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By Ted T. Biddle

The world energy crisis has created a greatly expanded exploration program for energy fuels. The demand for materials required for drilling operations such as barite, which is the primary component of drilling fluids, has increased proportionally. As in the case of many other minerals, existing high grade barite mines are no longer capable of producing the required tonnage. Consequently, exploration and development of lower grade ore bodies has been increased. The need to produce a high quality product at maximum recovery rates, along with the ever changing economics affecting both selling price and production costs has triggered accelerated research programs toward more sophisticated and efficient beneficiation methods. Taking into account the specific gravity differential between barite (4.5) and the normal gangue minerals such as silica and calcite (2.7), gravity concentration methods are the prime consideration with flotation as a scavenging process. Greater emphasis on particle size liberation, size reduction and concentration is also indicated. In order to accomplish these objectives, it has been necessary to revert back to the old adage, "Recover your minerals as soon as they are free."

Jan 1, 1980

By H. Demirel

This paper deals with concentration of hematitic-limonitic iron ores. The ore sample obtained from Karakuz (Turkey) contain:. about 40-46 I Fe. First, a low intensity magnetic separation process was employed to separate the strongly magnetic particles cf "-10+2 mm" and "-2+0.075 mm" size fractions and magnetic concentrates with 59.1 % Fe aid % 58.0 Fe were obtained respectively. The non-magnetics of both fractions were then fed to a nigh intensity permanent magnetic separator. The Fe contents of "-10+2 nun" and "2+0.075 mm" size fractions were increased from 28.2 to 51.13 and from 35.4 7. to 43.25 respectively after single pass. Easing on these results, it was concluded that the high intensity permanent magnetic separator could he used as a pre-concentrator f.7.1- hematitic-limonitic Karakuz iron ore.

Jan 1, 1991

By Rongdong Deng

A tower-like magnetic system comprising eight permanent magnets was installed at the center of a flotation column to separate chalcopyrite and pyrrhotite minerals. A cyclonic flotation was installed within the underpart of the column to separate the pyrrhotite from the gangues. A three-product magnetic flotation column was fabricated to create a magnetic field and a cyclonic zone. The products were Cu concentrates, pyrrhotite concentrates and tailings. The theoretical magnetic field strengths and the magnetic forces were calculated. The results of the flotation experiments showed that the Cu grade increased from 14.20% without the magnetic field to 26.40% in the presence of the magnetic field and that the S grade in the pyrrhotite concentrates increased in the presence of cyclonic flotation. The separation efficiency of this magnetic flotation column was evident. Therefore, this three-product magnetic flotation column may have a potential application, due to its high separation efficiency.

By H. Nematollahi

Numerous magnesite deposits are found in the south part of Khorasan state, east of Iran. During the past few years, production of high-grade magnesite ore was possible only by using selective mining method. The decreases of high-grade ore imply upgrading of the low-grade ore. To do so, the objective for the first phase is to obtain a material which contains less than 2.5% SiO2. The present study was carried out based on three different samples. The results obtained in laboratory indicate that the direct flotation of magnesite by fatty acids led to acceptable result.

Jan 1, 2003

By J. Groppo, W. Zhang, R. Honaker

"Rare earth elements (REEs) found in coal are in the form of minerals, ion-substitution with clays and organically bound. Rare earth minerals (REMs) such as monazite exist in coal and have a grain size less than 5 microns. Froth flotation was successful in concentrating REMs existing in a thickener underflow material derived from Fire Clay seam coal which contained around 300 ppm of rare earth elements (REEs). Conditioning with fatty acid followed by processing using multiple stages of conventional flotation produced a final concentrate containing 2300 ppm REEs. Using a laboratory flotation column, a concentrate containing around 4700 ppm of total REEs was produced equating to an enrichment ratio of 10:1. INTRODUCTION Rare earth elements (REEs) are becoming increasingly important and have been widely used as raw materials for the production of phosphor, metal catalysts, magnets, and batteries [1, 2]. REE recovery from alternative sources such as coal and coal by-products has the potential to stabilize the economic viability of coal mining operations while providing a dependable supply of critical materials. The average REE content of the world coal is around 60-70 ppm [2]. There are many well-known coal beds with high contents of REEs such as those in the Far East coalfields in Russia (300-1000 ppm), the Fire Clay coal seam in eastern Kentucky (500 ppm), and the Sydney Basin in Nova Scotia, Canada (72-483 ppm) [3-6]. The occurrence of REEs in coal and coal by-products can be classified into three types, i.e., rare earth minerals such as monazite and xenotime, ion exchangeable REEs in clays, and REEs associated with organic matrix. The particle size of the rare earth (RE) minerals in coal and coal by-products is very small and normally in the micron and/or nanometer scales. The flotation technique, which is based on the surface chemistry difference, has been widely used to treat fine rare earth industrial minerals such as monazite, xenotime, and bastnaesite [7-11]. As such, flotation is a promising method for the concentration of REEs from coal and coal by-products. In the current study, rare earth flotation was conducted using the fine coal refuse generated at an operating coal preparation plant treating coal from the Fire Clay seam. REE concentration by flotation required an appropriate amount of grinding and control of the pH value while using typical collectors. Prior to RE concentration, release tests were conducted to evaluate the floatability of the recoverable coal and the REE distribution in the flotation fractions in the fine refuse. Mineralogy of the REE was studied using SEM-EDX."

