Expanded Vermiculite[3]
Overview
Expanded vermiculite is a hydrous phyllosilicate mineral processed through exfoliation at high temperatures (900-1000°C), causing it to expand into accordion-like layers. This natural material is prized for its combination of thermal insulation, fire resistance, and water retention properties. Originally mined from metamorphic rocks, commercial vermiculite undergoes expansion to increase its volume by 8-30 times. The resulting lightweight flakes are chemically inert, odorless, and resistant to mold, making them suitable for diverse industrial applications. Major producers include South Africa, China, and the United States.
Physical and Chemical Properties
The expansion process creates a porous structure with trapped air pockets, yielding a density of 60-130 kg/m³ and thermal conductivity of 0.05-0.07 W/(m·K). Its layered silicate composition provides exceptional heat resistance, sustaining temperatures up to 1100°C without structural failure. Chemically, vermiculite exhibits high cation exchange capacity (CEC) due to its negatively charged layers, enabling nutrient retention in agricultural uses. The material is pH-neutral (7.0-7.5) and maintains dimensional stability across temperature fluctuations. Unlike organic insulators, it is non-combustible and emits no toxic fumes when exposed to fire.
Main Applications
In construction, expanded vermiculite is blended with cement or gypsum to create lightweight insulating concretes and fireproof sprays. It accounts for approximately 40% of the global refractory market due to its high melting point. Horticultural applications leverage its water retention (3-4 times its weight) and aeration properties as a soil amendment or standalone hydroponic medium. Industrial uses include brake linings, packaging materials, and as a carrier for fertilizers or pesticides. Recent innovations include its use in sustainable building systems and as an absorbent for hazardous spills.
Safety and Storage
While non-toxic, vermiculite dust may cause mechanical irritation to eyes and respiratory systems. OSHA recommends P2/N95 masks and goggles during bulk handling. Historical concerns about asbestos contamination (primarily from Montana deposits) have been addressed through modern quality controls. Storage requires protection from moisture to prevent compaction. Bulk bags should be stacked no higher than 3 layers to maintain flake integrity. Unlike fiberglass insulation, vermiculite requires no special disposal procedures, though local regulations for silicate materials should be verified.
