Blogs
Interaction of Grind Size Collector Dosage & Frother in Flotation
hile particle size is universally acknowledged to be important in optimizing industrial copper sulfide rougher flotation circuits, many of the various interactions that do occur at the industrial level with particle size are still being identified and/or quantified. In order to quantify the data collected, a simple two parameter model for fitting time-recovery data will be used: r = R[1-(1/(Kt))(1-exp(-Kt))]
Halide Leaching
Table of ContentsPressure Leaching and BrominationPretreatment of CCD Pulp and Subsequent Bromination LeachingOther Lixiviants The interest in using halogens for extracting precious metals from ores has increased due to changes in ore characteristics, environmental concerns and regulations. The rediscovery of halogen leaching capability has been the topic of these and other writers. Much work has been done on the performance
Metal Dissolution from Silver Copper Alloys in Ammoniacal Solutions
Table of ContentsTheoretical BackgroundExperimentalResults and Discussion The dissolution behavior of silver and copper from silver/copper alloys in ammoniacal solutions has been investigated using a rotating disc. Oxygen was used as an oxidant. The effect of composition of alloys, concentration of lixiviants, stirring speed and temperature on the overall dissolution kinetics has been studied. Theoretical Background The dissolution of copper and
Sulfuric Acid-Oxygen Leaching for In-Situ Extraction of Copper Chalcopyrite
Table of ContentsExperimental SetupStatistical Design MethodologyResults of Design AnalysisRate Constant ModelsEvaluation of Rate Constant ModelsDevelopment of the Arrhenius Activation Energy FunctionAcidity and Iron HydrolysisConclusions Hydrometallurgical treatment of chalcopyrite by sulfuric acid based systems for primary recovery of copper is limited by the refractory nature of the mineral (Bartlett, 1973; Gerlach et al, 1973; Vizsolyi et al, 1967). At ambient temperatures
Kaolin Ceramics
Kaolin is a clay comprised essentially of the mineral kaolinite which has the oxide composition of 46.3% SiO2, 39.8% Al2O3, and 13.9% combined H2O. The structural formula of kaolinite is (OH)8Si4Al4O10. These deposits are sedimentary and contain approximately 90% or more kaolinite along with minor quantities of quartz, mica, and smectite along with trace quantities of ilmenite, anatase, rutile, goethite,
How to Derate a Pump Curve for Slurry Pumping
The pump curves published by pump manufacturers are for the performance of the pump on water. Some pump manufacturers use a derating factor to correct the head and efficiency of the pump when pumping slurry. This a subject which has had a lot of controversy and disagreement It is suggested that the method used be left to the manufacturer The
Use of Calcium Sulfate Gypsum as a Fire Retardant
Although calcium sulfate dihydrate, commonly referred to as gypsum, has been utilized for some time in fiberglass reinforced polyester (FRP) applications, it does not have the fire retardant filler recognition of ATH. Gypsum is more commonly known for application in cement, soil and water treatment, plaster, and wall-board. Inherent characteristics of gypsum limit its use to low temperature and, until
Magnetic Separation of Sulphide Minerals
Laboratory investigations on the possibility for magnetic separation of sulphide minerals are reported. A survey of several sulphide ores and flotation concentrates shows that magnetic separation in most cases is not a suitable primary method of beneficiation. However encouraging results have been obtained in concentrate purification. Traditionally magnetic separation is associated with iron bearing materials/ specifically magnetite, as magnetite ore
Pressure Oxidation Treatment
Since start-up in 1985 the Cannon Mine has produced and shipped a 170 g Au/tonne (5 oz Au/ton) flotation concentrate to various smelters for gold and silver recovery. Several processes have been investigated to economically produce dore’ at the mine site from the refractory concentrate. The designed pressure oxidation circuit utilizes a series of vertical autoclave units operating at 170°C
How to use Column Flotation to Reduce Silica
The requirement for higher quality pellets demands that the silica content be lowered to levels ranging from 0.25% – 2.0% SiO2. Reverse flotation (silica is floated away from the iron concentrate) has proven to be an economical and effective method for reducing the concentrate silica content to very low levels. Laboratory and commercial test-work has demonstrated some significant metallurgical and
List Factors Affecting Grinding Ball / Media Wear Rate
In the mineral processing Industry, there are different grinding environments in which grinding media are used. These include semi-autogenous (SAG) mills, rod mills, conventional ball mills, and tower mills. The different types of grinding media available for these grinding applications include heat treated and as rolled grinding rods, forged steel balls, cast steel balls, cast high chrome iron balls, and
Collector Dosage – pH and Flotability Pyrite Galena Chalcopyrite Fe Pb Cu