Jan 1, 2017

By J. Groppo, W. Zhang, R. Honaker

"Rare earth elements (REEs) found in coal are in the form of minerals, ion-adsorbed onto clay surfaces or inner layers, or organically bound. Rare earth minerals such as monazite exist in coal and have grain sizes smaller than 5 µm. In this study, froth flotation was successful in concentrating rare earth minerals existing in a thickener underflow material derived from Fire Clay seam coal that contained around 431 ppm of total rare earth elements (TREE) on a dry ash basis. Conditioning with fatty acid followed by processing using multiple stages of conventional flotation produced a final concentrate containing 2,300 ppm TREE. Using a laboratory flotation column to limit hydraulic entrainment, the TREE content was further enriched to around 4,700 ppm, which equated to an enrichment ratio of 10:1.IntroductionRare earth elements (REEs) are becoming increasingly important and have been widely used as raw materials for the production of phosphor, metal catalysts, magnets and batteries (Binnemans et al., 2013; Zhang et al., 2015). REE recovery from alternative sources such as coal and coal byproducts has the potential to stabilize the economic viability of coal mining operations while providing a dependable supply of critical materials.The average REE content of the world’s coal resources is around 60 to 70 ppm (Zhang et al., 2015). There are many well-known coal beds with high contents of REEs such as those in the Far East coalfields in Russia with contents of 300 to 1,000 ppm, the Fire Clay coal seam in eastern Kentucky in the United States with contents around 500 ppm and the Sydney Basin in Nova Scotia, Canada, with contents of 72 to 483 ppm (Birk and White, 1991; Seredin, 1996; Hower, Ruppert and Eble, 1999; Blissett, Smalley and Rowson, 2014). The occurrence of REEs in coal and coal byproducts can be classified into three types: (1) rare earth minerals, such as monazite and xenotime, (2) ion-adsorbed REEs on clays and (3) REEs associated with organic matrices. The rare earth minerals in coal and coal byproducts are very small in particle size, generally on the micrometer and/or nanometer scales (Honaker et al., 2014). Froth flotation, which concentrates minerals based on surface chemistry differences, has been widely used to treat fine rare earth industrial minerals such as monazite, xenotime and bastnaesite (Abeidu, 1972; Cheng, Holtham and Tran, 1993; Pavez and Peres, 1994; Pavez, Brandao and Peres, 1996; Jordens et al., 2014). As such, flotation is a promising method for the concentration of rare earth minerals from coal and coal byproducts."

Jan 1, 2017

By W. L. Dalmijn, J. M. Versteegen

During the production of silicon carbide, a byproduct is generated that contains a mixture of crystalline and amorphous silicon carbide. Utilizing the difference in density, shape, and surface properties of the crystalline and amorphous silicon carbide, separation tests were carried out with gravity concentration. The processing of the coarse fraction of the silicon carbide mixture by jigs resulted in a high grade crystalline SiC concentrate with the desired specifications. The separation was largely influenced by the shape factor. A jig with a newly designed hydraulic drive was used to carry out the test program.

