model for the first time and the process can be better integrated into normal open pit slope engineering processes. Some examples of simulation of very large open pits are shown that demonstrate the challenges and some recent advances in modelling large slope behaviour. Significant limitations in the current measurement and observation regimes of open pits have been identified.

Jan 1, 2007

By SME SME

Full Article

Feb 22, 2026

By Al Campoli

One of the critical variables affecting resin bolt performance is the size of the resin annulus, defined as the difference between the hole and bolt radius. The vast majority of the millions of resin roof bolts installed each year in the United States employ an annulus between 0.125 and 0.188 inch. As the annulus size decreases the resin flow around the bolt becomes more difficult, increasing the resin pressure induced by bolt insertion. As the resin pressure increases the loss of resin into bedding planes and vertical fractures in the rock increases. As the annulus size increases the mixing of the resin paste and mastic becomes less efficient. Thus, the lower and upper limits of the optimum annulus size is determined by insertion pressure and mixing considerations, respectively. Previous U.S. Bureau of Mines researchers have concluded that a 0 125 inch annulus is optimal. However, others have recently reported that a 0.095 inch annulus with special rolled deformation (SRO) bolts provide superior anchorage to standard rebar with a very large 0.250 inch annulus, attributing SRD resin loss in weak ground to oversized holes. The effect of annulus size on unit length pull strength and resin loss to fractured rock was investigated. Short encapsulation pull tests with resin annuluses of 0.125 and 0.095 inch resisted an average of 2.25 tons per grouted inch, with no significant variation. However, annulus size has shown a dramatic effect on the magnitude of resin lost to simulated rock fractures. No. 5 standard . No. 6 standard, and No 7 J-Bar rebar were inserted into two different viscosity resin cartridges designed for 4 foot boll encapsulation into a one inch inside diameter metal tube, To simulate a rock fracture, a 0.250 inch diameter orifice was located near the capped end of the tube Resin loses increased as annulus size decreased, with a minimum loss of 35% and a maximum loss of 60% associated with 0.125 and 0.095 inch annuluses, respectively.

Jan 1, 1999

By John Conway, Gerald Bennett, John Herrick

Research efforts which have led to reduced resin bolting costs at White Pine Mine are described. Key factor was development of the capability to drill small holes (1 1/8 in. diam) in the hard (20,000-30,000 psi) White Pine roof rock. Economic data comparing the 1 1/8 in fully-grouted Resin Bolt to the conventional 1 3/8 in fully-grouted bolt is also included. The development of a method which allows the Resin Bolt to hold itself in the hole thus removing the requirement for the operator to break his "work momentum" while he stops and waits for the resin to set is also described. This technique increased bolter productivity by 23% in a recent full-scale unit test.

Jan 1, 1974

Roof bolting with resin bonded bolts has been developed extensively in French coal mines. There are three aspects of this development: 1. The reason for and the care used in the development of roof bolting from use as a reinforcement in a classical arched roadway to use as the only support in roadways in ad- vance of the working face (the roadway being reinforced behind the face); 2. The problems encountered and studied, such as choice of boltable roadways and determination of the technical data in designing a roof bolting pattern; 3. Only because roof bolting has been controlled by safety rules, and especially by accurate measurement of strata behaviour, has this system of support been expanded aapidly in France since 1967.

Jan 1, 1971

By I Thin, I Sheppard

Resin encapsulated rock bolting practices have been adopted by Mount Isa Mines since the early-1980s. Fully encapsulated rock bolt systems meet designated requirements for long-term ground support in the mines. A variety of rock bolts, resins and installation methods have been utilised over this period in underground mining. As a parallel to this evolving application, Mount Isa Mines have tested various resin encapsulated rock bolt systems. Testing has included routine underground pull testing and the development and implementation of the push test for the entire encapsulated bolt length. The latter test enables a greater understanding and representation to be had of the overall mixing, level of encapsulation and capacity of the system. Rock mechanics at Mount Isa Mines undertake evaluation of new bolt systems that become available, in addition to the maintenance of compliance with quality control measures for the existing systems. Improved methods of installation and systems are also investigated to further the cost-effective nature and minimise risks associated with resin rock bolt practices.

