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By George F. McIntyre

The subject of this paper is mineral processing chemicals - how they work and where they end up environmentally. First of all, it is necessary to recognize that water is the most universally and widely used chemical used by the mining industry to separate desirable minerals from unwanted wastes, sands, and slimes. Of the total world's water supply, over 97 percent is found in the oceans. Another two percent is tied up in the ice caps, leaving roughly only one percent for us to work with. This one percent is distributed either as ground or surface water and makes up the bulk of all water used industrially. Even with such a small proportion available for immediate use, there appears to be enough fresh water to meet our needs for at least another hundred years. This availability, however, depends heavily on how we handle our waste waters, how we process them, and how we plan for their reuse. Certain governmental agencies have been charged with the task of setting up standards of water quality which must be met prior to environmental discharge. There is even discussion of zero discharge from industrial operations. Due to limited supply and availability, the mining industry has always been forced to reuse its process water or to treat it prior to discharge. Consequently, we are in an enviable position and are presently able to live with the environmentalists demands. To stay on top of the situation, it is necessary to continually concern ourselves with the .effects of changing orebodies and reagents on the final mill effluent. From a process standpoint, it is also important to recognize the impurities of plant recycle water and how they might tend to influence overall operations

Jan 1, 1974

By William F. Butler

I propose to do three things today. First, take a broad look at the role of mining in the Latin American economy; then, review briefly the current situation in four principal metallic mineral exporting nations -- Chile, Mexico, Peru and Venezuela; and. finally, raise some, policy questions that seem to me to be important. The Role Of Latin America In World Mining First, let's consider Latin America's position in world mining markets. Latin America provides more than 5% of world output in 16 metals or ores, ranging from antimony and barite to Tungsten and Zinc. Latin America supplies a fifth or more of the world's antimony, beryl, bismuth, copper, fluorspar, silver and Tellurium.

Jan 1, 1962

By Henry B. Estabrooks

As was the case with many other mining companies, the management of Tennessee Copper Company' viewed with some interest reports in various trade and technical journals of the successful use of ammonium nitrate-fuel oil mixtures as an explosive in coal stripping., construction, open pit mining and finally in underground salt mines. The apparently simple transition from the "interested" stage to a point where in excess of 80% of the ex¬plosives used is ammonium nitrate may be of interest. The Tennessee Copper Company operates five mines in the "Copper Basin" of Polk County which lies on the extreme southeast corner of Tennessee. The ore is a massive sulfide principally pyrrhotite and pyrite with some tough lime silicates as gangue while the walls are greywacke interbedded with schist. Average total production is 28,000 tons per 5-day week and an average of 422 feet of development per week. Development work consists of 8'x 8?, 6?x 7?, 5'x 7? and 4'x 6? drifts driven with drifter drills using 1-5/8" carbide detachable bits and 5'x 5' raises driven with stopers using 1-5/8" bits.

Jan 1, 1962

By Joseph D. D?Annunzio

The report on cut and cover construction as assembled by the Organization for Economic Co-operation and Development covered 17 different countries based on a total of just under 400 individual replies of which about 30% of the replies were from the United States. In general, the review of replies to the questionnaire led to the impression that cut and cover construction is a very inadequate method which needed many improvements. This unfavorable judgment, however, resulted in the manner in which questions were asked rather than in the method itself, It can be concluded that the cut and cover construction method has proved itself as an excellent method and that it has reached a high degree of technological perfection, but inadequacies stilt exist, and for purposes of complete evaluation, comparisons with mining tunnelling methods should be carried out. The principal problem in cut and cover construction is the interaction during construction between the construction process and the existing use of the surface and subsurface environment. The greatest impediments to cut and cover construction have little to do with the physical works being constructed, but more with creating a site in which the work can be performed. Utility relocation, traffice maintenance, and protection of existing structures are major problems for the construction contractor, and too frequently receive insufficient attention in preconstruction planning and design. Some OF the areas in which research should be undertaken are as follows:

Jan 1, 1970

By James R. Miller

This paper will describe the balling disc operation of the Marcona Mining Company at San Nicolas, Peru, with special reference to green ball quality. The report covers experience during the period of September and October 1965 and will be, more a state-of-the-art at Marcona report rather than -a technical treatise.

