Blogs
Hindered Bed Classifier Modelling
Significant research has been conducted in the past to evaluate the application of hindered-bed settling devices for achieving efficient particle size classification. However, recent studies have been devoted to the interest of using the hindered-bed devices as gravity-based separators for multi-species suspensions having wide density differences between the various particulate components. The ability to achieve density separations is based on
Rare Earth Magnetic Separators
Several preliminary tests were conducted as a function of drum type (standard, interpole, etc.) and feed temperature. The results from these tests indicate that the deep field of the salient-pole drum vastly outperformed the other magnetic drum circuits. As a result, continued test work focused on the salient-pole drum and rare-earth roll separators. Initial tests were conducted to determine the
Copper Solvent Extraction Pulsed Column
Pulsed columns, like other pulsed columns, consist of an active column section with decanters on either end. Test columns are usually in the 40 mm to 150 mm diameter range and the decanters are typically twice the diameter of the column. Commercial columns can be up to 3 m in diameter with 6 meter diameter decanters. The height of the
Chalcopyrite Chlorination Process for Copper Extraction
Interests in the hydrometallurgical processing of primary sulfide concentrates have revived because leaching in chloride media is rapid and is capable of recovering sulfur in elemental form, and also because rapid advances are being made in corrosion-resistant materials. A process is proposed which consists of low-temperature chlorination and selective oxidation of chalcopyrite concentrates to produce copper chlorides, elemental sulfur and
Evaluate Underground Pillar Stress
Strain relief measurement techniques were used to quantify stress in the underground pillar and to compare stress relief to seismic and ultrasonic core velocities. These measurements represent a single point. The procedure for measuring strain relief (Girard and others, 1997) consists of — Drilling a hole 152 mm (6 in) in diameter to a pre-selected depth beyond the blasting overbreak
Ore Concentration Practice of the Consolidated Mining Smelting
Table of ContentsSullivan ConcentratorTreatmentPowerRecoverySt. Eugene Concentrator, Moyie, B. C.Tadanac (Customs) Concentrator, Trail, B. C.Flotation ReagentsHeatZinc SulfateComments on Special Subjects Three mills are now operated by the Consolidated Mining & Smelting Co. of Canada, Ltd.: (1) The Sullivan Concentrator, Chapman Camp, B. C. (near Kimberley, B. C.), (2) the St. Eugene Concentrator, Moyie, B. C., and (3) the Tadanac (Customs) Concentrator,
Factors Affecting Air Classifier Efficiency
It is also fairly well-known, that it is by far much more difficult to achieve high efficiency with dry classifying than with wet. Hence, it is highly desirable to create conditions for improving the dry air classifying methods, so that the high energy consumption associated with producing fine dry powders can be minimized. Particle Size Distribution: The classifier feed particle
On Stream Analyser Calibration OSA
The principle of the sample flows of the analyzer system is shown in Figure 4. As the analyzers are located in a separate room, many of the primary lines require pumping. The samples are returned mostly by gravity to the corresponding process pump sumps. The primary sample lines have a diverter that feeds the stream to the flow cell for
Leaching Pyrite Gold Ore without Cyanide
Table of ContentsThiourea Leaching of GoldNON Cyanide Gold Leaching TestsThiocyanate LeachingThiourea LeachingComparison of Cyanide Thiocyanate and Thiourea Systems Alternative reagents for gold leaching include thiocyanate (SCN-) and thiourea (SC(NH2)2). They are considered less toxic and more environmentally acceptable when compared to cyanide. One of the important features of thiocyanate and thiourea dissolution of gold is that the leaching can be
Hindered Settling Column
Table of ContentsEffects of Column HeightEffects of Operating Parameters After filling the column with water, the teeter water flow rate was set to produce the desired cut size. The feed water was adjusted to produce a feed slurry consisting of about 50 percent solids by weight The screw-feeder was then set to the desired rate. Solids were fed into the
AG & SAG Mills Curved Pulp Lifters
Curved pulp lifters have been incorporated in SAG and AG mills in Australia. The aims have been to ensure complete discharge, at high throughput, of both slurry and coarse solids, especially at high mill rotational speeds. Curved pulp lifters can overcome incomplete discharge and back-flow of solids down the pulp lifter that can occur in straight-radial pulp lifters (and is
Shaker Table Washability Curves
Although direct comparison of table performance with jig performance gives only a general idea as to the efficiency of tables, a better understanding of the subject can be obtained from a consideration of table efficiencies in relation to the washing difficulties reflected in the washability curves of various coals. Numerous methods of interpreting washability curves have been suggested by coal-washing
