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By David A. Milligan

This paper describes the Darwin Silver Recovery project, located 66 km (40 miles) outside of Lone Pine, near Darwin, Inyo County, California. A lead-zinc mine and a flotation concentrator were operated there from 1945 to 1957. By the time the mine was shut down, 1.53 Tg (1.69 million short tons) of tailings had been stored in ponds. An average silver assay of 47 mg/kg (1.38 troy oz/st) of tailings stimulated interest for commercial silver recovery. A heap leach process was developed in 1981 at the Tucson Research Center of Anaconda Minerals Company, a division of Atlantic Richfield Company. Agglomeration techniques were used on the ore since the fine grind did not allow direct heap leaching. Lime and cement were required as binders, Early laboratory tests showed that recoveries equal to those from an agitated leach could be achieved at lower capital and operating costs. Laboratory tests determined cyanide requirements, lime and cement usages, and percolation or leach rates, as well as confirming that a zinc precipitation step could recover the silver from the leach solution.

Jan 1, 1983

By R. K. Komarek, F. E. Jr. Briber, G. M. Hanson, Fred D. DeVaney, J. H. Blake, C. L. Matson, T. E. Ban, N. E. Shields, R. D. Frans, R. B. Greenwalt

Metallurgically, the term agglomeration is used to describe processes whose goal is to form balls, briquettes, nodules, flakes, or other sized shaped particles from loose, usually fine, incoherent particles. In practice it includes such varying processes as the briquetting of coal dust and other substances, the balling and induration (heating) of such nonmetallics as cement, fluorspar, lightweight aggregates, etc. It includes such widely used processes as the sintering of nonferrous concentrates, such as those copper, lead, zinc, etc. The agglomeration of specific nonferrous metal concentrates is discussed in detail in the section of this handbook devoted to that particular metal. Agglomeration processes are of particular value to the iron and steel industry where the nature of the primary reduction process, the blast furnace, requires for best results a burden essentially free of fines. This is a change that has taken place since about 1960. Prior to that time many fine unsized ores were fed to the furnace. The development of the pelletizing process gave to the industry a chemically controlled closely sized product that increased the produc¬tion rate and reduced the costs so much that unsized fines are seldom used in modem furnaces. Steel plants produce many fine sized waste products such as fine dust (fine ore coke and gangue) and mill scale. These products, which have a valuable iron content, are usually sin¬tered directly at the plant for reuse. Fine sized ore concentrates are usually pelletized at the mine and shipped as pellets to the steel plant. Common practice in some areas producing natural high grade ores is to screen the ore at the mine to about 3/8 in. The oversize is shipped "as is" and constitutes blast furnace feed. The / in. may be shipped to the steel plant where it may be sintered or otherwise agglomerated. At some mines the fines may be pelletizied prior to shipment. With the development of large ocean ore carriers, and with the transportation of slurried concentrates or fines, a trend has developed of constructing large pelletizing plants or other types of agglomeration plants near large consumption centers (i.e., in the Netherlands or Japan) where ores of many types are brought together, ground if necessary, blended, and agglomerated. As an indication of tonnages of agglomerated materials produced, for iron materials alone (the largest share of the total) production in 1970 in the U.S. was Million gross ton Sinter 40.7 Pellets 43.1 Briquettes, nodules, & others 0.1 Total 83.9 During the 1960s, U.S. production of sinter rose from 40.3 million gross tons in 1961 to a high of 48.7 million in 1964, then settled back to almost the 1961 figure in 1970. Pellet production rose steadily from 14.4 million gross tons in 1961 to the 59.9 figure for 1975. Worldwide, sinter production in 1966 was estimated at 340 million mt (mainly in Europe, Russia, Japan, and the U.S.) and pellet produc¬tion the same year at 64 mt (primarily Canada and the U.S.). World pellet production capacity rose to 200 million tons in 1976.

