The effect of pH modifier on the flotation of celestite with sodium oleate and sodium metasilicate
Abstract This paper studies the influence of two pH modifiers, namely sodium hydroxide (NaOH) and sodium carbonate (Na 2 CO 3 ), on the flotation of celestite ore using sodium oleate as the collector and sodium silicate (Na 2 SiO 3 ) as the depressant. The use of Na 2 CO 3 provides the best results for the concentration of celestite, under the same experimental conditions.
Surface Chemistry of Froth Flotation
I. Introduction.- 1.1. Scope of Froth Flotation.- 1.2. An Outline of a Mineral Flotation System, Definitions.- 1.3. Typical Flotation Procedures and Flowsheets.- 1.4. Mineral Liberation Size.- 1.5. Some Problems Encountered in Separations of Minerals.- 1.6. Examples of Industrial Separations of Sulfide Minerals.- 1.6.1. Lead-Zinc Ores.- 1.6.2. Copper Ores.- 1.7. Examples of Industrial Separations of Oxidized Ores of Copper, Lead, Zinc, Iron, and "Nonmetallic" Minerals.- 1.7.1. Separations of the Superficially Oxidized and Oxide-Type Minerals.- 1.7.2. Separations of the "Nonmetallic" Industrial Minerals..- 1.8. Separation of "Soluble Salts" from Saturated Brines.- 1.9. Flotation of Silicate Minerals.- 1.10. Separation of Naturally Hydrophobic Minerals.- 1.11. Recent Developments in Industrial Flotation Operations and Research Techniques.- 1.12. Flotation Literature.- 1.13. Selected Readings.- 1.13.1. Flotation Theory.- 1.13.2. Flotation Practice.- 1.13.3. International Conferences.- 1.13.4. List of Periodicals Regularly Publishing Papers on Flotation Theory and Practice.- 1.13.5. List of Periodicals Publishing Occasional Papers on Flotation Chemistry.- 2. Chemical and Molecular Bonding. Interfacial Energetics.- 2.1. Ionic Bonding.- 2.2. Covalent Bonding.- 2.3. Partial Ionic-Covalent Bonds.- 2.4. Dipole Moments and Dipole-Dipole Interactions.- 2.5. Hydrogen Bonding.- 2.6. London Dispersion Forces, van der Waals Interactions.- 2.6.1. Dispersion Forces Between Macroscopic-in-Size Aggregates of Atoms.- 2.6.2. Practical Significance of van der Waals Interaction.- 2.7. Metallic Bonding. Band Theory of Solids.- 2.8. The Importance of Steric (Size) Parameters in Interfacial Bonding.- 2.9. Interfacial Thermodynamics, Definitions and Concepts.- 2.9.1. Thermodynamic Relationships in Chemical and Electrochemical Systems.- 2.9.2. Thermodynamics of Adsorption at an Air/Liquid Interface.- 2.9.3. Thermodynamics of Adsorption at a Solid/Liquid Interface.- 2.9.4. Thermodynamics of Thin Liquid Layers.- 2.10. Interfacial Wetting and Contact Angle Relationships.- 2.10.1. Interpretations of Contact Angle.- 2.10.2. Dynamic Aspects of Wetting and De-wetting.- 2.10.3. Critical Surface Tension of Low-Energy Solids.- 2.11. Liquid/Gas and Liquid/Liquid Interfaces.- 2.12. Selected Readings.- 2.12.1. Chemical and Molecular Bonding.- 2.12.2. Thermodynamics.- 2.12.3. Interfacial Relationships.- 3. Structure of Solids.- 3.1. Atomic Packing.- 3.2. Crystal Structures of Simple Compounds.- 3.3. Structural Changes and Chemical Relationships.- 3.4. Structures Containing Finite Complex Ions.- 3.5. Silicates.- 3.6. Selected Readings.- 4. Water and Aqueous Solutions.- 4.1. Structural Models.- 4.2. Hydration of Ions.- 4.3. Debye-Huckel Model of Ions in Solution.- 4.4. Ion-Pair Formation.- 4.5. Dissociation of Water and Acids.- 4.6. Solubility of Gases in Water.- 4.7. Solubility of Hydrocarbons in Water.- 4.8. Dissolved Mineral Constituents.- 4.9. Antipollution Treatment of Mill and Mine Effluents.- 4.10. Selected Readings.- 5. Flotation Surfactants.- 5.1. Classification of Surfactants.- 5.1.1. Hydrocarbon Groups (R) Nomenclature.- 5.1.2. Less Common Flotation Surfactants, Mono- and Multipolar.- 5.1.3. Commercial Flotation Reagents.- Class I: Thio Compounds.- 5.2. Xanthates.- 5.2.1. Preparations of Alkali Xanthates.- 5.2.2. Aqueous Solutions of Xanthates.- 5.2.3. Insoluble Metal Xanthates.