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By W. Zieman

"The low consumption of reagents can probably be attributed to a good clean type of ore. The cyanide level is kept at 0. 8 lb/ ton of solution and the lime at 1. 8 to 1.9 lb per ton of solution (pH 12. 2 to 12 .3). Experience in cutting down the lime level in half produced troubles in the presses, in the refinery and resulted in higher cyanide consumption. Finally the residue increased under these conditions, High lime always seems to prevent the trouble from occurring.A survey at one mine of the taxable work, performed in the mine shops for use in the mine, showed that under the new regulations, this had increased some 30 times what it was before the new rules came into effect on June 14, 1963.A water softener idea is incorporated at Lamaque with the crude addition of 100 lb of lime per shift to a spare agitator to precipitate the bicarbonates as carbonates from the water before it enters the mill. The lime titration of the softened water is about 0,2 to 0.3 lb per ton of solution (pH 11). This water is used mainly on the filters as washes."

Jan 1, 1964

By I. M. Santos Moraes

The control of minor impurities (mainly As, Sb and Bi) in copper refineries has been a great challenge. Caraiba Metais' copper refinery produces a very high quality copper, registered in LME as grade A, and recognized as amongst the top ten in the copper world. At Caraiba's Tankhouse Bi and Sb are controlled by means of electrolyte bleed-stream removal after partial decopperizing in a set of electro-winning cells (liberators). Another way of reducing the Sb and Bi content in the electrolyte is by means of the arsenate precipitation chemistry. It is well known that the use of high arsenic concentrations in copper refinery electrolyte has the advantage of causing most of the bismuth and antimony to report in the anode slimes. However, the use of such mechanism of control may contribute to other undesired problems such as antimony and bismuth precipitation in the bulk of the electrolyte, what may cause severe contamination problems. This paper describes a period when some cathode contamination with Sb occurred at Caraiba Metais' Copper Refinery. It also presents an analysis of several process parameters related to the problem, the possible causes for the contaminations as well as the actions taken to correct the problem.

Jan 1, 2007

A small group of members of the Institute headed by W. H. Shockley, has insistently demanded that the Institute submit to the members for letter ballot the question of our using in our publications and corre-spondence certain so-called "simplified spellings." The principal argu-ment in favor of this proposal is written by Mr. Shockley and will be submitted in full to the membership for ballot. It rests chiefly on the desirability of saving the time of school children in the learning of the spelling of the English language. A sample of correspondence had with one of the gentlemen on this subject is given herewith in order that members may see what the correspondence and publications of the Institute would look like if we adopted the proposals. This sample was chosen at random: "Onse I condemd the report ov a president of the Institute. He did not pruve his case even on paper-"a hot air profet," I sed. Time has pruved he was." "I rote yu about the muvement to better the spelling in the Institute Bulletin, etc., neglecting to say some things that I mite hav said and things hav happened since which no member ov a democratically governed society shoud stand without protest."

Jan 12, 1919

By E. K. Albert

Title IV of the 1977 Surface Mining Control and Reclamation Act (SMCRA) provides for an abandoned mine reclamation fund. This fund, taken from fees collected from operating coal mines, provides capital for the reclamation process. The Act directs the Office of Surface Mining (OSM) to collect the fees based on coal production. Monies from the abandoned mine lands (AML) fund are distributed through two programs. The first provides OSM with capital to use in emergency situations resulting from abandoned mine sites and reclaiming high priority sites in states without established AML programs. The second distributes the money through a state's AML program in the form of grants. To provide for a flexible and customized selection procedure for AML projects, a management information system (MIS) that combines scientific selection procedures is being developed. This system employs objective and subjective methods developed in systems research in recent years. The MIS component is an essential part of any selection process involving large numbers of potential projects. It must contain all the necessary project parameters that can be applied to the selection of projects whether or not they are to be used in the immediate selection criteria. In addition, variable selection criteria will allow ‘what if’ types of inquiries for comparison of differing selections and benefits.

