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By DING TANG, JINGHE CHEN, Shuiping Zhong, CHEN KUANG

The Zijinshan gold-copper mine, in spite of the low-grade nature of the ore, has become one of the largest production-scale and most profitable non-ferrous metal mines in China. The successful application of hydrometallurgy as well as proper engineering design are the key factors for large-scale development of the Zijinshan gold-copper mine. In this contribution, the practical experience acquired in the development of the Zijinshan gold and copper mines is summarized. This covers most aspects of the production process including mining, beneficiation, ore stacking, heap (bio)leaching, carbon-in-leach, solvent extraction, electrowinning, wastewater and tailing treatments. The authors believe that this practical experience will not only help to promote the development of hydrometallurgy, but can also serve as a model for other gold and/or copper plants around the world.

Jun 3, 2020

By Jon Ike Isaacson, Michael Miller, Jarek Trela

Despite reef structures being relatively common in carbonate rocks around the world, tunneling experience in reefs is extremely rare. Impacts and risks associated with reef tunneling through these geologic features were also relatively unknown. A new reef was encountered during construction of the Lower Pogues Run Tunnel in Indianapolis, exposed over 5,000 linear feet along the alignment, resulting in adverse impacts on construction. Analysis of investigation data and construction from this encounter provide insight into the identification and characterization of reefs along tunnel alignments as well as the potential impacts on construction for future tunneling within reef structures.

Jun 23, 2024

By K. A. Lewandowski

Heap leaching efficiency is reduced by poor solution flow characteristics (channeling and ponding), which result from compaction and fines migration. Agglomeration of the ore can prevent compaction and immobilize fines, but copper leaching requires an acid-resistant binder to stabilize the agglomerates. Until now, there has not been a satisfactory way to evaluate whether a binder was effective, other than squeezing a handful to see if it ?feels right.? Procedures have been developed to quantitatively determine whether a binder produces agglomerates that can withstand compaction in an acidic solution, and have identified several binders that will provide sufficiently compaction-resistant agglomerates for copper heap leaching. Keywords: Copper heap leaching, Binder performance, Compaction

Jan 1, 2010

By R. L. Grayson

Conventional mine safety wisdom states that "the most efficient mines are also the safest." Since the 1980s, small mines (and contractors) have been targeted as the most dangerous ones because of their fatality records. Statistical testing of 1993 West Virginia safety and production data indicated that the most efficient WV mines were not the safest ones, considering correlations between the severity measure and tons per employee-hour, except for very small mines. This paper will present the results of an extended analysis of WV mine safety using 1993 and 1996 data, concluding with the method used to suggest current priorities for focusing interventions.

Jan 1, 1998

By William M. Greenslade

As the search for minerals leads to deeper mines the need to control water inflow into mine shafts and mine workings will grow. As shal¬lower more readily available minerals are exploited, ore bodies which were previously uneconomic be cause of their depth will now become attractive targets. In known mining districts new ore bodies are being discovered down dip of existing ones. In the west many metal deposits are being developed in rocks of the mountain front pediments, frequently covered by several hundred feet of saturated alluvium. Greater depth often means that workings are developed well below existing water tables, creating high hydrostatic heads adjacent to mine workings. The purpose of this paper is to review some of the methods available for determining if water control will be necessary and to present some of the techniques for locating water bearing zones and the amount of water to be expected. The paper will concentrate on problems associated with water control in mine shaft development, although many of the exploratory techniques are similar to those needed for assessing overall mine water inflow problems. A brief case history on water control problems in mine shafts in the Grants mineral belt of northwestern New Mexico is presented. Water control during shaft sinking presents some unique features. First, the problem is a relatively short term one, since water control is often necessary only while the shaft is being sunk. Control measures may be necessary only while the shaft is open into the water bearing zone and the lining installed and cemented. Secondly, limited working space within the shaft area presents difficulties in handling large amounts of water inflow. The presence of water in the shaft working area increases sinking time and the potential hazard to miners. Finally, there is the economics of shaft sinking. While the shaft is being sunk no ore is being produced and there is every incentive to minimize costs.

