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By Peter W. Harben

Once considered the dowdy country cousins of the glamorous metallics, industrial minerals are shedding their old image. They are neither common nor easy and their time has come in an age of increasing specialization. Consider that of the 45 or so industrial minerals and rocks listed in [Table 1], almost three-quarters have ten or fewer significant suppliers (i.e., those individual countries contributing 2% or more of total world production); in more than half the cases, 85% of world production is accounted for by only five countries or fewer. Curiously, even materials that appear to be virtually ubiquitous like crushed rock and common salt have significant production vacuums. For example, there is a severe lack of sound aggregates along the US Gulf Coast and common salt production on a large scale is virtually absent in central Africa. These examples all underline the obvious, but acute truism that "The single most important fact about mineral resources is that they are not distributed equally over the world" (Flawn, 1966). Just as significant today is that human resources are not distributed equally over the world, and so arise some interesting commercial incongruities. In certain regions raw materials are plentiful but consumers are not, and without a market a mineral deposit is merely a geological curiosity. Elsewhere, there may be a market but no local raw material supply. For example, despite a huge market there is no or virtually no commercial production of chromite, diamonds, and manganese in the United States and Canada, nor phosphate rock, diamonds, rutile, and zirconium minerals in western Europe. In contrast, Australia with its small domestic market is the world's largest supplier of bauxite, diamonds, ilmenite, natural and synthetic rutile, and zircon; the same is true for South Africa which is a leading producer of chromite, manganese, diamonds, andalusite, ilmenite, rutile, and zircon (Table 2). In the commercial world, Nature's uneven distribution is counterbalanced by deep sea international trade.

Jan 1, 1994

By E. W. Steele

IN THE copper-casting department of a modern electrolytic copper refinery there are two kinds of casting furnaces: the first, or anode furnace for casting crude copper into anodes for electrolysis; the second, or refined-copper furnace for casting the cathodes resulting from electrolysis into market shapes, such as ingots, wire bars, and cakes. Both furnaces are reverberatories of practically the same general design and are operated intermittently, putting through a charge normally in 24 hours. The treatment of the copper in both furnaces is similar, in so far that oxidation followed by skimming and reduction (poling) is carried on in both; but in the refined-copper furnace, the work must be done with greater care and it is of extreme importance that not the slightest trace of impurity be introduced into the copper. The furnaces usually hold from 150 to 300 tons of molten copper, which constitutes the daily charge. Except in the case of furnaces in the Lake district, where the concentrates from native-copper ores are charged through the roof, the furnaces are charged through the side doors by charging machines similar to those used in open-hearth steel practice. In 1916, at the Perth Amboy plant, of the American Smelting & Refining Co., located at Maurer, N. J., a study was made of the possibility of firing the copper refinery furnaces with pulverized coal instead of by hand. The proposed method possessed obvious advantages over hand firing and coal was a much cheaper fuel than oil at that time. It was realized, however, that there were several objections to its use, the principal ones being the liability of increasing the sulfur content of the refined copper, and the additional slag that might be produced from the ash. The increase of the sulfur content of the refined copper was the more serious, as more than 0.002 per cent. sulfur is objectionable. In the case of the slag, any increase would be expensive as the copper in this slag would have to pass again through the entire smelting and refining process.

Jan 3, 1925

By O. Kangal, G. Önal, G. Bulut, A. Gül

The recovery of copper and cobalt from the ancient copper slags, located in Küre-Turkey, is investigated. Fayalitic type of ancient copper slags containing 1.41% Cu, 0.53% Co and 53.16% Fe were subject to the experimental study. Magnetic separation, gravity concentration and flotation test were conducted. The results of magnetic separation and gravity concentration were not satisfactory. However, a concentrate containing 9.57% Cu could be produced with 44.7% recovery by flotation. Copper and cobalt that remained in the flotation tailings was recovered by roasting with sulfuric acid followed by hot water leaching. Complete cobalt dissolution was observed in 1 hour of roasting at 150°C and 3:1 acid/slag ratio, whereas the copper recovery was 83%.

