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 <±2%)
Intelligent Control Strategies:
—Fuzzy-PID based reagent dosing system (control accuracy: ±5%)
—Digital twin optimization platform (capable of 12-hour process indicator prediction)
Chapter 5: Environmental Protection and Comprehensive Resource Utilization
5.1 Wastewater Treatment Technology
Multi-stage Treatment Process:
—Primary treatment (neutralization/precipitation, pH=8.5-9.0)
—Secondary treatment (biological agents, COD removal efficiency >85%)
Reuse Water Standards:
—Heavy metal ion concentrations (Pb²⁺<0.5 mg/L)
5.2 Tailings Valorization
Valuable Component Recovery:
—Silver recovery (thiosulfate leaching, extraction rate >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%)