Jan 1, 1979

By Robert E. Baker

Cortez Gold Mines, the United States' third largest primary producer of gold, commenced continuous operations on January 10, 1969. The decision to proceed to production was made in March of 1968 and construction of the mill and stripping operations for the pit began in April and July, respectively. Anomalous conditions on the slope of Mt. Tenabo along the Roberts Mountain thrust fault zone were discovered by the U.S.G.S. while conducting geochemical surveys in the old Cortez silver district. Following the discovery of gold an intensive program of drilling was organized. Drilling outlined an orebody with 3.5 million tons of ore averaging 0.28 ounces of gold per ton. It was on the basis of this reserve that a 1700 t. p.d. cyanide plant was designed. Needless to say, with such a limited ore reserve, economies in design and construction would have to be observed. Cortez Gold Mines is a joint venture with American Exploration & Mining Co., The Bunker Hill Company, Vernon F. Taylor, Jr., and Webb Resources, Inc. , as partners. American Exploration & Mining Co. is the operating partner.

Jan 1, 1969

The 30th annual American Mining Hall of Fame Awards Banquet and Fundraiser sponsored by the Mining Foundation of the Southwest (MFSW) will be held at the JW Marriott Star Pass Resort, Tucson, AZ on Saturday, Dec. 1, 2012. Each year, one living inductee, two recipients of Medals of Merit and up to five honorees from mining history are chosen by the MFSW for their outstanding contributions to the mining industry. Gregory H. Boyce will be the guest of honor, featured speaker and inductee into the American Mining Hall of Fame. Boyce, chairman and chief executive office of Peabody Energy, is being honored for his leadership in the coal industry.

Jan 1, 2012

Since the beginning of the computing age, technical software packages have not been developed to address only programming specialists but have been dedicated to process engineers. For process analysis, BRGM is developing and commercializing three packages: ? sampling software: ECHANT 2.0 for Windows ? material balance calculation: BILCO 2.0 for Windows ? steady-state simulator for plant design, adaptation and optimization: USIM PAC 2.1 for Windows This paper deals in a first part with the main features of these three packages. In a second part, advanced models are presented for SAG/ AG mills and flotation columns. An industrial case of application is shown for each of them.

Jan 1, 1997

By W. Hitchcock

To enable the analysis of stability for a mine feasibility study a variety of geotechnical engineering parameters need to be obtained. At the early stage of a project it is usual for those responsible for the study to require a wide spatial distribution of RC holes in order to define a resource at the lowest possible cost. By the time a geotechnical study has commenced drilling priorities have usually switched to improving the definition of a resource, by drilling with diamond coring methods in the central area of the main orebody. The usual timing for geotechnical data collection is therefore after a wide distribution of holes have been drilled but which contain little geotechnical information. Conventional methods employed usually involve estimation methods, including book values and examination of disturbed core, or expensive additional drilling. With downhole geophysical methods we can economically take advantage of existing holes to obtain continuous values for density, defect orientation and ranking, elastic modulus values, unconfined compressive strength estimates and fracture frequency. This paper presents the results of a geophysical study and discusses the advantages and potential pitfalls of the method as compared to conventional methods of data collection.

Jan 1, 1999

By J. M. Avasthi

Gulf Research & Development Company conducted the nation's first underground coal gasification test in steeply dipping beds near Rawlins, Wyoming. The geotechnical considerations played a major role in the initial site selection. The test plan included a detailed geotechnical program for site evaluation, test design, permitting, and environmental studies before the burn. During burn, the geotechnical activity continued in the form of monitoring surface subsidence and acoustic emission. The postburn evaluation included studies of the drill cores obtained from the burn zone and effects on the surrounding rock mass.

Jan 1, 1981

By Ibezim J. Anazia

Electrothermal production of elemental phosphorous (P4) generates substantial amounts of highly toxic phossy water and sludges. Because of their high phosphorous content and lack of reliable processing technology, large tonnages of these hazardous wastes have accumulated from current and past operations. To date, the sludges are stored in ponds or above ground in special containment vessels at various locations around the country. Two samples of electric furnace phosphorous sludge obtained from the Tennessee Valley Authority (TVA) in Muscle Shoals, Alabama and FMC Corporation in Pocatello, Idaho were investigated using physical separation techniques to recover the elemental phosphorous in the sludge and to render the residual material non-hazardous. The techniques tested include sizing, froth flotation and dispersed air oxidation. Flotation and sizing produced concentrates containing 69 -90% P4 with a recovery in the range of 60 -87%. Dispersed air oxidation of the fines and tailing products was effective in removal of an additional 10 -15% of the P4 in the sludge.

