Kalite Flotasyon Reaktifleri & Köpük Flotasyon Reaktifleri Üretici

Gold Recovery from E-Waste Using Eco-Friendly Extraction Reagents I. Pretreatment Steps 1.1 Crushing and Screening Purpose: Increase surface area to facilitate subsequent gold leaching. Operations: ① Use a crusher to break down e-waste (e.g., circuit boards, CPUs, gold fingers) into 0.5–1 mm particles. ② Screen the material to remove oversized or undersized particles, ensuring uniform particle size. ③ Employ magnetic separation to remove ferromagnetic impurities (e.g., iron, nickel). ④ Rinse the crushed material with clean water to eliminate dust and impurities, then air-dry for further use.   1.2 Roasting Treatment (Optional) Purpose: Remove organic materials and break the bonding between metals and plastics. Operations: ① Place the crushed e-waste in a roasting furnace and roast at 500–600°C for 1–2 hours. ② Ensure proper ventilation during roasting to prevent the accumulation of harmful gases. ③ After roasting, allow the waste to cool to room temperature, then perform secondary crushing until the particle size is less than 0.5 mm.   II. Preparation of Eco-Friendly Gold Extraction Agent YX500 Solution 2.1 Preparation of Eco-Friendly Gold Extraction Agent YX500 Solution Reagent: Eco-friendly gold extraction agent YX500. Concentration: Prepare a YX500 solution with a concentration of 0.05%–0.1% (i.e., 0.5–1 g/L). Method: ① Add an appropriate amount of clean water into the mixing tank. ② Slowly add the eco-friendly gold extraction agent YX500 in proportion while continuously stirring until it is completely dissolved. ③ Dosing time: Ensure the operation is completed within 10–20 minutes.   2.2 Alkalinity Adjustment Purpose: Prevent hydrogen cyanide gas volatilization and ensure smooth leaching reaction. Operations: ① Add sodium hydroxide (NaOH) or lime milk to adjust the solution pH to 10–11. ② Use pH test strips or a pH meter to verify the solution's alkalinity reaches the appropriate level.   III. Leaching Process 3.1 Leaching Equipment Equipment: Tower leaching tank or mechanically agitated tank. Temperature: Ambient temperature (20–25°C). If leaching acceleration is required, temperature may be increased to 40–50°C.   3.2 Reagent Addition & Reaction Conditions Dosing sequence: ① First, add sodium hydroxide (NaOH) solution for pH adjustment. ② Then, add the pre-prepared eco-friendly gold extraction agent YX500 solution and start the stirring device. ③ Dosing time: Must be completed within 10–20 minutes. Stirring speed: 200–300 rpm to ensure full contact between materials and solution.   3.3 Leaching Time & Oxidant Usage Leaching time: At ambient temperature: 24–48 hours. At 40–50°C: Can be reduced to 12–24 hours. Oxidant: ① To accelerate gold dissolution, hydrogen peroxide (H₂O₂, 0.1–0.5%) may be added or air may be introduced. ② Addition timing: Synchronized with the YX500 solution dosing and maintained continuously.   IV. Solid-Liquid Separation Filtration and Washing Method: Vacuum filtration or centrifugal separation equipment shall be employed. Operations: ① Filter the leached slurry to separate the gold-bearing solution (pregnant solution) from the residue. ② Wash the residue with dilute alkaline solution (pH 10-11) to recover residual gold elements.   V. Gold Recovery Methods Method 1: Zinc Powder Replacement Process Steps: ① Slowly add zinc powder to the pregnant solution at a ratio of 5-10 g/L. ② Maintain continuous stirring with a reaction time of 2-4 hours. ③ Filter to obtain gold mud.   Method 2: Electrolysis Process Equipment: Stainless steel cathode, graphite or lead anode. Conditions: ① Current density: 1-2 A/dm², Voltage: 2-3 V. ② Electrolysis duration: 6-12 hours. Operations: ① After energizing the electrolytic cell, gold gradually deposits on the cathode. ② Remove the cathode and scrape off the deposited gold mud.   VI. Gold Mud Treatment and Refinement Acid Washing and Smelting Steps: ① Use dilute nitric acid or aqua regia to dissolve impurities, followed by filtration to obtain purified gold mud. ② Place the gold mud in a high-temperature electric furnace for smelting, then cast into gold ingots. Purity: Can reach ≥99.9%.   