1-5cm Pyrite Lump: Industrial-Grade Metallurgical Material

1-5cm Size: Practical Adaptability for Metallurgical Processes

The 1-5cm size is not randomly set but tailored to the actual needs of metallurgical equipment and processes, with each dimension parameter corresponding to specific operational advantages, verified by on-site application in 40+ metallurgical enterprises:

Feeding System Compatibility: 1-5cm lump size matches standard metallurgical feeding equipment (vibrating feeders, belt conveyors) without clogging or material accumulation. The feeding accuracy reaches ±0.5%, and the continuous feeding capacity is 8-14 tons/hour, suitable for 500-3000 m³ blast furnaces, 5-100t electric arc furnaces, and 18-40 m² sintering machines.
Reaction Efficiency Control: With a specific surface area of 0.75-1.15 m²/g, the 1-5cm lump can achieve 98.5%+ decomposition rate at 1150-1350°C (metallurgical working temperature), with a reaction time of 7-11 minutes—neither too fast (avoiding local over-sulfur) nor too slow (ensuring production efficiency), perfectly matching the rhythm of continuous metallurgical production.
Material Loss Reduction: The 1-5cm lump has high mechanical strength (compressive strength ≥12 MPa), with a transportation loss rate of only 1.0-1.6% and a storage loss rate of ≤0.8%, which is 60-70% lower than powder pyrite and 30-40% lower than large lumps (≥6cm). It does not require secondary crushing, saving 7-9 yuan/ton of processing costs.
On-Site Operation Safety: The lump size avoids dust pollution during feeding and handling, with dust emission ≤50 mg/m³ (meeting ISO 14001 environmental standards), reducing the risk of equipment wear and operator health hazards, which is an obvious advantage over small-particle pyrite.

Chemical Properties & Quality Control (1-5cm Pyrite Lump)

The 1-5cm pyrite lump maintains the stable chemical properties of natural FeS₂, with strict impurity control based on YB/T 4551-2016 and ISO 9001:2015 standards. The chemical indicators are closely matched with the 1-5cm size to ensure consistent application effect in metallurgical processes:

Core Chemical Indicators: FeS₂ purity ≥91% (qualified rate ≥95%), sulfur (S) content 44-49% (fluctuation ≤±0.4%), iron (Fe) content 41-47% (stable supply of iron elements). Fatal impurities are strictly controlled: phosphorus (P) ≤0.006%, arsenic (As) ≤0.022%, lead (Pb) ≤0.013%, zinc (Zn) ≤0.013%—effectively avoiding hot brittleness, furnace lining erosion, and casting quality defects.

Physical & Chemical Matching: Density 4.85-5.15 g/cm³, melting point 738-748°C, water content ≤0.5%. The moderate density ensures that the 1-5cm lumps can be evenly mixed with iron ore, coke, and flux, without floating or sinking; the melting point matches the metallurgical temperature, ensuring stable decomposition and sulfur release.

Practical Applications & On-Site Data (1-5cm Pyrite Lump)

The 1-5cm pyrite lump is widely used in free-cutting steel, gray cast iron, ductile iron, and ironmaking blending processes, with clear application parameters and on-site effect data, fully reflecting the value of its size advantage:

1. Free-Cutting Steel Production (Electric Arc Furnace)

As a sulfur additive for free-cutting steel (Y15, 12L14, 303), the 1-5cm pyrite lump has obvious advantages in sulfur control and machinability improvement:

• Addition Ratio: 0.5-1.7% of molten steel weight (accurate feeding due to fixed size, no over-addition risk); • Sulfur Control: Adjusts steel sulfur content to 0.07-0.29% (optimal range for machinability); • Effect Data: Machining efficiency increased by 36-53%, tool life extended by 26-34%, surface finish of workpieces up to Ra 1.5-3.0μm; • Size Value: Sulfur recovery rate ≥92.5%, avoiding sulfur fluctuation caused by uneven decomposition of large lumps and dust loss of small particles.

2. Blast Furnace Ironmaking Blending

For blast furnace ironmaking blending, the 1-5cm pyrite lump is the most suitable size for mixing and reaction, effectively optimizing furnace operation:

• Blending Ratio: 3.8-8.5% of total ore feed (even mixing with iron ore, no segregation); • Operational Advantages: Improves slag fluidity by 14-19%, increases iron recovery rate by 2.3-4.2%, reduces coke consumption by 2.8-4.8%; • Size Value: Withstands blast furnace pressure (1.1-1.4 MPa) without crushing, decomposes stably to release heat, supplementing furnace thermal balance, which is irreplaceable by small particles (easy to be blown away) and large lumps (slow heat release).

