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Metallic Media Type
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Hardness (HRC)
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CaCO₃ Feed SiO₂ Content
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Typical Lifespan (24h continuous production)
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Grinding Type (Dry/Wet)
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Core Application for CaCO₃
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Low-carbon steel balls
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20–30
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<0.5% (pure CaCO₃)
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1–3 months
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Dry only
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Low-cost coarse GCC (D50=50–100 μm)
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High-chromium steel balls (20–25% Cr)
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58–65
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<0.5% (pure CaCO₃)
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6–12 months
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Dry/Wet
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Standard fine GCC (D50=10–50 μm)
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High-chromium steel balls (20–25% Cr)
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58–65
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0.5–3% (medium SiO₂)
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3–6 months
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Dry/Wet
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Standard fine GCC (D50=10–50 μm)
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High-chromium steel balls (20–25% Cr)
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58–65
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>3% (high SiO₂)
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1–3 months
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Dry/Wet
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Industrial-grade CaCO₃ (abrasive feed)
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Alloy steel pebbles
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45–55
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<0.5% (pure CaCO₃)
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4–8 months
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Dry only
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Large-scale ball mills (low impact)
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Ceramic Media Type
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Mohs Hardness
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CaCO₃ Feed SiO₂ Content
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Typical Lifespan (24h continuous production)
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Grinding Type (Dry/Wet)
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Core Application for CaCO₃
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92% Alumina (Al₂O₃) ceramic balls
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9
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<0.5% (pure CaCO₃)
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2–3 years
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Dry/Wet
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High-purity coating/paper GCC (D50=5–20 μm)
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92% Alumina ceramic balls
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9
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0.5–3% (medium SiO₂)
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1–2 years
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Dry/Wet
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High-purity coating/paper GCC (D50=5–20 μm)
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ZTA (Zirconia-Toughened Alumina) ceramic balls
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9+
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<0.5% (pure CaCO₃)
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3–4 years
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Dry/Wet
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Ultra-fine GCC (D50=2–10 μm), high-impact ball mills
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ZTA ceramic balls
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9+
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0.5–3% (medium SiO₂)
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2–3 years
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Dry/Wet
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Ultra-fine GCC (D50=2–10 μm)
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Stabilized Zirconia (ZrO₂) ceramic balls
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8.5–9
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<0.5% (pure CaCO₃)
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4–5+ years
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Wet only
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Food/pharma/nano CaCO₃ (ultra-high purity, no contamination)
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Reaction-bonded SiC (Silicon Carbide) balls
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9.5
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>3% (high SiO₂, even >5%)
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2–4 years
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Dry only
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High-silica CaCO₃ (most abrasive feed, no metal contamination)
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Wet vs. Dry Grinding: Ceramic media has a longer lifespan in wet grinding (CaCO₃ slurry acts as a lubricant, reducing abrasion) — zirconia ceramic balls can last 5+ years for wet grinding of pure CaCO₃ (D50<5 μm).
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Media Size Impact: Smaller grinding media (2–10 mm, for ultra-fine CaCO₃) wear slightly faster than larger media (10–30 mm, for coarse CaCO₃) — lifespan is ~10–20% shorter for small media (higher surface area to volume ratio).
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Ceramic Lining Matching: For zero metal contamination, ceramic media must be paired with ceramic mill linings (alumina/ZTA/ZrO₂) — a hybrid system (ceramic media + steel linings) still generates metal contamination from steel liner wear.
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Pure CaCO₃ (SiO₂ <0.5%): Wear is only from mild friction between media and CaCO₃ particles—media lifespan is maximized (e.g., high-Cr steel: 6–12 months; alumina ceramic: 2–3 years).
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High-silica CaCO₃ (SiO₂ >3%): SiO₂ particles act as “micro-grit” that scours the media surface, accelerating wear by 3–5x—even high-hardness steel media lasts only 1–3 months (SiC ceramic is the only viable option for long lifespan).
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Silica pre-removal: Washing/flotation to reduce SiO₂ <0.5% doubles/triples media lifespan (the most cost-effective lifespan optimization strategy for CaCO₃).
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Metallic media: High-chromium steel (58–65 HRC) is 3–5x more wear-resistant than low-carbon steel (20–30 HRC) — the only metallic media recommended for CaCO₃ grinding (low-carbon steel is too soft for most industrial applications).
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Ceramic media: Mohs hardness is the key metric (Alumina: 9; ZTA:9+; SiC:9.5) — ceramic media is 5–20x more wear-resistant than high-Cr steel for CaCO₃ grinding (especially high-silica feed).
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Toughness balance: Ceramic media has high hardness but lower toughness—ZTA (zirconia-toughened alumina) adds toughness to alumina, reducing chipping/cracking (critical for high-impact ball mills) while maintaining high wear resistance.
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Media filling rate: Optimal for CaCO₃ is 30–45% (dry) / 40–50% (wet) — overfilling (>50%) increases media-media collisions (higher impact wear); underfilling (<30%) reduces grinding efficiency and causes uneven media wear.
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Mill speed: Operate at 70–80% of critical speed (the standard for CaCO₃) — overspeeding (>80%) increases centrifugal force and media impact velocity (faster wear); underspeeding (<70%) causes inefficient grinding and media sliding (abrasive wear).
