Blogs
Design Criteria of a New Precision Weighing High Capacity Conveyor Scale
In 1971, during the planning and design stages of a $300 million expansion, the Iron Ore Company (I.O.C.) of Canada Ltd. through its Engineers, Canadian Bechtel Ltd., came out with a preliminary request for two 10,000 LTPH belt conveyor scale systems. These Systems were to provide weighing accuracies within ±.5% of the iron ore pellets and concentrates in transit on
Heavy Metal Removal for Water Reuse and Effluent Treatment
Table of ContentsTreatment TechnologyCase Histories The mining and processing of basic metals relies on water as a medium for transport. Metallurgical ores are ground, concentrated, leached and refined in an aqueous medium. Water is used for temperature control during processing and in air pollution abatement during smelting. Treatment Technology The water and wastewater treatment technology required to meet treatment requirements
Pinto Valley Concentrator Grinding with Large Diameter Ball Mills
The Cities Service Company’s Pinto Valley mine and concentrator lie about 6 miles west of the town of Miami, Arizona at an elevation of approximately 4,000 feet above sea level. The concentrator started its first ball mill in July 74 and all six were available by November. Every effort was made to reduce capital costs, consequently, each unit process was
Geochemical Gold Prospecting
Table of ContentsGeologic SettingControls on Gold MineralizationTypes of Gold DepositsGeochemical SurveyAnalysis and Interpretation Gold was first discovered in Alabama in 1830. Before a decade had passed more than 20,000 people were employed in the various gold districts scattered across east-central Alabama. By 1849 most of the presently defined gold districts were known with such towns as Arbacoochee, Chulafinnee, Goldville, Pinetucky,
Dynamic Effects in Bubble Particle Collision
Rendering a solid hydrophobic and solid-fluid particle attachment in flotation are recognized is not necessarily related. The attachment is governed by forces of attraction and repulsion which need to be considered. The induction time required for attachment after solid and fluid particle are brought into proximity illustrates the point. Thinning and Rupture of the Disjoining Film The major recognized interacting
Design of Impoundment and Evaporation Ponds and Embankments – Cyanide
Table of ContentsImpoundment, Evaporation Pond and Dam InvestigationsReservoir SealingEmbankment SectionsSpecial Implications of Cyanide Effluents Most existing impoundment ponds and dams leak effluent into the soil or rock upon which they are constructed. However, proposed environmental legislation will require very stringent control on the release of toxic effluents such as cyanide. More exacting investigation, design, and construction techniques than have been
Pellet Degradation & Effect on Blast Furnace Performance
Table of ContentsLaboratory InvestigationsBlast-furnace test A full survey of the laboratory and blast-furnace tests on 2 types of acid pellets is given. From the laboratory tests out in an atmosphere containing hydrogen, it appears that type B, produced out of 100% magnetitic ores, has a far better low temperature disintegration index and a lower reductibility index than type A, produced from
Copper Recovery from Reverberatory Slag
White Pine reverberatory furnace slags contained economically recoverable amounts of copper for a variety of reasons. Among them: White Pine concentrates yield extremely high matte grades (65+% Cu) and viscous slags. The viscous slags hinder matte settling causing matte “prill” entrapment in the slag. White Pine’s total refined copper output is accomplished through fire refining requiring special techniques for impurity
Copper Precipitation Process
The system provides the following functions: (1) assays for copper and iron from ten process streams on a continuous rotating basis, (2) directs hardware to automatically flush and start up cone units based on measured performance variables, (3) provides continuous plant operating data and calculates metallurgical averages as well as production figures for shift and daily summaries, and (4) provides
How to Control a Grinding and Classification Circuit
The system chosen has a “fill in the blanks” process control compiler that permits the control loops to be constructed at the system teletype in the conversational mode. The control loops are constructed by linking together various computational and control blocks (which are control algorithms) to achieve the desired control. There are twenty odd blocks or algorithms available for use;
Coal Drying Methods
In the past, it has more or less been a general rule that any time the total product is being washed, both mechanical and thermal drying was required. The reason for this was that a product moisture of 3 to 4% was required and thermal drying was and is the only practical method by which this can be accomplished. Some
Chemical Oxidation of Cyanide by Ozone with Irradiation from Ultraviolet Light
Before the work was started, a review was made of possible oxidative and disposal processes, including: evaporation, ponding, lime-sulfur treatment, acidification-aeration, ion exchange, biological oxidation, permanganate oxidation, dichromate oxidation, hydrogen peroxide oxidation, electrolytic oxidation; but it was obvious that only ozone and alkaline chlorination had any significant potential for this application. After selecting ozone as the best oxidizing agent for