Jan 1, 1985

By Brij M. Moudgil

Flotation was introduced in phosphate rock processing in the late twenties and since then it has been an important part of the concentration process. More than two thirds of the rock produced in Florida is upgraded by the flotation process. Since no crushing or milling steps are involved in the material preparation, the flotation plant feed is coarser than in most other mineral flotation systems. During hydraulic processing of the rock, particles in the size range of -14, +150 mesh constitute the flotation feed. This size fraction is further classified by hydraulic sizers, stationary screens and vibrating screens into a coarse (-14, +35 mesh) and a fine (-35, +150 mesh) flotation feed. The flotation techniques for concentrating the fine feed as practiced by the Florida Phosphate producers have been standardized over the years, however, methods for upgrading the coarse feed differ from plant to plant. In this paper an effort has been made to present relative merits of the techniques employed for concentrating the coarse phosphate rock..

Jan 1, 1977

By C. A. Holley

The generation of coal fines is a growing problem which has serious environmental and resource recovery Impact. Several methods of agglomeration are studied including the production of briquettes for the consumer market. Simplified process flow diagrams, "order of magnitude" plant capital cost and operating costs are presented.

Jan 1, 1986

By Ataollah Nosrati

Agglomeration of fine mineral particles is an important step in heap leaching processes employed for a cost-effective hydrometallurgical extraction of value metals from low-grade ores. In this study, the effect of acidic binder composition and feed ore particle size on binder dosage requirement and isothermal, batch agglomeration behavior of siliceous goethite nickel laterite has been investigated. Agglomeration tests performed with tap water and 30, 44 and 98% w/w H2SO4 solutions as binders revealed the key role of binder formulation in controlling ore particle wettability, nucleation and granule growth behavior. Both lower binder acid content and higher dosage led to greater wetting, nucleation and granule growth rates. Variation of feed ore fine/coarse particles? mass ratio dramatically impacted on binder dosage requirement for effective particle wetting, nucleation, and growth agglomeration behavior. Increasing fine (-150 µm) fraction mass content in a -2 mm feed ore, led to higher binder dosage requirement and enhanced nucleation, however the overall agglomeration rate/granule size growth decreased. In contrast, the presence of coarse (5 ? 15 mm) particles in feed ore led to (i) lower binder dosage requirement, (ii) enhanced initial agglomerate size growth rate, and (iii) reduced coalescence. For dry agglomerates of similar sizes, competent coarser feed particles led to remarkably higher compressive strength than did finer feed particles. Microstructure analyses indicated that the granules containing coarser particles exhibited a distinctive, competent core/shell (fines) structure which led to their structural reinforcement. The appropriation of the findings for optimizing agglomeration behavior for enhanced heap leaching of complex, low grade laterite ores are discussed in this context.

Sep 1, 2012

By P. D. Chamberlin

Agglomeration for the heap leaching of gold and silver ores can be defined as the process of attaching fine ore particles (less than 100 mesh) to coarser particles so the fines are immobilized and uniformly distributed throughout the heap, thus making the heap more porous and uniformly permeable to the flow of a leaching solution. Agglomeration techniques and equipment to be described include drum and disc agglomerators, stockpile and belt agglomeration, and the use of vibrating deck and reverse running conveyors.

Jan 1, 1986

By G. Velarde

Agglomeration has as main objective to form a uniform and highly permeable heap for leaching. An inaccurate dosage of moisture during agglomeration leads directly to poor agglomerate quality and segregation of particle sizes during stacking. This causes a heterogeneous distribution of the leach solution inside the heap which invisibly and practically permanently affects the recovery. Unfortunately, only when this becomes serious and the mineral contains an excess amount of fine particles and/or clays then the poor permeability of the pile becomes obvious. This paper is based on the experience of Minera Cerro Verde in the development and application of a quantitative method to control moisture during agglomeration. As the amount of fine particles/clays varies, the quantity of moisture has to be altered in real time. The measurement of agglomerate electrical conductivity is used for it. This concept is based on the sharp change seen in conductivity when the mineral passes its absorption limit. A liquid conductive film then begins to form over the surface of the particles, which leads to the formation of agglomerates through liquid bridges, which are also electrical bridges. Moisture is adjusted to reproduce a value of conductivity established previously and is the guiding parameter. Moreover, moisture amount added to reach this conductivity parameter provides information about the fines/clays relative content for best leaching management.

