Search Documents

By R. O. Dannenberg

The Bureau of Mines conducted laboratory investigations with the objective of developing an alternative process for recovering cobalt and copper from complex sulfide concentrates. Processes currently used depend largely upon precipitation techniques to remove impurities and recover cobalt from sulfate liquors prepared by oxidative pressure leaching of the sulfide concentrates. The Bureau conducted bench-scale research on a process for treating cobaltite concentrates, comprising (1) oxidative pressure leaching, (2) jarosite precipitation followed by H202 oxidation and pH control to remove iron and arsenic, (3) copper solvent extraction with a mixed hydroxyoxime-amine extractant, (4) copper electrowinning from recirculating acidic strip liquor, (5) selective cobalt extraction from copper solvent extraction raffinate with a phosphinic acid extractant, and (6) electrowinning of cobalt from a recirculating weak acid strip liquor. Overall cobalt and copper recoveries were 91.7 and 84.1 pct, respectively. Electrowon products assayed 99.8 pct Co and 99.89 pct Cu.

Jan 1, 1987

By D. C. McLean, S. A. McKay

The purpose of this paper is threefold: 1) to describe actual ground control installations made at the various mines of the International Nickel Co. (Canada) Ltd mines in Sudbury, Ont. during a planned test program. 2) to suggest new ground control techniques which are now possible by the use of fully grouted bolts 3) to indicate the possible economic advantages to be gained by the use of resins and resin grouted bolts to control difficult ground conditions. Were a theme selected for this paper it would be: "Preserve the original roof in best condition possible by the use of smooth blasting techniques and fully grouted roof bolts — since the original rock is the best and cheapest material available for ground support." TYPES OF BONDED BOLTS As has been shown previously, there are several ways in which a bolt may be bonded. These are illustrated in Fig. 1 and 2. There are three general types of grouted bolts: 1) pretensioned, 2) post-tensioned, and 3) untensioned. The type which will be of most benefit to the user will depend upon the particular ground support problem involved. Despite the many arguments propounded for the necessity for using a tensioned bolt, ample evidence exists from actual experience that untensioned bolts can be effective in many instances. The outstanding characteristic of a grouted bolt is that it provides the user with a variety of rock consolidation techniques heretofore unavailable with conventional rock bolts. Many of the unusual characteristics of grouted reinforcing bar have been evaluated by researchers in the concrete structure field.' Underground application has largely been pioneered in the construction field, with especially good work being reported from the Snowy Mountains Hydroelectric Authority in Australia. Techniques developed there using cement grouted bolts are now being adapted in many large government construction projects in this country with excellent results. The ap- plications described in this paper are those in which Cyanamid's Roc Loc Mining Kits were used exclusively. SLUSHER DRIFTS AND FINGER RAISES (BOX HOLE BROWS, DASHES) A common mining problem especially where block caving methods are applied is that of maintaining the roof in slusher trenches particularly at the intersections of the trench with the feed raises (box holes) through which the large fragments of broken ore tumble. Typical sections are shown in Fig. 3 and 4. In Fig. 3, the drift is normally driven 7 ft wide by 8 ft high initially. The rock involved is a hard norite (diabase) which is usually competent but has "block cleavage". This roof has a tendency to fall out in large blocks when subjected to operating stresses. Depending upon the initial condition of the roof, the drift is either lined with 2 to 3 ft of concrete immedi-

Jan 1, 1964

By Ma Lijuan, Zhang Yubing, Wang Bo, Sun Huilan

The effect of lime ratio on phase composition and alumina leaching property of MgO-contained calcium aluminate clinker were investigated by analytical reagent, the XRD analysis of its mechanism was discussed. The results showed that: when the sintering temperature was 1350 ℃, C/A was 1.4, A/S was 1.3 and the content of MgO was 4%, the increase of the C/A promoted the formation of C12A7 and restrained the formation of Q-phase. The alumina-leaching ratio of the clinker (A/S was 1.3) was increased from 74.33% to 91.34% when the content of CaO was 5.21%.

