Blogs
Bench Scale Froth Flotation & Economic Estimate
Table of ContentsBench Scale Test ResultsAssumptions and Methodology for Capital EstimatesAssumptions and Methodology for Operating and Maintenance Cost Estimate ICF KE assembled a team that included members of industry, academia, and industry research organizations to conduct this multi-task program. The original design was based on a philosophy developed by the members that incorporates the DOE contract requirements and desires for
Pyrite Recovery Mechanisms in Coal Flotation
In many coal flotation operations, a significant amount of apparently liberated pyrite is seen to report to the froth, thus raising the sulfur content of the clean product and reducing its economic value. Prevention of this unwanted recovery of pyrite is therefore desirable. Theoretical Discussion It has long been known that mineral pyrite has some hydrophobic tendency, as do several
Pressure Oxidation of Silver Bearing Sulfide Concentrates
Silver bearing bulk sulfide concentrates from several Peruvian mines were autoclaved in a 19 liter (five gallon) laboratory autoclave. Cyanidation of autoclaved concentrates following a hot lime jarosite destruction step extracted over 98 percent of the silver and over 95 percent of the gold. Autoclave operating parameters such as time, temperature, pulp density and autoclaved solids recycle were investigated and
Overflow to Underflow Flowrate Ratio Effect on Dense Medium Cyclone Performance
In the dense medium cyclone separation of coal, the overflow to underflow (O/U) flowrate ratio has not been considered as a major parameter in correlation with the cyclone performance, since it is not directly adjustable. It is a common practice in the optimization of cyclone performance, however, to stipulate the range of cyclone orifice diameter ratios in respect to the
Extender Oils for Flotation of Coarse Potash
In order to float coarse sylvite particles, Potash Corporation of Saskatchewan Inc. (PCS) uses amines and extender oil. Since the content of polycyclic aromatic (PCA) compounds in Esso 904 oil is high, PCS has sought a suitable replacement. Various types of physicochemical tests, including measurements of the electrokinetic potential of emulsified oil droplets, oil/water interfacial tension and wetting of KCl
Segregation Process for Treatment of Copper-Cobalt Oxide Ore
The segregation process has been known for many years and applied industrially for the treatment of various refractory copper ores. The principles of the process are briefly reviewed; the process was tested in the laboratory on two copper-cobalt oxide ores from Gecamines, Shaba Province, Zaire. Various parameters of the process, such as segregation temperature, dosage of reducing and chloridizing agents
Flotation Frother vs Collector Interactions
In the froth flotation process, different types of surfactants are used to carry out specific and well defined functions. For example, an anionic surfactant such as xanthate is added as a collector in the flotation of sulphide minerals and adsorbs at the mineral/aqueous solution interface causing an hydrophobization effect. In addition, non-ionic surfactants are added and adsorb at the air/solution
Fluorspar Beneficiation by Packed Column Flotation
Acid-grade fluorspar is utilized in the production of hydrofluoric acid from which a variety of organic and inorganic fluoride chemicals are made, including synthetic cryolite and elemental fluorine. The manufacture of chlorofluorocarbons (CFCs) is the volume leader in the fluorine chemical industry. Price and market specifications for fluorspar depend on supply and demand, and often differ with locations as well
Microwave Digestion
Table of ContentsMicrowave Digestion EquipmentReagents and SolutionsMicrowave Dissolution ApparatusMicrowave Digestion MethodResultsMicrowave Acid Digestion of Metal & Mineral SamplesPolycarbonate Bottles We conducted research related to Microwave Digestion in hope it would lead to the improvement of analytical procedures used to characterise metal and mineral samples. In particular, this research is directed to the reduction in time, complexity, and expense of sample dissolution for chemical
How to Select a Sample Size for Ore Evaluation
The semivariogram is a geostatistical tool to show several geological features which are important in mineral deposit evaluation, such as the continuity, size and shape and it is used for many mining purposes. Stationary conditions must be satisfied if the semivariogram calculated in one part of the mineralization is to be used in another part, or if the model developed
Inductive Electrostatic Gradiometry IESG
Table of ContentsIESG Empirically Learned and TestedThe Keweenaw Fault from Ontario to MichiganBleached Basalt Flow Tops Did Not Lose Ferric Iron by ReductionGold in Some Chalcocite-Specularite OresRecommendations IESG is an inexpensive but valuable component of our interdisciplinary integrated effort to discover and to understand hydrothermal convective plumbing systems, with originally hot, reducing, upward-flowing components yielding present negative IESG anomalies, and
Bioleaching Refractory Oxide Ore to Recover Silver
Numerous manganiferous silver deposits occur throughout the southwestern United States which remain undeveloped due to their refractory nature. In some cases, silver (Ag) is entrapped within minerals such as pyrolusite (MnO2) and is not amenable to cyanide extraction. Similar deposits occur in which molybdenum (Mo) or copper (Cu) is entrapped within goethite (FeOOH) or similar minerals and is not amenable