Jan 1, 2004

By R. Hogg

"The basic population balance models for agglomeration processes are reviewed and procedures are described for extending their applicability to systems with size-dependent rate constants and to the formation and growth of porous agglomerates from rigid, solid particles. Simplified procedures for the further extension of the models to include simultaneous agglomerate growth and breakage arc also described. IntroductionThe association of small particles into clusters or agglomerates is a significant factor in many facets of particle processing. Agglomeration processes are widely used to facilitate handling, storage and utilization of fine powders. Processes such as coagulation or flocculation are used to aid solid-fluid separation in dispersed particulate systems. Agglomeration also occurs as an accompaniment, often unwanted, to other particulate processing operations such as fine grinding, mixing and blending, transport and flow.Reliable agglomeration models are needed for improved understanding of the processes in general and of the complex role of numerous, interacting variables as well as for direct application to the design and control of industrial processes such as flocculation, granulation and pelletization. Ideally, the models should account for the primary forces responsible for agglomerate ·formation and growth, the effects of external forces on process dynamics, the development of agglomerate structure and its role in the process itself, and the effects of concurrent processes such as structure modification (e.g. compaction) and agglomerate breakage or degradation.In its most general form, the process of agglomeration involves taking discrete, independent particles, bringing them into contact with one another, promoting (or allowing) interparticle adhesion to occur and then causing structure rearrangement, usually under the action of external forces. The relative importance of these steps varies with the nature of the particulate system being agglomerated and with the kinds of agglomerates being produced. Coagulation or flocculation of particles dispersed in fluids is generally dominated by the contact and adhesion steps. In the granulation of powders, on the other hand, particles are already in contact so that structure rearrangement is the principal step."

Mar 1, 1992

By R. Hogg

"The basic population balance models for agglomeration processes are reviewed and procedures are described for extending their applicability to systems with size-dependent rate constants and to the formation and growth of porous agglomerates from rigid, solid-particles. Simplified procedures for the further extension of the models to include simultaneous agglomerate growth and breakage are also described.INTRODUCTION The association of small particles into clusters or agglomerates is a significant factor in many facets of particle processing. Agglomeration processes are widely used to facilitate handling, storage and utilization of fine powders. Processes such as coagulation or flocculation are used to aid solid-fluid separation in dispersed particulate systems. Agglomeration also occurs as an accompaniment, often unwanted, to other particulate processing operations such as fine grinding, mixing and blending, transport and flow.Reliable agglomeration models are needed for improved understanding of the processes in general and of the complex role of numerous, interacting variables as well as for direct application to the design and control of industrial processes such as flocculation, granulation and pelletization. Ideally, the models should account for the primary forces responsible for agglomerate formation and growth, the effects of external forces on process dynamics, the development of agglomerate structure and its role in the process itself, and the effects of concurrent processes such as structure modification (e.g. compaction) and agglomerate breakage or degradation."

Jan 1, 1989

By D Readett

The most critical variable in the successful establishment of the Murrin Murrin Heap Leach plant was the effective agglomeration of the Ni laterite ore. This paper describes the test work undertaken to establish the key agglomeration parameters including state of the art testing and analysis procedures. These parameters were then utilised to establish the key design and operational concepts for the world’s first commercial scale Ni laterite heap leach. Following the technical and economic success of the operation, the actual operational data is compared back to the original test work data.

Aug 8, 2011

By S. M. Marshall

The investigations recorded in this bulletin were conducted by the Pacific Coke & Coal Co. in cooperation with the United States Bureau of Mines and the University of Washington. They cover one phase of a comprehensive investigation to determine whether coals from an extensive, undeveloped area of Pierce County, Wash., can be used in the manufacture of coke for the iron blast furnace. The completed investigation had three parts: (1) A geological survey of the coal property, (2) washing and crushing tests of the coals, and (3) coking and by-product tests. The geological survey, which was not conducted in cooperation with the Bureau of Mines and the University of Washington, included systematic tracing of the coal beds by test holes throughout the property, except some portions covered by an impenetrable layer of glacial drift. By this means all of the beds were correlated, their thickness and general character were determined, and tonnage estimates were made. Only such parts of the survey results as are necessary to a full explanation of the investigations described herein are included in this bulletin.