Jan 1, 2015

By D. A. Phillips

A procedure for designing an optimum pit to yield maximum profit is described. The volume in which a possible pit is considered is divided into discrete blocks, each of which is assigned an economic value equivalent to its worth as a block of mineable material. The profitability of a pit can then be generated by summing the blocks within the pit. The optimizing procedure starts at the surface level and proceeds downwards level by level, to obtain the optimum pit at each level. The method makes use of the fact that an optimum pit at a particular level must be completely contained in any optimum pit at a lower level. Procedures for generating block costs, and pits with various slope angles under the restriction of complete block removal are considered briefly. The main description is of the theory of the method and the computer program based on this. The method is applicable to any type of mineral deposit, the only requirement being that the orebody should be represented accurately by a block model.

Jan 1, 2014

By G. Vallebuona

Currently, empirical models are used for predicting the hydrocyclone performance in terms of capacity, cut size (d50,c), water split and partition curve. These models, for example those of Lynch and Plitt, have been developed and checked for hydro cyclones with diameters larger than four inches. For smaller diameter hydrocyclones little empirical modelling has been done. This paper reports extended experimental research on small hydrocyclones. For these cyclones, the suitability of existing empirical models has been checked and their accuracy compared. Modifications of the existing models equations are proposed, improving their predictive capability for the small cyclones performance.

Jan 1, 1994

By Mustafa Akser

The Pipestone Lake anorthosite complex in Manitoba, Canada, was recently been re-identified as a potential source for titanium, iron, and vanadium. The present study utilized a 350 kg hard rock sample, which originated from the "Main Central" zone of the deposit. Commercial pilot-size equipment, such as dry low intensity roll magnets, wet high intensity magnets (WHIMS), and high tension electro-dynamic roll separators, was employed. As products, ilmenite up to 48.5% TiO2, and magnetite concentrates up to 87.9% Fe3O4 with 5.25% TiO2 were obtained. The majority of the vanadium reported to the magnetite concentrate. Subsequent characterization of various separation products shed light on the potential grade and recovery of the minerals from this deposit.

Jan 1, 1996

By J. A. Kost

A dust-control manual was prepared for use by mine operations personnel. The manual documents state-of-the-art control techniques, dust sampling, and use of personal protective devices. Content addresses advantages/disadvantages of control techniques, design and operating specifications, and implementation and maintenance guidelines. An indexed list of selected references is also included. In addition to the completed manual, this report documents work performed in the course of its preparation.

Jan 1, 1981

By A. E. Aho

"The Pacific Nickel property lies 7 miles northwest of Hope and 100 miles east of Vancouver, in the Coast Mountains of southwestern British Columbia. Nickel-copper sulphides were discovered in ultrabasic rocks on this property in 1923 and the deposits were explored by Pacific Nickel Mines until 1937, then again between 1951 and 1954 by Pacific Nickel Mines and by Newmont Mining Corporation through its subsidiary,Canadian Ore DepositsWestern Nickel. The property was studied by C. E. Cairnes (1) in 1924, by W. E. Cockfield and J. F. Walker (2) in 1933, by H. C. Horwood (3), (4) in 1936 and 1937, and by the writer in 1951 and 1952. Except for a few thousand tons for trial shipments, the property has never been mined. Indicated ore reserves now total somewhat over one million tons averaging about 1.4 per cent nickel and 0.5 per cent copper, with lesser values in precious metals and cobalt.GEOLOGIC SETTINGThe nickeliferous ultrabasic rocks form part of the core of a 15-milewide block of Late Palæozoic metamorphic rocks and Mesozoic intrusives which extend north-south between the coast batholith of British Columbia and the Chelan batholith of Washington. Margins of this block are faulted in part against less metamorphosed volcanic and sedimentary rocks largely of Jurassic and Lower Cretaceous age (Geo/. Surv., Canada, Map 737 A, 1942). Serpentinites, suggestive of deep transgressive structure, occur within the block, and also at its east margin along faults which are southern extensions of the regional Yalakom-Fraser River fault zone. Some of the other mineral deposits in the Hope area appear to be spatially related to these major faults.The mineralization at Pacific Nickel occurs almost exclusively within a stock-like mass of ultra basic rocks which mingle with, and partly cut, a larger batholithic mass of genetically related diorites and norites of late Mesozoic age (Figure 1 ). The ultra basic mass consists essentially of fresh, medium-grained hornblendic pyroxenite with peridotitic cores and with a remarkable margin of pegmatitic hornblendite. The most hornblendic rocks appear to be chiefly products of reaction and replacement of the pyroxene and olivine rocks. The mineralization consists of disseminated and massive pyrrhotite, with subordinate pentlandite and chalcopyrite, amongst fresh olivine, bronzite, and, Jess commonly, augite and hornblende. Both the ultrabasics and mineralization are cut by small hornblenditic and dioritic dykes, and by veins and alteration zones."

