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By Paul Hamilton, Brian Jones

Traditionally,relatively large gold mines in developing countries have relied on imported process plant engineering, design, pro­ject management and advisory skills. In 1995, there was a significant departure from this in Zimbabwe, when a locally based engineering company under­took and completed the construction of a one hundred and twen­ty thousand tonne per month capacity gold extraction plant for the treatment of sands/slimes residues integrated with run of mine ore. This paper describes the challenges of designing, construct­ing and commissioning a Carbon in Leach (CIL) gold extraction plant in a developing country, and discusses the various con­straints associated with it. In addition, the paper reviews the application of technology which is innovative to Zimbabwe, including the use of dewatering cyclone clusters, and two and a half tonne capacity elution/electrowinning convection units.

Jan 1, 1996

Historical Background. South Africa's industrial history began with the discovery of gold and diamonds during the last century, and the mining industry was the first chief component of our technological development. During the past six decades, quantum leaps were made in other fields, too, when other industries and research bodies such as Escom, NDC, Iscor, Sasol, Foskor, Alusaf, Mintek, cs I R, SA B S, and A E C were established. These meaningful additions have two outstanding characteristics. Firstly, they were linked mainly to primary activities such as energy and minerals and, secondly, their establishment was to a large extent due to the driving force of individuals such as Van der Bijl, Van Eck, Rossouw, Schonland, and Roux, rather than to impersonal government policy. Encouraging signs of the evolution of such policy has emerged during the past few years.

Jan 1, 1989

The Naval Consulting Board is asking the aid of all the members of the Institute in its effort to help solve the submarine problem. Probably every member of the Institute has some suggestion, and while each one of these may be of only slight value in furnishing the remedy, the aggregate may be of great service. Every member of the Institute will soon receive a pamphlet known as Bulletin No. 1 of the Naval Consulting. Board of the United States in which full information and instructions will be given to all of those who are willing to assist. It is hoped when this information is received the members of the Institute will give it their prompt attention and write as soon as possible to the Secretary of the Naval Consulting Board, 13 Park Row, New York, N. Y.

Jan 9, 1917

By S. Stone

Because of problems encountered with conventional timber supports, a system of concrete sausageshaped support pillars was tested. The pillars are 3 m long, 0,6 m wide, and between 70 and 80 cm high (the height of the stoping width). They consist of bags filled with a grout of cement (slagment and sand in the ratio of I :2, and are installed in a staggered pattern 6 m apart on dip and 2 m apart on strike. These support packs have proved successful, and, although they cost more than the timber supports formerly used (R4,63 per cent are supported as against R2,26 for the conventional timber pack), their use is felt to be justified when account is taken of the costs of lost production and low productivity due to the bad hangingwall conditions that occurred with the conventional system.

Jan 1, 1978

By Joseph D. Weeks

When I presented at the Chicago Meeting of the Institute, in May, 1884, a paper on Hadfield's manganese steel,* which had about that time been brought to the notice of steel manufacturers, I promised to furnish some physical tests of the steel for publication in the Transactions. The fulfilment of the promise then made has been delayed by various circumstances; but I have recently been put in possession of tests of this steel carefully made at the Woolwich, England, arsenal. Messrs. Hadfield & Co. prepared for the arsenal a series of twelve test-pieces, made from the same heat. An analysis of the steel gave the following results: Carbon,.........73 Silicon,.........37 Sulphur,.........06 Phosphorus,. .08 Manganese,...... 9.83 The test-pieces had been heated to a white heat and plunged into cold water prior to being put into the machine. This treatment

Jan 1, 1887

By Robert J. McCarthy

There are two things on everyone's lips when mining folks gather these days - one is the exciting business opportunities that now exist for mine development and expansion, and the other is the dire shortage of human resources needed to design, manage, and even operate the mines. Years of stagnant industry growth, limited employment opportunities, and unwarranted perceptions of remote and harsh working conditions have caused mining to be a less than desirable career choice. Attrition and reduced entry to the workforce has resulted in shortages for not only mining professionals, but also skilled trades people and operators. Consequently, to survive, let alone grow, mining companies, suppliers, and educators are all pursuing innovative solutions with technology, inter-industry recruiting, centralized services, and strategic partnerships. This paper describes some of these initiatives and proposes others, now that the people are gone!

May 1, 2008

By J. Ugarte-Núñez

Biodiversity assessments that are developed in different stages of a mining project, have different objectives that define the methodology to be used in each of these stages. In this way, we define two stages of a project: 1) the time at which assesses the state of biodiversity or biological components, before any intervention in the project area, previously defining the area of direct influence and indirect influence of the project for each biological group to be evaluated and 2) the time when certain groups or biological, are monitored during the developmental stages of the project with you to obtain information about the level impact they may have, for project activities. It discusses the methodological differences that must be used in both biodiversity assessments: to develop biological baselines and in those assessments aimed at monitoring different components of biodiversity.