3. Gray Cast Iron & Ductile Iron Production

In gray cast iron (HT250, HT300) and ductile iron (QT500-7, QT600-3) production, the 1-5cm pyrite lump optimizes casting performance and reduces defects:

• Gray Cast Iron: Adjusts sulfur content to 0.07-0.11%, optimizes graphite morphology, tensile strength increased by 17-24% (up to ≥230MPa), casting qualification rate improved by 8-12%; • Ductile Iron: Controls trace sulfur (0.04-0.14%), ensures ductility and toughness, reducing shrinkage defects by 10-15%; • Size Value: No dust pollution, ensuring molten iron purity, uniform sulfur release avoids local impurity accumulation.

Size Comparison: Why 1-5cm is Superior to Other Specifications?

In metallurgical applications, the size of pyrite directly affects production efficiency, material utilization, and product quality. The 1-5cm lump solves the inherent defects of other sizes, as shown in the practical application comparison:

vs. ≤1cm (Powder/Small Particles): 1-5cm lump has 5-8% higher sulfur recovery rate, 7-9% higher utilization rate, and 70% lower dust emission. It avoids clogging of feeding equipment and dust loss during transportation, reducing environmental protection treatment costs.
vs. ≥6cm (Large Lumps): 1-5cm lump decomposes 30-40% faster, with 8-10% higher sulfur recovery rate. It avoids uneven sulfur release and local over-sulfur, ensuring stable steel/cast iron quality, and is easier to mix with other raw materials.

Quality Assurance & Technical Support

Our 1-5cm pyrite lump is produced by high-precision crushing, screening, and purification equipment, with a size qualification rate of ≥95% (each lump is strictly inspected to ensure it meets 1-5cm range). We have 16+ years of experience in metallurgical raw material production, with a professional R&D team composed of senior metallurgical engineers (20+ years of on-site experience).

Each batch of products undergoes strict quality testing, including size distribution, chemical composition, decomposition rate, and mechanical strength, with complete testing reports available for inspection. We provide free on-site technical guidance, including feeding ratio adjustment, process adaptation, and problem solving. Free samples (500g-1kg) are available for trial, ensuring the product meets your production needs before bulk purchase.

FAQ (Practical Operation Focus)

Q1: How to ensure the 1-5cm size is consistent in each batch?

A: We use fully automatic screening equipment with 3-level screening (1cm, 3cm, 5cm) to ensure each lump is within the 1-5cm range. The size qualification rate is ≥95%, and each batch is sampled and tested (size distribution test report provided), avoiding unqualified sizes that affect feeding and reaction.

Q2: Is the 1-5cm pyrite lump suitable for small blast furnaces (≤1000 m³)?

A: Yes. The 1-5cm size is highly adaptable, and we can slightly adjust the size range (e.g., 1-4cm) according to the capacity of small blast furnaces, ensuring feeding convenience and reaction efficiency. It has been widely used in small and medium-sized steel mills with ≤1000 m³ blast furnaces, with stable application effect.

Q3: What is the difference between 1-5cm pyrite lump and other sizes in terms of cost?

A: The 1-5cm pyrite lump has the most balanced cost performance: compared with powder pyrite, it saves 7-9 yuan/ton of crushing cost and 3-5 yuan/ton of environmental protection cost; compared with large lumps (≥6cm), it saves 5-7 yuan/ton of secondary crushing cost and reduces 2-3% of material waste, which is more in line with metallurgical enterprises’ cost control needs.

Q4: How to store 1-5cm pyrite lump to avoid oxidation?

A: The 1-5cm pyrite lump has low water absorption (≤0.5%), so it only needs to be stored in a dry, ventilated, and moisture-proof warehouse, avoiding direct contact with water and rain. It is packed in moisture-proof woven bags (25kg/50kg per bag), which can be stored for 12 months without oxidation or agglomeration.

Q5: Can you provide on-site technical support for the application of 1-5cm pyrite lump?

A: Yes. Our professional metallurgical engineers have rich on-site experience, and we can send technical personnel to your factory to guide feeding ratio adjustment, equipment adaptation, and process optimization, ensuring the 1-5cm pyrite lump exerts the best effect. We also provide 24/7 online technical consultation to solve practical problems in production.