Jan 1, 2004

By Evgeny G. Gurvich

While direct study of high temperature hydrothermal activity and the associated mineral formation as well as study of their scales are possible in the modern ocean, researchers are deprived of such opportunity for past geologic time. Even in cases where hydrothermal deposits that formed in the geological past are preserved they have been covered by sediments or overlain by lava and have become inaccessible after a time for obser-vation and sampling. Rarely are these buried hydrothermal deposits found during deep-sea drilling or coring operations, and their direct study on an ocean scale is impossible at present. Even within hydrothermal fields, without special preliminary detailed surveys, the probability of intersecting hydrothermal edifices that are covered by sediments becomes a rare event.

Aug 24, 2006

By E. B. Snyder, H. M. Kraner

This paper shows that volume stability, low porosity and decreased pyroplasticity are desirable for blast-furnace linings, partitularly for the hearth. It shows further that a hot load test is a valuable means of testing the fusion or softening behavior of a refractory at operating temperatures. The effect of carbon monoxide on commercia1 blast-furnace refractories in their as-received condition and after refiring is reported, showing that many commercial blast-furnace refractories disintegrate badly but that refiring decreases the effect and certain special refractories are now available which are almost free of the tendency. Factors Affecting Choice of ._ Refractories If one were to depend entirely upon experience or trial in the selection of clay refractories, the solution of a problem would be a slow process. Furnace campaigns are so long and attended by so many variables that it is difficult to draw fine distinctions within a reasonable period of time in regard to the quality of refractories used. It could be said, of course, that if service results do not yield the proper information for intelligent choice, there is no difference in the quality of brick being considered, but this is not necessarily true. Conventional ceramic tests are designed to give the ceramic engineer information as to the refractoriness and firing tempera- . ture, which he in turn internrets in terms of volume stability, ability to withstand load at high temperature (pyroplasticity), permeability, chemical stability and re-. sistance to the action of slag. In most refractory applications . several of these factors are involved. In a particular instance, one requirement may be predominant, while in others some other factors may be of primary importance. In this country, clay refractories are generally made from mixtures of plastic and flint fire clays. The process of firing a clay refractory is one of slowly melting the constituents, and during this operation its porosity is gradually reduced. The process is arrested, of course, in its incipient Stages and the Progress is determined by measuring slight changes in porosity, volume, bulk gravity, etc., that have taken place. Often the temperatures to which clay refractories are exposed in service are higher than those employed in their firing. However, if the manufacturer were to fire them at such high temperatures the brick would distort. Therefore it would be difficult for the manufacturer to fire all of his clay refractories to temperatures at which they are to be used, although in many cases it would be desirable from the user's point of view if he would do so. The porosity of clay refractories decreases by firing, to a minimum limit, after which a further increase in the temperature causes expansion in certain clay constituents and bloating in others. Both may occur in the same refractory containing two such clays.

Jan 1, 1944

By H. M. Kraner, E. B. Snyder

This paper shows that volume stability, low porosity and decreased pyroplasticity are desirable for blast-furnace linings, partitularly for the hearth. It shows further that a hot load test is a valuable means of testing the fusion or softening behavior of a refractory at operating temperatures. The effect of carbon monoxide on commercia1 blast-furnace refractories in their as-received condition and after refiring is reported, showing that many commercial blast-furnace refractories disintegrate badly but that refiring decreases the effect and certain special refractories are now available which are almost free of the tendency. Factors Affecting Choice of ._ Refractories If one were to depend entirely upon experience or trial in the selection of clay refractories, the solution of a problem would be a slow process. Furnace campaigns are so long and attended by so many variables that it is difficult to draw fine distinctions within a reasonable period of time in regard to the quality of refractories used. It could be said, of course, that if service results do not yield the proper information for intelligent choice, there is no difference in the quality of brick being considered, but this is not necessarily true. Conventional ceramic tests are designed to give the ceramic engineer information as to the refractoriness and firing tempera- . ture, which he in turn internrets in terms of volume stability, ability to withstand load at high temperature (pyroplasticity), permeability, chemical stability and re-. sistance to the action of slag. In most refractory applications . several of these factors are involved. In a particular instance, one requirement may be predominant, while in others some other factors may be of primary importance. In this country, clay refractories are generally made from mixtures of plastic and flint fire clays. The process of firing a clay refractory is one of slowly melting the constituents, and during this operation its porosity is gradually reduced. The process is arrested, of course, in its incipient Stages and the Progress is determined by measuring slight changes in porosity, volume, bulk gravity, etc., that have taken place. Often the temperatures to which clay refractories are exposed in service are higher than those employed in their firing. However, if the manufacturer were to fire them at such high temperatures the brick would distort. Therefore it would be difficult for the manufacturer to fire all of his clay refractories to temperatures at which they are to be used, although in many cases it would be desirable from the user's point of view if he would do so. The porosity of clay refractories decreases by firing, to a minimum limit, after which a further increase in the temperature causes expansion in certain clay constituents and bloating in others. Both may occur in the same refractory containing two such clays.

