Blogs
Whole Ore Oxygen Roasting
The complex geology of the ore body prevented good segregation of a pure oxide fraction in sufficient tonnages to maintain the two circuit operation. Before plant start-up, Freeport recognized that small quantities of carbonaceous ore added to the oxide circuit would produce unacceptable reductions in gold recovery. The carbonaceous ore contributed sufficient preg-robbing organic carbon contaminants, even in minute proportions,
Rare Earth Element and Gold-Bearing Breccia Pipes Geology
Table of ContentsGeologic SettingGeology of the DepositGenesis of the Rare Earth Element-Bearing Breccia Pipes Rare earth element (REE)- and gold-bearing breccia pipes are a potentially significant economic target in the Pea Ridge iron ore mine, Washington County, Missouri. The Pea Ridge deposit is one of eight known volcanic-hosted iron ore deposits in the Middle Proterozoic St. Francois terrane, which are
Recover Metal from Acid Leach Processing of Arsenic Rich Copper Wastes
Table of ContentsMaterialsSmelter Flue DustBleed ElectrolyteContinuous Leaching of Flue DustLeaching with Sulfuric AcidMetal Extraction Via LeachingLeaching with Bleed ElectrolyteArsenic Removal from Leach Liquors Via Solvent ExtractionExtraction With TBPSelective Stripping of TBPArsenic and Molybdenum ProductsCopper CementationCopper Recoveries Arsenic, copper, and molybdenum were effectively removed from arsenic-bearing flue dust using a three-stage continuous sulfuric acid leach. Leach conditions to maximize arsenic and
Germanium Gallium Ore Leaching with Sulfuric Acid
Table of ContentsMaterial and EquipmentGermanium ExtractionAvoiding Germanium PrecipitationTwo-Stage Counter-Current LeachingIncreasing Germanium Extraction A sulfuric acid leach technique for extracting gallium and germanium from Apex ore without the use of a reducing agent, such as SO2, was investigated. Leaching studies showed that with increasing sulfuric acid concentrations, gallium extraction increased to over 95%, while germanium extraction reached a peak of 71%
Heavy Mineral Placers
Table of ContentsTrap and Bed PlacersBed Placer ExamplesPlacer Exploration Concentrations of minerals between 3.5 and 5 specific gravity such as ilmenite, rutile and zircon in large accumulations of sand constitute “heavy mineral” placers. Two fundamentally different modes of formation characterize “trap” and “bed” placer variants. Smaller and generally higher grade trap placers form during sediment erosion or reworking. Because of
Grinding Circuit Controls
MOCCA is a Multivariate (Optimal Constrained Control Algorithm developed specifically for non-square industrial control applications with practical difficulties such as interactions, time delays, constraints, modelling development, etc. MOCCA consists of an off-line simulation/translation module, for tuning the control parameters, and an on-line module that implements the designed control law. An alternate means of constructing advanced control strategies is model based
Variable Speed SAG Mill
Table of ContentsComminution Circuit DescriptionMill Availability and MaintenanceAdvantages and DisadvantagesVariable Speed SAG Mills Motor Capability vs Mill Capability The single line grinding circuit at Bond Gold’s Colosseum mine consists of variable speed drive semi-autogenous (SAG) milling and secondary grinding with a fixed speed ball mill. There are several advantages and disadvantages of operating SAG mills with variable speed drives. Discussion
Design CIL Circuit
Table of ContentsCIP or CILDesign Considerations for a CIL Circuit at Mill No. 4 Carbon-in-Leach (CIL) is conventionally used in gold processing operations when preg robbing components are present in the ore. CIL process is becoming attractive even in other situations when preg robbing is not a factor. This paper discusses the situations in which the CIL circuit can be
Treatment of Gold Tailings in High Rate Thickeners
Table of ContentsAuto DilutionRecovery of Water in Arid Areas Degradation of cyanide occurs in the tailings water discharge to slimes dams. The degree of degradation or cyanide loss in the water recovered depends on a number of factors, but is usually assumed to be about 90%. The most important mechanisms of CN loss are through HCN losses and oxidation by
Improve Coal Flotation Rate and Recovery
Table of ContentsFroth Flotation TechniquesExperimentalResults and Discussion A unique collector dispersion techniques was developed and used to improve the flotation rate and recovery of coarser and ultrafine coal-rich particles in the froth flotation processes. In this novel collector dispersion method, the collector such as hydrocarbon-oil is gasified and transported by gas phase (air stream) into the pulp. In addition to
Bacterial Oxidation of Refractory Ores
Table of ContentsBIOX Plant OperationBIOX Process ImprovementsStability of Precipitates The bacterial oxidation (BIOX) process for the pre-treatment of refractory ores for gold recovery was developed by the Genmin Process Research laboratory. Early work started in the late 1950’s when the bacteria strain, “Thiobacillus ferrooxidans” was isolated from effluents pumped from the West Rand Consolidated underground mine but at this stage
Mining Engineers Training Exercises
Table of ContentsPurposeField TestingEffectiveness In the past mining accidents were often a consequence of poorly designed equipment and inefficient mining systems. As mining equipment and technology has become better engineered, safer, and more complex, the frequency of accidents has dramatically decreased, but the proportion of accidents occurring because of decision errors made by the person or persons involved have increased.