The relationship between sodium diethyldithiophosphate collector concentration and pH for conditions of incipient flotability of pyrite, galena, and chalcopyrite. If one considers that hydroxide ions compete with collector ions for the adsorption sites on the surface of these minerals, that the amount of collector adsorbed is constant under conditions of incipient flotation, and that the standard free energy of adsorption
Prevent Silver Jarosite Formation
Pressure oxidation of refractory (arseno)pyrites results in residues from which nearly all the gold can be recovered. This is not the case for silver. Under prevailing autoclave conditions, which favour hydrolysis and precipitation of ferric iron, the silver becomes associated with jarositic species, limiting its subsequent cyanidation to less than 10 %. Effective enhancement of the silver extraction can be
Silver Chloride Chemistry
To appreciate the development of industrial silver chloride processing it is helpful to outline some of its general properties. Since more comprehensive reviews are available, only basic concepts will be covered here. Silver chloride is a white, curdy, crystalline solid compound. In the lab, it is prepared from a solution of AgNO3 by precipitation with NaCl solution. It is roughly
Effect of Air Flowrate on Flotation Column
On a flotation column cell, the variation of concentrate flowrate, clean coal yield and product grade with air flow rate are shown in Figure 4. These tests were carried out using a 5 wt. % feed slurry. The results show that the concentrate flow rate, yield and product ash content increased with air flow rate. This trend is expected since
Horizontal Cyclones
Horizontal cyclones can reduce the quantity of fines in the cyclone underflow as described by Hochshied (1984). A number of plants are now operating horizontal cyclones with a substantial reduction of the circulating load and the amount of fines returning to the mill. However, circuit capacity did not increase due to the reduction of fines in the cyclone underflow at
Pyrite Oxidation Kinetics
The oxidation kinetics of pyrite and refractory gold concentrates in acidified ferrous sulfate solutions in the presence of oxygen-sulfur dioxide gas mixtures has been studied. The effect of temperature, pulp density and gas composition were determined. The optimum oxidation rate was obtained at 80°C and 2 percent sulfur dioxide in the gas mixture. The oxidation of the sulfide minerals is
Visman’ General Sampling Theory
A comprehensive analysis of the entire range of related studies would require a lengthy discussion. Instead, this paper will focus only on the work of Visman (1962, 1969), because his work is part of the current ASTM D2234 standard on coal sampling (American Society for Testing and Materials, 1985). Visman’s work attempts to empirically determine a formula for sampling error.
Eudialyte Magnetic Separation Recovery
The most common zirconium bearing minerals are zircon, the zirconium silicate ZrSiO4, typically produced from heavy mineral sands in Australia and India, and baddeleyite, the zircon dioxide ZrO2, produced for example at Phalaborwa. A much less common zirconium mineral is eudialyte, a trigonal calcium-zirconium silicate occurring in silica-undersaturated nepheline syenite complexes, such as the Lovozero complex, Kola Peninsula and the
Dry Grinding Example
The claims which supply oxide and refractory ore feed to the Cortez milling facility are located in both Lander and Eureka Counties. These include the Cortez and Horse Canyon deposits all operated by C.G.M. Joint Venture. Other deposits outside the C.G.M. claim area include; Fire Creek, Buckhorn, Gold Bar and Tonkin Springs. These deposits all occur along the Battle Mountain/Eureka
Oxide Sulfide Copper Ores Leaching
Table of ContentsChemical Analysis of Oxide and Sulfide Copper MineralsThe Chemistry of Leaching Copper OresModeling the Leaching of Mixed Oxide Sulfide Copper Ores The results of column leaching tests on 3 different mixed oxide/sulfide ores from a Chilean deposit are presented. The 3 samples contained different ratios of oxide copper minerals to chalcocite and chalcopyrite. The results of the column
Rhenium Extraction by Leaching in Ammonium Iodide Iodine
Pure rhenium is a refractory metal with a very high melting point of 3180°C. Extraction of rhenium from molybdenite concentrates and other primary sources has been studied for many years. Hydrometallurgical methods using Br2, HNO3, Ca(OH)2, NaOH or Na2CO3 have been investigated. Recently, a new process using halogen salts and ammonium as well as oxygen for recovery of platinum group
How to Reduce Ball Mill Overload Risk
Two different circumstances must be addressed for the reduction or elimination of overload risk: a) in existing operations, or b) in the design of new grinding circuits. The methods necessary are in the first case an adjustment of operating conditions; and in the second an adjustment of mill shapes. Existing Operations: from Equation (1) for mill power with a system
How Freezing Affects Rock Breakage
Critical size material is defined as ore that is too small to be effective grinding media and too large to be ground. This data showed that both specific energy consumption and critical size production increased during the winter months. The increased energy consumption was in part a result of an increase in the viscosity of the mill pulp at colder