Blogs
Drying & Calcining Ammonium Diuranate
‘Yellow cake’, so named because of its inherently bright yellow color, is a finely divided precipitate that can be formed after the leaching step when refining uranium ores. Feed solids enhancement then occurs to at least 50% by weight using filters or centrifuges. This is followed normally by drying and then calcining with the conversion of ammonium diuranate to triuranium
Waagner-Biro ASL Liner System
A unique type of grinding mill liner has been developed by Waagner-Biro A.G. of Austria. This liner system, termed an angular spiral lining (ASL), was successfully tested by Magma Copper Company’s San Manuel concentrator in both their 10 Ft x 10 Ft (3.05m x 3.05m) and 12 Ft, 6 In x 14 Ft (3.31m x 4.27m) grate discharge wet grinding
How to Treat Water Containing Cyanide
Table of ContentsEffect of Process Variables in the Removal of Cyanide and Related SpeciesTreatment of Industrial Waste Waters Metallurgical processes involving the use of cyanide such as gold cyanidation, metal plating and flotation, generate effluents containing cyanide and cyanide in complex combinations with heavy metals in quantities exceeding those regarded as being safe for discharge into streams. A new, inexpensive
Carbon-In-Pulp Process Examples
Table of ContentsAdsorptionElutionElectrowinningReactivationInstrumentation and Process Control There are no major innovations in any of these plants. In fact, Australia is really only beginning to get started in CIP research and in process and design development. The plants described here have borrowed from technology, primarily in the United States and South Africa, and although the plants were carefully designed and based
Swirl Flotation in Centrifugal Field by Air Sparged Hydrocyclone
Table of ContentsFluid FlowFlotation of Copper Porphyry OreDiscussion of Particle/Bubble Interaction The effects of operating variables on water transport to the overflow, classification of hydrophilic particles and the recovery of copper and molybdenum from a low-grade porphyry ore are presented. Recoveries of copper and molybdenum exceeding 90 percent at a grade of 8 percent Cu and 0.2 percent Mo were
Recover Rhenium by Solvent Extraction
Table of ContentsProcess SynthesisExperimental WorkPilot Plant Extraction Study Rhenium is industrially recovered all over the world as a by-product of molybdenite processing. There are no separate deposits of rhenium minerals. Molybdenite concentrates, produced as co-products of porphyry copper deposits, contain 0.01 to 0.2% rhenium occuring as a substitutional impurity in the molybdenite lattice. Process Synthesis The solvent extraction process is
Use Sodium Silicate as Dispersant in Selective Flocculation
In the upgrading of finely-disseminated iron ores, selective desliming is the critical step which must be controlled in order to achieve efficient flotation. A prerequisite for selective desliming is a properly-dispersed pulp; sodium silicate is commonly used as a dispersant. The mechanism by which sodium silicate acts as a dispersant in the presence of calcium ions was examined by streaming
Separation of Copper-Nickel by Flotation and Magnetic Methods
Table of ContentsRaw MaterialsMatte PreparationSlow CoolingLaboratory ProceduresResultsFlotation CollectorEffect of Slow Cooling on Matte StructureEffect of Slow Cooling on FlotationFlotation of Mattes with DPGEffect of pH on Flotation ResponseGrinding and ConditioningInspection of Flotation ProductsDistribution of Cobalt and Precious MetalsDistribution of Iron and SulfurSummary and Conclusions As part of our mission to investigate technology options for the development of domestic mineral resources,
Selective Flocculation
Table of ContentsDesign of Selective Flocculation ProcessesApplications of Selective FlocculationSelective Flocculation Process DesignDispersion of the Mineral SuspensionAdsorption of the Flocculent and Floc FormationSeparation of the Flocs from the Dispersed Slurry Selective flocculation utilizes the differences in the physical-chemical properties of the various mineral components in the mixed suspension. It is based on the preferential adsorption of an organic flocculant on
Screen Bowl Centrifuge for Dewatering Fines
Dewatering of the fine clean coal fraction, — 28 mesh (595 microns) represents one of the most difficult and costly separations in typical plant circuits. Since 1969, the Screen Bowl Centrifuge has offered an economical alternative to filtration/thermal dryer combinations. The performance of Screen Bowl Centrifuges has been continuously modified and improved to dewater not only coarser coals, but also
Roof Bolt Bond Tester
A measured pulse of energy is sent into the bolt by a piezoelectric transducer, and the instrument listens for reflected energy. Where the bolt is properly bonded, the energy passes from the bolt, through the resin, and out into the rock mass. Where proper bonding does not exist, a portion of the energy is reflected back along the bolt. The
How to Recover Rhenium from Uranium Leach Liquor
Table of ContentsRhenium LoadingRhenium Sulfide Precipitation The discovery of rhenium on the ion exchange resin used at the uranium in-situ leach operations at Palangana (Texas) led to a laboratory study on the possible methods of recovery. Rhenium, present in small amounts in the ammonium carbonate leach liquors as the perrhenate anion, ReO4-, concentrated on the anion exchange resin, which was