Jan 1, 1949

By L. E. Puddington, A. L. Mular

"Since the inception of spherical agglomeration, few investigations to exploit commercially the technique in the metallurgical field have been conducted. Of these, none appear to have been carried sufficiently far to demonstrate commercial feasibility.This paper describes a continuous agglomeration-separation process that can rapidly handle large tonnages of ore material. A small pilot plant de-signed from information obtained with the semi-batch unit described herein is currently in operation.In the absence of a reagent recovery system or cheap reagents, the process is probably not economically attractive for many common ores. However, for iron ores, the fuel content of the agglomerates can be used in a subsequent step such as direct reduction."

Jan 1, 1968

By Chuanyao Sun, Zhenguo Song, Aijun Ren

"Lead-Zinc sulfide ore containing carbon is one of typical refractory resource. Because organic carbon has natural floatability, it has a great negative influence on flotation of lead-zinc sulfide ores. It is difficult to obtain qualified lead concentrate by flotation using conventional reagent system. In order to reduce the influence of organic carbon on lead and zinc flotation, two alternatives, i.e., removal carbon by pre-flotation or adding carbon depressant in lead and zinc flotation, can be adopted. If the flowsheet of removal carbon by pre-flotation is adopted, the lead and zinc recovery which are lost in the carbon tailings is often higher. If conventional carbon depressants are used in lead and zinc flotation, it has a certain depression effect on lead minerals. In the paper, the ore grading 1.49% Pb, 5.73% Zn, and organic carbon 3.14% has been carried out by flotation tests. In the bulk flotation of carbon and lead minerals, Pb concentrate is only about grading 21.00% Pb. In the pre-flotation of organic carbon, it’s hard to remove most of carbon, and the loss of Pb and Zinc recovery is too much in carbon tailings. New carbon depressant BK547 and three conventional carbon depressants including sodium lignosulphonate, Fe-Cr-lignosulfonate, and dextrin, are used in comparative tests of Pb flotation, and results show that BK547 have a good depression on organic carbon, and have almost no effect on Pb flotation. Using BK547 as carbon depressant, cycle test in flowsheet of two-stage Pb and Zn selective flotation and coarse concentrate regrinding have been carried out, and results show that concentrates grading 62.51% Pb and 41.33% Zn are obtained at recoveries of 70.24% Zn and 83.58% Zn.INTRODUCTION Lead and zinc mineral resources are still the main source of lead and zinc metal. For lead-zinc sulphide ore, lead concentrate and zinc concentrate are obtained by flotation. Minerals separation by flotation is a complex process and is dependent, along with other factors, on the relative distribution of hydrophobic (e.g. collector, polysulfide, elemental sulfide) and hydrophilic (e.g. metal hydroxide) species between different particles of the same mineral phase and between mineral phases (Piantadosi & Smart, 2002; Boulton, Fornasiero & Ralston, 2003). Organic carbon has natural floatability and is often associated with lead-zinc sulphide ores. If the content of organic carbon in the ore is more, the flotation index will become worse. The main problem is that the concentrates has too low grade to be qualified grade products for sale. At the same time, the consumption of reagents is more than ordinary ores without organic carbon. In order to solve the influence of organic carbon on the flotation of lead and zinc and other sulphide ores, a lot of research works have been carried out."