- 5.3. Dithiocarbamates.- 5.4. Mercaptans (Thiols).- 5.5. Dithiophosphates.- Class II: Non-Thio lonizable Surfactants.- 5.6. Dissociation and Hydrolysis.- 5.7. Surface Tension Versus Concentration Relationship.- 5.7.1. Aqueous Solutions of Non-Thio lonizable Surfactants..- 5.7.2. Surface Tension-Concentration Relationships for Surfactants Which Do Not Form Micelles.- 5.7.3. Ideal and Nonideal Mixtures of Soluble Surfactants, Synergistic Effects.- 5.7.4. Dynamic Surface Tension.- 5.8. Krafft Point and Cloud Point.- 5.9. Micelle Structures.- 5.10. Carboxylates.- 5.10.1. Carboxylic Acids.- 5.10.2. Metal Carboxylates (Soaps).- 5.11. Alkyl Sulfates and Sulfonates.- 5.12. Alkyl Amines and Substituted Amines.- Class III: Nonionic Surfactants.- 5.13. Alcohols.- 5.14. Ethers.- 5.14.1. Polyoxyethylene Nonionic Derivatives.- 5.14.2. Polyoxypropylenes and Block-Polymer Nonionic Surfactants.- 5.15. Organic Regulating Agents.- 5.15.1. Cellulose, Starch, and Their Hydrolysis Products.- 5.15.2. Derivatives of Starch and Cellulose.- 5.15.3. Wood Extracts: Quebracho and Wattle Bark, Lignin and Tannin Derivatives.- 5.16. Commercial Flocculating Agents.- 5.17. Selected Readings.- 6. Physical Chemistry of Surfaces and Interfaces.- 6.1. Types of Interfaces. Colloids.- 6.2. Characteristics of a Solid Surface.- 6.3. Adsorption and Its Characteristics.- 6.4. Thermodynamic Models of Isotherms for Physical Adsorption.- 6.4.1. The Henry's Law Isotherm.- 6.4.2. The Langmuir Adsorption Isotherm.- 6.4.3. Adsorption Isotherms for Mobile Adsorbates.- 6.4.4. Polanyi's Potential Theory Isotherms.- 6.4.5. BET Theory [Brunauer, Emmett, Teller (1938)] of Multilayer Adsorption.- 6.4.6. Frenkel-Halsey-Hill Slab Theory of Adsorption.- 6.5. Mechanical Effects of Adsorption at Solid/Gas Interfaces.- 6.6. Models of Isotherms for Chemisorption.- 6.7. Characterization of Adsorption from Solutions (in Particular at Solid/Liquid Interfaces).- 6.8. Oxidation of Surfaces of Metals and Metallic Sulfides.- 6.9. Hydration of Surfaces. Thin Films.- 6.10. Insoluble Monolayers of Surfactants at the Air/Water Interface. Interactions Among Surfactants.- 6.10.1. Monolayer Penetration, Molecular Association of Surfactants at the Air/Liquid Interface.- 6.10.2. Solidification of Ionized Monolayers on Reaction with Counterions.- 6.10.3. Interactions Between Surfactants at the Solid/Liquid Interface.- 6.11. Selected Readings.- 7. Electrical Characteristics of Interfaces. Electrical Double Layer and Zeta Potential.- 7.1. Definitions and Electrochemical Concepts.- 7.2. Models of the Electrical Double Layer.- 7.3. Experimental Testing of the Double-Layer Theory (Using an Ideally Polarizable Electrode).- 7.4. Adsorption of Neutral (Nonionic) Surfactants at the Mercury/Electrolyte Interface.- 7.5. Charge Transfer Across the Electrical Double Layer.- 7.6. Semiconductor/Solution Interfaces.- 7.7. Electrical Double-Layer Studies Relevant to Flotation.- 7.8. Electrokinetic Effects.- 7.9. Examples of Zeta Potential Changes.- 7.10. Utility of Electrical Double-Layer and Electrokinetic Data.- 7.11. Selected Readings.- 8. Adsorption of Flotation Collectors.- 8.1. Requirements for Collector Adsorption.- 8.2. Mechanisms of Xanthate Adsorption.- 8.2.1. The Nature of the Adsorbate Species.- 8.2.2. The Critical Role of Oxygen in Sulfide Flotation Systems.- 8.2.3. Flotation Problems Caused by Excessive Surface Oxidation.- 8.3. Mechanisms of Adsorption of Non-Thio Collectors.- 8.3.1. Chemisorption of Carboxylates Accompanied by Physical Coadsorption.- 8.3.2. Molecular Interactions Among Surfactants at Solid/Liquid Interfaces.- 8.3.3. Specific Adsorption of Ionized Collector Species in the IHP (Without Charge Transfer).- 8.3.4. Adsorption of Surfactants to a Network of Polymerized Counterion Complexes, Activating Agents.- 8.4. Adsorption of Surfactants to Highly Soluble Salts in Their Saturated Salt Solutions.- 8.5. Adsorption of Surfactants Leading to Suppression of Floatability.