Jan 1, 1944

By Hobart M. Kraner, E. B. Snyder

THIS paper shows that volume stability, low porosity and decreased pyroplasticity are desirable for blast-furnace linings, particularly for the hearth. It shows further that a hot load test is a valuable means of testing the fusion or softening behavior of a refractory at operating temperatures. The effect of carbon monoxide on commercial blast-furnace refractories in their as-received condition and after refiring is reported, showing that many commercial blast-furnace refractories disintegrate badly but that refiring decreases the effect and certain special refractories are now available which are almost free of the tendency. FACTORS AFFECTING CHOICE OF REFRACTORIES If one were to depend entirely upon experience or trial in the selection of clay refractories, the solution of a problem would be a slow process. Furnace campaigns are so long and attended by so many variables that it is difficult to draw fine distinctions within a reasonable period of time in regard to the quality of refractories used. It could be said, of course, that if service results do not yield the proper information for intelligent choice, there is no difference in the quality of brick being considered, but this is not necessarily true. Conventional ceramic tests are designed to give the ceramic engineer information as to the refractoriness and firing temperature, which he in turn interprets in terms of volume stability, ability to withstand load at high temperature (pyroplasticity), permeability, chemical stability and resistance to the action of slag. In most refractory applications several of these factors are involved. In a particular instance, one requirement may be predominant, while in others some other factors may be of primary importance. In this country, clay refractories are generally made from mixtures of plastic and flint fire clays. The process of firing a clay refractory is one of slowly melting the constituents, and during this operation its porosity is gradually reduced. The process is arrested, of course, in its incipient stages and the progress is determined by measuring slight changes in. porosity, volume, bulk gravity, etc., that have taken place. Often the temperatures to which clay refractories are exposed in service are higher than those employed in their firing. However, if the manufacturer were to fire them at such high temperatures the brick would distort. Therefore it would be difficult for the manufacturer to fire all of his clay refractories to temperatures . at which they are to be used, although in many cases it would be desirable from the user's point of view if he would do so. The porosity of clay refractories decreases by firing, to a minimum limit, after which a further increase in the temperature causes expansion in certain clay constituents and bloating in others. -Both may occur in the same refractory containing two such clays.

Jan 1, 1944

The resolution drafted by J. W. Richards, J. V. N. Dorr, and Allen H. Rogers on the death of J. E. Johnson, Jr., and adopted by the Board of Directors, is as follows: "The Boards of Directors of the American Institute of Mining and Metallurgical Engineers wishes to place on record its great personal loss in the sudden death of Mr. J. E. Johnson, Jr., our fellow Director of the activities of the Institute, a member our Executive Committee, Chairman of the Institute's Committee on Admissions, and Vice-chairman of its Iron and Steel Committee. "A mere recital of these positions of trust and responsibility, which he filled with conscientious efficiency and marked ability, shows how greatly the Institute has lost by his death. No one else of the Institute's officers could have been so illy spared. We, his colleagues, take up his tasks with a sense of our inability to discharge them as well as he, and this with a doubled sense of our loss. "Others have written and spoken of the blow which his death has been to the furtherance of the metallurgy of iron and steel. His pre-eminence in this line is one of the facts of which the Institute is justly proud. Here his personality, originality, courageousness in advocating new principles, clearness of writing and forcible presentation of facts, are irreplaceable. His two great treatises on the blast furnace are his literary and scientific memorial.

