CO₂ Gas-Hardened Sand Molding & Acid-Proof Refractory Cement with Sodium Silicate Na₂SiO₃
Rapid Carbon Dioxide gas-hardened sand casting (Sodium Silicate-CO₂ Sand Process) and acid-resistant refractory silicate cement manufacturing utilizing Liquid Sodium Silicate (Na₂SiO₃, silicate modulus n = 2.4 - 3.3, delivered via dedicated 5–30-ton road tankers or 300kg drums) from Loc Thien Chemical serve as vital technological foundations across precision metallurgical foundries and chemical engineering civil works. Injecting pressurized CO₂ gas triggers sol-gel silica transformation within 60–90 seconds, producing a rigid SiO₂ · mH₂O binder matrix achieving instantaneous compressive strengths exceeding 1.5 MPa and eliminating 70% of casting gas porosity defects. Concurrently, potassium/sodium silicate-based cements resist boiling H₂SO₄, HCl, and HNO₃ at temperatures up to 900°C. Technical proposals delivered within 15 minutes via Hotline: +84 979 891 929.
1. Chemical Sol-Gel Hardening Kinetics of Silicate-CO₂ Sand
Sodium silicate adheres to the stoichiometry Na₂O · nSiO₂, where the modulus (n) denotes the molar ratio of silica to soda. Gaseous CO₂ permeation triggers instantaneous sol-gel polymerization:
Silica gel coats quartz sand grains rapidly, forming strong mechanical micro-bridges across the entire mold structure. Regulating gassing duration at 0.15–0.20 MPa delivers superior surface hardness while preserving mold permeability during molten metal pouring.
2. Acid-Resistant Silicate Refractory Cement Formulations
Acid-proof mortars are compounded by blending Liquid Sodium Silicate (modulus 2.6–2.8) with quartz fillers and Sodium Fluorosilicate (Na₂SiF₆) curing catalysts:
The cured inorganic silica polymer resists all mineral acids (except hydrofluoric acid HF), functioning as the gold standard for lining electroplating chemical tanks, fertilizer plant floors, and thermal power plant flues.
3. Loc Thien Sodium Silicate Technical Specifications
| Specification | Foundry Grade (CO₂ Gassing) | Acid-Proof Cement & Civil Grade |
|---|---|---|
| Silicate Modulus (M) | 2.2 – 2.5 (Fast set, easy breakout) | 2.6 – 3.2 (Maximum compressive acid resistance) |
| Density (°Baumé at 20°C) | 48 – 52 °Bé | 40 – 45 °Bé |
| SiO₂ Content | ≥ 28.5% | ≥ 26.0% |
| Supply Format (SSOT) | 5–30-ton Road Tankers / 300kg Drums | 5–30-ton Road Tankers / 300kg Drums |
4. B2B Case Study: 800 Tons/Month Steel Casting Foundry in Nam Sach (Hai Duong)
Stainless Steel Pump Housing Foundry Conversion
- Initial Challenge: Traditional bentonite sand required 4–6 hours of oven baking, causing an 11.5% defect rate from mold distortion and blowholes.
- Loc Thien Solution: Converted to Loc Thien Liquid Sodium Silicate (modulus 2.3) at 4.2% sand binder, with automated CO₂ gas injection at 0.18 MPa curing molds in 90 seconds.
- Audited Results: Mold fabrication cycle dropped from 4 hours to 15 minutes. Porosity defects plunged from 11.5% to under 1.5%, yielding 380 million VND/month in net savings.
5. Frequently Asked Questions (FAQ)
What is the optimum silicate modulus to ensure good mold collapsibility?
To facilitate clean shakeout (collapsibility), maintain the modulus within 2.2 – 2.4 and limit liquid silicate content to under 4.5% by weight. Over-gassing or excessive silicate will vitrify molds into rock-like masses upon steel pouring.
6. Modifying Silicate Sand Collapsibility & Shakeout Enhancement
To eliminate high-temperature sintering of sodium silicate sand molds after pouring (>1,200^°C), integrate 1.0%–1.5% combustible carbonaceous additives (coal dust or starch). Burning out during cooling creates micro-voids, enabling effortless mold shakeout without casting fracture.
7. Formulating Acid-Proof Silicate Cements (ASTM C398)
Blend Loc Thien Liquid Sodium Silicate Na₂SiO₃ (5–30-ton tankers) with 12%–15% sodium fluorosilicate (Na₂SiF₆) hardener and quartz filler. Cured silicate mortars resist concentrated mineral acids (Sulfuric Acid H₂SO₄, Hydrochloric Acid HCl) up to 900°C. Calculate mix proportions via Loc Thien Online Dosage Calculator and review our industrial bulk chemical catalog.
⚡ Request Liquid Sodium Silicate Bulk Quotation (15-Minute Response)
Loc Thien Chemical delivers bulk Liquid Sodium Silicate via dedicated 5–30-ton tankers nationwide.
- Direct B2B Technical Hotline: +84 979 891 929
- Official Corporate Email: [email protected]