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By J Shillabeer

Paste backfill has been adopted by many underground mines in North America and a growing number elsewhere. Paste offers a number of advantages. This paper suggests wider applications of paste technology to surface tailings disposal and water management. Advantages include improved overall stability, potentially easier permitting, smaller water inventory and earlier reclamation. It may be feasible to use the same plant to prepare backfill and to dispose of surplus tailings. Example cost models are given to illustrate potential applications.

Jan 1, 1998

By G. Demi

The biggest chromium mineral processing plant in Albania is Bulqiza plant. It has been in operation for more than 20 years, treating low-grade chromium ores grade 20 ? 26 % Cr2O3 and producing chromium concentrates grade 48 ? 50 % Cr2O3. About 2 million tons of tailings with 13 % Cr2O3 content are stocked in a dam close to the plant. Mineral processing of low-grade chromium ores with less than 16% Cr2O3 content is unprofitable because the mining expenses are high comparing with the current market prices of chromium concentrate. Recycle and enrichment of existing tailings is profitable, because there are no underground mining expenses in this case and because that this kind of raw material does not need expenses operation of crushing and grinding. The existing plant is in operation for more than 8 years treating existing tailings as raw material. Grade of concentrate in the value 40 % Cr2O3 and Cr2O3 recovery in the value 30-35% in the plant are considered low. The main reason of low concentrate grade and recovery is high content of particles under 100 microns, the slimes, in raw material. In the paper is described the study carried out to improve enrichment of the tailings, as well as analyses of existing process, raw material and products. It is concluded that majority of lost is present in the slimes which are not separated in existing spiral separators and shaking tables. Basing in the study is composed the new flow sheet of recycling and concentration of the tailings to produce chromium concentrate grade 41 ? 42 % Cr2O3 and recovery 60 %, decreasing in this way the concentrate production cost two times. In the paper are presented the tests and results of concentration of particle size fraction under 100 microns, using gravimetric, magnetic and flotation methods, as well as equipment and machines suitable for slimes treatment and concentration.

Sep 1, 2012

By Robert R. Walden, LeMont West

K ENTUCKY'S first acid-grade fluorspar flotation Kmill, shown in Fig. 1, was placed in operation Aug. 1, 1952, by the Pennsylvania Salt Manufacturing Co. at Mexico, Ky. During 1951 a critical shortage of acid-grade fluorspar developed and it became necessary for the company to produce part of its fluorspar requirements. In 1951 the company purchased the Crider and Lennen metallurgical fluorspar mill and an adjacent stockpile of tailing at Mexico, Ky. The tailing, assaying about 26 pct calcium fluoride, originated from log washer and jig mill concentrators in the area. As the mill did not have a fluorspar dryer or convenient rail facilities, the company leased the Burleson concentrator at Marion, Ky., where these facilities were available. At Marion, Ky., on the Illinois Central Railroad, dry acid-grade fluorspar is transported direct to the company's Calvert City, Ky., hydrofluoric acid plant. The Mexico flotation plant was reconditioned and designed to produce acid-grade fluorspar from the jig tailing stockpile. The new plant flowsheet is shown in Fig. 2. The ore feed, old tailing, which contains 10 pct of waste rock and coarse gravel assaying approximately 8 pct CaF,, is bound together by sticky clay

