Blogs
Solving Flocculation Problems
This is the case history of how two nearby plants in Southwest Virginia solved their water clarification problems. While the solutions should not be considered applicable industry-wide, the methods used in arriving at the answers deserve, consideration. As the plant tonnage increased, it became evident that the amount of coal fines produced in the mining and preparation was greater than
Small Mine Operation Shattuck Denn’s Bardon Mine
Small tonnage ore bodies can be developed at a profit on a short life basis. Such is the case of the Bardon Mine in the Big Indian Mining District in San Juan County Utah. Faced with a small initial tonnage of high grade uranium ore, the Shattuck Denn Mining Corporation Engineers developed some new ideas for sinking the shaft and
Retention Time in Continuous Vibratory Ball Milling
Basic Principles: In a batch mill the length of time during which the material is ground is a direct measure of the energy expended on the material, except possibly for exceedingly fine grinding. The following analysis pertains to a continuous mill operating under these conditions. dE = -C dx/x n…………………………………………..(1) where dE is an infinitesimal energy expenditure, C a constant,
Pulp Density Measurement and Control
Measuring the specific gravity of a pulp in concentrating plants is a relatively simple procedure, but the desired accuracy is often difficult to attain. Many plants use the system of weighing a known volume of the pulp on a scale. In many cases, this method is quite accurate, but obtaining a true sample presents quite & problem. The first density
Processing Bastnasite Ore
Average composition of ore from the San Bernardino deposit is less than 0.1 pct ThO2, 25 to 35 pct calcite, 10 pct rare earth oxides, 15 to 20 pct silica, and 30 to 40 pct barite. Rare earth content of the ore analyzes 50.7 pct CeO, 4.2 pct Pr6O11 11.7 pct Nd2O3, 1.3 pct Sm2O3, and 34.3 pct La2O3 and
Magnetic Roasting of Marginal Iron Ores
Table of ContentsExperimental Roasting ConditionsExperimental ProcedureMarginal Ore ConsiderationsReduction Studies An experimental procedure was developed for studying magnetic roasting on a accurately-controlled laboratory scale. The loss-in-weight method was used and the course of reduction could be followed under a reducing gas atmosphere containing as many as five different components. Some important variables of the operation were checked on a marginal Mesabi
Magnetic Recovery of Germanium Sulphide
Table of ContentsHow does germanium occurMagnetic properties of renieriteFlotation of renieriteWet magnetic separator on laboratory scaleDesign and operation of industrial installation The Kipushi deposit, where the Prince Leopold Mine has been installed belongs to Union Miniere du Haut-Katanga and is located in the Belgian Congo, 20 miles SW of Elisabethville, at the vicinity of the Northern Rodhesian Border. How does
Effect of Pulp Depth and Pulp Density in Thickening
The two principal attributes of a thickener pulp are its settling rate and the ultimate pulp density of the thickened mud. Testing for evaluation of thickening attributes of a pulp has usually been done batch-wise by placing the pulp in a one-liter glass graduated cylinder and noting the position of the boundary between clear liquor and mud as a function
Deep Well Turbine Pumps
Deep Well turbine pumps receive constantly increasing application to the problem of mining water and other fluids from great depths. Many installations of medium settings are presently operating successfully and it is felt that much greater depths are immediately within reach. Settings and lifts in excess of 2000 feet are not at all out of reason with present knowledge, experience,
Copper Segregation Process
Table of ContentsThe ProcessReactions InvolvedSide ReactionsThe Scope and Results of the InvestigationFactors Influencing Segregation and Flotation of CopperTime and TemperatureMoistureCoke Particle SizeType of Reducing AgentSize of the Furnace FeedFlotation Feed SizeCurrent ResearchEstimated Operating Costs The recovery of copper from low-grade oxidized and mixed oxide-sulfide copper ores by acid leaching is standard practice in the Southwest. Some ores, however, are unamenable
Heavy Rare Earths Separation by Ion Exchange
The equipment for the separation of the rare earths consists of nearly 200 columns thirty inches in diameter by twenty feet high. They are constructed of materials which will not contaminate the rare earth products. Most of the cation exchange resin in the plant is a styrene-divinylbenzene sulfonic acid resin such as Amberlite IR-120 and Dowex 50. Included in the
Percussion Drilling
Table of ContentsBasic ConceptsExperiments With Drop TesterDiscussion of Test Results The past 15 years have seen rapid advances in the metallurgy of materials for drill machinery and bits, but rock drilling itself continues to be largely an art. Jet piercing, roller bit rotary drilling, and rotary percussion are all promising new techniques, but the percussion rock drill, still used for
Tube-Furnace Method for Rapid Determination of Sulfur in Coal