Jan 7, 1919

By Carl R. Peterson, John Herrick

INTRODUCTION The need for substantial advances in underground excavation technology has produced considerable research activity on a wide variety of concepts under a variety of Government funded programs. One goal of this "Rapid Excavation" effort has been the development of a means to apply the well-known virtues, both technical and economic, of the drill and blast method in a continuous process. The spiral blast concept, aimed at this specific goal, has been funded for initial studies (1) by the ARPA Rapid Excavation Program and, for the experimental work reported herein, by the Department of Transportation (2). The economy enjoyed by the drill and blast method stems from two factors: explosive energy is relatively cheap; and this energy is released so as to cause rock fragmentation largely through tensile failures. The relative ease and efficiency of tensile rock failures have long been recognized. The drill and blast process of course cannot be truly continuous since drilling and blasting (and other necessary functions) simply are separate, distinct operations. Although some surface explosive work has been done to avoid the need for drilled blast holes (3) it does appear that the high performance associated with explosive excavation requires placement of the explosive beneath the rock surface. This paper describes studies of blasting pattern which, in simplest terms, replaces the occasional heavy blast of conventional practice with frequent, much smaller blasts. The objective, of course, is to reduce the size of individual blasts

Jan 1, 1974

By A. T. Tye

REGARDING the results of preferential flotation at Cananea, Weinig has stated that "The concentrating mill of the Cananea Consolidated Copper Company at Cananea, Mexico, furnishes an excellent example of modern flotation practice. The complete figures are given because they present so forcibly the advantages of modern selective flotation."' L. 0. Howard notes that "Perhaps the outstanding example so far published of improvements in results through the use of selective flotation is that at Cananea, Mexico."2 The following notes indicate the conditions under which the results were obtained at Cananea; also the effect of preferential flotation at the concentrator and at the smelter. In the majority of cases the full benefit of selective flotation is not fully realized, as the concentrates are shipped from the mill to smelters owned by other companies. The saving made at a certain concentrator by this method of flotation may be well understood but the saving resulting at the smelter from the results of preferential flotation at the mill is not so apparent, as the data are contained in the smelting records of some other company. Even at the smelter the great gains following preferential flotation may not be noted, as a variety of ores and concentrates from various sources are received and the difference from the changed concentrator operations of a certain mill may be obscured. As noted by Professor Weinig and Professor Howard, the results obtained at Cananea brought about a veritable metallurgical revolution at the smelter.

Jan 1, 1927

By J. C. Van de Water

In June the supply of M3 army demolition powder being used for mudcapping was depleted and we switched to 4 by 8, 60% Special Quarry Gelatin dynamite. This size cartridge has proved convenient, as a half stick will handle the average boulder. By keeping the gelatin in the paper while cutting it in two, there is little contact with the gelatin and therefore fewer headaches among the powdermen. To further help prevent the headache nuisance the men are furnished with plastic coated gloves. Boulder breaking costs as reported last year were $0.426 using M3. This year, 8180 boulders have been broken with M3 at a cost of $0.472 each and 7479 with 60% Quarry Gelatin at a cost of $0.660 each. This rise in cost is due entirely to the greater cost of the Gelatin as the method has not changed.

Jan 4, 1950

By Lætitia H. Delmau

SXFIT is the latest in a series of programs developed in our group to model solvent extraction systems of increasing complexity. SXFIT permits the user complete freedom to define the constituents from which the composition of each phase is to be specified in the data and from which all species of a model for a system are assumed to be formed. Activity coefficients in the nonaqueous and aqueous phases, water activity, apparent molar volumes of aqueous species, and solution density needed for the conversion of concentration from the molarity to the molarity scale are all taken into account by the program. Several extraction systems relevant to nuclear-waste treatment were modeled successfully using this program. As an example, the cesium extraction efficiency of the CSSX process chosen by the USDOE for cesium removal from high-level waste stored at the Savannah River Site can be predicted correctly for varying feed composition.