Jan 1, 1990

The Australasian Institute of Mining and Metallurgy brings together, voluntarily, people with a professional interest in the disciplines and skills which are employed in the mineral indus- try, and in relation to that industry. We come together because we have a mutual interest in improv- ing what is done by the mineral industry, in all its aspects. It is this sense of continuing improvement, of doing better, of doing as well as we can, as our knowledge and skills improve, that unites us in creating and fostering a professional association of like- minded people. We know from our professional training and experience that enormous progress has been made, at an ever-increasing rate, in the mineral industry, particularly in this Century. We know that the mineral industry has played a very major role in providing the means by which so many more people survive to live longer, healthier and more interesting lives, than ever before. Indeed together with the oil and gas industry, which is an integral part of the mineral industry but has achieved its own commercial dis- tinction, it is fair to claim that the mineral industry has played the major role in providing the means for the advancement of the human quality of life.

Jan 1, 1988

Dunn has written an excellent paper providing a wealth of advice on what is often the most costly consumable in the mineral processing plant. As he pointed out, grinding media selection and quality control can play a major role in successful plant operation. Owing to the economic importance of this topic, there are some important factors related to media sizing that I believe merit further comment. Dunn made reference to a slightly simplified version of the Azzaroni (1981) equation and pointed out its successful use for the Henderson SAG and Climax ball mills. Although both formulas are empirically based on successful plant experience, a notable discrepancy between them is that Bond has factored the work index by the ore specific gravity. This is invariably so, as the Bond work index is derived from the mass grindability (in grams per revolution) measured in a test mill with a fixed volume of solids load (Bond, 1961). A material having the same structural integrity but double the density of another will have double the grindability and just over half the work index. Thus, for the general case, specific gravity should be incorporated into any media sizing formulation that uses work index as the criterion for resistance to breakage.

Jan 1, 1990

By Hermann A. Derbuch

Twin Mining made a conscious decision when it changed from gold mine explorer and developer to become a diamond explorer in Canada?s Arctic. It was a decision of survival in an environment that saw junior gold companies either disappear or turn into dot com companies. Twin Mining learned fast and staked within weeks of that decision the first 50 sq. km of claims on, what became, its TORNGAT property at 59½° latitude on the east coast of the Ungava Bay in northern Quebec. This land position, 724 diamonds later (including 322 macro diamonds of gem quality, white and transparent) grew to 507 sq. km today. The 74° latitude called when Twin Mining exercised the option to acquire 3 claims owned by Helix Resources Inc. which revealed exceptional diamond potential. A gem quality 5.4 mm (0.768 carat white and transparent) diamond and the discovery of 16 pipes on 15.2 ha convinced Twin Mining?s board to sanction the deal. Both properties have outstanding features. Kimberlite Dykes and Pipes are in outcrop. The property locations have deep-sea access near existing infrastructure. Their locations are in an environment that is stable and development friendly and has a positive track record with successfully operating mines near-by.

May 1, 2001

By Dan Adams, Thomas Post, Paul Kubera, Mike Preston

Mixing is a common unit operation in the mining industry. Mixers are often used in agitated leach, bio-oxidation, and pressure oxidation. In all of these cases it is important to understand the application and what it requires from a mixer in order to be opti­mized. In the mining industJy, it is obviously important to suspend solids. However, the shear level of each of these three applications is ve1y different. In acid leaching, the mixer needs to suspend solids and produce a good degree of blending. In pressure oxida­tion, the agitator must also disperse air or oxygen by creating fine bubbles. Because of the presence of microorganisms, bio-oxida­tion requires less shear than the other two processes, but the agita­tor must be able to suspend the solids, provide excellent blend­ing/heat tJ·ansfer and distribute the air. Thus, in the mining indus­tiy there is an application spectJ·um that requires different impellers to perfotm different jobs. Specifically, these jobs are blending, solids suspension, gas dispersion, mass transfer and heat transfer. It is important to determine whether the process is mass transfer or kinetic rate limited. Mixers affect a mass transfer limitation but have no affect on the kinetics.