Jan 1, 1931

By G. V. Henderson

The San Gabriel Valley contains some of the richest and most extensive sand and gravel deposits in California. Operating quarries within the San Gabriel area mine more than 15 million tons of high quality aggregate per year. This represents about 45 percent of the total mined in the greater Los Angeles area, one of the nation's largest aggregate markets and producing regions. Popular opposition to continued aggregate production in the San Gabriel Valley is high, especially in the city of Irwindale where 40 per-cent of the city's property is made up of "excavated holes," some 150-200 feet deep. Reclamation of 70 years of mining is now an almost impossible task. Zoning regulations have the effect of depleting these vast reserves rapidly by changing the definition of total reserves to include only "legally minable reserves." All but two or three of the aggregate mines now operating will be depleted or zoned out of business by the year 2000. Some studies indicate that there will be no aggregate mining operations by 1995. Recent studies show a drastic change in land use patterns within this valuable mineral resource area over the past 20 years. The San Gabriel Valley is a classic example of the lack of adequate regional planning with regard to urban development in MRA's and represents a "too little, too late" effort by local government and industry.

Jan 1, 1978

By P. A. S. Manning

Eastern Jamaica consists predominantly of non-carbonate rocks reaching elevations of over 2200 m. The area is drained by a well established river network which supplies close to 30% of the sand and gravel used by the building and construction sector. Present high extraction rates and slow rates of replenishment will result in early exhaustion of this source of aggregate. A number of volcanic and carbonate rocks are being examined as a possible source of high quality aggregate which meet the requirements for all types of construction. Preliminary evaluations show a dacitic deposit to be the most suitable source for aggregate use.

Jan 1, 1998

By J. R. Low, M. Gensamer

During the course of an investigation into the drawability of automobile-body sheet steel, it became apparent that certain advantages would be possessed by a deep-drawing steel with a very low yield strength, but almost normal tensile strength, provided a reduction in yield strength could be accomplished without sacrifice of ductility and fine grain size. It would also be desirable to have this steel free from strainaging; that is, free from the tendency for the yield point to return after it had been eliminated by straining. It was known that wet hydrogen treatment acted to eliminate aging, but as carried out by other investigators, at relatively high temperatures, this treatment resulted in grain coarsening. It has been established by some of the experiments reported in this paper that all of these objectives can be accomplished by treatment in wet hydrogen at a low temperature, in the neighborhood of 720°C. The time of treatment is relatively short (about 3 hr. to completion with 20-gauge sheet) if the water content of the hydrogen atmosphere is made fairly high, say almost 30 per cent by volume. At this temperature, the grain size remains fine in the time required. After this treatment sheet reduced the usual amount by cold-rolling has a grain size of about A.S.T.M. No. 7. The yield point is completely eliminated, and the yield strength is reduced to a very low value, in the neighborhood of 15,000 lb. per sq. in. The stress-strain curve departs gradually from the straight-line elastic part after the fashion of nonferrous deep-drawing alloys. This elimination of the yield point is accompanied by a very low indentation hardness; for example, 32 Rockwell B or even lower. There is no aging as measured by increase in the yield strength upon aging at room temperature or for 3 hr. at 200°C., after stretching about 10 per cent in tension. Tensile strength is only slightly less than the box-annealed sheet, seldom dropping much below 40,000 lb. per sq. in. Elongation is practically unchanged, or increased slightly. The term yield point, as here used, refers to the phenomenon of heterogeneous deformation occurring at a substantially constant load, observed principally in annealed low-carbon steels. If such a steel is loaded in tension, the load increases steadily with elastic strain, suddenly falls, fluctuates slightly about some constant value for a time and then begins to rise again as deformation proceeds. The maximum initial load before the sudden drop is generally called the "upper yield point"; the value of the load where deformation proceeds at a

Jan 1, 1943

By C. A. Holley

Agitative agglomeration is a rapidly expanding field related to many chemical processes. This paper reviews many processes and the particular type of agitative agglomeration that is utilized with each. Many new innovations to produce granular products in place of powder are explored. The operation and theory of the many types of agitative agglomeration equipment is reviewed.