Jan 1, 2003

By Farzad Mohammadi, Patrick Littlejohn, David Sanguinetti

Arsenic levels in metal concentrates are increasing as mining companies turn to developing low grade and complex ores. When arsenic bearing minerals are smelted, arsenic deports as gases which must be neutralized by a scrubber system. The resulting scrubber effluent is high in dissolved arsenic and requires treatment before the wastewater can be discharged or re-used. Conventional arsenic removal relies on lime addition followed by calcium arsenate formation and precipitation as hydroxides. As an alternative, arsenic removal with sulphide precipitation is receiving more attention due to potential advantages of the technology. Process streams high in arsenic often contain concentrations of dissolved metals that may be selectively recovered during sulphidization, producing a product that can be reprocessed and reducing waste generation. This paper will review laboratory testing completed for arsenic removal through sulphide addition and precipitation of arsenic (III) sulphide in combination with metals recovery to offset arsenic removal costs.

Jan 1, 2014

By M. H. Caron

D. C. Ralston—The fact that none of the organizations that have worked on these ammoniacal leaching processes have contributed discussion of Mr. Caron's papers today is a matter of some disappointment. Adaptations, modifications and improvements have been made by several organizations or individuals and to complete the record I want to document a number of them. The Nicaro Nickel Co. operated a Government owned plant at Nicaro, Oriente, Cuba, during the past war. A report on the project was written for Reconstruction Finance Corp. and is in the document file collected by the Office of Technical Services, Commerce Department and filed with the Library of Congress, where it can be consulted or bibliofilm or photostat copies obtained by asking for copies of PB 97271. Nicaro Nickel Co. has obtained a series of U.S. Patents, my list (probably incomplete) of which bears the following numbers: 2,400,098; 2,400,114; 2,400,115; 2,400,461; 2,400,612; 2,458,902 and 2,473,795. International Nickel Co. has also studied the problem and U.S. Patent 2,478,942 shows that some of the complications involving occasional low extractions have been unraveled. Forward, Samis, and Kudryk, of the University of British Columbia, have also published a study of copper-nickel sulphide concentrate.' Others are interested and it is evident that this type of hydrometallurgy is likely to find a happy application in the not-too-far distant future. Caron's two papers practically amount to a summation of his life's work on the important subject of nickeliferous iron ores and the American Institute of Mining and Metallurgical Engineers is fortunate to have been chosen the medium of publication. M. Rey—The ammonia leaching process has been the subject of certain studies in New Caledonia, but at the present time, the conditions are not very favorable to its adoption. The process is a combination of a thermal and a hydrometallurgical process. As a result, the first costs and the operative costs are rather high. To counteract this unfavorable situation, it would be necessary to make a very high extraction. But unfortunately, the process is delicate and in spite of all of Caron's valuable work, there are still many unknown factors. It is difficult to obtain regularly a high extraction, exceeding 75 to 80 pct. It would be interesting to have the opinion of Inter-national Nickel on the process and to know what the Dutch are doing in Celebes. M. H. Caron (author's reply)—I am quite familiar with the different types of nickel and cobalt ores as found on New Caledonia, and it may be pointed out that the Celebes ores are quite the same in their properties. Their behavior when treating the ores by the ammonia-leaching process is also alike and in my opinion, there is no reason why a high extraction of the New Caledonian ores could not be obtained if the process is properly applied. For the sake of completeness I may add that one of my patents has not been discussed in the papers. This patent deals particularly with the treatment of serpentine nickel ores. (Netherlands No. 62693 40a, French No. 965.786 April 21. 1948. and Cuban No. 13.625 Jan. 1950.) O F. A. Forward, C. S. Samis, and V. Kudryk: Trans. Canadian Institute of Mining and Metallurgy. (1948) 151 (Bull. 434) 350-355.