Centrifuge System
The unit consists of two rotary carriers between which there is a mounted series of independently rotatable slurry receiving baskets which are circumferentially spaced and, therefore, during rotation of the carrier, orbit about the axis of rotation of the carrier. The speed of the rotating carrier plates determines the centrifugal force available, while the speed of the orbiting baskets on
Nickel Cementation onto Iron
Table of ContentsThe Cementation StepGeneral Model for Precipitation ReactionsExperimental Equipment and Method Nickel ores may be classified into two major categories : sulphide ores, and oxidized lateritic ores, these latter containing nearly 80% of the known reserves of the metal. Unfortunately, no economically viable process for the concentration of nickel from low-grade deposits has yet been developed, and so only the
Blue Flame Burner
Table of ContentsHow Does Our Burner Work?Gas Firing the Blue Flame BurnerWhy Does the Blue Flame Reduce Air Pollution?Selection Of Burners You have all seen a gas stove. Gas burns with tiny, bright-blue cones of flame; they are very hot, very clean, very quick to burn. You have also seen a hardwood fire; when the yellow flame disappears, the charcoal
Bismuth Dissolution at Smelter
The processing of residues derived from various operations in the mining and metallurgical industry for by-product recovery is becoming more prevalent. A principal target for by-product recovery is flue dust produced by conventional smelting operations. Flue dust from zinc smelters has been processed for many years for the recovery of cadmium. The cadmium recovery technique which consists of a selective
Anodic Dissolution of Zinc Sulfide Suspensions in Aqueous Solution
A new suspension electrolysis method has been developed, which enables without any gas or dust pollutants a direct anodic extraction of zinc from zinc sulfide concentrates, while simultaneously oxidizing sulfide sulfur to elemental sulfur. The investigations were performed in a laboratory scale electrolytic cell with suspended zinc sulfide concentrate particles with or without graphite powder additions in dilute sulfuric acid
How Maintenance Practice Affects Wire Rope Life in Surface Coal Mining Draglines
As part of a larger study to identify factors influencing the practical operating life of wire rope used on large draglines in surface coal mining, field trips to operating surface coal mines were made during late 1975. Wire rope performance information was obtained from personnel at thirteen mine sites west of the Appalachians. Data Acquisition During the field visits, mine
Control Wet Grinding Circuits
Table of ContentsLinear Mill Models and Stochastic Control TheoryDevelopment of a Model for a Gold-Ore Milling CircuitApplication of Theory to the Design of a Control Strategy for a Gold-Ore Milling Circuit Ideally, mill circuits should be controlled so that excessive random disturbances are reduced in frequency and amplitude. It is difficult to derive an objective measure of the effectiveness of
Vacuum Filtration
Table of ContentsFundamentals of Vacuum FiltrationTypes of Vacuum FiltersControl of Drum Type Vacuum FiltersAccessoriesSelection of Filtration Equipment In reviewing available vacuum filtration equipment in this paper, several types of filters have been included which are probably not familiar to operators in the mining industry. However, it was felt that these units might be of interest in the event that an
Uranium In Situ Leaching its Advantages – Computer Simulation
Table of ContentsEnvironmental OverviewState-Of-The-ArtLeaching SolutionsProblems with In Situ LeachingComputer Simulation In Situ leaching for the recovery of uranium from low grade sandstone deposits is one of the newest technological advances in the mineral industry. It is rapidly developing into a commercially feasible mining system which has economic, environmental, and social advantages over conventional mining systems. Because of the current uranium
Solvent Extraction Economics
Table of ContentsReagentsEquipmentSystems The equipment which is used in solvent extraction plants for contacting the organic and aqueous phases and separating the same is varied. Most common to the industry is the mixer-settler unit which, in itself, can be of varied design; but many new innovations in contacting and separating equipment have been recently introduced or are now being studied.
Recycling Plastics from City Waste
Table of ContentsIncinerationPyrolysisLandfill and CompostSalvage and ReuseExperimental Investigation and ResultsCharacterizationCleaningSeparationDisposition of Separated FractionsRefabricationThermochemical Recovery of Values Nearly 4 billion pounds of plastics were consumed by the packaging industry in 1970, about one-fifth of the total plastics production. Urban refuse from the city of Madison, Wis., was found to contain 2.9 weight-percent plastic before drying and 3.3 weight-percent after drying. Plastic
Sulphidized Cassiterite & Iron Oxides Separation
Table of ContentsApparatus and Experimental ProcedureProcedure for Thermal Decomposition of Pyrite and Sulphidization of Cassiterite by PyriteSummary of ResultsSulphidized Products vs. TemperatureFlotation Tests of Sulphidized Products Low recoveries of cassiterite are obtained by gravity concentration of lode deposits, particularly if the cassiterite calls for fine grinding of the ore. And it is precisely this finely ground ore that is the