Jan 1, 1955

By J. A. Woolf, E. S. Leaver

"So much has been written on the ore genesis of the Comstock Lode that it is sufficient here to describe the original ores as consisting chiefly of quartz and some calcite. In places .a considerable amount of pyrite appears. There are also minor amounts of galena, chalcopyrite, and sphalerite. The chief silver minerals are argentite, stephanite, and polybasite. Most of the gold is native.A composite analysis of the ore; obtained by averaging the results from the early workings of several mines, is shown in Table 1.The history of the milling of Comstock ores from the Sixties to date would call for a review of the development of precious-metal metallurgy. However, a brief outline of the methods employed will give a better basis for studying the difficulties that are to be expected in the final retreatment of the remaining residues.In the earliest days amalgamation was accepted as the main recovery method. The large tonnage of good-grade ore from the Comstock Lode attracted the best metal¬lurgical talent of the time, and developed there the highest skill in the art of amalgamation, including the auxiliary chemical preparation of the ores and the mechanical operation. In this work 0.5 to 6.0 pounds of mercury was used per ton of ore. The mercury loss probably averaged about 2.5 pounds per ton of ore treated.The better grade of tailings from the ores milled were impounded, often near the works. In many cases the same tailings were reworked several times before they entered the main outflow waste stream that had its course down Seven Mile Canyon to the Carson River. Following the water course down the canyon the tailings were re-impounded, and, as metallurgy advanced, new plants were erected to again re-treat them. The most successful of these plants used forms of amalgamation, chlorination, and cyanide methods of recovery. To the tailings from the re-treatment plants, smaller tonnages of untreated tailings produced by milling lower-grade ore are continually added.Along the stream bed down the canyon a series of blanket runways were constructed, and each was independently operated for years by one or more men. All, or the heavier portion of the stream flow was run over the blankets; in this way much of the heavier concentrate, mostly sulphides and mercury products, was reclaimed.All of the residues finally entered the run-off flow along with the sewage from Virginia City and waste from the gas works, saw mills, and stables. As the accumulation along the bed of the Carson River became a nuisance, the lighter and better grade of tailings was impounded on the banks of the river. This accounts for the large dumps locally known as ""Douglas tailings."""

Jul 1, 1928

By Allan M. Hale

Taconite tailings reclamation, especially the stabilization of tailings ponds, .dams, and slopes, can be effectively accomplished through the use of appropriate vegetation. Utilizing vegetation provides both aesthetic and ecological enhancement of a site while at the same time protecting tailings structures against wind and water erosion. Generally, the methods and techniques for establishing vegetation are well known; however, there are many site-specific factors that can alter a particular reclamation approach. Those factors include slope gradient, tailings material size, solar exposure, and physical and chemical properties of tailings. In addition to the site-specific factors, variations in climate, geography, and physiography of a region can have a pervasive influence on the success or failure of a revegetation program. Both the site-specific and regional factors control reclamation planning in such areas as plant variety selection, methods and times of plants establishment, maintenance techniques, and subsequent monitoring methods. As a result of this multifactor relationship, it is important to establish a data base that identifies both the site-specific and location conditions in order to tailor the reclamation plan to the specific area. When an appropriate data base has been collected, detailing the various site-specific and regional factors that will influence a revegetation program (in the absence of previous testing), it is very beneficial to apply experimental techniques to develop the reclamation plan for a specific site. The reclamation plan for a specific site may include several techniques adapted for the differences found within the specific site as the result of topographic or other influences. Considering this, the Reserve Mining Company and Dames & Moore undertook to develop a successful reclamation plan based on a detailed test plot program conducted at the Mile Post 7 location.

Jan 1, 1980

By I. L. Box

IN planning retreatment of tailings, the material to be retreated should be thoroughly investigated, tak- ing into consideration the total tonnage, the blende content, the specific gravity of the different particles, and the grinding necessary to liberate the mineral. The tailing pile is surveyed by making a closed trav-erse around the outer edges, locating the stations at points from which a considerable portion of the pile is visible. From each of these points the pile is sur-veyed by stadia and a contour map made. The yardage is then calculated from the contour interval and the area inclosed by the contours obtained with a planim-eter. A party of three men can survey an average tailing pile in one and one-half, days. In calculating tonnage it is assumed that 22 cu. ft. of tailing in place equal one ton. Sampling is done by the use of an auger with casing to prevent the hole from caving. These holes may be bored 12 to 15 ft. deep by hand, but to penetrate the entire pile some kind of power is applied to drive the casing and raise or lower the auger. The latter method is more expensive but the increased cost is more than compensated for by the value of the information obtained.