Jan 1, 1951

By Stanley W. Ivosevic, Mark E. Emerson

Introduction Metals exploration activity is moderately intense in the US despite the 1981-82 recession in the mining industry. Although exploration expenditures are significantly less than the 1981 peak, quality and goal orientation of current exploration are high. Major foreign and domestic mining companies as well as nonmetal companies had been attracted to invest in minerals in the US. Its capital markets, political stability, and open-door policy are attractive for hard mineral explo¬ration, particularly in the West. The approach was to either acquire fully or partially developed ore bodies through merger and acquisition, or to fund large scale exploration programs in search of bulk-tonnage deposits. The acquisition avenue has not proved the panacea envisioned for overcoming lack of substantive mineral development. Nor has the decentralized approach to exploration that was adopted proven cost-effective. The emphasis on gold, to the exclusion of all other commodities, raises questions regarding the direction of exploration in the US for the rest of the 1980s. Overview More than 300 companies are active in metals exploration in the US. These range from established, well-known domestic and foreign corporations to hurriedly incorporated, unknown companies financed by having promoted mineral prospects or occurrences of questionable quality. Junior companies tend to be oriented toward property entrepreneurship, rather than the development of minerals resources. These companies have helped maintain mineral lands from prospect to production by holding blocks of property intact during periods of exploration inactivity. This was done through promotional efforts, even though few properties that attracted major venturers proved to have real merit. Exploration objectives of senior and junior exploration companies currently embrace only a few commodities. Arranged in approximate descending order of priority, these are: precious metals; base metals in monometallic or polymetallic deposits; strategic metals, such as tungsten, tantalum, and tin; unconventional commodities, such as diamonds; ferrous metals; and commodities such as beryl, zeolites, and barite. Prospectors are important in searching for these targets. In the US, where they have been financed by major and junior companies, prospectors have proven a useful and low-cost means of locating gold prospects (e.g. the Alligator Ridge property in Nevada). The tenacity and persistence of independent prospectors have been factors in discovering properties rejected or overlooked by professional geologists (e.g. Lornex mine in British Columbia). This has been realized by the provincial government that grubstakes bona fide prospectors. Exploration interest in commodities has always been cyclic with price. Gold is one of the few metals that has experienced a price increase of such magnitude to warrant attention. The potential for realizing adequate operating margins for the Nevada open-pit "no-see-um" gold deposits is great. The present declining gold price, however, may indicate that this emphasis on gold, to the exclusion of other commodities, is shortsighted. Mining companies have been the last to react to price increases, opening new mines based on unrealistic market expectations. A scenario could develop where plummeting gold prices bring recession to the gold industry, as lately occurred in uranium, molybdenum, and copper. US Exploration Climate The US is attractive for exploration due to its strong mineral po-

Jan 4, 1984

By Daniel Adolfsson, Ryan Robinson, Fenwei Su, Jelena Blagojevic

"Cold bonded briquetting of steel plant by-products has proven to be a viable recycling alternative concerning technology, economy and environment in both the traditional blast furnace route and the direct reduction process. A critical parameter in cold bonded briquettes is the type and amount of binder used during production. The binder material must meet certain quality requirements concerning low and high temperature strength, chemistry and economy. Currently, SSAB Tunnplåt uses ordinary Portland cement (OPC) as binder in their cold bonded briquettes. In order to improve binder quality and possibly decrease OPC dependency, a binder feasibility study has been conducted concerning an internal by-product, ladle slag, as a supplement and/or partial substitute for OPC. Several characterization techniques have been used to study the behaviour of ladle slag, these include: XRD, XRF, SEM, glass content analysis, calorimetric analysis, particle size distribution and thermochemical stability considerations concerning the CaO-Al2O3-SiO2 system.IntroductionRecently, a project was initiated at SSAB Tunnplåt AB, in Sweden, which aimed at reducing the amount of ordinary Portland cement (OPC) as hydraulic binder in cold bonded briquettes by partly replacing it with ladle slag. OPC is traditionally used within civil engineering, and widely accepted as a hydraulic binder in a number of different applications. OPC consists of four major crystalline phases, i.e. C3S, C2S, C3A and C4AF. Tricalcium aluminate as well as the ferrite phase in OPC reacts very quickly with water, for this reason gypsum is added to the clinker in order to retard these reactions. The fact that gypsum is present in the system limits the recycling of briquettes to the BOF, since the presence of gypsum during steelmaking results in a significant amount of sulphur emissions. The latter along with the expense that follows, makes it worthwhile to consider alternatives for OPC as binder in cold bonded briquettes."