Jan 1, 1991

By Johan M. Versteegen

During the production of silicon carbide a by-product is generated, which contains a mixture of crystalline and amorphous silicon carbide. Utilizing the difference in density, shape and surface properties of the crystalline and amorphous silicon carbide, separation tests were carried out with gravity concentration and flotation equipment. The flotation results of the fine fraction of the silicon carbide mixture were not encouraging. The processing of the coarse fraction of the silicon carbide mixture by jigs resulted in a high grade crystalline SiC concentrate with the desired specifications. The separation was largely influenced by the shape factor. An IHC-jig with a newly designed hydraulic drive was used to carry out the test program.

Jan 1, 1988

By Immo H. Redeker

The Kings Mountain area of North Carolina is the lithium pegmatite center of the U.S., if not of the whole world. We have two spodumene and by-product mineral producing companies, Lithium Corp. of America, and Foote Mineral Company. We also have Kings Mountain Mica and Kings Mountain Silica Companies producing mica. feldspar, quartz and clay from weathered pegmatites in that area. Figure 1 gives the location of the spodumene pegmatite area in North Carolina. The two spodumene producers mine typical pegmatite ore in open pits after removing amphibolite or mica schist overburden which is sold to aggregate producers. The ore reserves are discussed elsewhere in this session. They are in the order of plus 50 million tons but not unlimited. 1.2 The major minerals found and concentrated from the North Carolina spodumene pegmatite ores are tabulated on Table 1.

Jan 1, 1977

By Andrzej Wala

Constantly increasing demand for energy materials and metal ores brought about tremendous progress in mining techniques which are characterised by a high degree of mechanization and concentration of works. One of the recent trends in underground mining mechanization is connected with an application of heavy machines with diesel engines [l],[2]. The introduction of diesel engines in mining all over world caused not only improvement in economic conditions but also the necessity to prevent contamination of air in the mine by toxic agents in diesel exhaust emissions. A generally used way of eliminating exhaust gases is proper ventilation of the cross cut by means of providing permanent exchange of air that would guarantee in every point of the cross cut and in every moment the decay in concentration of exhaust gases beyond threshold limit [3][4][5][6][7][8][9][10]. The present paper is an attempt to define a mathematical model describing the changes of concentration in cross cut face to which fresh air is distributed by ventilators and tubes in a forcing way. Obtained model should offer its practical adaptability to engineering calculation of the amount of fresh air needed for diluting and eliminating exhaust gases beyond threshold limit. Justness of these models has been confirmed by investigation of the growth of nitrogen dioxide concentration in air environment in some cross cut faces of Kiirunavaara iron ore mine in Kiruna (Sweden).

Jan 1, 1980

By J. Liniecki, w. Chruscielewski, T. Domanski

INTRODUCTION Mining is the Polish greatest industry employing about 350 thousand miners in more than a hundred underground mines. The mining regions are located mainly in the south of the country - see Fig. 1. [ ] The coal mining dominates, however, and the zinc-lead and copper-ore mines presently employ about 16000 miners. All these mines are rather deep and wet. Their drawing shafts are between a hundred to more then thousand meters deep. The cross-adit of working area of mines ranges from several kilometers to a few tens of kilometers. The numbers of mines per mine differ also considerably and depend on the territory and type of mines. The largest coal mines employ about ten thousand miners but the largest metal ore mines do not employ more than four thousand miners. In all the mines the electric motors or diesel engines are being used. The intensity of mine ventilation, characterized by the volume of fresh air injected in to the main ventilating shaft per miner and per unit of the power consumed by the engines is about 6 cubic meters per minute per man and per horsepower. The studies of the potential alpha energy of radon daughter products /RnDP/ could be divided into the three developmental stages: I-st - stage /1966-1970/ the stage of so called Pilot Survey. During this stage concentration of potential alpha energy of RnDP in the air was measured in selected typical mines in all mining regions of the country. II-nd - stage /1972-1974/ was the periodical control of concentration of potential alpha energy of RnDP in the air of zinc-lead and copper-ore mines which have been chosen and recognized during the first stage as being the most hazardous ones. Air-sampling system /ASS/ measurements were applied during this stage.

Jan 1, 1981

By W. D. Macleod

This paper describes a mineral dressing process for the upgrading of tin ores. The process described is called 'agglomeration' and. is similar in many respects to flotation. Many variables have been examined experimentally both on batch and continuous operations and are reported upon herein... Using a Mt. Pleasant tin ore, assaying 0.5% Sn, an upgrading to 8% Sn, with a recovery of 95% could be obtained by this process.