Jan 1, 1966

By W. L. Chen

In the United States hydraulic cyclones have been used for thickening, classification and cleaning in coal preparation plants for many years. The cleaning cyclones presently in use are based on using a "heavy medium", such as a fine magnetite and water pulp. The latest addition to cleaning cyclones is the one which uses ?water only?, or simply called "Hydrocyclone". Just as was the heavy medium cyclone, the hydrocyclones were originated in the Netherlands (1, 2). Plants using hydrocyclones were built in Europe (3) and test plants were erected in Canada (4, 5, 6) and India (7). Roberts and Schaefer Company has built four plants using hydrocyclone circuits. One additional plant is in the process of construction.

Jan 1, 1965

By B. G. McNish

Neutron Activator Laboratory Analyzer used for Rapid Analysis for Ore Blending, Stripping, and Mine Control BAUXITE is a rock and not a mineral. Since it is a rock, its mineral content varies depending upon the parent material, the topographic location of the deposit and the severity of the weathering and oxidation processes which produced it. At Bauxite, Arkansas the major mineralogical constituent of the bauxite is gibbsite with ~IL- purities of silica, iron oxide, and titania minerals. Minor amounts of other minerals are found. Chemical composition varies from 45% to 60% alumina, 5% to 25% silica, 1% to 15% ferric oxide, and 1% to 3% titania. The Arkansas bauxite region is located entirely within the north- central area of the West Gulf Coastal Plain near the northwestern boundary with the Interior Highlands. The region trends northeast-southwest and is about 42 kilometers long. It is divided into two districts; one in Saline County and the other in Pulaski County. The Saline District is the most important since it has produced most of the bauxite. This district is located at Bauxite, Arkansas and the deposits are found around the flanks of the Saline Dome. It is roughly square-shaped and is about 190 square kilometers in area. The source rock for the deposits is a Late Cretaceous, grey, nepheline syenite.

Jan 1, 1979

By J. D. Grace

[Screening by centrifugal force is an unique, subject, for with the exception of only one vibrating screen presently on the market, all vibrating screens depend upon, gravity to pass material through a sizing mesh or screen cloth. This one screen that sizes by centrifugal force and utilizes gravity only to convey materiel along the screen, is the SYMONS V-Screen. This screen was designed by Loren Symons, a member of the family that has contributed so much to the metallic and non-metallic mineral processing industries. Among Symons' other outstanding contribution to these industries are the original Cone Crusher which revolutionized reduction crushing practice, the first high-speed horizontal vibrating screen, the original Rod Deck Screen, and one of the earliest vibrating Bar Grizzlies.]

Jan 1, 1965

By K. A. Grace

"An ore is a rock regardless of its rarity or value."* The application of geology does not cease with the discovery and delineation of a mineral resource, but continues in the calculation of the economic parameters that determine reserves. Reserve determination, reduced to essentials, is the determination of the cost of production of a mineral commodity from a resource. This cost comprises mining, processing, waste disposal, reclamation and marketing costs. Geological input is vital in the calculation of the individual cost parameters from mining to reclamation, and even has some impact on marketing. Geology thus has a critical role in the determination of reserves.

Jan 1, 1985

By Salim Akhtar

The operation of a mineral processing plant with a complex flowsheet is represented by a mathematical operator. Such a representation permits a quantitative evaluation and monitoring of the separation processes in different sections of a processing plant, and gives an overall separation efficiency of the plant.