Jan 1, 2008

By Thomas E. Garnar

Zirconium and hafnium are the twin elements of the periodic table because they are always found together. They resemble each other so closely that hafnium was not discovered until 135 years after the discovery of zirconium. Zirconium was discovered by Klaproth in 1789 and isolated 35 years later by Berzelius. Because hafnium's chemical properties are so close to those of zirconium, it was not discovered until 1923 when Coster and von Hevesy detected it using X-ray spectrographic analysis. These elements occur most commonly in nature as the mineral zircon (ZrSiO,) and less commonly as baddeleyite (ZrO,). They also are found as a variety of other silicates. Zircon was identified as a component in alluvial and beach sands in 1895, but it was not produced in any quantity until 20 years later. During World War I, it was produced as a coproduct of beach sand mining for titanium minerals just south of Jacksonville Beach, FL, and was patented as a refractory. It was not until the 1930s, when Zircon Rutile, Ltd., began mining at Byron Bay on the east coast of Australia, that zircon was first used as foundry sand. Later in the 1940s, NL Industries and Humphreys Gold Corp. began production of zircon sands from fossil beaches in northeast Florida. Baddeleyite first became available as a commercial product in 1916, but never in the quantity of zircon. Zircon holds a unique position as an industrial mineral because it is used for both its physical and chemical properties and as an ore of zirconium and hafnium metals. Australia is the major zircon producer followed by the Republic of South Africa and the United States. Zircon is also produced in India, Sierra Leone, Sri Lanka, Malaysia, the former USSR, China, Thailand, and Brazil. The location of world zircon mines, baddeleyite mines, and undeveloped zircon ores are shown in [Fig. 1]. World production of zirconium mineral concentrates is shown in [Table 1].

Jan 1, 1994

By Steve R. La Brooy

Techniques for dealing with copper-gold ores are reviewed. Cyanide has little selectivity of gold over copper, and depending on the reactivity of the copper minerals cut-off grades for gold recovery by direct cyanidation are generally below 0.5% copper for oxide ores and 1 % for sulfide ores. Non-cyanide gold leachants also tend to be reactive to copper. The cheapest option for sulfidic ores is to produce a flotation concentrate for smelting, while transition ores generally need a sulfidisation pre-treatment. The requirement for the concentrate to have a high enough copper grade to be acceptable to a smelter may compromise copper and gold recovery. This can lead to significant gold grades in the flotation tailing, and copper levels in the tailing that are too high for direct cyanidation to be able to recover the gold. Oxidised ores, flotation tailing or other material not amenable to flotation represent the greatest grey area for gold recovery. Copper removal by acid, alkaline or ferric pre-treatment is possible though not generally used. Cyanide pre-leaching to remove copper, followed by copper and cyanide recovery represents a potential option that has been installed at one Australian gold plant, where copper is recovered onto carbon, ahead of the slower leaching gold. Actual cyanide recovery depends on ore mineralogy, allowing for losses as cyanate, thiocyanate, carbonate and ferrocyanide. Alternative options for gold recovery following cyanide leaching include precipitation, ion exchange and solvent extraction of the gold. Ammonia-cyanide leaching may offer another option for more selective gold dissolution from flotation tailing and oxidised materials. A plant is currently under construction in Mauritania.