Jan 7, 1928

By Fred W. Brackebusch

"The use of paste technology for surface tailings disposal may offer economic, technical, safety, and environmental advantages for both underground and surface mining operations. Paste is a non-Newtonian fluid having some shear strength during transport and placement. The strength is augmented after placement by consolidation, water loss, and by addition of chemicals. Economical dewatering systems are necessary to the success of surface paste tailings disposal. In an underground mine, the paste backfill plant can produce paste for surface disposal about 50% of the time because only about 1/2 of the tailings are needed for backfill. The distribution of paste to the surface stack involves expensive pumping equipment and thus a nearby location of the stack is desirable. The viscosity of paste can often be manipulated by modifying pH. Placement of the paste in a designed stack configuration depends on topographic and climatic factors as well as paste properties.INTRODUCTIONThe use of paste technology for mine backfill is becoming accepted for underground mines mainly because of ground control and economic reasons. Paste technology is just starting to be applied for tailings disposal with only a few hardrock metal mines worldwide using the technology; however, it has been used extensively for red mud disposal in the aluminum industry. The disposal of dry tailings is very attractive from environmental and safety points of view because of limited water which might potentially escape and pollute river systems. Dry stacking systems, however, are expensive because of filtration and truck transportation costs. Paste can be produced from most tailings streams by special types of thickeners. Furthermore, it can be transported in pipelines, therefore paste technology may be more economic than dry stacking but still have some of the major advantages. Understanding of paste technology has improved through experience with operating underground backfill systems in recent years and because of testwork and research programs by mining companies, consultants and equipment vendors. Thus we may be on the verge of taking a new look at tailings management using paste technology."

Jan 1, 2002

By Fatma Arslan

Alada (Kayseri-Turkey) lead-zinc sulfide-oxide ores contain 10.17% Pb, 10.98 %Zn, 164 g/t Cd and 57 g/t Ag. During the laboratory scale flotation tests of these ores, it was found that almost all zinc was remained in the tailings that contain 12.31% Zn, 1.35%Pb, 198.3 g/t Cd, and 22.3%Fe. Three different methods were studied such as basic (NaOH) leaching, roasting+acidic (H2SO4) leaching and direct acidic (H2SO4) leaching for recovering metals that these tailings contain. In the direct acidic leaching, which gave the best results, dissolution efficiencies of 91.5% zinc, 78.2% cadmium, and 14.3% iron were reached at the optimum leaching conditions while Pb remained in the leach residues and the acid consumption was 422.3 kg/ton of tailings.

Jan 1, 2006

By S. R. Abt, J. D. Nelson, G. M. Smith

An empirical investigation was conducted to formulate a design criteria for predicting the beach profile of hydraulically deposited tailings. Field data were obtained from mining operations producing gold sulfides, silver, molybdenum, copper, platinum, and uranium. Site-specific parameters were collected that included the beach slopes, tailings soil properties, slurry properties, and the slurry distribution system characteristics. Each of the beach profiles were dimensionlessly plotted, and regression expressions were computed. It was determined that either a power expression or exponential expression closely predicted each beach slope. A general power expression and a general exponential ex¬pression were developed resulting in a design criteria. A procedure was formulated to determine which expression, power or exponential, is applicable to any specific site. A slope designation chart was developed as a function of the discharge, the tailings critical tractive shear stress, and the inertial forces exerted by the slurry on the beach.