Jan 1, 1991

By H. -S. Yoon, C. -J. Kim, K. W. Chung

"With the final goal of ultrasonic application to ion exchange in a resin-in-pulp (RIP) system, the feasibility of an indirect ultrasonic application with a submersed ultrasonic probe was investigated first for the enhancement of ion exchange in the following resin-in-solution (RIS) system: Lewatit MonoPlus MP 600XL in an artificial solution with 106 ppm uranium. Ultrasonic radiation enhanced the ion exchange efficiency without mechanical degradation of resin. For 3.6 g/L of resin, the enhancement was 79 percent after 10 min of ion exchange and it gradually decreased to 11 percent at 60 min. In addition, a preliminary test of the mechanical stability of the resin in the RIP system showed little mechanical fracture of the resin due to ultrasound, which indicates that indirect ultrasonic application by a submersed ultrasonic probe is applicable for RIP systems. IntroductionIn uranium ore processing, the ion exchange process has been used on a commercial scale for preconcentration and purification (Gonzalez-Luque and Streat, 1984). The ion exchange process is divided into two processes: (1) a resin-in-column process with the uranium-bearing solutions passed through columns containing resins and (2) a resin-in-pulp (RIP) process with the leached ore pulp exposed to resins. The latter does not require the separation process of leach liquor and ore solids, which reduces process costs. This process, which has been developed commercially since 1955, has a certain drawback. The adsorption rate and efficiency in the RIP process are relatively low, so numerous contacts between resins and leached ore pulp are needed, which adds to the cost (Merritt, 1971). It is necessary to study methods to reduce process costs.Ultrasound can intensify mass transfer, increase the rate of chemical reactions, and change reaction pathways (Thompson and Doraiswamy, 1999; Luque de Castro and Priego-Capotem, 2007; Adewuyi, 2001; Luque-Garcia and Luque de Castro, 2003). It has great potential in chemistry and is especially considered to be a promising method for enhancing mass-transfer-limited processes, such as ion exchange. Enterzari and Tahmasbi (2009) reported the effect of ultrasound on water softening by ion exchange. Band et al. (1997) proposed a modulated ultrasound application to water desalination with ion-exchange hollow fibers. These reports revealed that ion exchange kinetics could be enhanced by the application of ultrasound. As for hydrometallurgy, Feng and Aldrich (2000) reported that the elution of an ion exchange resin was enhanced by the use of ultrasonication."

Jan 1, 2015

By Stig Premfors

Lamco Joint Venture is operating a Dravo Pelletizing machine to produce pellets from the natural slimes of an earthy hematite ore. The grate area of the machine 3.3 x 106 m equal to 350 m2 (3800 sq. ft.) and the installed fan capacity is 8200 HP. The limiting factor for production is normally fan capacity. This means that the processing fans can not pull the additional air (i.e the additional calories or BTUs) through the bed which would be required for increased production. A way to increase production without major modifications is to supply the additional calories needed for increase production by adding coal to the pellet feed. After successful laboratory tests following method of coal addition has been chosen and the following results have been obtained. 1. The ground coal is added to the slurry prior to the filters and the rotary dryer. 2. By adding 0.6% coal, an increase of about 15% in production rate has been obtained. 3. No significant changes of metallurgical properties have been observed (i.e. tumbler index, compressive strength, ferrous iron content, reducibility, Linder degradation and swelling). 4. No unexpected operation problems have been experienced. The pellet discharge temperature increases and is the limit for how much production can be increased by coal addition without making plant modifications.

Jan 1, 1971

By R. Maurice King

In the operation of today's large scale ore-processing mills, it is extremely important to have some way of making an objective evalu¬ation of the performance of the available flotation reagents. Attempts to do this may often result in inconclusive findings since the magnitude of the difference in the mill results for any two reagents is apt to be quite small compared to the variability introduced by the process and 'the analytical procedures used to measure them. In cases where two reagents give vastly; different mill results, evaluation becomes a simple matter and as such deserves no further attention here. A question of primary concern, however, is how a mill can go about evaluating the performance of two reagents which may, for example, give a difference of only 0.001% copper in the-tailings or of 0.2% in copper recovery. The casual observer may feel that such small differences may be of little importance, but in a mill-whose daily tonnage is between 30 and 40 thousand, these differences could mean a substantial savings. Before the presentation of an actual example of a reagent testing scheme designed for just this-purpose, perhaps a few minutes should be devoted to a review of some statistical methodology to be used later in the discussion.