- 8.6. Concluding Remarks on Adsorption Mechanisms.- 8.7. Selected Readings.- 9. Flotation Froths and Foams.- 9.1. Single Gas Bubbles in Liquid.- 9.2. Foams and Froths (Two-Phase Systems).- 9.3. Kinetics of Drainage in Single Films Supported on Frames.- 9.4. Characteristics of Single Thin Liquid Layers (Thin Films). Disjoining Pressure.- 9.5. Theories of Foam and Froth Stability.- 9.6. Destruction (Collapse) of Foams and Froths.- 9.7. Theoretical Conditions (From Analysis of Film Thinning) for Particle-Bubble Attachment (Mineralization of Bubbles)..- 9.7.1. Effects of Surfactants on Induction Time in Particle-Bubble Attachment.- 9.7.2. The Role of Surfactants and Their Diffusion in Particle-Bubble Attachment.- 9.7.3. Withdrawal of Water To Establish the Area of Particle-Bubble Contact.- 9.8. Joint Action of Collectors and Frothers in Flotation.- 9.9. Flotation Frothers: Their Requirements and Mechanisms of Their Action.- 9.10. Mineralized Flotation Froths and Their Stability.- 9.11. Bubble Generation in Mechanical Flotation Cells.- 9.12. Selected Readings.- 10. Inorganic Regulating Agents, Activators, Depressants.- 10.1. pH Control.- 10.2. Control of Charge Density at the Solid/Liquid Interface.- 10.2.1. Sodium Silicate.- 10.2.2. Sodium Polyphosphates.- 10.3. Additives Regulating the Oxidation States of Various Components in the Pulp.- 10.4. Complexing Additives.- 10.5. Hydro Complexes.- 10.5.1. Selective Flotation Using Control of pH.- 10.6. Complexing Additives Containing Sulfide, Sulfite, or Thiosulfate Ions.- 10.6.1. Use of Sulfur-Containing Inorganic Additives in Selective Flotation.- 10.7. Cyanides, Cyanates, Thiocyanates, and Ferrocyanates.- 10.8. Use of Cyanide Ion as a Depressant.- 10.9. Halide Ligands.- 10.10. Closing Remarks-Problems Created by Fine Particles.- 10.11. Selected Readings.- References.
Genesis and evolution of strontium deposits of the granada basin (Southeastern Spain): Evidence of diagenetic replacement of a stromatolite belt
Abstract There are important strontium deposits in the Granada Basin, the most noteable of which (Montevives) has an annual production of approximately 50,000 tons of almost pure celestite. Two types of mineralization can be recognized: a primary variety consisting of stromatolitic carbonate that has been partially replaced by celestite, and a secondary variety consisting of celestite-pebble karst deposits. Both are included in an evaporitic Messinian succession. The primary variety of mineralization is within carbonates that interfinger with, and prograde across, gypsum deposits. The development of these deposits can be interpreted in the context of the general evolution of the Granada Basin during Late Tortonian and Messinian times. Open marine conditions prevailed during the late Tortonian. During the transition from Tortonian to Messinian a restriction of the basin resulted in evaporite sedimentation, with stromatolites thriving at the basin's margin. The stromatolites were distributed along a coastal belt that was limited on the east by the tectonically active Sierra Nevada with its local alluvial fans. Runoff from the Sierra Nevada produced a freshwater lens and surface salinities that permitted the development of stromatolites, rather than the accumulation of gypsum. The replacement of stromatolitic carbonate by celestite occurred within the mixing zone of the coastal aquifers during sedimentation and/or early diagenesis. An essentially marine origin is considered for the strontium. Supplementary influxes from continental weathering are also thought to have been produced. Further restriction of the Granada Basin led to complete desiccation and the deposition of a 20 m thick halite layer. Later, gypsum deposits were exposed, and resulting cavities (“dolinas”) were filled with celestite pebbles. The return of sediment accumulation within lakes buried and preserved these deposits.