Jan 1, 2002

By W. B. Beerbower

Resin bolting has enjoyed wide acceptance for coal mine roof support. Beginning in 1973, the first year of significant resin bolting in coal mines, we estimate that 2.5MM resin bolts were installed. This grew to 7MM resin bolts in 1974 and 13MM in 1975. Resin bolts are currently being used in over 300 coal mines throughout the major coal producing areas of the U.S. and barring major work stoppage we expect more than 17MM will be installed in 1976. Although not a cure-all, the number of unintentional roof falls occurring in many mines has been dramatically reduced as a result of converting to this "new" method of support. 1 The improved anchorage strength of resin bolts provides better roof support. (Slide #1) This anchorage strength provides a mechanism to resist changing roof stresses along the entire length of the fully grouted resin bolt, thereby assuring stabilization of rock strata over long periods of time. The ability to resist roof displacement is borne out by readings obtained from strain gauged bolts. These findings can be summarized as follows.2

Jan 1, 1977

By S. C. Tadolini, J. M. Goris, J. L. Gallagher

Cable supports offer several advantages over traditional secondary support methods by enhancing stress redistribution to pillars and gob areas, minimizing or eliminating timbers and cribs that reduce ventilation, eradicating material-handling injuries related to placement of crib supports, and providing a cost-effective alternative to secondary support. The U.S. Bureau of Mines (USBM), researching alternatives to traditional roof support methods, designed and installed high-strength cable supports to improve the stability of longwall gate road entries in a western U.S. coal mine. With the cooperation of industry, methods were developed to install and evaluate cable supports in a tailgate area using traditional resin cartridges. The cable-bolted areas successfully maintained roof support throughout the developed entries. Cable supports have replaced wood cribbing as secondary support in the bleeder entry system and have minimized or eliminated the use of cribbing in the longwall tailgate entries. This paper describes the theory, application, and advantages of cable supports and presents some mine measurements made to assess the cable performance during the retreat process of longwall mining.

Jan 1, 1999

By Stephen C. Tadolini

The U.S. Bureau of Mines (USBM) is conducting research to provide alternatives for traditional secondary support methods. These cost-saving methods are proving to afford safer installation, improve entry stability, eradicate material-handling injuries associated with crib supports, and enhance ventilation. In cooperation with Mountain Coal Company, the USBM replaced timber cribbing with high- strength cable supports to provide stability in a gate road that was used for two longwall panels. The support design consisted of 2.1-m (7-ft) full-column resin-grouted bolts and 4.8-m- (16-ft-) long high-strength resin-grouted cable supports. Three support concepts were evaluated: passive, stiff, and tensioned systems. Cable loading and roof deformations were monitored to evaluate the behavior of the immediate and main roofs during panel extraction. The stress and loading histories for both panels and the abutment and yield pillars were monitored to assist in evaluating the stress transfer and pillar performance in conjunction with the roof behavior. The test results indicated that resin- grouted cable support systems successfully maintained the immediate and main roofs during the extraction of two longwall panels. This paper describes the theory, application, and advantages of resin-grouted cable supports and presents the mine measurements made to assess the cable performance during the retreat process of longwall mining.

Jan 1, 1994

By J. B. Hiskey, V. P. Atluri

Resin-in-leach (RIL) cyanidation experiments were performed on a refractory carbonaceous gold ore. The objective of this investigation was to determine if strong-base ion exchange resins could adsorb the soluble aurocyanide complex in preference to natural "preg robbing" organic constituents. Direct cyanidation of the carbonaceous gold ore used in this study resulted in less than 2% gold extraction in 24 hr. RIL cyanidation resulted in about 70% gold recovery onto the resin. Kinetic experiments indicated that 50% of the gold is extracted after 1 hr of leaching. Resin breakage was investigated for as-received and preattrited resins. Similar results were obtained with three different strong base resins.