Jan 1, 1964

By John H. Canterford

The adsorption of uranium onto Wyoming bentonite was measured in carbonate media over the range pH 8-11. Uranium was removed from solution onto the solids by a rapid reaction, proposed to be adsorption of the anionic uranyl tricarbonato complex onto edges of the clay platelets, and a slow reaction which may be precipitation of a hydroxide. The changes in uranium content of the aqueous and solid phases of a uranium ore carbonate leach slurry were also measured as the slurry was progressively diluted. There was an increase in the uranium content of the solids as the pH of the suspension was lowered, as was observed with the Wyoming bentonite. The results indicate the conditions that should be met with respect to pH control in order to prevent the problem of excessive uranium adsorption in the counter-current decantation washing circuit of a conventional leaching process, as well as in the leaching and restoration phases of carbonate solution mining.

Jan 1, 1983

By A. D. Rovig

Metallurgical evaluation of autogenous grinding of Anaconda's Berkeley Pit ores indicated that tonnage throughput increases, at a finer flotation feed size, were possible by converting autogenaus mills to steel ball mills. In addition, initial test work showed that the improved grind resulted in slight recovery gains in subsequent flotation processing.

Jan 1, 1974

By Robert T. DeGavre

I have been asked by the Society of Mining Engineers to present a paper on Inco Limited's Indonesian nickel project as a case study in the financing of large overseas mining projects. I welcome this opportunity It is a story worth telling not only because the project itself represents a significant human achievement but also because there are certain important lessons that can be derived from our experience in financing the project. The paper will be divided into four sections: (i) a brief history of the project, (ii) a critical appraisal of the project's financing plan in terms of the goals that we sought to achieve, (iii) some comments on certain factors underlying the relative success of the financing plan, and (iv) the contributions that the engineering staffs must make to a successful financing plan. The paper will not present a technical assessment of the project since Inco Limited has been asked to submit a series of papers on this subject at the International Laterite Symposium as part of the 108th Annual Meeting of the AIME in February 1979.

Jan 1, 1978

By W. J. Martin

At the termination of mining, the quality of ground water in the ore-zone aquifer must be returned to a condition predetermined by the permitting agency. To immobilize the redox-sensitive elements (e.g., uranium, arsenic, selenium, molybdenum), it has been suggested that a reducing agent be circulated through the leached ore zone. We have conducted laboratory experiments to test the ability of sodium sulfide as such a reducing agent. Sodium sulfide lowered the redox potential of the effluent such that insoluble minerals containing the redox-sensitive elements should be stable. The uranium concentration of the solution decreased by more than three orders of magnitude. In column experiments, by the time ten pore volumes of the sulfide solution had flowed through, sulfide minerals were forming. The experimental results indicate that the addition of sodium sulfide should cause the chemical reduction of the leached sediments, thereby producing long-term stability of the ground-water/sediment system.

Jan 1, 1986

By Shu Fan Chau, Innes Duncan, Harry Asche, Bill Newns

The North Auckland Line (NAL) in Northland, New Zealand, is being upgraded to pass Hi-Cube containers. The line includes many tunnels and bridges which need to be refurbished to improve structural clearances and line capacity. Tunnel 2 along the line, the Makarau Tunnel, has posed special challenges. Opened in 1898, the tunnel suffered multiple collapses during construction and has shown significant distortion during operation. The tunnel has been repaired many times since opening. Successfully enlarging this delicate and distressed structure has involved historical research, advanced analysis and design, and careful construction. The results provide lessons for dealing with brick lined tunnels and poor ground conditions

Jun 13, 2021

By Roy H. Paddon

This paper describes the 6, 000 tpd, three stage haulage system at the Ozark Lead Company's mine in southeastern Missouri. It details the methods and problems pertinent to the loading, hauling, sorting, crushing, storing and hoisting of waste rock and ores obtained from underground development headings and production areas. The Ozark Lead Company is a wholly owned subsidiary of the Kennecott Copper Corporation. Its mine is located nine miles south of Bunker in Reynolds County at the south end of the "New Lead Belt" mining district. Development started in May, 1964, by drilling a seven foot diameter (six foot cased), 1, 250 foot development-ventilation shaft. Drifting began in August, 1965, to obtain a bulk ore sample, to test ore continuity, and to drive two mine levels while the pre-grouted production shaft was being sunk. Over 7, 900 feet of 12 by 24 foot drifting was done from this small shaft. In March, 1966, a 20 foot diameter, three compartment, concrete lined production shaft was collared. It intersected existing development headings at a depth of 1, 195 feet in April, 1967, and was completed along with a concentrator and other facilities in June, 1968. Mine production began that month, with 5, 000 tpd reached in 1970.\

Jan 1, 1971