Blogs
Hydrolytic Precipitation
In the chemical and hydrometallurgical industries, solvent extraction is a well established and widely used extractive metallurgical process by which desired metals are loaded onto an organic phase from an aqueous solution. However, the recovery of such metal values is conventionally carried out by suitable fluid stripping, whereby metal ions in the loaded organic are extracted, usually by acidic solutions.
Integrated Heavy Media Cyclone & Flotation System
Heavy medium cyclones make use of a medium which is a homogenous mixture of water and dispersed magnetite. Density of the medium is regulated by adjusting the amount of magnetite in the mixture. Coal is mixed with the medium in a sump and fed to the HMC where the heavier ash material is separated from lighter coal due to density
Flash Smelting Process
Table of ContentsFlash Smelting FurnaceGeneral Smelter Performance Process Flow Description: Concentrates and other copper bearing material are blended and conveyed from two separate areas of the plant to three 464 ton capacity wet charge bins located above the rotary dryer. Flash furnace silica flux is conveyed to a 250 ton capacity fine flux bin located adjacent to the wet charge bins.
Solid Suspensions Settling Modeling
Table of ContentsAnalysis of Settling CurvesThickener Area Calculations Sedimentation is used to clarify process effluents or to thicken process slurries. The sedimentation cycle of a suspension is presented as a settling curve. This curve is simply a plot of the height of the interface between the settled suspension and clear liquor versus time. The interface between the supernatant and suspension is
Leach Pad Cyanide Neutralization
In a “load/unload” gold heap leach operation, the time that a heap is on the reusable leach pad is of critical economic importance. The turnover of heaps must flow in a consistent and cyclic manner in order to leach the gold bearing ore in an economically feasible manner. The process cycle is time dependent on two main stages, leaching and
Froth Viscosity & Flotation Efficiency Relationship
Flotation efficiency is governed by the wettability of the solid as well as the surface tension at the liquid/gas interface. Both these properties in turn determine the frothing characteristics encountered in a flotation process. A number of studies have focussed on the correlation between wettability as monitored by contact angle and flotation recovery. Frothing properties which are relevant in a
Effects of Non-Darcian Flow
Table of ContentsDevelopment of Numerical Flow CodeDemonstration Problem When excavating open-pit mines below the water table, two of the more important water-related problems potentially faced by mine operators is the amount of ground water that could flow into the pit and the effect of pore water pressure on the stability of the highwalls. The ability to predict the nature and
Zircon Uses
Table of ContentsZirconOrigin of Placer DepositsZircon Properties Zircon Uses: Refractory minerals can be defined as minerals or synthetic inorganic crystal phases that have high melting points. Refractoriness has been defined by Committee C-8 of the American Society for Testing and Materials as ” the capability of maintaining the desired degree of chemical and physical identity at high temperatures and in
Refractory Grade Bauxite
Table of ContentsGeneral SpecificationsProcessingEconomic ConsiderationsSources of SupplyDemandOutlook Refractories are commercial products created from nonmetallic minerals that possess the capacity to maintain their form and strength when subjected to highly elevated temperatures amid varying extremes of mechanical stress and chemical attack by hot gases, liquids, or molten and semi-molten substances. In the modern economies of the world, alumina (Al2O3), the oxide
Mini Pilot Plant in Mining & Mineral Processing
Study of the behaviour of an ore during concentration by flotation process starts, in general, with a series of tests in laboratory cells. Given the discontinuous nature of these tests, the information obtained by such a study is somewhat limited. It has long been recognized that laboratory test results are not always reproducible in pilot plant tests and subsequently, the
Dual-Alkali Scrubbing
SMC’s smelting process is composed of a submerged-arc electric furnace and a top blown rotary converter (TBRC). The 1.5 MW rated furnace operates continuously while the 0.15 M³ TBRC is operated on a batch basis. Process flue gases are combined with tapping hood exhaust air and ducted to a gas cleaning system prior to release to the atmosphere. The gas
Leaching Nickel & Cobalt from Acid Mine Drainage Sludge
Acid mine drainage sludge is produced when an acid drainage stream is treated with lime, sodium hydroxide, ammonium or sodium carbonate in order to neutralize the acidity of the solution. It was found that a sludge sample taken from southern West Virginia contained significant amounts of nickel, cobalt and manganese. Nickel was 0.26%; cobalt 0.21%; and manganese, 4.5%. Such high
Clay-Polymer Floc Decay Dewatered Kinetics