Assess Permeability Enhancement In Situ Mining
Table of ContentsConfinement CellsCharge ConfigurationCharcoal Granite In situ recovery of minerals has great potential as a mining technology to mine deposits that might otherwise be overlooked by conventional techniques. Some hard-rock deposits, however, will not have adequate permeability to permit successful in situ mining and will require permeability enhancement of the rock deposit prior to leaching. The leaching process in
Aerophine 3418A Promoter Precious Metals Flotation Performance
Table of ContentsChemistry And Handling PropertiesApplicationAdvantages in Use The origins of AEROPHINE 3418A promoter date back to the 1960’s, when it was established that sulfide mineral collectors based on phosphine chemistry demonstrated efficacy. This new collector chemistry was found to provide flotation performance differing significantly from those of more traditional thiol collector chemistries such as xanthates, dithiophosphates, mercaptobenzothiazoles, thionocarbamates and
Blast Optimization and Ore Fragmentation Modeling
Table of ContentsModelling Blast FragmentationOptimization of Unit OperationsOptimization of Fragmentation in an Underground MineComparison of Costs of Mechanical and Explosive Comminution Blasting plays a key role in all facets of operations. Obviously, drilling and blasting costs are determined by blast design, but the downstream costs that are closely related to blasting results are often treated as separate functions: loading, hauling,
Mine Ventilation Recirculation Systems
Table of ContentsReview of Basic PrinciplesStudy of a Hypothetical Ventilation NetworkSpecial Cases of Controlled RecirculationLaboratory Tests In many deep mines, the design of a ventilation system to satisfy the airflow requirements might be difficult to implement and expensive to maintain. The problem may even be more serious when the mine workings are dispersed and located a considerable distance from the
Extract Tantalum & Niobium from Pegmatites
Table of ContentsArea Description and Geologic SettingSampling and MineralogyTantalite Upgrading and RecoveryCoarse Crushing and Mica RemovalGravity BeneficiationMagnetic Upgrading of TantalitePilot Plant TestingHigh-Grade Material Sample ALow-grade Material Samples B, C, and DConclusionsAcknowledgements The Bureau of Mines’ Intermountain Field Operations Center, Denver, CO; and the Bureau’s Salt Lake City Research Center, Salt Lake City, UT, jointly studied domestic sources of tantalum and
How to Increase Germanium Extraction from Zinc Hydrometallurgy Waste
Table of ContentsMaterial and EquipmentUnderstanding Germanium InsolubilityZinc Processing StepsPossible Solutions to the ProblemSummary Germanium is an important strategic metal used in fiber optics, infrared detectors, and semiconductor devices including transistors, diodes, and rectifiers. Substitution for germanium cannot be made without substantial loss in performance in most cases. Germanium is generally not concentrated naturally, although trace amounts are found in many
Apatite Leaching using H2SO4 & Methanol
Table of ContentsIdentification of a Coating on Acid-Alcohol Treated Apatite CrystalsPreparation and Description of ApatiteAcid-Apatite Ratios for Leaching ApatiteEquipment and ProceduresResultsConclusions Current practice for the production of wet-process phosphoric acid (H3PO4) involves leaching beneficiated phosphate rock with aqueous H2SO4. Typical processing involves mining the ore, also called matrix, using a dragline, then forming a water-based slurry to facilitate pumping the
What is the Effect of Chromium on Wet Grinding Performance
Table of ContentsElectrochemical measurementsLaboratory flotation testsResultsDiscussion Because of higher efficiency, wet grinding is more widely used than dry grinding, but leads to an increased consumption of grinding media due to corrosion in some ores. In dry grinding, the wear rate of high chromium cast irons is frequently ten times lower than cast or forged steel with a cost ratio of
Heap-Leaching Pad Volume Calculations
The estimating of volumes is a routine practice in an open pit-heap leaching operation. Until recently, the conventional cross-section manual method has been used at Wharf Resources’ South Dakota operation for the estimate of material mined from the pits, crushed ore delivered to the heaps, unload spent ore, ore and topsoil stockpiles, waste dumps and other earthwork projects. MINE-SURVEY is
Reprocessing Gold Tailings by Gravity Methods
Tailings originating from the gravity concentration of a gold ore containing about 14 g/t Au have been treated by various beneficiation methods. These tailings have been screened on the 147 and 74 micron sieves and the two coarsest fractions have been separated on shaking tables with unsatisfactory results, but the concentrates have been examined in polished sections for mineragraphic analysis.
High MgO Blast Furnace Pellets
Table of ContentsSoftening and Melting Mechanism With PelletsSignificance of The Results The pellets were produced in the pilot plant, and followed the steps bellow: – Definition of pellet chemistry – Model for high MgO blast furnace – Pellet production run Pellet chemistry was defined based on the fact that high MgO levels have the capacity to attain improved softening and
How to Make Lead Metal by Molten Salt Electrolysis
Table of ContentsTheoretical ConsiderationsEquipment and Experimental ProceduresElectrode Designs Tested On Bench ScaleSawtooth Electrode Assembly for 3,000-A CellElectrode Assemblies in Bench-Scale CellOperation of 3,000-A Cell with Sawtooth Electrodes Molten-salt electrolysis of lead chloride is an integral unit operation in a ferric chloride leaching process that was developed by the U.S. Bureau of Mines for treating galena concentrates as an alternative to