Jan 1, 1987

By Áureo Del Vecchio, Lídia Dely Alves de Sousa, José Pereira

The potassium demand for agriculture purposes has increased in Brazil, which has great deficit of internal demands. Potassium-rich rocks have been used as fertilizers as technological alternatives for agriculture aimed to reduce the amount of chemicals and the sector dependence for such products. Vermiculite tailings from União Brasileira de Mineração - UBM, at Santa Luzia - PB, was studied aiming their application in agriculture by potassium release. The sample was analyzed by XRF and XRD; studies on release kinetic with particles smaller than 2 mm added of organic acids (citric and oxalic) at 10-2 mol/L concentration; samples were analyzed by XRD after kinetic assays. The work was conducted using a shaker incubator at 300-rpm agitation and time variation to better understand the potassium availability in the ground. Results show the presence of K2O at 3.46% concentration. Citric and oxalic acids increased the release speed to almost the same level with speed coefficients (k) of 2.61x10-2 h-1/2 and 2.55x10-2 h-1/2 respectively. In statistical terms for both acids, the linear equation represents more than 99.0% of the experimental assays. Stonemeal was applied to banana seedlings in experiment conducted in a greenhouse. The use of vermiculite tailings in banana seedlings promoted potassium absorption, which influenced its growth. The amount of potassium liberated from vermiculite tailings could be used as a long-term alternative to fertilizers in agriculture cultures.

Jan 1, 2014

By P. Goosen, A. Paterson, E. Paulsen

Ticor South Africa is currently involved in the mining and processing of a heavy mineral oredeposit at Hillendale Mine on the KwaZulu-Natal north coast. The orebody is characterized by a high ultra fine fraction (-45µm) that has a variable rheological behaviour when subjected to shear and hydration. Experience at Hillendale has shown that the ultra fine mineral tailings are sensitive to shear history in terms of shear intensity and shear duration as well as hydration history. This phenomenon expresses itself right through the primary beneficiation process influencing the mineral separation, but is especially prevalent on the residue disposal i.e. slurry transport and deposition on the tailings impoundment. Tube viscometer test work was conducted on the flocculated fine tailings that indicated that there was a change in rheology as a result of shear. This paper presents the results of the on-site test work conducted at the mine to measure the rheology at various stages in the process.

Jan 1, 2003

By William J. Attwooll

The development of gold heap leach projects in the Cripple Creek, Colorado, mining district has required utilization of heap leach pad sites other than relatively level natural ground. This paper describes the construction of a heap leach pad adequate to accommodate 907,000 tonnes (1,000,000 st) of ore over the surface of a tailings pond constructed during previous milling activities at the site. Based on the design parameters and the observed behavior to date, it has been found feasible to construct a major heap leach pile on the surface of a conventional tailings pond.

Jan 1, 1987

Haematite Recovery from a Tailings Stream Laboratory and pilot scale testing were carried out in 1999 on a tailing sample from a North American iron ore plant using gravity, magnetic and flotation techniques. The ore contained 16 per cent iron mainly in the fine (-38 ¦m) size fraction. Two methods of evaluating the separation efficiency were used; Selectivity Index and Z factor analysis. Tabling and magnetic separation produced poor results, with flotation testing showing some promise, generating concentrates assaying more than 40 per cent Fe. High grade concentrates containing more than 67 per cent Fe were generated using the Kelsey Centrifugal Jig, and it was recommended that this technique be pursued at a larger scale to verify the results obtained.

Sep 13, 2010

By Franco Oboni, Iain G. Bruce

The design of tailings containment structures relies on well-understood engineering methods being applied consistently. Unfortunately, not all facilities are designed or managed to the same level of competency. To standardize procedures, the Mining Association of Canada (MAC, 1998) prepared a “Guide to Tailings Management.” It recommended review of designs and an assessment of the risks associated with tailings impoundments be implemented during all phases of amine life. This paper describes how the quantitative risk assessment (QRA) process can be used to define risks associated with the design, construction and operation of a tailings management facility. And it discusses how, once the risk tolerability curves (RTC) are defined for a project, they can assist the risk management (RM) process.