Jan 1, 1973

By R. W. Smith

A number of investigators have studied the electrokinetic potential (?) of kaolinite as a function of pH. (1,2,3,4,5) These investigators all agree that the ? is negative except at quite acid pH values. The actual shapes of the curves reported by the several authors vary considerably. In spite of the general negative character of kaolinite the mineral has a rather high anion exchange capacity. (6,7,8) The cation exchange capacity is the lowest for the clay minerals. (6) It has been shown that anionic surfactants adsorb readily onto the mineral even up to neutrality, often in quantities exceeding the reported anion exchange capacity. (7,8) At least part of the anionic adsorption should be onto positive edge sites thought to exist on the mineral. (9,10) In the present study ? of kaolinite was measured as a function of pH using both the streaming potential (sp) and microelectrophoresis (m.e.p.) methods. In addition ? was measured at various pH values as functions of sodium dodecyl sulfate (SDS) and trimethyldodecylammonium chloride (TMDAC) concentrations. In some experiments decyl alcohol (DA) was added.

Jan 1, 1968

By Gene Mattila

Each installed rock bolt costs in excess of 520.00. High cost in conjunction with the primary purpose of safety makes it only logical to install the highest quality anchors possible. Each bolt has designed support capabilities in axial, shear and fluctuating ground condition, if installed to manufacturers recommendations. The quality of anchor is not; however, only affected by material specifications, but by transportation, handling storage, installation procedure, machine performance and geology. The quality is not only affected by many variables, but reliability should be assured. Non-destructive methods of testing reliability are only available for several types of bolts.

Jan 1, 1985

By B. F. Westfall

Throughout the 1960's and 1970's world trade grew rapidly, reaching a peak of USS1.8 trillion in 1980. Since then the world recession of the early 1980's shrunk trade to about US$1.6 trillion. The reduced cash flow to developing economies made it difficult to service their huge international debts, Nowadays lenders are reluctant to grant Third World countries additional credit. The shortage of export financing, plus trade barriers set up by developed countries, is further inhibiting international trade. Therefore, countries are turning to new and creative alternatives to financing imports of consumer as well as of investment goods. Non-cash transactions, including different forms of countertrade, are rapidly growing alternatives to traditional trade financing patterns. In 1983 about 30% of international trade, or close to US$600 bill ion, were presumably done by non-cash transactions, up from barely 2% in 1976. By year 2000, half the world trade is likely to be conducted on basis of barter. As of mid-1984 some 88 nations used countertrade regularly and Governments of at least 15 Latin American countries had arranged or mandated commercial countertrade.

Jan 1, 1986

By T. K. McMahon

Formally, a mathematical model could be defined as: A set of equations whose solution will approximate the response of a physical process or system to a set of stimuli which appear as parameters in the equations. The purpose of a mathematical model is to permit the rationalization of experience to proceed by simulation rather than by physical experimentation. In the application of digital computer control to an industrial process, the mathematical model of the process (subsequently called the process model) is needed to calculate the present process performance from the measured variables and to predict the response of the process to a control change. Functionally, the cardinal element in process model development is a concise set of control objectives. These, besides implicitly defining the boundaries of the system to be modeled, will determine the accuracy demanded of the model its nature: dynamic or steady-state, and so forth, The objectives should explicitly define what process efficiencies, production rates, qualities are to lie within the scope of the computer control project, thereby providing a basis for simplifying assumptions in the development of the model. This requirement, a limited set of control objectives, is so often disregarded in formulating industrial control problems that its repetition can scarcely be avoided.

Jan 1, 1965

By Paul Kents

The Canadian Javelin Limited Cerro Colorado copper-porphyry deposit in Panama, possibly the largest known copper-porphyry, contains between 1350 and 450 meter elevations, drill proven and probable ore in excess of 3.0 billion tons averaging 0.65% of copper equivalent. The deposit is located in the Central Cordillera Range, straddling the Continental Divide at 1500 meter elevation. Local topography is very steep. Accessibility is difficult, all logistics made by helicopter, and only recently a 52 km. road from the Pan-American highway was completed into the area. The deposit was discovered in 1969, and since then 75 shallow exploratory holes and 98 deep holes, the deepest 1340 meters, totalling 45,000 meters have been drilled. Deep holes were drilled at the corners of a regular rectangular 150 meter grid.

