Blogs
Remove Sulfur Dioxide from Off Gases of Coal Burning
The purpose of this article is to present design information and operating data on a pilot gas scrubber which is believed to be a new approach for removing noxious gases and particulate matter from the off gases of coal burning power plants and smelters. In addition, gas scrubbers on stream or being developed for coal burning power plants and smelters
Open Pit Equipment Selection and Maintenance
Table of ContentsSite PreparationLoadingHaulageField Support and ServiceMaintenance Principal factors influencing equipment selection can be grouped into five basic categories. Tonnage Requirements, Ore and Waste, Topography and Property Line Considerations, Ore Control Requirements, Physical Characteristics of Ore and Waste, and Climatic Conditions. Site Preparation Specialized Machines: This type of equipment generally operates on the principle of leverage uprooting and mechanical breakage of fallen vegetation. It is
Mobile Crushing Plants
The transportation of mine products incurs a cost which can have a significant bearing on the competitive position of the product. This statement not only holds true for the transportation of the finished product but certainly as much for the in-plant haulage of the raw materials. First of all, it should be differentiated between 3 categories of movable equipment. a) The
Miller Number – Slurry Rating Index
Table of ContentsTest EquipmentMiller NumberCalculations The development of a new means of measuring the relative abrasivity of a slurry came about by necessity in 1967 during a full scale loop test of a 560 H.P. reciprocating pump handling magnetite slurry. In order to evaluate the life of expendable fluid end parts, the question of the amount of attrition in a
How to Remove Mercury from Copper Concentrate
Table of ContentsTypes of MineralisationSelective MiningChoice of Process ParametersDescription of Commercial PlantProcess DataStart-Up ProblemsSoot HandlingMetallurgical Balance The copper-silver-mercury orebody of Gortdrum Mines (Ireland) Limited is located 3 miles north of the town of Tipperary in the Republic of Ireland. The first shipments of concentrates were made to the smelter in Europe in late 1967. In the spring of the following
Low-speed Gearless Converter Drive
Table of ContentsTechnical principleMechanical coupling problemsThe 6800 HP mill drive at Rohrdorf, West-Germany The first motors of this type were built to drive ball mills in the cement industry, which are very similar to those employed for ore processing. Here, too, the tendency is to build units of ever increasing capacity. In the case of conventional drives with mechanical gearing,
Hydraulic Excavator
First, the hydraulic excavator enjoys tooth forces of the shovel because the dipper is attached to the machine with a dipperstick and boom, and can often actually realize greater tooth forces than a shovel because of the prize action of the dipper in hard digging. Digging range can be as deep as 35′ while dumping range in a 360°circle, can
Gypsum Calcining
Gypsum is the crystalline chemical compound CaSO4·2H2O. A close chemical relation – and frequently occurring with Gypsum – is Anhydrite which is CaSO4. Gypsun has wide commercial use because relatively simple heat processing reduces it to Plaster of Paris. While Anhydrite can be converted to Gypsum and thence to Plaster of Paris, the procedure is not simple and is quite
Grinding and Concentration of Conglomerate Copper Ore
Table of ContentsAutogenous Grinding TestsComminution by Crushing and Rod Mill-Ball Mill Grinding The conglomerate ore analyzed approximately 1.2% copper. The specific gravity of the ore was 2.72 and the bulk density was 108 pounds per cubic foot (determined on “as is” ore). The Bond laboratory ball mill work index was determined as 22.0 at 65 mesh. Autogenous Grinding Tests Crude
Simulation of Dry Ball Milling using Specific Power
Table of ContentsExperimental DataPredictive Simulation The energy-size reduction relationship was the dominant form of mathematical model used in the description of tumbling mill grinding processes. Typically, in these models some single measure of product fineness (e.g. the 80% passing size, the size modules, the specific surface area) is chosen as the dependent variable and the energy input per unit mass
Continuous Particle Size Analyzer for Metallurgical Slurries
Table of ContentsSampling and Slurry HandlingSensor and AnalyzerTypical ResultsThe Analysis of Heterogeneous Mixtures A continuous on-line particle size analysis system for solid/liquid suspensions is described. The basic sensor utilizes a centrifugal principle to separate particles according to size, the resultant separation being measured by means of beta-ray attenuation. Results obtained when analyzing a variety of materials at sizes from 65 mesh
Adsorption Flotation Plagioclases
Table of ContentsSulfonate CollectorDiscussion of Results Sulfonate Collector Data on sulfonate adsorption by silicate minerals are very scarce in the literatures. The experiments were divided into two groups. The first group included the study of the flotation response of plagioclases as a function of pH and sulfonate concentration. This group also included the study of the effect of Ca(II) and Al
Acid Mine Drainage Control Methods
