Blogs
Hydrologic Data by Performing Tracer Test on Situ Stope Leaching
Table of ContentsTest Site GeologyRock Mass CharacterizationHydrologyDescription of Tracer TestsTracer ObservationsBorehole 6Borehole 7Borehole 3Borehole 4Summary Recommendations Conventional underground mining involves the excavation and transportation of ore to the surface for processing. Tonnes of solid material is extracted from underground mining systems to produce kilograms, and sometimes only grams, of final product. Surficial processing of ore results in the disposal of
Surface Tension of Wetting for Minerals
Critical Surface Tension of Wetting for Minerals: Another criterion satisfying the requirement for complete wetting can be deduced from Zisman’s concept of the critical surface tension of wetting (γc). Zisman and co-workers (as reviewed by Zisman, 1963; 1964) found a linear relationship between the cosine of the contact angle and the surface tension of a homologous series of n-alkanes when contact
Water Powered Jackleg Drills
Table of ContentsPenetration and advance ratesPotential Benefits of Water-Powered Drilling The idea of using the energy of water (hydropower) for the purpose of deep-level mining has its origins in South Africa. It stems from necessity and practical considerations. With a constant increase of the depth of mining, ventilation and cooling requirements made it essential to chill the service water sent
Drilling & Blasting of Gold Heap Leach Pads
The permitting for the copper project required time beyond what was initially anticipated and stand alone gold reserves were exhausted. While leaching of the gold heaps continued, it was recognized that to continue active leaching into start up of the copper project, some actions had to be taken to increase production. The leach pads were built to an overall height
Gemini VS Wilfley Shaker Table
Table of ContentsTest Procedures and Unit Processes DescriptionsComminutionGravity ConcentrationClassificationAnalysesResults and Discussion Previous work has shown that significant, free milling gold values exist in the Ryan Lode ore. This project used pilot scale equipment to estimate the percentage of gold recoverable by gravity methods from the circulating load of a conventional, closed-circuit, grinding mill. The pilot scale flowsheet employed three stages
Improve Copper Recovery Leaching Solvent Extraction Electrowinning L-SX-EW
The design of the DOP ensures, that proper pumping with right head-flow characteristics can be combined with a mixing tuned according to the requirements of the liquid-liquid contact to be performed. As this is not easily realized the DOP design has been backed up by Flow laboratory tests to determine the influence of a variety of design details. A right
Coal Dewatering & Briquetting
When the bitumen emulsion is mixed with the ultrafine coal filter cake, the bitumen droplets are evenly dispersed throughout the coal sample, due to its water based characteristics. The moisture content of the coal-bitumen mixtures can be as high as 55% for this briquetting process. Because of the hydrophobic nature of the bitumen material and its chemical affinity for coal
Ground Calcium Carbonate Ore Mineralogy Processing
Table of ContentsMineralogyProcessingMarkets Ground calcium carbonate (GCC) is used in the paper, plastics, paint, rubber, caulks, and sealants industries. The favorable properties of GCC include high whiteness and brightness, low hardness, and outstanding rheology in water systems. The quality of calcitic GCC ores, which include chalk, limestone, and marble, is dependent on calcite purity and the nature and quantity of
Application of Percolation Theory to Assessment of Permeability Enhancement by Micro-Hydrofracturing for In Situ Copper Leaching
Table of ContentsCollection of Fracture DataAnalysis of Fracture DataPercolation Modeling of Connectivity A numerical model is being developed to assess the enhancement of permeability by improved fracture connectivity by micro-hydrofracturing. A generic two-dimensional percolation model has been developed to test the impact of various field conditions on permeability. Field data from Cyprus Minerals’ Mineral Park Mine has been used to
Pilot Scale Testing Coal Air-Lift Hydrohoist
Table of ContentsPilot-Scale Model DescriptionTest ObservationsData AnalysisApplication of an ALH in Underground Coal MinesOther Mining ApplicationsConclusions Primary underground coal transportation systems, such as conveyor belts, rail haulage, and mechanical hoists, have numerous inherent safety hazards. During the period 1990 to 1992, 12% of all the reported 31,266 accidents that occurred at underground coal mines were associated with powered haulage, and
Cyanide Safety
Table of ContentsCyanide TrainingProper care and handling of Sodium CyanideInternational Cyanide CodePrincipals of the codeCyanide UsesCyanide Shipping and storageCyanide StorageSodium Cyanide (NaCN) sign out procedurePersonnel Protective EquipmentCyanide SafetyMixing roomRoutes of entryCyanide SafetyRisk assessmentFires involving CyanideREMEMBERSpills involving Cyanide in solid formEmergency Response PlanNaOHChemical InjuriesChemical Eye InjuryCyanide 24 Hour Emergency Response NumbersExposure effectsSymptoms of poisoningMedical Treatment FacilitiesMedical Treatment at SiteMedical TreatmentCyanide Treatment
Flow Behavior Change Determination in Mineral Suspensions
Mineral suspensions show Newtonian flow properties at lower solid concentration, but change into non-Newtonian regime as the solids content is increased. For Newtonian fluids viscosity is independent of shear rate, but for non-Newtonian fluids it varies with rate of shear. Therefore, measurement of viscosity at a shear rate, different from the process will be futile unless the slurry is Newtonian.