Jan 1, 1992

At 5:30 p.m. a social hour was held for all RMCMI registrants on the lawn area south of the Gondola Lift House. This was followed by a western steak fry and dancing to the country western band, "The Cat's Night Out". MORNING SESSION Tuesday, June 29,1982 RMCMI golfers came out in force for a shot-gun start of the Championship Golf Tournament at Vail Municipal Golf Course which began its first session at 7:30 a.m. followed by a second at 1:15 p.m. The tournament was headed by William Carpender, chairman and his committee members Gary Bennewitz, Jr. and Gene Christmann. RMCMI members were treated to early morning rolls and coffee in the Conference Center preceding a showing of the RMCMI slide/tape program on enhancing the image of coal mining, by telling the story of the Institute. Following this, the meeting was called to order by President McKeever at 8:30 a.m. when he introduced Mr. Carl Terzian who presented a workshop entitled "Sure You Have an Image - But What Kind?". MR. McKEEVER: Good morning Carl. I see you're ready to address this bright and busy tail audience. One of the things that I really want to point out this morning and I knew we would have a second chance with Carl Terzian but Carl is someone that will leave a good lasting impression on you and what he will hopefully be talking about, as I remember, is that what he's saying here can be used personally, or for company, or for the Institute, or anything else on image. Carl is Chairman of the Board of Carl Terzian Associates. He is a prominent author, lecturer and consultant. He is headquartered in Los Angeles and he's nationally known: governmental affairs, man¬agerial development and executive speech training and has served nearly four hundred clients since 1969. Each year he travels nearly 300,000 miles to address conventions, conferences and sales and management meetings as a motivational speaker. Carl has been speaking professionally for more than twenty-five years. He was graduate magna cum laude 1957 from the University of Southern California where he was elected Phi Beta Kappa and student body president. He later served as State Department goodwill ambassador for President Eisenhower; public relations director for Lutheran Hospital Society of Southern California; dean and professor of political science and speech at Woodbury University and public affairs director for architect Charles Luckman. He has been honored for his civic and philanthropic and professional accomplishments by the Congress and State Department, California Assembly and Senate, City and County of Los Angeles, Her Majesty the Queen of England, and six times by the Freedom Foundation of Valley Forge. Carl, welcome to our Coal Mining Institute and it's been kind of a historical situation on Tuesday morning that we will probably have people straggling in after that wonderful steak fry that we had last night. You're very welcome to come and takeover the command. MR. TERZIAN: Thank you very much Ira. This gives me an opportunity for those who were in my luncheon audience yesterday to again thank you for giving me the opportunity of that platform and for the very kind comments that were made following the address. Those of us who had been working for some months with Ira, Charlie, Betsy and many

Jan 1, 1982

The Ranger Project Area covers 78.6sq km and is approximately six km east-west by 14km north-south (Fig. 1). The area is known to con- tain two uranium orebodies, Ranger No. 1 and No. 3, two uranium occurrences, Anomalies 4 and 5 and three significant radon anomalies, Ranger 18, 19 and 48. The Ranger No. 1 and No. 3 Orebodies con- tain approximately 120 000 tonnes of U308 in highly chloritised metasediments of the Lower Proterozoic Cahill Formation. The orebodies occur as suboutcrop and exhibit significant radiometric anomalies. These occur within approximately 400m vertically of the projected unconformity with the sandstone of the Middle Proterozoic Kombolgie Formation. Oxidised and reduced uranium minerals occur in quartz-rich schists containing variable muscovite, chlorite and sericite and in the chloritic matrix of chert breccia. Secondary uranium minerals namely saleeite, metatorbernite and gummite associated with earthy iron oxides occur from the surface to 50m depth in No. 1 Orebody and up to 80m depth in No. 3 Orebody. Below the oxidised zone, uranium occurs as pitchblende finely disseminated throughout sequences of quartz muscovite chlorite schist up to 150m thick and as open space fillings in zones of structural deformation. The uranium-bearing schists directly overlie up to 300m of dolomite and magnesite containing minor interbedded schist units and are themselves overlain by approximately 2 000m of more micaceous schists of the upper part of the Cahill Formation. Regional metamorphism has occurred to at least amphibolite facies and has been followed by retrograde metamorphism to a greenschist facies equivalent. The metasediments are intruded by granitic pegmatites and dolerites. Uranium is associated strongly with chlorite of which there are at least five textural varieties. Not all of the various generations of chlorite have associated uranium. Graphitic schist horizons occur which are often less than one metre thick and discontinuous. These are best developed at the base of the quartz chlorite schist sequence where uranium grades up to 1 000ppm U may extend for several hundred metres beyond the main ore zone. Uran- ium is not common in the carbonate sequences and only occurs in chlorite segregations in disrupted zones. The unoxidised ore contains sulphides, mostly pyrite, which are low in abundance (

Jan 1, 1984