Jan 1, 1998

By A. L. Murray, D. Harrington

From 1870 to the end of 1929 the coal production of Utah has been some- what less than 110,000,000 tons. During this period at least three major disasters have occurred with fatalities totaling about 380, establishing a decidedly bad record of approximately 3.5 persons killed by major mine explo- sions per million tons of coal produced. Even during the period when there have been no disasters, such as the years 1914 to 1920, inclusive, the fatalities in ordinary working were about 5.4 per million tons produced, against 3.7 per million tons for the whole United States for the same years. The 5-year period following the World War, 1918 to 1922, inclusive, had 4.7 fatalities per million tons; hence, the fatality record in the coal mines of Utah has uniformly been in excess of the average of the coal mines of the entire country. Notwithstanding this poor record, Utah has given to the coal-mining world many excellent safety methods and practices, and Utah coal mines in general take greater measures toward safe mining than do the coal mines of any other State; if practices and methods allowed and pursued in coal mines of other States were tried in Utah coal mines, there would be a succession of disasters.

Nov 1, 1931

Contribution by W.D. Ortlepp? The authors are to be commended for publishing their interesting view of an aspect of deep-level mining technology that is becoming increasingly topical and vitally important. This is the second paper in the journal within four months to deal with the crucial needs of highly stressed tunnel construction, the other being the paper on the design and testing of rockburst support in the February 1994 issue. Both papers re-examine important innovative ideas that are more than a quarter of a century old, but that have not yet been implemented by the industry. It is to be hoped that they will now, taken together, serve as a new starting point for a definitive examination of what constitutes proper tunnel-support design. There can be no question that the need to develop a design approach that will solve the problems of tunnelling at depths of 4000 m or more has now become crucial. Contribution by A.M.J. Vervoort* Although the overall paper is very interesting and the future research (comparison between numerical simulations and underground measurements) will be very challenging, I would like to make some remarks regarding the set-up of the numerical model and the interpretation of the elastic results.

Jan 1, 1995

By John V. Beall

Many months ago, the ME staff began thinking about what to put on the February cover of the Centennial Commemorative issue. We have considered photographs of mines, equipment, symbolic artwork and various collages. Our theme is "the next 100 years in mining" and the cover ideally should convey a related message or idea. All of us are convinced that there are many exciting technical changes that will be coming. But even so, we decided that, in our opinion, the engineer is the most vital factor. For this reason we chose to put a man on the cover of this issue. At first it was going to be the face of a man with whom each member could conceivably identify himself. It was one of the Bobs on our staff (we have four) who came up with the thought that since it's the future we are talking about, we should have a young man's or a student's face. Of course we firmed up our idea at the ninth hour, and it was too late to canvass the mining schools. However, by a stroke of luck, we were rapping with a group of University of Arizona students on the terrace of the Pioneer Hotel on December 7, 1970, and met Dave Bolles.

Jan 1, 1971

The School of Mineral Industries is dedicated to education in mineral conservation and research by which the means may be found to make conservation effective. This includes diligent search for mineral truths and the energetic discovery, complete recovery, and maximum utilization of irreplaceable mineral resources. Standards of living depend upon two factors: human resources-intelligence, imagination, initiative, know-how, work; and natural resources-plants, animals, and minerals, including water, air, soil, heat and light from the sun, and all other such resources that are useful to man. Human relationships have not kept pace with scientific achievement; as a result man, in desperation, wittingly, premeditatively sacrifices freedom for security. Many natural resources, through overproduction, mismanagement, and greed, have definitely moved over into the exhausted or exhaustible category. The United States cannot maintain present standards of living on an agricultural economy alone, and serious harm can ensue if there are marked disproportions in numbers and relationships between city and rural populations. The most materialistic New Yorker must see virtue in bucolic loveliness. The United States is rated wasteful and inconsistent most of the time. It does not make sense to dole out through the keyhole what a wage earner can bring through the open door; to raise wages to lower the cost