Jan 1, 1988

By Kevin Telmer, Daniel Merino, Scott Smith

El Aglomerado de Carbón y Aceite (COA) es un método práctico, eficiente y fácil de utilizar para la recuperación de oro libre; el método destaca por el bajo costo y fácil acceso a los insumos utilizados, por eso es considerado una alternativa limpia para el beneficio del oro sin uso de mercurio. El método se basa en la formación de aglomerados o pellets compuestos por carbón, agua y aceite, los cuales capturan partículas de oro libre. Esto ocurre gracias a las propiedades hidrófobas/oleófilas que tiene el oro, que permite adherirse a los aglomerados; el aceite actúa como líquido puente entre el carbón y las partículas de oro, facilitando su unión.

Sep 29, 2023

By Pedro Antunes Amaral

Currently there is a constant and essential concern of preserving nature. Over the years the concern with the environment is increasing, new environmental laws are emerging and being applied more rigorously and consequently emerge economic needs and mineral processing practices and other materials. In this sense briquetting becomes an alternative to fine particles agglomeration by means of pressure and or temperature, with the aid or not of a binder, which allows to get a product not only compressed, which presents shape, size, and adequate mechanical properties. The reduction in volume of the material in some cases (beyond the technological benefits) also allows fine materials can be transported and stored more economically, safely and effectively. The production of coke is greater as the content of better coking coal is, thus he low capacity coking coal is not much used in coke ovens. This research aims to demonstrate that briquetting of mineral coals with low coking coal capacity is possible, additionally allows increased coke production, obtaining then a better yield of coke. Basically they take advantage of low price of no coking coals without changing the quality of the coke produced. Anyway, briquetting became a smart alternative to aggregate values, economy and care for the environment.

Oct 30, 2017

By J. Cayouette, C. Bolduc, P. Blatter

"The LaRonde mill was commissioned in 1988 and began treating ore from the Penna shaft in 2000. The mill has been expanded to accommodate 7,500 t/day, but ramped down to 6,000 t/day since the deep extension began. The process recovers gold, silver, and base metals. In 2008, the Goldex plant began trucking gold-pyrite concentrate to a treatment plant feeding pulp to the LaRonde mill, increasing gold output by 40,000 oz. In 2009, the high-grade Lapa ore processing facilities were annexed to the LaRonde plant, increasing gold output by 120,000 oz. This paper outlines the metallurgical considerations related to the treatment of different ore types.RÉSUMÉ Le concentrateur de la mine LaRonde a été mis en service en 1988 et a commencé à traiter le minerai du puits Penna en 2000. La capacité du concentrateur a augmenté afin de permettre le traitement de 7 500 tonnes de minerai par jour, capacité qui est retombée à 6 000 tonnes par jour (tpj) depuis le début de l’extension en profondeur de la mine. Ce procédé permet de récupérer de l’or, de l’argent et des métaux communs. En 2008, l’usine de traitement Goldex a commencé à transporter par camion du concentré de pyrite et d’or vers une usine de traitement alimentant en pulpe le concentrateur de LaRonde, augmentant ainsi la production d’or de 40 000 onces. En 2009, les installations de traitement du minerai à haute teneur de Lapa ont été annexées à l’usine de traitement de LaRonde, augmentant la production d’or de 120 000 onces. Cet article passe en revue les considérations métallurgiques liées au traitement de différents types de minerai.INTRODUCTIONThe LaRonde metallurgical plant in the Abitibi region of Quebec, Canada, evolved into a mature milling site following expansions in 2000–2003, thanks to improved processes, manpower, and water treatment capabilities that better accommodate the complex constituents of the LaRonde ore. The ore requires a sequence of grinding, copper- lead and zinc flotation, and precious metals leaching, ending with a carbon-in-pulp (CIP) gold recovery. A portion (35%) of the tailings is sent back underground as paste backfill after being treated with the SO2-air cyanide destruction process. The tailings area has a dedicated cyanide destruction and metal precipitation area through which the used water passes before returning as recycled water. A biological water treatment plant was built in 2004 to address water toxicity in the final effluent. The water toxicity was the result of the high sulfide content of the LaRonde ore (from thiocyanate or stable cyanide species buildup) and the use of 90% recirculated water in the mill. The water treatment plant uses bacteria to transform thiocyanate into nitrates and precipitate phosphorus from the water before it is discharged into the environment."