Jan 1, 2018

By Z. C. Zhen

Basing on character of fine ores, and employing all the advantage of dissolved-air flotation, the study within the dissertation put forth the methods of superfine metal mineral flotation with dissolved-air flotation equipment, and constructed a full set of laboratory flotation system. Experiments both in water and in slurry were respectively carried out by means of this flotation equipment. Further study was also fulfilled on mechanism of air-dissolved released devices, and the key components of system including ejector, releaser and saturator were designed. Optimizing devices parameters were chosen by taking ideal performance of the devices into consideration, according to orthogonal experiments and tests on bubbles factors, those performance factors were called air release rate, air release efficiency. The results with some minerals are better than JJF flotation machine with 30 litres bulk. The Dissolved-air Flotation(DAF) machine shows great potentiality in treating super-fine metal mineral concentration. The research indicates the Dissolved-air Flotation(DAF) system has superiority over mechanical flotation machine in fine flotation. Air-dissolved released bubbles appear on the surface of hydrophobic minerals in priority, solving collision probability less in the tradition fine mineral separation, such that the metallurgy technology of fine metallic minerals are improved. The exploratory research is a foundation for industrial pilot, commercial test and equipment maturity in the future.

Jan 1, 2014

By Jafar Safarian, Gabriella Tranell, Stine Espelien

Hydrometallurgical treatment of silicon is an effective process for the removal of metallic impurities for producing solar grade silicon feedstock. In the present research, the removal of impurities from silicon is studied through the addition of Mg into a commercial silicon, its solidi fication, and acid leaching. The effect of concentration of HCl, temperature and leaching duration on the removal of impurities are studied. It is shown that the impurities such as P, Fe, Al, Ti, Ca, …are effectively removed through the applied method and Mg improves the segregation and the removal of the impurities. Scanning electron microscopy examination of the samples indicates the disintegration and dissolution of Mg2Si phase in acid leaching which causes the chemical and physical removal of the impurities existing in the phases between the silicon grains. It is shown that the leaching process rate can be optimized through the control of the acid leaching conditions.

Mar 1, 2017

By G. Mihaylov

The basic principles of systems analysis are presented. A model has been designed to determine the location of the Main opening in the presence of three or more stock orebodies. The necessary condition is to find a location for the Collection point which is an essential element in opening up each orebody (stock). The model takes into account the total transportation costs from each orebody to the collection point. Three variants are considered provided that the orefield is divided into two levels at least: - a collection point is designed at every level; - a collection point is designed at the lowest level, i.e. where the so-called concentration level is formed; - the collection point is located at a point between the planes of the two levels; The effect of the depth of mining and mine output on determining the method of opening up the orefield has been analyzed by considering a vertical and/or an inclined shaft. A function has been constructed which allows for investigating in both a static and dynamic regime the capital costs for constructing the whole complex including the shaft. The character of the function does not allow finding the global limits. Therefore, it is of particular importance to specify the limiting conditions. In this case these are the flow capacity of development openings and the shaft. The basic groups of cost and natural indicators for assessing and selecting an optimal technological solution have been systematized. The combined analysis of the two approaches to finding the location of the Main opening and determining the mining method enables us to determine when an inclined shaft is best, and the depth at which opening by a vertical shaft has no alternative. Thus, a transition area is formed for which the selection of an optimal technological solution requires an analysis similar to that proposed in this paper. Conclusions are finally drawn which serve as a basis for determining the areas of application of each opening, including the use of a combined scheme of mine opening. The approach presented can be used in both investigating the possibilities for opening up new orefields and reconstructing existing ones in cases when the mining operations go deeper.