Jan 1, 2002

By Steven L. Webb

In 1965, Monsanto started planning of a new dike (No. 15) for use in disposing of ore tailings at its Columbia, Tennessee phosphorus plant. Generally, in the phosphorus industry only clay tailings are produced making it necessary to borrow fill for construction of a retaining dike. Borrow area investigations indicated that weathered shales and limestones adjacent to the dam site would provide adequate construction materials. It was proposed that the more clayey weathered shales would be used for the impervious core and the more granular weathered limestones would be placed in the outer shell of the dike. A dike section is shown in Figure 1 with gradation curves for core and shell materials in Figure 2. Figure 3 shows an aerial view of the tailings pond and dike during first-stage construction. Although the borrow area explorations indicated that the weathering of the sedimen-tary deposits was highly irregular, it was not considered necessary, at the time, to specify special excavation techniques that would ensure a thorough blending of the materials in the borrow pit. Instead, because of the short haul distance, a scraper operation for both clay core and granular shell materials was adopted as the most economical construction method. Using this materials-handling technique, variations in permeability could be expected in the compacted layers inthe embankment. Where continuous layers of less clayey limestones were placed in the core of the dam, extending from the upstream to downstream shells, seepage losses would be expected to increase substantially. Upon completion of the damn 1966, and shortly after reservoir filling, it was apparent that the construction technique used had resulted in the formation of pervious layers through the clay core. Excessive seepage on the downstream face of the dike was noticeable within a very short time. A monitoring program was established, using piezometric observations and flow measurements. These data indicated that seepage should be reduced and the application of an asphaltic emulsion

Jan 1, 1971

By Jamie Deuel

The a ad on Connection" For the purpose of this paper, we will concentrate on the ubquitous radon gas as the principle, low-level radiation effect from uranium tailings piles. Standards are also proposed for gamma radiations but, by most accounts, this is much less of a low level problem than is radon. I am also aware of some just completed research at Oak Ridge National Laboratories that suggest polonium may be a major concern in tailings, but those data are preliminary at this time. What is radon gas? In the first place it is not a gas in the accepted sense in that it has no driving pressure head. It might prove a more convenient description to call it radon vapor. Radon vapor, then, is 7-1/2 times heavier than air. Radiologically, it is an alpha emitter which means it spontaneously gives off high ionizing potential but low penetrating power particles. In fact, the alpha particle has such low penetrating power that this sheet of paper will completely shield a person. The problem, though, is breathing the radon decay products, called radon daughters. If radon daughter products are ingested into the lungs, their alpha emissions may cause cancer. The principle carcinoma associated with breathing radon, or more basically, associated with radiological effects is oat cell car- cinoma of the undifferentiated mall cell type. Radon has a 3.8 day half life which means in less than four days half of its initial radioactivity has decayed away. In less than a month it essentially becomes inert or non-radioactive. The Tailings Situation The NRC, in its April 1979 Generic Environmental Impact Statement

Jan 1, 1983

By Lawrence Addicks

(San Francisco Meeting, September, 1915) THROUGH the courtesy of Dr. James Douglas I am permitted to give, a summary of some of the results obtained in leaching slimes tailings in a series of experiments conducted under my direction at Douglas, Ariz.. during the past year. While the test run for which the data are given deals with a particular case, much of the work is general in its application and may therefore be of interest. This work was done upon the ores of the Burro Mountain Copper Co. A description of the geology of the district will be-found in the paper by R. E. Somers published in the May, 1915, Bulletin of the Institute. The mineral is pyrite and chalcocite very finely disseminated throughout the gangue and a characteristic of all the ores is the large amount of alumina present. A representative analysis of the particular ore under consideration would be about as follows: Cu, per cent 2.35 S, percent 3.0 Ag, ounces per ton 0.05 CaO, per cent 0.5 Au None K202, per cent 4.0 Fe, per cent 1.5 SiO2, per cent 70.0 A120,, per cent 13.0 The leaching of the ore direct was early dismissed from consideration for the following reasons: 1. The ore would have to be quite finely crushed to liberate the mineral for leaching; concentrating after crushing would cost but a few cents a ton; and a higher total recovery would result from leaching tailings rather than ore. 2. Rough concentration would yield a suitable material for roasting to make sulphur dioxide or sulphuric acid in connection with the leaching scheme. 3. Such a program put the question of cost vs. recovery on a basis where flotation and discarding of tailings were directly comparable.