VII. Waste Liquid Treatment and Environmental Protection Measures Compliant Discharge Testing: Verify cyanide concentration to ensure it remains below 0.2 mg/L. Discharge: After meeting standards, release into wastewater treatment system.   VIII. Safety Precautions ① Ventilation: Maintain adequate ventilation in work areas to prevent hydrogen cyanide gas accumulation. ② Protection: Operators must wear gloves, masks, and protective goggles to ensure safety. ③ First Aid: Prepare amyl nitrite and other antidotes for emergency treatment of cyanide poisoning.       Detection of Cyanide Ion (CN¯) Concentration in Eco-Friendly Gold Extraction Reagents   Testing the cyanide ion (CN¯) concentration in eco-friendly gold extraction agents is a critical step to ensure their safety and effectiveness. The following outlines commonly used detection methods and their key operational points, categorized into two main types: laboratory testing methods and on-site rapid testing methods.   I. Laboratory Precision Detection Methods 1.1 Silver Nitrate Titration (Classical Method) Principle: Cyanide ions react with silver nitrate to form soluble [Ag(CN)₂]¯ complexes, with excess silver ions reacting with an indicator (e.g., silver chromate) to produce a color change. Steps: ① Dilute the sample and add sodium hydroxide (pH >11) to prevent hydrogen cyanide (HCN) volatilization. ② Use silver chromate as an indicator and titrate with standardized silver nitrate solution until the color changes from yellow to orange-red. Scope: Suitable for high cyanide concentrations (>1 mg/L); provides precise results but requires laboratory conditions.   1.2 Spectrophotometry (Isonicotinic Acid-Pyrazolone Method) Principle: In weakly acidic conditions, cyanide reacts with chloramine-T to form cyanogen chloride (CNCl), which then reacts with isonicotinic acid-pyrazolone to produce a colored compound. Quantification is achieved by measuring absorbance at 638 nm. Steps: ① Distill the sample if necessary to remove interferents. ② Add buffer and chromogenic reagents, then measure absorbance using a spectrophotometer. Calculate concentration via a standard curve. Advantage: High sensitivity (detection limit: 0.001 mg/L), ideal for trace-level analysis.   1.3 Ion-Selective Electrode (ISE) Method Principle: A cyanide electrode responds to CN¯ activity, measuring concentration via potential difference. Steps: ① Adjust sample pH to >12 with NaOH to avoid HCN interference. ② Calibrate the electrode, measure potential, and convert to concentration. Advantage: Rapid operation, broad detection range (0.1–1000 mg/L), but requires regular electrode calibration.   II. On-Site Rapid Detection Methods 2.1 Rapid Test Strips Principle: Strips contain chromogenic agents (e.g., picric acid) that change color (yellow to reddish-brown) upon reaction with cyanide ions. Procedure: Immerse the strip in the sample, then compare the color against a reference card for semi-quantitative reading. Features: Highly portable but relatively low accuracy; suitable for emergency screening.   2.2 Portable Cyanide Detectors Principle: Miniaturized spectrophotometric or electrode-based devices (e.g., Hach, Merck). Operation: Direct sample injection with automatic concentration display. Advantage: Combines speed and high precision, ideal for field use in mining areas.   2.3 Pyridine-Barbituric Acid Colorimetry (Simplified) Reagent Kit: Pre-packaged tubes with chromogenic agents; add water sample for colorimetric analysis. Detection Limit: ~0.02 mg/L, suitable for low-cyanide testing in eco-friendly gold extraction agents.   III. Precautions Safety Measures Cyanide is highly toxic! All testing must be conducted in a fume hood to prevent skin contact or inhalation. Waste liquid treatment: Oxidize with sodium hypochlorite (CN¯ + ClO¯ → CNO¯ + Cl¯). Interference Factors Sulfide (S²¯) and heavy metal ions may cause interference. Pre-distillation or masking agents (e.g., EDTA) should be used to eliminate their effects. Method Selection High-precision testing: Laboratory titration or spectrophotometry is preferred. Rapid screening: Test strips or portable devices are more practical.  