Jan 1, 1966

By J. D. Miller

Physical separation of bitumen from low-grade Utah tar sand deposits containing a relatively high viscosity bitumen phase (Sunnyside and Tar Sand Triangle deposits) has been accomplished by traditional size reduction and froth flotation techniques. At appropriate experimental conditions more than 90 percent of the bitumen can be recovered in a concentrate, containing more than 20 weight percent bitumen, which should be a suitable feed material for subsequent hot water or thermal processing. The efficiency of bitumen recovery depends on the extent of size reduction, promoter and dispersant addition. Rejection of greater than 60 percent of the sand at ambient temperature and ease of water removal from the concentrate make such a process strategy both energy and cost effective. The energy required to achieve effective separation by the ambient temperature process is significantly less than the energy required for the recently developed hot water process. The flotation behavior of the tar sand has been analysed with respect to flotation pH, contact angle measurements and the apparent iso- electric point of the bitumen. The best flotation response at pH 7.8 to 9.0 can be correlated with the maximum in contact angle developed between the air bubble and bitumen surface and with the apparent iso-electric point of the bitumen (-pH 8.0).

Jan 1, 1981

By Geoffrey G. Hunkin

This is a brief state of the art paper describing current (1975) Uranium recovery plant flowsheets, some notes on system selection, design philosophies, and materials of construction. The in-situ, or borehole solution mining, of Uranium is a process which has been developed over recent years to better match Uranium mining and milling technology with the size, shape, grade and territorial distribution of the remaining identified Uranium deposits of western United States. Solution mining recovery plants are pure hydrometallurgical units ideally suited to automation, modular design, and mobility. Similar to conventional Uranium mills, two basic flowsheets, one acid and one carbonate, are in use, but the predominance is reversed so that the majority of plants employ the alkaline carbonate flowsheet, All plants incorporate resin bead ion exchange Uranium recovery for both acid and alkaline circuits.

Jan 1, 1976

By Andrea Koschinsky, Peter E. Halbach, Margret Halbach, Andreas Jahn

"Ferromanganese crusts contain hydrous Mn and Fe oxides as main metal compounds together with some economically interesting minor elements such as Co, Ni, Ti and Cu and trace metals such as Mo, W, Nb, Te, Ga, Pt, and REEs. Some of these metals or semimetals have a great future potential as innovative high-technology constituents. All of them are highly enriched in the crusts compared to seawater composition.The Mn in the crusts mainly originates from the O2 - minimum zone in the oceanic water column. The agent for Mn2+ oxidation is dissolved oxygen, transported upwards from colder deep water layers by turbulent eddy diffusion. The Mn itself descends from surface waters and is carried down to the O2-minimum zone by fecal pellet transport. In contrast, Fe is mainly supplied from carbonate dissolution of planktonic skeletons in the water column. These relationships result in the fact that the oceanic water depth strongly controls the metal composition of ferromanganese crusts: the Mn - group metals are more enriched in shallower water, whereas the concentration of the Fe - group metals increase with water depth. The REEs play a very important role with regard to the trace metal composition of the crusts: their concentrations increase with water depth mainly controlled by a decreasing Mn/Fe ratio.In seawater, REEs occur as carbonate complexes; preferably, the light rare earth elements (LREEs) form REECO3 +(aq) and the heavy Rare Earth Elements (HREEs) REE(CO3)2 (aq) complexes. The REEs are transition metals, their 6s orbital of the outermost shell is filled before the filling of lower 4f electron shells is completed, thus the configuration of the valence electrons is similar in all the REEs, and all REEs exhibit similar chemical behavior and exist, dominantly, as 3+ cations. The ionic radius decreases progressively from La3+ (1.18 Å) to Lu3+ (0.97 Å), this phenomenon is called "lanthanide contraction". Due to the fact that REEs in seawater form cationic and anionic carbonate complexes, the two main hydrogenetic constituents, hydrous !-MnO2 and Fe-oxyhydroxide, fractionate the group of REEs by surface absorption processes. According to the pHZPC-concept the ?- MnO2 phase has an electronegative surface, and Fe-oxyhydroxide a slightly positive surface charge at seawater pH. These relationships are the main reason for the observed REEs fractionation."