B2B Procurement Guide
Key specifications include expansion ratio (higher ratios indicate better insulation), bulk density (lower for lightweight applications), and particle size distribution (coarse grades for construction, fine for horticulture). Verify certificates for heavy metal content (especially cadmium and lead) and absence of asbestos. For construction projects, request fire resistance test reports (ASTM E136) and thermal conductivity data (ASTM C518). Leading manufacturers provide customized gradations and hydrophobic treatments for specialized applications. Container-load purchases (typically 20-25 m³) often yield 15-20% cost savings versus palletized shipments.
Related Manufacturers
- 主营：--
- 主营：五彩石、黑色鹅卵石、机制鹅卵石、膨胀蛭石、彩砂、陶瓷球、染色彩砂、造景彩砂、粉色彩纱、烧结彩砂、钢渣、黏土、夜光石、铁砂、玻璃砂
- 主营：磁粉、铁粉、铁砂、硅藻土、膨润土、轻钙、重钙、氢氧化钙、氧化钙、煅烧滑石粉、膨润土颗粒、硅灰、活性白土、萤石粉、石英粉、高岭土、沸石粉、煅烧高岭土、莫来砂、珍珠岩粉、玻璃粉、贝壳粉、远红外粉、凹凸棒土
- 主营：海泡石、矿物纤维、绿沸石、蛭石、膨胀珍珠岩颗粒、滑石粉、金刚砂、膨润土、硅灰、核桃壳粒、石英粉、小石子、云母粉、云母片、增碳剂、珍珠岩、玻璃纤维、木粉、漂珠、石棉绒、绿沸石粉、绿沸石颗粒、木质纤维、云母矿、石英砂
- 主营：玻璃粉、火山石粉、云母粉、蛭石、云母片、电气石粉、陶瓷砂、石英粉、莫来石粉、硅酸铝粉、轻钙粉、珍珠岩颗粒、透明粉、铝矾土、重钙粉、煅烧高岭土、玻璃鳞片、煅烧贝壳粉、硅灰石粉、高硅滑石粉、低硅滑石粉、全加密硅灰、半加密硅灰
- 主营：云母、轮胎粉、彩砂、蛭石、蛭石板、阻火模块、石英砂、无石棉矿物复合纤维、木质纤维、海泡石
- 主营：石油焦、石墨粉、海泡石、膨胀石墨、蛭石、矿物纤维、云母、橡胶颗粒、轮胎粉、漂珠、重晶石、膨润土、碳酸钙、叶腊石、人造石墨、鳞片石墨、木质纤维、喷涂棉、钾长石、氧化铝、铝矾土、滑石粉、配重砂、硅藻土
- 主营：鸡蛋托、营养土、纸浆蛋托、蛭石粉、膨胀蛭石、蛭石颗粒、保温材料、保温防火材料、建筑工程蛭石、育苗扦插蛭石、龟蛇孵化蛭石、宠物卵化用蛭石、防火涂料、火山岩板、发根育苗、土壤改良、锂辉石粉、磁铁矿粉、塑料蛋托、建筑涂料、绿色沸石粉、生物质颗粒、园艺多肉植物、纳米仿瓷颗粒、园艺种植土壤
- 主营：硅藻土、椰糠、稻壳碳、蛭石、金刚砂、玻璃粉、麦饭石、火山石、重晶石、高岭土、白炭黑、玻璃砂、贝壳粉、氧化铁、重钙、沸石
- 主营：铁砂、玻璃粉、高岭土、蛭石、染色玉米芯、白炭黑、轮胎塑料、滑石粉、石英砂、云母、发酵树皮、防火涂料、火山石、硅灰、硅藻土、生物质颗粒、玻璃砂、氧化铁、椰糠、水洗贝壳粉、白色石英砂、化妆品陶瓷、阻燃防火涂料
- 主营：火山石、火山岩、火山石板材、火山石粉、硅藻土、铁粉、氧化钙、松树皮、云母、氧化镁、竹炭、活性炭、灌浆料、陶粒、玻璃块、锆英砂、重晶石粉、木粉、锆英粉、硅酸锆、萤石
- 主营：硫酸钡、海泡石粉、小苏打、膨胀蛭石、碳酸钙、生石灰、熟石灰、煅烧高岭土、硅藻土、工业尿素、三聚氰胺、氧化铁颜料
- 主营：石墨、导电石墨粉、防静电墨粉、膨胀石墨、阻燃石墨粉、鳞片石墨粉、超细石墨粉、云母、云母片、茶色云母片、云母粉、电气石、电气石粉、电气石颗粒、天然云母片、透明云母片、导热石墨、绝缘云母片、耐高温云母、云母板、岩片、贝壳片、膨润土、钙基膨润土、纳基膨润土
- 主营：润滑剂、石墨粉、超细石墨粉、膨胀蛭石粉、阻燃石墨、超细石墨、高纯石墨、煅烧高岭土、耐火泥造纸、润滑石墨铅粉、合成氟金云母粉、高岭土、种子包衣粉、麦饭石粉、白色电气石粉、远红外粉、导电石墨粉、耐高温石墨粉、云母片、天然云母片、耐高温云母片、透明云母片、云母板、沸石、沸石粉、麦饭石颗粒
- 主营：贝壳粉、硅灰、重钙、蛭石粉、轻钙、碳酸钙粉、膨润土、煤矸石粉、硅酸铝粉、硅酸铝纤维、滑石粉、珍珠岩粉、方解石粉、硅藻土、玻璃粉、氧化镁粉、白云石粉、火山石粉、铝矾土、全加密硅灰、半加密硅灰
- 主营：水晶盐、水草沙、草坪沙、蛭石、目沙子、白沙子、玻璃砂、轻钙粉、核桃壳、矿物质、夜光石、火山石、雪花白、玻璃粉、养生房、金刚砂、粘土粉、烘干河、火焰沙、烘干沙、高岭土、白石子、赤铁粉、硅藻土、娱乐沙、圆粒沙