Jan 1, 1950

By B J. van Loggerenberg

The capital cost of major items of mining equipment is very high. The operating cost of such equipment is also high. It is therefore important that such expensive equipment is used productively. To this end mine management uses production data systems and management accounting systems to monitor events and provide data for analysis to enable management to make operating and business optimisation decisions. This could be done better if there was an understanding of productivity in terms of its utilisation and efficiency components. What has been missing has been a methodology to properly account for the productivity of equipment in terms of its contribution in dollars to the costs and profit of the mine. An explanation of the Productivity Accounting methodology will be given. It will then be shown that productivity has two components, that of capacity utilisation and efficiency. These are defined and the dollar contribution of each to costs and profit shown. The efficiency component tracks the effect of proportional changes in input cost quantities used in the mining process as mining production changes. The capacity utilisation component tracks the effect of step changes in the input cost quantities used in the mining process as mining production changes.

Jan 1, 2003

The subject of the present paper will be combustion of fuel and as the combustion of fuel requires a certain amouut of air to effect combustion the question might be asked what is air?Air is composed, we will say, principally of two gases, oxygen and, nitrogen, but our business is with the former gas, and its leading feature as a supporter' of combustion. In point of fact no fire will burn without its presence, nor can animal life be sustained when this gas ls absent, because it is the life-sustaining element. For example, if we take a piece of charcoal, which is pure carbon, and burn it in the open air combustion takes place in the union of the carbon of the charcoal with the oxygen of the air, forming the compound known as carbonic acid (0.0.)The rust we see on iron and other metals is a kind of slow combustion, which is termed oxydation. When oxygen unites with any other element heat is given off in the process, and it may be here stated that the most intense heat is produced, by burning the two gases-oxygen and hydrogen in precisely the same proportions as that forming water.

INTO their great Pacific Northwest counting house went the members of the Industrial Minerals Division recently, to count their blessings amidst the scenic grandeur and mineral wealth of the State of Washington. From their vantage point in Seattle, those who attended the IMD's fourth Pacific Northwest meeting turned their sights to the South and Southeast, scanned Montana, Idaho, Oregon and Utah, and predicted a very healthy economic future for their region. The praises of Idaho's booming phosphate industry were sung by Earl W. Murphy, secretary of that State's Chamber of Commerce. He said the establishment of Fort Hall, on the banks of the Snake River near Pocatello, first turned the eyes of the world toward what is now the center of the greatest known deposits of phosphate rock-the section adjacent to the common corners of Idaho, Wyoming and Utah. With the founding of Fort Hall, Mr. Murphy said, historians will also rank the construction of the first electric furnaces for the production of elemental phosphorous as equally significant in the commercial history of the West. Those furnaces were installed only last year by the Westvaco Chemical Div. of the Food Machinery & Chemical Corp. at Pocatello, at a cost of $8 million.

Jan 7, 1950

J. E. JOHNSON, JR., New York.-It seems to me that it ought to be somebody's job to tie these notch tests with the reversed-stress tests, because the thing that causes failures in structures, in a great majority of cases, is where the material is stressed repeatedly up somewhere near the elastic limit, and the repetition of that stress seems to bring about what I suppose you may call a growth of crystals and that eventually develops into a break. It seems to me that it would be of the greatest value if there could be a coordination of the results of a shock test of some kind with the reversed-stress test, so that we could be sure that a material that had shock-test resistance would have reversed-stress resistance. H. F. MOORE,* Urbana, Ill.-The question raised by the speaker concerning the correlation of results from impact tests of notched bars with the results of repeated-stress tests is a very complicated one. Impact on a specimen sends energy into the specimen, and if the specimen absorbs this energy without fracturing there must be developed both stress and elongation. A notch in the specimen allows but little elongation to take place before rupture, and develops the ductility of the