Sep 1, 2014

By Robert E. Charles

Much has been said about digital computer control of metal and mineral ore dressing processes, but little has been done. This pa- per discusses what practical use can be made today of a digital computer in an ore concentrator and how such application can be made successfully. A hypothetical, but commercially common, grinding and flotation circuit is presented in terms of analog measurements which can and are being made in existing plants and a centralized computer control system which is reasonable in terms of today's technology. Dangers and possible disadvantages of such an approach are discussed as well as estimated benefits. Possible future benefits are presented in terms of improved control technology. Development of new measuring devices is not considered as a criterion for computer benefits. The control systems described have been utilized successfully in existing ore dressing operations. However, the degree of success or failure of analog systems is generally left to the interpretation of management rather than absolute analysis. Many factors affect the economic operation of a mineral recovery circuit such as size of facility, flow sheet design, number of operating personnel, percent of recoverable mineral in the ore body, loss to tails, and haulage rates. In existing mills where little or no instrumentation has been used, it is extremely difficult to prove or disprove the advantage of analog control systems on one mill line versus its sisters due to the lack of standards and the lack of ability to separate final products by ton.

Jan 1, 1969

By George M. Meisel

This paper is devoted to a discussion of the factors governing design of concentrators for large grinding circuits. Emphasis is placed on the manner in which use of ever larger grinding mills has affected the size of grinding bays, service cranes, gear reducers and electric motors, and the selection of ancillary equipment for cushioning of the starting load of large mills. Information is presented on the effect of using large grinding mills on the capital and operating costs of concentrators, e. g. : (Fig. 1) ? Benefits in lower cost of mills, drives and materials handling equipment, plant space, power, grinding media, operating labor and maintenance, and in ease of instrumentation and automation. ? Penalties in distribution of materials from the grinding mills to multiple lines of equipment which have not been developed to commensurately large sizes, and higher cost of ancillary equipment.

Jan 1, 1968

By Rick Coleman

PT Freeport Indonesia’s (PTFI) latest expansion has increased total mill throughput to 125kt/d (137,700 stpd). The most recent expansion included the installation of a semiautogenous mill (SAG) designed to treat more ore than any other single SAG mill currently operating in the world. Also included in the expansion were two large ball mills, rougher and cleaner flotation, including conventional and column cells, and a regrind circuit. All equipment is supported by a modern distributed control system. PTFI’s operations are located in the Ertsberg mining district of Irian Jaya’s Jayawijaya Mountains, the eastern-most province of the republic of Indonesia on the Island of New Guinea. PTFI, the operator, is owned by Freeport McMoRan Copper and Gold (81.3%), the government of Indonesia (9.4%) and private Indonesian investors (9.3%).

Jan 1, 1996

By Terry S. Maio

In 1978, Ozark Lead Company made the decision to expand the capacity of its mine/mill complex by 33%. The objectives of the expansion were to (a) increase mine' production capacity by 1816 tonne/d(2000 TPD), (b) increase lead metal pro¬duction by 21,790 tonne/y (24,000 TPY) and to (c) construct new facilities and/or modify exis¬ting equipment to accomodate the increased pro¬duction. The intent of this paper is to give a brief explanation of the equipment installed and the overall production and metallurgical benefits-realized from this expansion. The expansion was completed in the second half of 1980 with all equipment debugging and fine tuning completed by the first' quarter of 1981. The concentrator modifications and improvements were basically restricted to four areas: (1) materials handling, (2) automation: of the mill grinding circuit, (3) the increase of flotation capacity, and (4) concentrate dewatering.

Jan 1, 1983

By R. P. Schneider

The Chino mine, concentrator, and smelter are located in Grant County in Southwestern New Mexico. Chino Mines Company is a partnership two-thirds owned and operated by Kennecott Santa Fe Corp., and one-third owned by MC Minerals Corp. (Mitsubishi) of Japan. The Chino Ore Body The Chino ore body is a widely varied deposit of rock types and contains intrusive stocks and sediments. The stocks contain chalcocite in a matrix of quartz, mica, and feldspar. Much of the feldspar is altered to clay. Some of these stocks are enriched with native copper. The sediments contain chalcopyrite associated with gangue minerals including magnetite, pyrite, garnet chlorite, and epidote. The contact of the stock and sediment is heavily altered to chlorite and clay. The stock ores contain economic quantities of molybdenite. The operating work index of Chino ore varies from 5 to 20 kwh/ton and averages 8.5 kwh/ton. The ore head to the concentrator averaged 0.81% copper and 0.010% molybdenum. Fifteen percent of the total copper head exists as nonsulfide mineralization.

Jan 1, 1985