Aug 1, 2013

By O Arafat, R E. McIvor, K M. Bartholomew

It is well known in the industry that good classification system performance is vital to efficient ball mill circuit performance. But what is meant by good classification system performance, and how is it achieved? Unfortunately, the perceived complexity of classification systems, and the day-to-day time demands placed on the practicing metallurgist, all too often put the low-hanging fruit of classification system optimisation in the ‘I’ll do it later’ basket. Additionally, lingering confusion about basics such as the relationship between circulating load ratio and ball mill circuit performance makes the optimisation objective seem nebulous to both plant metallurgist and designer.Some of this confusion can be eliminated by taking a step back from the overwhelming detail of sharpness of separation curves, circulating load ratios, cyclone feed pressures, vortex and apex sizes etc, and focusing on the purpose or function of the classification system – to apply mill power to particles that need further size reduction! The classification system efficiency (CSE) metric captures how well the classification system is performing its function with two quick and easy size distribution analyses.Once CSE is understood and implemented as the optimisation criteria, well-tested methods for improving CSE can be implemented and quickly measured at plant scale to give confidence that the right change was made.This paper will describe CSE and how it is measured in practice. Next, a guide for improving CSE through manipulation of design and operating variables in the classification system will be provided. Examples and case studies will illustrate the gains in ball mill circuit efficiency that can be achieved by maximising CSE.CITATION:Bartholomew, K M, McIvor, R E and Arafat, O, 2018. A guide to maximising ball mill circuit classification system efficiency (CSE), for operators and equipment designers, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 553–558 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By Roberto Parreiras Tavares, Frederico da Costa Fernandes, Guilherme Antonio Defendi, Vangleik Ferreira da Cruz, Júlio César de Sousa Pena

"Near-net-shape casting is an important area of research in the iron and steel industry today. Among the near-net-shape casting processes, the single-belt caster seems to be the most promising, since it is the only one that can achieve levels of productivity similar to those obtained with conventional continuous casting machines. One of the most important aspects in the single-belt casting is the feeding system used to deliver liquid metal over the belt. This system determines the velocity distribution and the levels of turbulence of the liquid metal and affects the quality of the strips. In the present work, a metal delivery system having a simple geometry was proposed. Using the CFD code CFX 5.6, a mathematical model to simulate three-dimensional turbulent fluid flow and heat transfer in that system has been developed. This model was used to analyze different configurations of the metal delivery system and the free surface shape of the fluid was also determined. A physical model of the feeding system was built and used to validate the predictions of the mathematical model. The fluid flow calculations have been validated by dye injection experiments and laser doppler anemometry. Measurements of the free surface levels have also been performed. These experiments provided supporting evidence for the predictions of the mathematical model.IntroductionTo maintain its competitiveness in the present market, the metallurgical sector, particularly the steelmaking companies, are developing new techniques of production. Some of these new processes are focussed on the strip casting technologies. Among these technologies, the SingleBelt process is considered the most interesting option, reducing the number of rolling steps and, consequently, the final cost of the product, especially the part associated to the energy consumption (fuel and/or electric energy). This process can also reach levels of productivity that can not be matched by other strip casting methods(1). One of the most important aspects concerning these new processes is related to the liquid metal delivery system. This system can have a significant effect on the final quality of the strips, since it determines the velocity distribution and the levels of turbulence of the liquid metal."

Jan 1, 2004

By Peter Yen

This session consists of five papers. Three involved research on the properties of grout materials, specifically ultrafine cements and polyurethane grouts. Two papers present the development of soil grouting technology and monitoring methods. Of great interest are the papers on ultrafine grout penetrability testing focusing on the pressure filtration effects encountered in permeation grouting applications (Ericksson, Stille and Mittag, Savidis). The comparison testing of hydrophilic and hydrophobic polyurethane grouts submitted by Vrignaud, Ballivy, Perret and Fernagu assessed the long-term performance of these materials for repairing saturated cracks in concrete, subject to thermal expansion and contraction. Two very practical papers present the development of soil grouting, where permeation, fracture, replacement, jetting and other grouting techniques are utilized. The papers by Lees with Chuaqui and Warner present experience with ultrafine and other commonly used grout materials. Methods to measure and monitor the injection process and verify production progress are discussed.