Jan 1, 2017

By Jean Cayouette, Paul Blatter, Paul Cousin

"The Laronde mill was commissioned in 1988 and has been treating the Laronde Penna ore since 2000. The Laronde plant, situated in the Abitibi region of Quebec, has experienced mill expansions to accommodate 7500 mtpd and to recover gold and silver as well as important amounts of base metals (Cu, Zn, Pb). Ten sequential metallurgical and environmental processes are responsible for metals recovery and process viability. Over 200,000 ounces of gold, 4,5 million ounces of silver, 7000 tonnes of copper, and 78,000 tonnes of zinc are produced annually.In 2008, the Goldex plant began trucking high grade (35-45 g/t Au) pyrite sulphide concentrate (TCGO) for gold extraction at a newly constructed treatment plant, increasing gold output at Laronde by 40,000 ounces. In 2009, the high gold grade Lapa ore processing facilities were annexed to the Laronde plant increasing output by 120,000 ounces of gold. TCGO and Lapa productions are forecasted until 2018 and 2015 respectively, with known reserves of each mine.Today, up to 140 permanent employees run and optimise the Laronde plant operation. As a result, Laronde has intricacies intrinsic to a large and varied operation. The paper will outline the metallurgical highlights, challenges, and future outlook related to the treatment of each ore type (Laronde, TCGO, and Lapa).INTRODUCTIONFollowing the 2000 to 2003 expansions, the Laronde plant evolved into a mature milling complex with developed processing, man power, and water treatment capabilities able to accommodate the complex Laronde ore. The ore requires a series of grinding, copper/lead flotation and separation, zinc flotation, zinc tails precious metals leaching, followed by a counter-current decantation circuit and Merrill Crowe precipitation. A paste backfill and SO2-air cyanide destruction operate intermittently. The tailings area has a dedicated cyanide destruction and metals precipitation plant prior to water recycling to the mill. A biological water treatment plant was put into service in 2004 to address the build-up of thiocyanate in the tailings ponds at Laronde. This was the result of the high sulphide content of the Laronde ore and 90% recirculation of the process water. The plant uses bacteria to oxidize and destroy thiocyanate, and removes phosphate from the water before it is released to the environment."

Jan 1, 2011

By Steven A. Savage

Agrico Chemical Company, as we presently know it, is the result of the coming together of several different fertilizer operations. The Williams Companies, our parent organization, first entered the fertilizer business in 1971, when it acquired the fertilizer operations of the Gulf Oil Company. This gave us, among other things, the manufacturing facility at Donaldsonville, Louisiana. In 1972, The Williams Companies acquired Agrico Chemical Company from Continental Oil Company, bringing in a manufacturing facility and phosphate mines at Pierce Florida. Our Florida Mines are in the region commonly known as the Bone Valley Region of Florida. The majority of the phosphate fertilizer produced in the United States utilizes rock mined in this region. The Donaldsonville Plant was originally built in 1967-68 on the site of the old Faustina Plantation at an approximate cost of $80,000,000. (This plant is commonly referred to as our Faustina Plant.) Until such time as Agrico was acquired from Continental Oil, the Donaldsonville Facility was solely used to upgrade phosphoric acid into finished granular products.

Jan 1, 1986