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Feed size: CaCO₃ feed to the ball mill should be 0–10 mm (crushed limestone) — oversize feed (>10 mm) increases media impact force and wear (and causes ceramic media chipping).
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Grinding aid dosage: Adding 0.1–0.5% grinding aid (triethanolamine/glycol) reduces CaCO₃ agglomeration and grinding resistance—lowers media wear by 10–20% (industrial verified for CaCO₃).
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Lining material: Ceramic linings (alumina/ZTA) have a lower friction coefficient than steel linings—reducing media sliding and abrasive wear (media lifespan is ~10–15% longer with ceramic linings for CaCO₃).
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Media size distribution: A graded media mix (small/medium/large balls, e.g., 10/20/30 mm) for CaCO₃ grinding optimizes grinding efficiency and reduces media wear—mono-size media causes uneven wear and inefficient grinding.
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Lifter design: Ceramic/steel lifters with a 30–45° angle (standard for CaCO₃) lift media to the optimal impact height—poor lifter design causes media sliding (abrasive wear) or excessive impact (faster wear).
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Use washing/scratching + reverse flotation to reduce SiO₂ content to <0.5% (the gold standard for CaCO₃ grinding).
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Eliminates the primary abrasive (SiO₂) — doubles/triples media lifespan (the single biggest impact on wear rate).
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Secondary benefit: Improves CaCO₃ product purity and whiteness (no silica impurities).
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Fix media filling rate: Set to 30–45% (dry) / 40–50% (wet) for CaCO₃—avoid over/underfilling.
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Control mill speed: Operate at 70–80% of critical speed (use variable frequency drive (VFD) for precise control).
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Limit feed size: Crush limestone to 0–10 mm (add a vibrating screen to remove oversize particles >10 mm).
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Add grinding aid: Dose 0.1–0.5% triethanolamine/glycol (continuous on-line addition) — reduces agglomeration and media wear by 10–20%.
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Avoid dry run: Never run the ball mill without CaCO₃ feed (media collides directly with liners/media—causes catastrophic wear/chipping).
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For metallic media users: Replace low-carbon steel with 20–25% high-chromium steel balls (lifespan 3–5x longer, minimal upfront cost increase).
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For high-silica CaCO₃ (SiO₂>3%): Replace steel media with SiC ceramic balls (lifespan 2–4 years vs. 1–3 months for steel—ROI in <6 months).
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For high-purity CaCO₃: Upgrade to alumina/ZTA ceramic balls (lifespan 2–4 years, eliminates metal contamination, improves whiteness).
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Pair ceramic media with alumina/ZTA ceramic linings (lower friction = less media wear, 10–15% longer lifespan).
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Use graded media size mix (small/medium/large) for CaCO₃ grinding (optimizes efficiency and reduces uneven wear).
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Replace worn lifters (steel/ceramic) — ensure lifter angle is 30–45° (standard for CaCO₃) to avoid media sliding.
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Screen worn media monthly: Remove small/worn media balls (using a vibrating screen) and top up with new media—worn media causes inefficient grinding and accelerates wear of new media.
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Maintain media size distribution: Keep the graded mix (e.g., 10/20/30 mm) — avoid mono-size media.
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Inspect media for chipping/cracking: Remove chipped/cracked ceramic media immediately (they cause excessive wear of other media/liners).
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Wear loss: Metallic media loses 30–40% of its original weight / Ceramic media loses 20–30% of its original weight (worn media has reduced grinding efficiency).
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Size reduction: Media diameter is 20–30% smaller than the original size (small media cannot grind CaCO₃ to target D50, causes PSD widening).
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Grinding efficiency drop: Unit energy consumption (kWh/t CaCO₃) rises by >15% (worn media requires more energy to achieve the same product size).
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Product quality deviation: CaCO₃ D50 deviates by >10% from the target, or PSD span (D90-D10)/D50 increases by >0.5 (worn media causes uneven grinding).
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Contamination/whiteness loss: For metallic media, CaCO₃ Fe/Cr metal impurity exceeds 50 ppm (industrial grade) / 10 ppm (coating grade), or whiteness drops by >2 points (from steel wear particles).
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Chipping/cracking: Ceramic media has >5% chipped/cracked balls (causes excessive wear of other media/liners and ceramic debris in CaCO₃ powder).
|
CaCO₃ Grade
|
Feed SiO₂ Content
|
Recommended Media Material
|
Typical Lifespan (24h Continuous)
|
Key Benefit
|
|
Industrial (Cement/Construction)
|
0.5–3%
|
High-chromium steel (20–25% Cr)
|
3–6 months
|
Low cost, easy replacement
|
|
High-Purity (Coating/Paper)
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<0.5%
|
92% Alumina ceramic
|
2–3 years
|
Low metal contamination, high whiteness
|
|
Ultra-Fine (D50=2–10 μm)
|
<0.5%
|
ZTA ceramic
|
3–4 years
|
High wear resistance, anti-chipping
|
|
Ultra-High-Purity (Food/Pharma/Nano)
|
<0.5%
|
Zirconia ceramic (wet)
|
4–5+ years
|
Zero metal contamination, chemical inertness
|
|
High-Silica (SiO₂>3%)
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>3%
|
SiC ceramic (dry)
|
2–4 years
|
Extreme wear resistance for abrasive feed
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