Copper Extraction from Smelter Flue Dust
Table of ContentsLime Roast Ammoniacal Heap LeachingLeaching Copper with Ammoniacal Solutions Process Elements The process flow sheet is shown in Figure 1 and consists of the following steps: roasting a pelletized mixture of hydrated ground lime and flue dust to fix arsenic and sulfur; a venturi scrubber removes dust and any trace of escaping arsenic and sulfur. heap or vat
How to do a Mass Balance in Spreadsheet – Excel
The “mass balance” is unquestionably the most common class of problems for the process engineer. Closely related, mathematically, is the “heat balance”. Every laboratory test requires a mass balance to describe the results. Mass balance calculations can be subdivided into several sub-categories based on whether the results are time dependant or not and depending on whether the input data are
Heap Leaching Software
Several research groups have spent considerable time investigating coarse ore leaching. Coarse ore leaching includes both heap and dump leaching. The terra “heap leaching” will be used in this paper to mean any type of coarse ore leaching. The results of their work are generally in agreement: the progress of leaching can be described by the shrinking core model and
Coal Cleaning Technology
Table of ContentsThe Coal Preparation ProgramAdvanced Physical Coal CleaningAdvanced Froth FlotationSelective AgglomerationAdvanced CycloningSummary The National Energy Strategy (NES) and the Clean Air Act Amendments (CAA) of 1990 are examples of the nation’s commitment to a clean environment. The need to utilize our energy resources in an environmentally sound manner presents critical challenges and opportunities for coal preparation during the next
Pebble Crushing in SAG Mill Circuit
Full Scale Test Circuit Based upon the results of the pilot plant test work, a decision was made to conduct a full scale test in 1990 utilizing one of the ten (10) primary mill lines at the National Steel Pellet Plant. Primary Mill Line No. 10 would be converted to a fully autogenous grinding mill with pebble extraction and crushing.
On-Line Particle Size Analyzer
Table of ContentsPC-Based Image-Analysis SystemExperimental TestingResults and Discussion On-line coarse particle size analyzers can be used in crushing circuits to monitor ore size distribution of both feed and product streams. Fast and accurate information concerning these particle size distributions can improve the efficiency and lower crushing costs. There are several coarse particle on-line size analyzers commercially available, but most of
Hydrostatic Trunnion Bearing Design
Table of ContentsTrunnion deformationBrief description of “NIMAN”Hydrostatic Bearing DesignHydrostatic Bearing PerformanceDiscussionSydvaranger VS St. Lawrence Cement Hydrostatic trunnion bearings were recently provided on large Semi-Autogenous Grinding (SAG) mills driven by wraparound motors assembled on the head to shell flanges. A conventional SAG mill would have a ring gear driven through one or two pinions. The effects of the magnetic air gap
Pebble Crushing
The Bagdad mill, built in 1977, was designed for a mill capacity of 36,300 tpd. An ABC (Autogenous Mill-Ball Mill-Crusher) grinding circuit was chosen. The original mill contained three completely independent grinding circuits, each containing one 9.75 m diameter by 3.96 m long fixed speed autogenous mill, one 4.72 m diameter by 6.71 m long ball mill and one 2.13
Improve Strength of Steel Alloys
Table of ContentsNitrogen AlloyingApplication of Ultra-High PressureAdvantages of Nitrogen AlloyingApplicability of Nitrogen-Alloyed SteelsAdditional Benefits of Nitrogen-Alloyed SteelsPatent Status Improve the strength and other properties of steel alloys. Approach Research by the U.S. Bureau of Mines indicates that steels melted and solidified under high nitrogen pressure acquire yield and tensile strengths that are up to four times the strengths of comparable
Recovering Platinum-Group Metals in Catalytic Converters
Develop new technology to encourage domestic processing of automobile catalytic converters for recovering platinum-group metals. Background Automobile catalytic converters are used to convert pollutants in automobile exhaust into water vapor, carbon dioxide, and nitrogen. About 1 million troy ounces of platinum-group metals arc used each year in the United States to manufacture catalytic converter. It has been estimated that about
Foam Concrete Seals for Abandoned Mine Shafts and Adits
Investigate and demonstrate the possible use of low-density (45-lb/ft³) foam concrete for sealing abandoned mine openings. Although foam concrete has been used in the construction and geotechnical industries tor some decades, it has not previously been used in abandoned mine shaft reclamation. Approach A structurally engineered permanent mine seal for an abandoned coal mine shaft, using low-density foam concrete and
Wet Semi-Autogenous Grinding Mills
The primary mill liner task force was formed in 1977. Its function was to improve the operating costs and milling efficiencies of the ten 8.2-m x 5.5-m (27 ft x 18 ft) wet SAG mills that were operating at the time. The SAG mills are driven by two 3500 HP motors drawing a total of 5450 kW at 76% of