10-50mm Calcium Silicon Lumps (abbreviated as CaSi Lumps) are critical composite ferroalloys with a controlled composition of calcium (Ca: 28-35%), silicon (Si: 55-65%), and iron (Fe: balance), plus strict impurity control (C≤0.8%, Al≤1.5%, S≤0.05%, P≤0.05%). Their 10-50mm blocky form is tailored for bulk steelmaking processes (converter, electric arc furnace, ladle refining), enabling stable feeding, uniform dissolution, and dual-function performance (deoxidation + desulfurization). Unlike single-element additives (e.g., ferro silicon, calcium metal), 10-50mm CaSi Lumps integrate calcium's strong oxygen/sulfur affinity and silicon's deoxidation efficiency, making them indispensable for producing high-purity steel (e.g., automotive sheet steel, pipeline steel) and solving pain points like incomplete deoxidation, high sulfur content, and brittle inclusions.

10-50mm CaSi Lumps are produced by smelting limestone, silica, and coke with iron scrap, then casting and crushing to a 10-50mm size-optimized for automated feeding in large-scale steel mills. Their unique value lies in three critical traits:

Dual-Function Efficiency: Calcium (Ca) reacts with oxygen (O) and sulfur (S) to form low-melting CaO and CaS (melting point ≤1500℃), while silicon (Si) enhances deoxidation depth-achieving O≤20ppm and S≤0.015% in steel water (vs. single deoxidizers with O≤30ppm, S≤0.03%).
Bulk Feeding Compatibility: 10-50mm lumps fit ladle addition systems (chute feeding, pneumatic conveying) in converter/EF steelmaking, avoiding clogging (common with fine granules) and ensuring stable dosage (±0.2kg/ton).
Inclusion Modification: Transforms brittle Al₂O₃ inclusions into spherical Ca-Al-Si-O inclusions (diameter ≤3μm), improving steel's toughness and fatigue resistance-critical for high-stress components (e.g., automotive crankshafts).

These traits make 10-50mm CaSi Lumps the preferred choice for medium-to-large steel mills producing high-quality carbon steel, low-alloy steel, and special steel.

10-50mm Calcium Silicon Lumps

chemical composition

Parameter	Standard Range	Metallurgical Significance
Main Components	Ca: 28-35%, Si: 55-65%, Fe: 5-15%	28-35% Ca ensures desulfurization (S≤0.015%); 55-65% Si enhances deoxidation-synergistic effect improves steel purity.
Key Impurities (Max.)	C≤0.8%, Al≤1.5%, S≤0.05%, P≤0.05%	C≤0.8% avoids carburization in low-carbon steel; Al≤1.5% prevents AlN inclusions; S/P≤0.05% avoids brittleness.
Physical Form	Lumps: 10-50mm (95% within range), irregular block	10-20mm for ladle refining; 20-50mm for converter/EF steelmaking-stable feeding without hopper bridging.
Reactivity	Deoxidation Rate: ≥90%, Desulfurization Rate: ≥70%	Reduces steel water O from 80-100ppm to ≤20ppm, S from 0.05-0.08% to ≤0.015%-meets high-purity steel standards.

Advantages of using calcium silicon alloy lumps

10-50mm CaSi Lumps outperform single-function additives (ferro silicon, calcium metal) and fine CaSi granules in bulk steelmaking, solving the "purity-efficiency-cost" triangle:

Efficient deoxidation and desulfurization effect:

The calcium silicon alloy lump can quickly react to remove oxygen, sulfur and other impurities in molten steel, significantly improving the quality of steel and cast iron.

Improve alloy uniformity:

The use of calcium silicon alloy lumps can promote the uniform distribution of alloy components, reduce inclusions in the metal, and improve the strength and toughness of the finished product.

Good spheroidizing effect:

Especially in the production of ductile iron, the calcium silicon alloy lump helps to improve the graphite morphology and improve the comprehensive mechanical properties of the cast iron.

Suitable for a wide range of metallurgical operations:

Calcium silicon alloy lumps are suitable for various smelting and casting operations, especially the alloying processes of various metals such as steel, cast iron, and aluminum alloys.

10-50mm CaSi Lumps

Verify Lump Size & Quality

- Size Distribution: Ensure 95% of lumps are 10-50mm-avoid oversize (＞50mm, slow dissolution) or undersize (＜10mm, dust loss).
- Impurity Control: Request SGS/BV test reports-C≤0.8% for low-carbon steel, Al≤1.2% for automotive steel.
- Reactivity Test: Check surface oxidation (oxide layer ≤0.2mm)-oxidized lumps reduce deoxidation rate by 10-15%.

Our 10-50mm Calcium Silicon Lumps Solutions

As a professional ferroalloy supplier with 18+ years of steelmaking additive experience, we offer tailored 10-50mm CaSi Lumps to meet bulk steelmaking needs:

- Standard Grade (Ca30Si60): Ca29-31%, Si59-61%, 10-50mm lumps-for general carbon steel (Q235, Q355).
- High-Desulfurization Grade (Ca35Si55): Ca33-35%, Si55-57%, 20-50mm lumps-for pipeline steel (X70, X80).
- Automotive Grade (Ca32Si62): Ca31-33%, Si61-63%, 10-30mm lumps-for automotive sheet steel (IF steel) and alloy steel (40Cr).

Contact us today to request a free sample and customized quote-elevate your steel purity and production efficiency with 10-50mm Calcium Silicon Lumps!

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