Gravity Concentrators & Jigs Compared
A Gravity Concentrator has the bed fluidized 100% of the time. A Jig is fluidized only 50% of the time. A Gravity Concentrator works at 150 g forces. A Jig works at 1 g. Material is caused to move in a lateral movement through the Gravity Concentrator. A Jig has a lateral movement and a vertical movement. The Gravity Concentrator
Double Cycloning
In conventional closed circuit grinding practice including classification in one hydrocyclone, or in a group of hydrocyclones in parallel, classification takes place in a single stage. Under conditions where the fineness of the overflow product is expressed e.g. as 95 % – x microns, the normal sharpness of size separation (recovery) at size x into the fine product is of
Carbonaceous Gold Ore Mineralogy
Mineralogy and Occurrence of Gold: The term “carbonaceous” has been loosely applied to ore constituents of widely varying characteristics. Laboratory investigations by A. S. Radtke and B, J. Scheiner (1970) of the U. S. Geological Survey and the U. S. Bureau of Mines on carbonaceous ores from Carlin showed that they contained: (1) an activated carbon component capable of adsorbing gold
Titanium Castings by Sand Molding Process
Objective To produce industrial-grade titanium castings by processes that are nonpolluting and lower cost than the currently used rammed-graphite process. Approach Foundry-grade zircon and olivine sands, bonded by waterglass or bentonite, are used to make shell or rammed molds which require relatively low-drying temperatures and do not generate noxious fumes during drying or casting. Procedures Three separate processes have been
Thiourea
Thiourea (H2NCSNH2) is an organic compound, the crystals of which dissolve in water to yield an aqueous form stable in acidic solutions. The unique feature of thiourea is that, in aqueous solution it reacts with certain transition metal ions to form stable cationic complexes. For example, the following generalized reaction illustrates the complexing role of thiourea. where Me is the
Sulfurous Acid Leaching of Kaolin for Preparing Alumina
Table of ContentsProcess ChemistryMaterials, Equipment, and ProcedureLeachingSolid-Liquid SeparationPrecipitationDecompositionClosed Circuit OperationPurification of Crude ProductMiscellaneous Observations and DataConclusions The Bureau of Mines is conducting a program to evaluate technology for the recovery of alumina from domestic resources. Bauxite, the major alumina ore, is mainly imported. In recent years, bauxite-producing countries have formed an organization that attempts to control the supply and price
Dry Washer
Dry washers have been used for many years in the Southwestern United States, where water is scarce, and especially in New Mexico where several million dollars in gold has been produced during the last century by dry washing. The Cerrillos, Golden, and Hillsboro districts are among those having produced gold by dry washing. In years when other employment is scarce
How to Stake a Mining Claim on Open Land
Table of ContentsProblems with Water Rights, Water Supply, and Stream PollutionWho Can Advise You Instructions on staking claims and filing for patents can be obtained from the U.S. Bureau of Land Management. In addition to Federal regulations, individual States also have certain requirements pertaining to the location of claims on public lands. Information on these requirements is available from the
Gold Dredging Costs
Table of ContentsSpecific Cost DataGeneralized Relations between Direct Costs and Production In the section that immediately follows, specific cost data for dredge operations considered representative in the industry have been updated and listed. Following this is a section on general cost data that correlates operating costs to annual production according to bucket size. These costs cover dredge operations in the
Gold Dredge Sizing & Capacity
Determining Suitable Dredge Size: After the placer deposit is properly prospected the miner has a reasonable knowledge of the volume and grade of the placer together with information on its geometry, formation, and the distribution of values by size and location as well as information on bedrock topography, surface topography, water supply, and a host of other information that is pertinent
How to Determine the Value of a Placer Gold Deposit
Table of ContentsValue, Character, and Distribution of GoldPhysical Characteristics of FormationCharacter and Contour of BedrockAvailability of Water and Problems Inherent in Stream OperationsTopographyPowerLaborLand AcquisitionAdverse ClimateLocal and National Regulations The functioning and capacity of a dredging system must be keyed to the environmental and natural conditions of climate, water availability, location, and the physical and geologic characteristics of the deposit. The
Ferrous Scrap Steel
Table of ContentsMaterialsEquipmentProcedureResults and DiscussionConclusions For the past decade, the Bureau of Mines has addressed the problem of using low-grade scrap, such as the ferrous fraction of municipal refuse, to produce steels of acceptable quality. The investigations are a part of the Bureau’s 65- year commitment to minimize the requirements for mineral commodities by devising new technologies for the recovery