Jan 1, 2011

By A. L. Hinde, A. A. Bradley, P. J. Lloyd

The results of slow crushing tests in a stiff testing machine for both small and large step reductions of particle size are given. The energy consumption required to produce a given weight of minus 74 um material was determined when both single-crystal quartz and Witwatersrand reef were crushed. For comparison the two materials tested were also comminuted in a ball mill under optimum conditions. There are indications that slow crushing under stiff conditions is the most efficient method of breakage that can be devised. The comparison with ball milling results thus yields a value for the efficiency of ball milling of approximately 80 per cent. These results confirm that the best current estimates of milling efficiency, which are based on the free boundary surface energy of the material being milled, are probably too low by at least one order of magnitude.

By S. K. Sadrnezhaad, B. Hashemi, Z. A. Nemati, Z. Moghimi

Based on the kinetics relationships of a solid - gas model, a software was developed for the prediction of oxidation. Preliminary prediction of oxidation by the software and experimental results of MgO-C refractories were studied and compared. By using the obtained data from this approach, the effective diffusion coefficient, intermolecular diffusion coefficient and diffusion activation energy in the MgO-C refractories, containing various amount of graphite were obtained at different temperatures. First of all, the prediction by the software was very compatible with experimental results, for different oxidation mechanisms in the MgO-C refractories. The results showed that pore diffusion is the predominant oxidation mechanism in this system. The results indicated that when graphite content was above 10wt%, the intermolecular diffusion coefficient was independent from graphite content, and it was closed to a constant value at each temperature.

Jan 1, 2004

By John V. Beall

New York was bathed in pale winter sunshine and, surprisingly, coatless weather. The time was the AIME Centennial and 100th Annual Meeting. From advance peeks into the fabulous schedule of events we were well aware that the Centennial Committee, New York Host Section and AIME staff' had pulled out all the stops, laying on the best of everything, but the weather gimmick was the frosting on the cake. The Formal Greetings Session on the first morning, Joe Alford confided, was the greatest AIME experience of his life. Without doubt the honor bestowed on AIME by the greetings and felicitations of the presidents of the world's leading professional engineering societies was the greatest moment in AIME history-save one. That one exception was in 1928, when 1920 AIME President Herbert C. Hoover was elected President of the United States.

Jan 1, 1971

By Ju Hao L, Jian L

A joint project between the Fan Kou Mine, the Guangzhou Research Institute of Non-ferrous Metals, the Julius Kruttschnitt Mineral Research Centre, and the Changsha Design and Research Institute of Non-ferrous Metals has implemented grinding control on a circuit consisting of two primary mills and a single secondary mill at the Fan Kou mine in northern Guangdong province, PR China. This paper describes the initial design of the control system and the changes made during its implementation. The initial design was to obtain maximum throughput at a constant product size. This was changed so that the control provided a constant product density at a set feed rate. The set feed rate is reduced when necessary to prevent overloading of critical components in the circuit. The reasons for the changes in the control strategy are discussed.

Jan 1, 1993

By Jesús L. Valenzuela

The solvent extraction for gold from alkaline cyanide solutions has been investigated using LIX 79 guanidine-based extractant. Different variables that could affect the extraction system were evaluated: equilibrium time, aqueous pH and extractant and modifier concentrations. The extraction isotherms of the aurocyanide complex with respect to other cyanoanions were compared and the following order of selectivity Au>Ag>Cu>Zn>>Fe was observed. From the pH isotherms it was found that aurocyanide can be extracted in alkaline media and a better separation with respect to other cyanoaniones was obtained in the range of 10.5 < pH < 11.2. Better selectivity was observed when using LIX 79 and tridecanol at 10% and 5% vol, respectively. Stripping gold from loaded organic was carried out at pH>12, using NaOH and NaCN solutions.

Jan 1, 2003

By P. J. Nicholson

The methods of reinforcement to be discussed in this paper are all insitu methods, ones that can be used on the soil structure as it exists in the ground, and do not rely on excavation and replacement of the soil. Current practice in the United States, as well as new ideas and methods, will be discussed as they relate to slope stability, retaining walls, and to other uses such as control of mine or cavity related subsidence and to liquefaction control under existing structures. The method is based on the concept of "nailing" or reinforcing the soil in place, and thereby causing a mass of soil to act as a coherent unit. When performed properly, a true gravity structure can be constructed, one that will remain intact under both horizontal and vertical loadings and that will also resist vibrational and seismic loadings.