Jan 1, 1975

By D. C. Ridenour

The pressure system of ventilation with large diameter bore holes has been very effective in the ventilation of two gaseous mines, the Olga No. 1 and No. 2 Mines in McDowell County, West Virginia. The No. 4 Pocahontas Coal Seam on the Olga property lies 580 feet below the valleys. The seam is very gaseous as well as dry and dusty, which makes good ventilation all the more essential. Irregular and often extensive areas of the coal seam have been replaced with impervious shales and sandstones in "Fault" or "Want" areas. The replacement materials have sealed the methane in the coal seam and thus increased the quantity of gas that must be handled as mining is done. Often the No. 5 Pocahontas Seam comes down to meet the No. 4 Seam at the Faults and considerable methane is sometimes released from the upper seam. The factors mentioned, together with the irregular and unpredictable lateral shape' of the faults, result in long narrow stringers of coal that are very gaseous and difficult to mine. So far as the Olga Coal Company is concerned, the most effective ventilation under the conditions outlined has been the use of large diameter bore holes with a pressure ventilation system. The ventilation of a mine can be accomplished in two fundamental ways. The mine atmosphere maybe reduced below atmospheric pressure by an exhaust fan; or it may be raised above atmospheric pressure by a pressure fan. In either case, the coursing of the air is so planned as to have the haulage and traveling ways on intake air. While the majority of the coal mines in the United States, no doubt, use the exhaust system of ventilation, there are several advantages of the pressure system which are extremely beneficial.

Jan 1, 1960

By R. Cohen-Alloro

Classical apparatus for granulometric separation generally have limited applications which are found either in the level of the size of separation or in that of the accuracy and the efficiency of the separation or in that of the rate of feed. In industrial practice, the classification of the products of coarse dimensions generally poses no problems. On the contrary, the separation of fine particles presents some difficulties, however the apparatus is used (mechanical classifiers, curved screens and sieves, hydrocyclones, etc...). These difficulties are due to hprfections of separation, rather high cost prices, and sometimes large amounts of recycled materials.

Jan 1, 1970

By Alfred F. Savage

The Oglebay Norton Company has traditionally been a supplier of metallurgical grade fluorspar gravel to the American steel industry and, in the early sixties, fluorspar pellets were entered into the market. The gravel has been imported from Mexico, the pellets were produced by the Minerva Company in southern Illinois. While the acceptance of the pellets by the industry was satisfactory, overall marketing considerations caused the Minerva Company to discontinue the pelletizing operations. Thus it was that Oglebay Norton came to the decision to revive earlier plans to produce fluorspar agglomerates. A survey of the market and related factors led into two basic conclusions: 1) Because of steel plant safety considerations, flat, pillow- shaped briquets were preferable to easily rolling, marble-like pellets. 2) Briquets competitive with gravel could be produced by cutting imported, low-duty, acid grade spar to metallurgical grade by limestone and binders. A plant was built in Brownsville, Texas, and started operations in early 1970.

Jan 1, 1975

By S. C. Sun

[There are significant quantities of anthracite silt deposits in Pennsylvania, known as 'liver silts" (l,2). These contain from 20 to 55 per cent of non-combustible materials, the major portion of these impurities being clay slimes. Both the anthracite coal and impurities are mostly of extremely fine particle size. The utilization of these raw silts in power-plants faces such serious problems as, handling difficulties causing plug-up in equipment, disposal of enormous ash-residue, and corrosion. These problems may be solved by upgrading the raw silt with a cleaning process, which will be capable of removing most of the clay slimes and electrolytes.]

Jan 1, 1964

By Donald H. Dowlin

The design of a preparation plant for minimum maintenance and clean up requires both the skills of the Engineer and the practical experience of the Operator. From the initial flow sheet and preliminary design until the plant is completed and operating, each phase of the work must be thoroughly explored for simplicity, workability and high efficiency. It is the responsibility of the Designing Engineer to develop the plant around the basic flow sheet, selecting equipment and materials not only with regards to Initial cost but also required upkeep and repair.

Jan 1, 1962