Feb 10, 2003

By Joseph T. Singewald

The possible value of the red hematite iron ore of the southern Appalachian States, if some practicable method of concentrating it could be devised, has long been recognized. The ore is very low grade, and although in enormous quantities, particularly in the States of Alabama, Tennessee, and Georgia, is only at a few points rich enough to work, and even the best of it ranks among the lowest grade iron ores being mined in the United States. A cheap method of beneficiating this ore would make enormous quantities available and vastly increase the iron-ore resources of the country. However, this low-grade ore in effect constitutes a potential iron reserve, and as long as ample quantities of ore can be obtained elsewhere the question of its utilization does not demand immediate notice. Where these ores are in part of workable grade, however, a problem of more immediate importance arises which, from considerations of economy and prevention of waste in their mining, ought to be solved or, at least, attacked as quickly as possible. Where these ores are being worked they are usually intimately associated with lower-grade material that in mining is left behind. The difficulty and expense of going into ground broken by old workings makes the recovery of this lower-grade ore practically impossible and it is lost forever. Success in concentrating the red ores, therefore, would save material that is now being irretrievably lost. The successful large-scale concentration of law-grade ore in the last few years on the Lake Superior iron ranges should encourage the attack of similar problems in the Birmingham district.

Jan 1, 1917

By L. Shasko, M. Hurlbert

As climate change is increasingly perceived as a problem, and fossil fuel based power production options are increasingly limited through regulatory restrictions and public distaste, future options become constricted. Reflexivity and social learning elicited through qualitative and mixed research methods offer important insight into what future power production pathways might be. Given factors of cost, baseload requirements, and energy density, options such as nuclear may be increasingly accepted. This paper explores this literature and possible methods of pursuing the reluctant acceptance of nuclear energy.

Jan 1, 2020

By T. H. Jeffers

The Bureau of Mines conducted laboratory tests to devise a procedure for extracting copper from low-grade discarded mill tailings. A solid extractant consisting of an organic solvent extraction reagent adsorbed on granular activated carbon was investigated and proved to be satisfactory for extracting copper directly from leach pulps. When this material was used in a cyclic leaching, stripping, and electrowinning pro-cess, 95 pct of the acid-soluble copper was recovered from oxidized mill tailings. The weathered tailings contained 0.24 pct Cu (total) and 0.20 pct acid-soluble Cu. The copper was recovered as cathodes containing, in parts per million, 1.6 Pb, 3.6 Fe, 0.5 Sb, 1.5 AI, 1.9 Mn, and <1 Mg.

Jan 1, 1985

By John R. Bartels

In laboratory testing, the Bureau of Mines established criteria by which common resin-grouted roof bolting systems can be evaluated and compared. Ultimate strength and stiffness were determined for nonten-sioned full-column, point-anchor, tensioned full-column, and debondable resin-grouted bolts, and for variations on full-column boltsn Bolt per-formances were compared using the performance of the 3/4-in full-column resin-grouted bolt as the standard. New and innovative systems can also be qualitatively compared against this standard. Since the medium into which a resin-grouted bolt is installed is one of the most important parameters affecting bolt performance, various host mediums were used in the testing: sandstone, concrete, simulated coal, simulated shale, and plaster. Bolt performances expected in other mediums can be inferred from the response patterns obtained in these mediums. Results indicate several functional differences among bolt types. Where resistance to shear is important, point-anchor bolts may outperform nontensioned full-column bolts at a lower cost. In medium-to soft-strength rock, tensioned full-column bolts perform best. Also, varying the resin-steel ratio seems to have little effect on the properties of a full-column bolt, when proper resin mixing is ensured.

Jan 1, 1985