  Chapter 1: Characteristics of Lead-Zinc Ore Resources and Beneficiation   1.1 Global Resource Distribution Features Main Mineralization Types: Sedimentary Exhalative Deposits (55%) Mississippi Valley-Type Deposits (30%) Volcanogenic Massive Sulfide (VMS) Deposits (15%) Representative Deposits: China's Fankou Deposit (Proven reserves: Pb+Zn >5 million tonnes) Australia's Mount Isa Mine (Average zinc grade: 7.2%) Mineralogical Associations: Intimate PbS-ZnS intergrowth (Particle size distribution: 0.005-2mm) Precious metal associations (Ag content: 50-200g/t, often occurring as argentiferous galena)   1.2 Process Mineralogy Challenges Variable Iron Content in Sphalerite (Fe 2-15%): Impacts flotation behavior due to changes in surface chemistry, High-iron sphalerite (>8% Fe) requires stronger activation Secondary Copper Minerals (e.g., Covellite): Causes copper contamination in zinc concentrates (typically >0.8% Cu), Requires selective depression reagents (e.g., Zn(CN)₄²⁻ complexes) Slime Coating Effects: Becomes significant when -10μm particles exceed 15%, Mitigation methods: ---Dispersion agents (sodium silicate) ---Stage grinding-flotation circuits       Chapter 2: Modern Beneficiation Process Systems 2.1 Standard Selective Flotation Process Grinding and Classification Control ---Primary Closed-Circuit Grinding: Hydrocyclone classification, Circulating load: 120-150% ---Target Fineness: 65-75% passing 74μm, Galena liberation degree: >90% Lead Flotation Circuit ---Reagent Scheme: Reagent Type Dosage (g/t) Mechanism of Action Lime 2000-4000 pH adjustment to 9.5-10.5 Diethyl dithiocarbamate (DTC) 30-50 Selective galena collector MIBC (frother) 15-20 Froth stability control ---Equipment Configuration: JJF-8 Flotation Cells: 4 cells for roughing + 3 cells for cleaning Zinc Activation Control ---CuSO₄ Dosage: 250±50 g/t, Optimized with mixing intensity (power density: 2.5 kW/m³) ---Potential (Eh) Control Range: +150 to +250 mV   2.2 Innovative Bulk Flotation Technology Key Technological Breakthroughs: ---High-efficiency composite collector (AP845 + ammonium dibutyl dithiophosphate, 1:3 ratio) ---Selective depression removal technology (pH adjustment to 7.5±0.5 using Na₂CO₃) Industrial Application Cases: ---Throughput increased by 22% (reaching 4,500 t/d) at an Inner Mongolia mine ---Zinc concentrate grade improved by 3.2 percentage points   2.3 Dense Media Separation-Flotation Combined Process Pre-concentration Subsystem: ---Medium density control (magnetite powder D50=45μm) ---Three-product cyclone (DSM-800 type) separation efficiency Ep=0.03 Economic Analysis: ---When waste rejection rate reaches 35-40%, grinding costs are reduced by 28-32%       Chapter 3: Lead-Zinc Ore Beneficiation Reagents 3.1 Collector Types & Applications (1) Anionic Collectors Reagent Target Mineral Dosage (g/t) pH Range Notable Features Xanthates (e.g., SIPX) ZnS 50-150 7-11 Cost-effective, requires CuSO₄ activation Dithiophosphates (DTP) PbS 20-60 9-11 High Pb selectivity over Zn Fatty acids Oxidized ores 300-800 8-10 Needs dispersants (e.g., Na₂SiO₃) (2) Cationic Collectors Amines (e.g., Dodecylamine): Used in reverse flotation for silicate removal, Dosage: 100-300 g/t, pH 6-8 (3) Amphoteric Collectors Amino-carboxylic acids: Selective for Zn in complex ores, Effective at pH 4-6 (Eh = +200 mV)   3.2 Depressants & Modifiers Reagent Function Dosage (kg/t) Target Impurities Na₂S Zn depression in Pb circuit 0.5-2.0 FeS₂, ZnS ZnSO₄ + CN⁻ Pyrite depression 0.3-1.5 FeS₂ Starch Silicate depression 0.2-0.8 SiO₂ Na₂CO₃ pH modifier (buffer at 9-10) 1.0-3.0 -   3.3 Composite Reagents for Lead-Zinc Ore Beneficiation Composite beneficiation reagents refer to multifunctional reagent systems formed by integrating two or more functional components (collectors, depressants, frothers, etc.) through physical blending or chemical synthesis. Based on their composition, they can be classified into: (1) Physically Blended Type Mechanical mixing of individual reagents (e.g., diethyldithiocarbamate (DTC) + butyl xanthate at a 1:2 ratio) Typical example: LP-01 composite collector (xanthate + thiocarbamate) (2) Chemically Modified Type Molecularly engineered multifunctional reagents Typical examples: Hydroxamic acid-thiol complexes (dual collector-depressant functionality) Zwitterionic polymer depressants       Chapter 4: Key Equipment and Technical Parameters 4.1 Flotation Equipment Selection Guide Roughing Stage: KYF-50 flotation machine (aeration rate: 1.8 m³/m²·min) Cleaning Stage: Flotation column (Jameson Cell, bubble diameter: 0.8-1.2 mm) Comparative Test Data: Conventional mechanical vs. aerated cells: Recovery rate difference of ±3.5% 4.2 Process Control Systems Online Analyzer Configuration: ---Courier SLX (slurry XRF, analysis cycle: 90 s) ---Outotec PSI300 (particle size analysis, error 85%) Reuse Water Standards: ---Heavy metal ion concentrations (Pb²⁺65%) ---Sulfur concentrate production (combined magnetic separation-flotation, S grade >48%) Bulk Utilization Methods: ---Cement additive (15-20% blending ratio) ---Underground backfill material (slump control 18-22 cm)       Chapter 6: Techno-Economic Indicator Comparison 6.1 Typical Concentrator Operating Data Production Cost Structure: Cost Item Proportion (%) Unit Cost (USD/t)* Grinding Media 28-32 1.2-1.5 Flotation Reagents 18-22 0.75-1.05 Energy Consumption 25-28 1.05-1.35 *Note: Currency conversion at 1 CNY ≈ 0.15 USD 6.2 Technological Upgrade Benefits Case Study: 2,000 t/d Concentrator Retrofit Parameter Before Retrofit After Retrofit Improvement Zinc Recovery 82.3% 89.7% +7.4% Reagent Cost 6.8 CNY/t 5.2 CNY/t -23.5% Water Reuse Rate 65% 92% +27%       Chapter 7: Future Technological Development Directions 7.1 Short-Process Separation Technologies Superconducting Magnetic Separation (Background field intensity: 5 Tesla, processing -0.5mm material) Fluidized Bed Separation (Air-dense medium fluidized bed, Ecart Probable Ep=0.05) 7.2 Green Beneficiation Breakthroughs Bio-Reagent Development (e.g., Lipopeptide-based collectors) Zero-Tailings Mine Construction (Comprehensive utilization rate >95%)