Table of ContentsMaterials and ProceduresTheoryResults and DiscussionConclusions The mining and mineral industries generate large amounts of fine particle slurries which are presently dewatered by impoundment, thickening, filtration or flocculation. Flocculation is a primary unit process that plays a major role in solid-liquid separation throughout the processing industry and waste water treatment facilities. The flocculation is carried out by agglomerating fine
Coal Wettability & Floatability
In testing and designing coal flotation circuits, there are still a lot of unanswered questions. It is still not clear whether it is better to work with the use of flotation feed obtained from a plant and then to cope with all types of sample storage problems, or to rely on a coarse coal sample and the fines generated in
Stripping Gold & Silver from Carbon – Chemistry
Stripping of gold and silver from carbon is effected by means of two main processes (AARL and ZADRA). The main rate-enhancing parameter in the stripping of gold and silver is temperature. A secondary rate-enhancing parameter is ionic strength. (1) Stripping is usually conducted within a solution containing sodium cyanide (0.1 – 0.5%) and caustic (1 – 3%). Several different analogous
Microwave Digestion Systems
Microwave Digestion Systems (MWD) were popularized by the US Bureau of Mines (USBM) back in the early 1980’s. The USBM published a series of papers on the topic and discussed the advantages of the system. Basically MWD is used to replace the traditional hotplate or digestion block digestion systems employed for sample digestions. This system results in a significant savings
Refractory Minerals in Canada
Canada is a producer of natural refractory minerals, electrofused minerals, and synthetic refractory minerals. Several deposits also have good potential for development. During the past two years three new graphite mines have been developed. The mines produce flake type graphite and they have a combined production capacity of about 55,000-60,000 t/y of concentrates that grade in some cases, up to
Surface Charge in Flotation
The selective flotation of alkali halide salts such as KCl and NaCl is of great industrial significance and has been considered by flotation chemists for many decades. The surface-charge model was rather controversial when it was first presented at the SME Annual Meeting in Los Angeles in 1967. Basically this model suggested that the alkali halide salts were charged in
Mine Drum Hoist Rope Maintenance
Table of ContentsRound StrandFlattened StrandHow to Select a Drum Hoist RopeDrum Hoist Rope Maintenance Mining Companies employ the use of mine hoists to transfer ore, men and materials through a vertical shaft or slope. With varying depths, payloads and equipment, it is necessary to select a rope construction that is best suited for these parameters and that can also provide the
Gold & Copper Dissolution from Gold & Copper Alloys
The dissolution behavior of copper and gold from their pure state and from Au/Cu alloys in cyanide solutions has been investigated using a rotating disc. Oxygen was used as an oxidant. The effect of the composition of the alloys, stirring speed of the disc, concentration of lixiviants and temperature on the overall dissolution kinetics has been studied. Theoretical Background As
Elutriation Flotation for Recycling of Waste Plastics
Table of ContentsDescription of SampleFlotation SeparationsBrine Separation-Flotation ProcessDiscussionSummary and Conclusions The management of solid waste is an ever increasing concern in the United States. Every year our nation generates between 140 to 160 million tons (Lichstein, 1990 and Thayer, 1989) of municipal solid waste. Only about 10 pct of the waste is recycled, mostly aluminum and paper. About 135 million
How to turn Dust into Gold
The primary metals sector was particularly hard hit early on, to develop the technology, acquire the equipment, and implement the programs to eliminate or reduce the by-products of metal making. To this end, through a combination of technological innovation and extensive capital expenditures, the metals industry has net, and in many cases, exceeded the minimum standards. Recognizing the challenge of
Slurry Ash Analyzer Theory
Table of ContentsTheory of OperationExperimental Procedure and Results Coal cleaning plants have traditionally been operated with the primary goal of minimizing the operating cost, with little attention to quality control. However, increasingly stringent air-quality regulations have made the product quality more critical. Without automatic controls, plants often must sacrifice recovery in order to meet specifications. Instrumentation and control, by providing
Geology of the Red Dog Mine
Table of ContentsThe OperationGeologyWeatheringDiscussion Red Dog is a Mississippian to Permian aged sulfide deposit located in the western Brooks Range north of Kotzebue, Alaska. It belongs in the family of black shale hosted sedimentary exhalite deposits but lacks classic sulfide sedimentary textures. Pervasive silicification, and a significant portion of the mineralization, is replacement in nature. An extensive feeder vein system