Jan 5, 1919

Nearly eighteen months ago Newmont Waihi Operations joined with the local district council and members of the Waihi community in the initiation and running of a community liaison forum.   This forum û the Waihi Community Consultative Committee (WCCC) û was set up with the objective of improving communication, providing a forum for discussion and ultimately working through a range of issues relating to the future of the town and district after the projected closure of Martha Mine in late-2006.   After 18 months of meetings where all represented groups have presented their views, the challenge now is to work together to investigate likely options, seek sources of funding, produce business proposals and plan for the future of Waihi in what we call the Golden Legacy Project.   This paper backgrounds the companyÆs experiences to date, the issues the group has addressed and its proposals for the future. Methods employed to set up an effective community liaison forum are considered, drawing on specific examples from the WCCC. The actions and structures required to ensure effective and ongoing community æbuy inÆ at all levels are also discussed.   This paper develops themes addressed in Taking it to the Streets presented in 2003.

Jan 1, 2004

By M. C. Fuerstenau

Each year during the AIME Annual Meeting, the MBD Division has its Business Meeting. Because many members cannot attend, it has be- come policy for the secretary of the Division to present highlights of the business conducted at the Meeting in Fine Grind. This year the Meeting was held on March 1 in the Americana Hotel. Five major items of business were brought up for discussion. These were: (1) the proposed name change for the Division, (2) institution of the Taggart Award, (3) a name change for a Unit Committee, (4) MBD funding of scholarships, and (5) authorship of Fine Grind articles. The Matter of What We Should Call Ourselves A lively discussion was held on the issue of a name change for the Division. Two names have been proposed: (1) Mineral Processing Division, and (2) Mineral Engineering Division. A number of strong reasons for changing the name from Minerals Beneficiation Division have been pointed out. Perhaps the most important of these is that the term "beneficiation" does not describe all of the functions that engineers in our Division perform. Further, there are inherent problems associated in the term, in that beneficiation is a long word which has the twofold disadvantage of being both difficult to pronounce and difficult to spell.

Jan 1, 1971

By D Alexander

For nearly 100 years, the flotation plant metallurgist has often wondered what is happening æbeneath the frothÆ. To assist in unravelling this mystery, new technology has been developed as part of the Australian Mineral Industries Research Association (AMIRA) P9 project, to measure gas dispersion characteristics (such as gas hold-up, superficial gas velocity and bubble size) in industrial flotation cells. These measurements have been conducted in a large number of cells of different types and sizes by researchers from the Julius Kruttschnitt Mineral Research Centre (JKMRC) and JKTech. A large database has been developed and the contents of this database are described in this paper. Typical cell characterisation measurements show a wide spread in values, even in the same cell types and sizes performing similar duties. In conventional flotation cells, the typical gas hold-up values range from 3 - 20 per cent, bubble sizes range between 1 and 2 mm, and superficial gas velocity ranges from 1 to 2.5 cm/s. The ranges of cell characterisation measurements given in this paper will enable plant personnel to compare their operation to other similar types of operations from around Australia and the rest of the world, giving opportunities for further improvement to flotation plant operations.

Jan 1, 2005

By J. R. Finlay

THE other day, I fell into conversation with two gentlemen who desired to improve the condition of the people; so that the talk was semi-political. They seemed to agree that I was inclined to be "con-servative," "reactionary," perhaps an "evolutionist," looking upon "reform" with suspicion. Finally I rejoined somewhat in this manner: "You attach to me phrases that I have heard all my life but which convey no meaning to me. It is quite true that I do not make a fetish of terms like reform, liberty, democracy and so forth; neither do I worship the idea that `things are good enough as they are,' `leave well enough. alone' and so forth. There is more satisfaction in building something up than in tearing something down, or in just maintaining something that is already built. Progress is a popular word; but what is progress? In my opinion it is comprised, so far as public welfare is concerned, of two elements: Improvements in production of goods and knowledge; improvements in keeping order." This substitute for politics, economics, reform, pro-gress, conservatism, radicalism, democracy, socialism, monarchism and all the phrases of public welfare may seem over-simple; perhaps it is, but at least it defines something. It seems to me to be at least worth attention.

Jan 4, 1922