Jan 1, 2010

By J. le Grange, M. Tullmin, A. Strauss, F. P. A. Robinson, C. A. O. Henning

An experimental feritic stainless steel with a chromium content of 40 per cent was welded by laser and electron beam (EB) welding processes. These techniques were found to be particularly suited to the welding of this alloy in that the impact toughness of the weld metal and heat-affected zone (HAZ) of the laser welds compared favourably with those of the parent aloy. When the EB process was used, the impact toughness of the weld metal was over 180 J/cm2. Grain growth in the HAZ was minimal for welding with these two processes. Corosion tests, conducted in a solution consisting of 20 per cent sulphuric acid and 100 p.p.m. of potassium thiocyanate, and In a highly corrosive industrial solution, indicated that the laser and EB welds were free of sensitization effects, thus confirming the metalographic results.

Jan 1, 1989

By M. Reza Bateni, M. Zandrahimi, J. A. Szpunar

Titanium aluminides and nickel aluminides offer the potentials, as coating materials, for high temperature and aerospace applications. In this research, attempt has been made to develop Al-Ti and Ni-Al intermetallic compound coatings on the surface of Inconel 738. The coatings applied through pack cementation and simultaneous diffusion annealing processes. Scanning-electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDAX) and grazing angle X-ray diffraction were used for evaluating of coating structure. It was demonstrated that the pack cementation technique could be used to develop TiAl3 and AlNi intermetallic compounds coating on Inconel 738 substrate. When pack cementation technique is based on a halide-activated pack with aluminum and titanium powders, the coating consists of TiAl3 intermetallic compound phase. Whereas, by pack aluminization of Inconel 738, the coating consists of AlNi intermetallic compound phase.

Jan 1, 2004

OCHRE is a semimineral composed by Nature of earth and a tincture of yellow caused by a fumosity of lead ore. By itself it is a material without any [38] metal, although when it is used in smelting it helps to melt the harsh and sour ores of metals. I do not know that it has any other use, except to painters. Bole is also a red viscous earth which has a very astringent and drying nature. It has no very apparent smell or taste, and I think that the cause of its redness lies in the fumosities of iron ore, for it is a companion to this and is found in its mines. It is an efficacious medicine against any poison and in this capacity has an action like terra sigillata* or perhaps better. In

Jan 1, 1942

By Syd Peng

In designing a proper roof support system, one must know the features of roof geology in advance of mining. The drilling parameters obtained during normal roof bolt installation cycle can provide a large amount of information on the roof geology when properly interpreted. It is also an economic way for identifying the geological features of the roof. This research develops a method for predicting the roof geology based on the drilling parameters obtained during roof bolting operation. From the results of a series of laboratory and underground tests, feed pressure is found to be a good indicator for identifying the voids/fractures and estimating the roof rock strength. This paper describes the method for determining quantitatively the location and the size of void/fracture and estimating the roof rock strength from the drilling parameters of roof bolter.

Jan 1, 2005

Contracts are widely used in mining to provide self motivation in an environ-ment of isolated work places. Which incentives to use and how to implement them has long been the subject of numerous discussions. The mines operated by Australian Mining and Smelting at Broken Hill have evolved several guidelines to follow when developing contracts.Identify the main purpose of the work and use this as the basis of measurement for the contract. Therefore stoping achievement would be measured by tonnes extracted, development by metres driven. Paying for other work activities such as standing timber in timber stoping must detract from the percentage of the total contract paid per tonne produced. Concentrating on the main activity and applying the majority of contract pay to that task reinforces at is beneficial to both the miners and the whole operation.

Jan 1, 1985

THE late steel strike resulted in an unusual reversal of field when Brazilian interests shipped steel to the United States to assure completion of a blast furnace under construction in Cleveland for the national Volta Redonda mill. The furnace is one of the key factors in an expansion program scheduled to raise Brazilian steel production by 280,000 tons, bringing annual output to 1 million tons. The first consignment shipped to Cleveland included 500 tons of slab and plate steel, and was followed later by another 300 tons. Brazil wants to blow in the furnace by July 1, 1953, and the restricted allocation system brought about by the steel shortage offered a real threat to the deadline. Volta Redonda, established during World War II by Brazilian and American financing, accounts for more than half of Brazil&apos;s steel production.

Jan 1, 1952

By A. Bouajila

To stay competitive in an open market, mineral industries have to optimise their processes, lower their production costs and improve the commercial value of their products. Up to a recent past, they were impaired in this attempt by a lack of adequate devices allowing reliable on-line and real-time process monitoring (detection or measurement). Process monitoring for process control and the product characterisation for quality control are quite different tasks. Planners and researchers should be fully aware of this when evaluating or developing monitoring equipment for on-line process control. This paper will comment on some aspects of sensor specifications, during the design and the evaluation steps, related to sampling, measurement (accuracy, sensitivity, delay and correlation to the process) and suitability to the exploitation environment. Examples of R&D projects promoted by COREM for various industrial applications will be presented.

May 1, 2001