Jan 1, 1990

"This paper reviews the chemistry involved in the recovery of gold from cyanide solution with anion-exchange resins, and also discusses the most critical aspects of the engineering of an effective resin-in-pulp (RIP) process. As far as the chemistry is concerned, the conclusions reached by a great many researchers, as well as the performance of the only operating RIP plant in the Western World, at the Golden Jubilee Mine in South Africa, support the view that the process is technically viable and, in many cases, could prove to be more attractive economically than alternative processes such as zinc cementation and carbon-in-pulp (CIP). On the engineering side, there is still a need for further development before larger scale ( > 50,000 tpm) RIP plants can be designed, built and operated with confidence. However, the experiences gained during nearly 3 years of operation of the Golden Jublee RIP plant indicate that the process can be engineered with confidence for smaller operations ( < 50,000 tpm), and this will probably be the scope of application of the first-generation RIP plants. INTRODUCTIONThe use of anion-exchange resins in gold processing has, for a number of years, been proposed as an alternative to more conventional processes such as zinc cementation and carbon adsorption, and detailed research programs that have been carried out at a number of laboratories have demonstrated the technical viability of the process. (Burstall et al, 1953, Davison et al., 1960, Tataru, 1973, Laskorin et al. 1978, Hosking, 1984, Riveros and Cooper, 1987 and Palmer et al., 1988)The main incentive for this work was the fact that resins have several characteristics that are quite different from carbon, which make them potentially more attractive substrates for the recovery of gold. The following are examples: -"

Jan 1, 1991

"Some of the tools developed for the processing of nickel laterite ore by resin-in-pulp (RIP) may be applicable to the remediation of metalliferous mine drainage (MMD). In both cases, recovery of metal value and production of a stable waste stream appropriate for long term storage is desired. MMD typically has the additional challenge of management of toxic low-value metals. Seen in this light, innovations in RIP reactor configuration, selective elution strategies and novel synthetic ion exchange resins become useful tools for taking on the MMD challenge in a way that maximizes both environmental and economic benefit. INTRODUCTIONAcid mine drainage (AMD) is a common problem in any country with significant past mining activity. When sulphide containing minerals, tailings or slag are exposed to water, oxygen and sulphur oxidizing bacteria, AMD will result. Abundant and reactive iron sulphide minerals leach first, providing acidity and the ferrous/ferric couple that can enhance the oxidation kinetics of other minerals. If this runoff contacts encounters acid consuming carbonates or silicates, the acidity may be neutralized, but certain heavy metals remain in solution and can continue to be an environmental hazard (Gray, 1997). For this reason, the remainder of this paper will refer to the broader term metalliferous mine drainage (MMD) rather than acid mine drainage. In either case, such drainage, containing high heavy metal concentrations and often significant acidity, is toxic to aquatic life and can lead to significant damage to ecosystems and to public watercourses. MMD is a problem most commonly associated with now defunct sulphide mineral mines, but similarly toxic streams can result from many types of waste, such as poorly stabilized leach tailings, slag heaps, and coal flotation tailings (Johnson and Hallberg, 2005; Lee et al., 2002; Sainz et al., 2002; Schüring et al., 1997). In any case, the management and remediation of MMD is an important ongoing problem for the resource industry, particularly for the many mines in Canada closed before the advent of more stringent environmental standards. MMD remediation represents a significant long term expense for the resource industry. Multi-disciplinary efforts to understand and mitigate this problem range from creation of artificial wetlands (Poulin and Lawrence, 1996; Sheoran and Sheoran, 2006) to sophisticated biochemical reactors and precipitation processes (Hatami, 2010). Certain remediation technologies such as ion exchange offer methods to make a saleable product by recovering valuable dissolved metals. This paper will show how these technologies can help defray the cost of remediation, and offer potential to turn a dangerous waste stream into a useful product."

Jan 1, 2012

By G. P. Richards

RIP is the process of recovering uranium from an unclarified slime pulp which comes in contact with a moving bed of ion exchange resin, T e sand-slime separation of the acid-leach slurry is accomplished through the use of cyclones and spiral, akins type classifiers. Course sands are discarded to tailings and the combined slimes and leach liquor become the IX feed. Uranium in the IX feed is absorbed on the resin and after exhaustion the barren pulp is directed to tails, Following the uranium exhaustion cycle an eluant solution passes through the resin bed stripping the uranium from the beads, The uranium is precipitated from the clarified pregnant eluant, filtered, dried and packaged for shipment to the AEC, Normally, the ore received at the Mines Development plant is a loosely cemented sandstone containing small quantities of clay and bentonite, The ore is easily crushed and requires only a 1/3 load of rods in the rod mill to reduce the ore to grain size, Very little of the ore is recirculated by the 42" spiral classifier.

Jan 1, 1958