Effect of Particle Size on Gold Flotation Recovery
Natural or collectorless flotation of native or free gold is generally possible, at least to a degree, with many gold containing ores. The first factor in such flotation studies is the quantification of what the limitations are of particle size on the flotation process. Some unique studies have been conducted by this author at a number of plants. Figures 1
Assay Laboratory Standards & Quality
Table of ContentsAcceptable Assay Lab Standard MaterialProcedures for Using Assay StandardsSteps to Improve Assay Results Quality It is important to have Assay Laboratory standards over a range of grades. This alone may preclude the material being sampled from serving exclusively for the preparation of standard material. One of the standards must have as close to an absolute zero value as
Nitrous Sulfuric Acid Pressure Leaching of Platinum Group Metals Sulfide PGM
Simplistically, nitrogen species oxidize the sulfide and solubilize some of the metal values. In essence, the silver, copper and less noble metals are dissolved in the leach. The slurry is screened, thickened and filtered. Two different solids are produced. First, sulfur pellets are recovered. Then, the insoluble fine leach residue, consisting primarily of lead sulfate, is filtered away and shipped
Flotation Bubble Contact Angle Measurement Method
Among the wide variety of modern surface chemistry analytical techniques, contact angle measurements still remain attractive for wetting characterization of solid surfaces. It is demonstrated that the contact angle value depends on the technique used when nonideal, heterogeneous and rough, solid surfaces are examined. Reagents and Materials Three different solid surfaces were used in the experiments: 1) a polyethylene (PE)
Mineral Reserves, Mineral Resources and Estimation
The goal of the exploration program is to proof up resources and reserves and to estimate the value of what is being found. In short to answer the question; Can we make money from this pile of rocks or not? Some background to this question of resources and reserves. In 1969 the Vietnam War was in full swing and the
Cementation of Gold on Copper & Zinc Electrochemistry
The cementation of gold on to copper and zinc in ammoniacal solutions has been investigated using electrochemical techniques and conventional cementation experiments: Studies of cathodic reduction of Au(NH3)2+ have shown that the cathodic reaction can be expressed as: Au(NH3)2+ + e = Au + 2NH3 and the standard reduction potential, E°, has been estimated to be 0.330 V. The stability
Nonconventional Fluid Bed Drying
Table of ContentsDrying System DesignDryer Operation and ControlUndergrate Temperature ControlDesign Comparison to Conventional Fluid Bed Coal Dryers Drying System Design The fluid bed dryer has been designed for the specific requirements of drying a 6 mm x 0 (¼” x 0) feedstock of anthracite culm and occasional intermittent feeds of anthracite silt. The feed moisutre of the culm ranges between
Efficient Crushing in Comminution
Table of ContentsThe Characterization of Comminution EfficiencyParticle Breakage ConsiderationsEfficiency Comparisons for Crushers and MillsMechanical InefficienciesExamples of Comminution Circuit PerformanceCompaction Type Crushing in Roll CrushersOperating Improvements To Conventional Crushing And Grinding Circuits — The Cyprus Sierrita OperationPlant Design using high Energy Crusher TechnologiesUsing Efficiency Factors in Comminution Flow Sheets Recent research into the mechanisms of crushing processes has led to the
Carbon In Pulp Interstage Screening using Submerged High Frequency Screens CIP
Table of ContentsMechanical Development – Laboratory TestworkMechanical Development – Design & Plant InstallationMechanical Development – Prototype TestingCarbon-Slurry CirculationEngineering and DesignCapital Cost Mechanical Development – Laboratory Testwork Derrick Manufacturing Corporation originally developed the 1.22m x 2.44m Flo-line screen for rock chip removal from drilling muds. It features a 3° reverse angle deck slope and is powered by dual 1.1 kW TENV
Adsorption of Silver Cyanide on Activated Carbon
Table of ContentsThe Nature of Activated CarbonExperimental Materials and MethodsCharacterization of Activated CarbonAdsorption IsothermEffect of Ionic StrengthEffect of pH The Nature of Activated Carbon “Activated carbon” or “activated charcoal” is a generic term applied to amorphous carbon materials that have adsorptive capability. These materials are made from different sources and are available as powder, pellets, or grains. Their common characteristic
Laboratory Testing in a Tri-Flo Heavy Media Separator
Table of ContentsOperating VariablesTest Procedure Heavy media separation is one of a number of pre-concentration techniques for coarse feed which, when the ore is amenable, offers economic advantages in the mining stage and/or the processing stage. In mining, simpler and cheaper methods may be used if a greater proportion of waste material can be included in the mining blocks that
Thiourea for Extraction of Gold & Silver from Silver Ores
Table of ContentsLeaching Chemistry of Gold Silver and ManganeseLeaching ExperimentsInfluence of Sulfuric Acid ConcentrationInfluence of Thiourea ConcentrationA Two-Stage Thiourea LeachingSO2 Leaching Followed by Thiourea Leaching Leaching Chemistry of Gold Silver and Manganese Thiourea is a reducing and complexing agent and can be used for the processing of gold and silver. The redox potential of gold(I) and silver(I) thiourea complexes in