1. プロジェクトの概要

1.1 Project Positioning

This plan is designed for small‑scale mineral processing plants with a daily throughput of 30–100 tonnes. It is suitable for grinding and beneficiation of ores such as gold, copper, iron, and quartz sand. Small‑scale plants offer low investment thresholds, short construction periods, and flexible operation, making them an ideal choice for early‑stage mine development or when ore supply is inconsistent.

1.2 Design Principles

• Controllable investment – core equipment investment kept in the range of RMB 0.8–1.5 million.
• Mature technology – single‑stage grinding plus a single beneficiation circuit, avoiding excessive complexity.
• Energy efficiency – priority given to energy‑saving equipment to reduce operating costs.
• Expansion reserve – equipment selected with some spare capacity for future production increases.

2. Ore Characteristics and Process Route

2.1 Applicable Ore Conditions

2.2 Recommended Process Flowsheet

Single‑stage closed‑circuit grinding – beneficiation:

Run‑of‑mine → Jaw crusher → Hammer crusher → Vibrating screen → Ball mill → Spiral classifier (or hydrocyclone)
                                                                       ↓
                                                               Qualified pulp → Beneficiation (flotation / magnetic separation)
                                                                       ↓
                                                               Tails → Tailings pond
                                                               Concentrate → Dewatering

For small plants where the final grind of –200 mesh is below 80%, a single grinding stage is sufficient. The ground pulp is classified by a spiral classifier; the qualified product goes to the next process, while coarse particles are returned to the ball mill for regrinding.

3. Main Equipment Configuration and Quotations

3.1 Core Equipment – ボールミル Selection

Common ball mill models for small plants and their indicative prices:

Note: Prices are market references as of 2025–2026. Actual costs vary with shell material, liner type, drive system, brand, and customisation. Small ball mills (drum diameter ≤1.5 m) typically range from RMB 80,000 to 250,000.

Recommended option for 50 t/d: Φ1500×3000 wet overflow ball mill with 55 kW motor – approximately RMB 180,000–250,000.

3.2 Complete Equipment List (for 50 t/d configuration)

Subtotal for equipment: approximately RMB 600,000–950,000

3.3 Laboratory‑Scale Equipment (optional)

If ore amenability testing or routine assaying is required, consider:

3.4 Used Equipment Option

For very tight budgets, used ball mills are an alternative. Prices typically range from 40–60% of new equipment. A small used ball mill may cost as little as RMB 50,000 or over RMB 300,000 depending on condition and age. Inspect service life and maintenance records carefully.

4. Total Project Investment Estimate

4.1 Investment Breakdown (50 t/d flotation plant)

Reference: For a 50 t/d small gold flotation plant, equipment investment is about RMB 650,000–850,000, civil and installation about RMB 300,000–400,000. A standard 100 t/d flotation plant typically totals RMB 0.8–3.0 million.

4.2 Investment by Scale

5. Operating Cost Analysis

5.1 Per‑tonne Processing Cost Estimate

Reference: Small flotation plants typically report ~RMB 55–70/t.

5.2 Annual Operating Cost (50 t/d, 300 working days/year)

• Annual throughput: 50 × 300 = 15,000 tonnes
• Annual operating cost: 15,000 × 50 = RMB 750,000 (approx.)

6. Economic Benefits Analysis

6.1 Revenue Estimate (gold ore example – for reference only)

Assume:

• Feed grade: 3 g/t Au
• Recovery: 85%
• Annual throughput: 15,000 t

Annual gold production: 15,000 × 3 × 85% = 38,250 g = 38.25 kg
At a gold price of RMB 450/g, annual revenue: 38.25 × 1000 × 450 ≈ RMB 17.22 million

6.2 Payback Period

• Total investment: ~RMB 1.5 million (mid‑range)
• Net annual profit (after costs and taxes): highly variable depending on ore grade and commodity prices.
• Typical payback for small plants: 1–3 years.

7. Implementation Schedule

8. Risk Analysis and Mitigation