Table of ContentsRestriction of Water EntryTreatment by NeutralizationTreatment by Reverse OsmosisTreatment by Ion Exchange In past years, water drainage control in coal mines has been primarily directed on the basis of water quantity rather than quality. Due to the recent intense interest in total ecology and environment, emphasis has shifted to the point where the water exiting from a mining
Accident Prediction Techniques
Table of ContentsThe Potential Accident Situation – The PASAccident Analysis – Problem DefinitionCritical Incident Technique The secret to accident prediction is to utilize the tendency for history to repeat itself. The same circumstances and the same human behavior that produced accidents in the past tend to produce accidents in the present and the future. The ability to predict accident occurrence
Underground Storage of Mine Wastes
In 1960 the management of International Salt Company made the decision that all waste material from the Watkins Glen plant would be stored in underground salt cavities. The cavities which they contemplated using had been depleted of salt to a point where continued operation would have impaired their structural stability. Originally, the waste to be disposed of included vacuum fan
Thiosorbic SO2 Scrubbing Process
Table of ContentsThiosorbic Process ChemistryPilot Plant Experiences Lime and limestone-based SO2 scrubbing processes have demonstrated reasonably good success in removing low concentrations of SO2 from flue gases. While most of the operating problems experienced in the early days of scrubbing have been worked out, problems usually increase and removal efficiency drops with increased amounts of SO2 present in the gas
Slurry Pipeline Economics
Table of ContentsGeneral ExplanationTheoryCase Study A technique is presented for the economic selection of a slurry pipeline with the aid of a computer. Mathematical models for the flows of homogeneous slurries are utilized. Only the pipeline and its prime movers are considered. Slurry flow properties are first obtained from rheology and/or pipeline data measurements. A rheological model is then selected
Flotation Plant Simulation
Table of ContentsProgramming Methods For Plant SimulationsThe Flotation ModelExamples of Plant Simulations Knowledge of the behaviour of flotation machines had developed and increased considerably over the last few years. Although much work remains to be done on the study of the fundamental processes that influence the collection of hydrophobic particles at an air-water interface, there is enough information to permit
Recovery of High Grade Copper from Ammonical Solutions
Table of ContentsDetailed Description of the ProcessExamples of the Process The present process refers to a method for efficiently obtaining high purity metallic copper from copper ammonium sulfite. Essentially, this process consists of submitting the copper ammonium sulfite to the action of heat and pressure with the object of obtaining by the decomposition of it, metallic copper, ammonium sulfate, sulfur
Recovery of Aluminum by High Tension Separation
The high tension process which separates materials based on relative differences in surface conductivity has been very successful in recovering non-ferrous metals from municipal waste. Aluminum is by far the largest constituent of the total non-ferrous metal fraction; accounting for >95% in most localities. Wire and insulation mixtures from industrial wastes have been treated commercially for several years by a
Pre-Concentration by Sorting – Photometric
Table of ContentsPhotometric Sorting of OrePresentationSignal ProcessingSeparation Pre-concentration by sorting is as old as the mining industry. Inevitably waste rock is broken with ore. Separation may take place in the stopes by selective mucking and transport, or selective loading and transport of ore and waste by 12-cu. yd. shovels and 100-ton trucks in large open pit operations. Hand sorting of
Miniplant Project to Evaluate Alumina Recovery Processes
Table of ContentsTest ProgramBureau of Mines Funding and TimingBureau of Mines Program PhasesProcessing Clay With Nitric AcidProcessing Clay With Hydrochloric AcidProcessing AnorthositeProcessing Clay With Sulfurous AcidProcessing AluniteProcessing DawsoniteCooperative Funding and TimingFirst Phase ActivitiesClay-Nitric Acid Miniplant ConstructionClay-Nitric Acid Miniplant OperationCalciningLeachingSolvent ExtractionEvaporation and CrystallizationSalt Decomposition Bureau of Mines forecasts of the aluminum situation show that U.S. demand for the metal in the
Leaching of Low Grade Gold Ores Economic Evaluation
The treatment methods applicable to comparatively higher grade ore averaging better than 0.2 ounce gold per ton and having a cutoff grade of about 0.07 ounce gold per ton, include gravity concentration, amalgamation, flotation, cyanidation or direct smelting. Such processes involve high capital investments as well as high operating costs. A conventional cyanidation plant used in processing lode gold ores
Lime Slaking Mill
A horizontal ball mill can be used as in a lime slaking circuit just as well as a vertimill. Some operations apply the raw quicklime directly to the ore on the belt moving toward further crushing or grinding. In this application, it is necessary only to have a suitable lime storage tank with a live bin bottom and a means