Sinter Plant Operation
Table of ContentsProcess Control of Sintering PlantOxide Use in SinteringEnergy Savings of the Sintering Process The sintering process for the preparation of raw materials to be fed to the Imperial Smelting Furnace (I.S.F.) is rather diversified in its characteristics. In comparison to the other preparation process for zinc extraction, i.e., fluidized bed roasting, the sintering process enables the Imperial Smelting
Gearless Warp Around SAG Mill
For almost a decade now, very good operating experiences have been gained with a total of 28 gearless ring motor drives in the cement industry, driving tube mills with diameters of 2.5 to 4 meters with drive powers ranging from 3000 to about 5000kW. Why then did the mineral ore processing industry hesitate till 1980 to adopt this successful concept
Flotation Kinetics Data Analysis
Several reasons contribute to the wide gap in the industrial application of the academic models. These include: 1) the lack of generality in the model, e.g., the model is limited to certain size ranges; 2) the academic models involve complicated mathematics 3) confusion about the order of the flotation rate, e.g., several authors proposed a first order rate model, whereas
Mill Design Example
Pinson Mining Company was formed to develop a gold orebody located in northern Nevada near Winnemucca. A feasibility study was undertaken in 1979 by a consortium of three Toronto-based mining companies arid a Reno-based exploration company. The Pinson plant has been described in some detail by Mcquiston and Shoemaker in the AIME’s Gold and Silver Cyanidation Plant Practices. I will
Large Flotation Cells Mechanism
Table of ContentsDesign ConsiderationsDevelopment Programs The development of larger size flotation machines, which started in the 1950’s and 1960’s, is still proceeding. The largest mechanical flotation machines available today have unit volumes in the range of 38 to 42 m³ (1,350 to 1,500 cft). In fact, the motivating forces of increasing capital and energy costs and decreasing ore grades, which
Kivcet Process
Table of ContentsFeatures of Kivcet metallurgyFeatures of the Kivcet smelter in Bolivia It has long been recognized that the conventional method of producing lead bullion from concentrates via the sinter-blast furnace route presents problems in meeting the tight regulations for environmental protection which have been introduced in many countries. As described by Chaudhuri and Melcher, 1978, this has led to
High-G Centrifuges
Table of ContentsHigh-G Centrifuge Test Results Fine Coal DewateringHigh-G Centrifuge DescriptionHigh-G Centrifuge TestsTest Results A great deal is known, in a qualitative sense, about the performance of High-G centrifuges. The manufacturers of these machines can give reliable guidance on the conditions necessary for the proper operation of their centrifuges and can give general estimates of the product moisture and recovery
High Porosity Pellets
Since the petroleum crisis in 1973, the effect of the energy cost in the pellet production has been very severe with great risk to this economic activity. The countries that import petroleum, specially those under way of industrialization, felt a great impact in their payment balance due to the high expenses in oil. The testwork has been developed based on a
High Gradient Magnetic Separation of Uranium Ores
Table of ContentsHGMS TechnologyEffect of Process Variables Continuing interest in processes that will effect separations in the fine particle size range has prompted intense interest in the use of high gradient magnetic separation (HGMS) for beneficiation of uranium ores. Some of the uranium minerals are paramagnetic and hence are amenable to concentration by HGMS. HGMS is a powerful method in
Heavy Media Selection Functions Circuit Analysis
Current coal cleaning technology uses heavy media (HM) for the recovery of coal in particles larger than 1/16 of an inch. Through the use of float sink measurements of the feed and products to commercial HM unit operations, a selection function, sometimes called Tromp curve in the coal industry, can be computed. Samples respectively from industrial heavy media vessels and
Froth Flotation Rate Limitations
Table of ContentsPhysical Model of FlotationCopper Sulfide FlotationMechanistic Implications of Mechanical Model A physical model of flotation, derived from viewing froth as a kinetic species since it constitutes the carrier of ore particles, not only agrees with and is simulated by engineering math models, but is statistically verified by actual laboratory flotation data. The model couples the mechanical removal of
Testing Failure Criteria for Grinding Mill Structures
Table of ContentsTesting For Stress Model EvaluationTesting For Casting StressesTesting For Failure Criteria The trend of the past five years toward larger mill sizes shows no signs of reversal. Indeed, the current view of capital requirements for projects, coupled with decreasing ore grades, indicates at least a constant if not accelerating demand for the use of the larger mill, rather