Jan 8, 1915

An important consideration in any mining operation is waste disposal management. Tailings management at Macraes gold mine allows for the disposal of tailings into fully engineered embankment dams and overburden material to be incorporated as construction material into those embankment dams. This paper outlines the current tailings management practices.

Jan 1, 1992

By R. W. Jigins

OPERATIONS of the Braden Copper Co. are in the Chilean Andes, southeast of Santiago. Most remote of the company communities is Sewell, a town of 12,000 people, 7000 ft above sea level at the junction of the Coya and Teniente rivers. Four miles down the Coya River is the smelter town of Caletones, elevation 4500 ft, with a population of about 3000. At the junction of the Coya and Cachapoal rivers 24 miles below Sewell is Coya, eleva- tion 2500 ft, location of the company's two hydro- electric plants. The principal accounting offices; steel, iron, and brass foundries; railroad shops; and major mechanical repair and fabricating shops are at Rancagua in the central Chilean valley, 44 miles from Sewell. The company owned narrow-gage railroad connects with the Chilean national railroad at Rancagua and above Coya is the only modern means of travel. El Teniente mine at Sewell is the largest under- ground copper mine in the world. The mill, at the portal of the main tunnel, has a capacity of 34,000 tons of crude ore daily, although production is lower during the winter beacause of electric power restrictions. When operating at capacity the mill produces 2000 tpd of copper concentrates and 32,000 tpd of tailings. Tonnage of tailings is equivalent to about 100,000 tons of pulp at normal water to solid ratio.

Jan 10, 1957

By A. G. Roach

THIS paper deals with a plant built under joint agreement between the Canadian and United States Governments to supply the strategic mineral, corundum, at a time when African production was dwindling and war demands still increasing. The operation began in September 1944, retreating the tailings from a former mill by gravity methods, and is still in production (Sept. 1946). In 1942, when it became apparent that South African production would be insufficient to meet mounting wartime requirements of corundum, a survey was made of Canadian sources of the mineral, at the request of the Foreign Economic Administration of the U. S. Government. The investigation1 indicated that the quickest and cheapest supply would be obtained by reworking the tailings deposit at Craigmont, Ontario. Sampling of the dump by Canadian Government engineers revealed that 125,000 tons of tailings, averaging 2.96 pct corundum, was available for retreatment. Ore-dressing tests on representative samples of the deposit were conducted by the writer in the laboratories of the Industrial Minerals Section of the Department of Mines and Resources at Ottawa; and gravity concentration on tables was indicated as the most suitable method of treatment. Decision to proceed with the project was deferred until May 9, construction was begun on May 18, and tune-up operation of the plant begun on Sept. 15, 1944. CORUNDUM-ITS PROPERTIES AND USES Corundum is an oxide of aluminum having the formula A1203. Its outstanding characteristic is its great hardness; 9 in the Mohs scale. In this respect it is second only to the diamond. It usually occurs in barrel-shaped crystals in nepheline syenites and other feldspathic rocks deficient in silica. It has a specific gravity of 3.95 to 4.1 and is insoluble and infusible. In color it ranges from white, through red and green, to black. Ruby and sapphire are gem varieties of corundum. Corundum is supplied to industry as closely graded grain.2 The coarser products (10 to 24-mesh) are used largely for snagging wheels in the steel-castings industry, while the finer grades (from 70-mesh down to flours) find a wide application in the polishing of lenses and for other uses in the optical trade. All sizes of corundum grain are in close competition with synthetic abrasives such as carborundum and alundum. In some fields of application the artificial product is superior to the natural grain but not in all. The shape of the particle and its behavior under conditions of actual use determine its sphere of employment. The United States is the largest consumer of corundum, annual consumption in peacetime approaching 3000 tons; during the war this figure was roughly doubled. During the years 1902 to 1913, the bulk

Jan 1, 1946