Table of ContentsMaterials and Experimental WorkAnalytical ProcedureResults and Conclusions Subsequent to the work of A. Vita in 1920, a number of investigators have published data dealing with the rapid determination of sulfur in coal using a high-temperature combustion furnace. These, together with several unpublished methods, involve wide differences in technique although they are all similar in principle. . Materials and
Economics of Long Transport Conveyor Belt
In 1955, the Ideal Cement Company decided to increase the production at its Ada, Oklahoma operations. After many studies it was decided to build a complete new plant along side the old, near the site of the original 1907 plant. The new plant was to have a production of three million barrels annually while the plant then in operation had
Mineral Aggregate Specifications
Table of ContentsAbrasion TestSoundnessShape of ParticleGradationDeleterious Substances The largest use of aggregates is for highway construction. Furthermore, the majority of sales for other than highway uses is dependent upon compliance with state highway specifications because it is widely accepted that, if an aggregate is satisfactory for state highway uses, it will be safe for almost any other construction purpose. It,
Selective Maintenance of Hydraulic Components on Mining Equipment
Commonly accepted maintenance methods are being outdated by the rapid acceptance and use of more complicated hydraulic circuitry on modern mining equipment. It is no longer adequate to use the maintenance program to merely repair or sustain equipment operation. Ever increasing operating costs place a huge premium on lost production time. It has therefore placed the maintenance programs in the
Type of Continuous Miner
While coal production over the past 25 or 30 years has been on a horizontal plane, coal’s share of the total energy market has declined. To participate more effectively in this total energy market, it is necessary to produce coal more efficiently. It is the obligation of all management, employees, and mining departments to gear the deep mining industry to
Determining the Tensile Strength of a Rock
The tensile strength of rock is its weakest property, and this property apparently enters into all failure phenomena, whether underground or on the slope of an open pit. Therefore, it is essential that detailed quantitative information is known about the tensile strength of rock if the design engineer is going to select the proper pit slope, pit orientation, or orientation
Sodium Vanadate under the Salt-Roast Process
Table of ContentsDescription of ProcessTechnical Discussion A study has been made of the reaction mechanisms occurring during the salt-roast process to form water-soluble sodium vanadate compounds from the vanadium oxide compounds present in vanadium-bearing ores and concentrates. Two reactions have been identified, either of which lead to water-soluble compounds oxidation of sodium chloride by water vapor and oxidation of sodium
Grinding Ball Wear & Radioactive Tracer Technique
Table of ContentsProcessing of Grinding BallsIrradiation of Grinding BallsDry and Wet Cement Grinding Procedures This paper summarizes the results of an investigation sponsored by The Coates Steel Products Company. The objective was to determine the relative effects of certain chemical and physical properties on the wear resistance of grinding balls when grinding cement. In making this study, a number of
Solid Liquid Separation by Flocculation
When is use of a flocculant justified in terms of overall process economy? when it results in process improvement, such as producing a clear liquor for electrolysis, precipitation, ion exchange, or solvent extraction; when it results in satisfying requirements of pollution abatement ordinances; when it results In increased recovery of values that would otherwise be lost; or when it results
Energy Aspects of Single Particle Crushing
Table of ContentsLoad-Deformation Theory for SpheresTesting ProcedureEnergy-Input Product Size EquationsComparisons With Published Data A unique compression testing machine was constructed to load individual 1/8 to 1-in. spheres of glass, etc., at rates from 100 to 100,000 lb per min. During loading the applied load was continuously plotted vs the deformation of the sphere-platen system. The load-deformation curve conforms to the
Mill Design Economics
Talking about engineering economics in mill design reminds me of an old saying “There are several ways to handle women but nobody knows what they are.” I’m sure that the same economic factors do not apply to each of our mill designs, but for the sake of emphasis, it is well to review a few of them. They are so
Cement Plant Grinding Mills Power Consumption
To calculate theoretical horsepower required by a grinding mill to reduce feed material to a certain size from Bond grindability test data, it is necessary to apply the “Bond Third Theory of Comminution.” The first step in this procedure is to calculate from the following formula the work index, which is the kw-hr required to grind one short ton of