Overview
Light gray bentonite is a naturally occurring clay mineral composed primarily of montmorillonite. This phyllosilicate mineral is formed from volcanic ash weathering and is characterized by its distinctive light gray color and fine, powdery texture. Bentonite's unique properties stem from its layered structure and high cation exchange capacity, which enable it to absorb water and swell significantly. Industrial classification typically divides bentonite into sodium bentonite (high swelling) and calcium bentonite (low swelling), with light gray varieties often being sodium-rich. The material is mined through open-pit methods and processed through drying, milling, and sometimes activation treatments to enhance specific properties for different applications.
Physical and Chemical Properties
The physical properties of light gray bentonite include a soft, earthy texture with particle sizes ranging from 1-200 microns. When mixed with water, it can expand up to 16 times its original volume, forming a viscous, thixotropic gel. This swelling behavior is due to water molecules entering the interlayer spaces between the aluminosilicate sheets. Chemically, bentonite exhibits high cation exchange capacity (80-150 meq/100g) and surface area (around 750 m²/g). Its composition includes silica (50-70%), alumina (15-20%), and smaller amounts of iron, magnesium, and calcium oxides. The light gray coloration typically indicates lower iron content compared to darker bentonite varieties, making it preferable for applications where color matters.
Main Applications
In foundry applications, light gray bentonite serves as an essential binding agent for molding sands, providing green strength and thermal stability during metal casting. Its high plasticity and bonding strength make it ideal for creating precise molds that can withstand molten metal temperatures. The construction industry utilizes bentonite in waterproofing applications, particularly in slurry walls and as a sealant for ponds and landfills. Its swelling properties create an impermeable barrier when hydrated. In agriculture, it improves soil water retention and nutrient delivery, while in environmental applications, it's used for wastewater treatment and spill containment due to its adsorption capabilities.
Safety and Storage
While bentonite is generally non-toxic, the fine dust particles can pose respiratory hazards during handling. Appropriate personal protective equipment including dust masks and eye protection should be used in industrial settings. Prolonged skin contact may cause dryness, requiring moisturizing creams for workers. Proper storage involves keeping the material in moisture-resistant packaging in a dry warehouse environment. Bulk storage should be in silos or covered containers to prevent moisture absorption, which can lead to clumping. The material is stable under normal conditions but should be protected from extreme temperatures that might affect its moisture content and performance characteristics.
B2B Procurement Guide
When procuring light gray bentonite, buyers should specify the required montmorillonite content, swelling index (typically 20-30 ml/2g), and moisture content (usually 8-12%). Industrial buyers often require certification of chemical composition and physical properties to ensure consistency for manufacturing processes. Quality indicators include the material's free swell volume, viscosity in water, and methylene blue absorption value. For bulk purchases, consider logistical factors like moisture protection during transportation. Established mining regions include Wyoming (USA), Greece, and China. Always request samples for performance testing before large orders, and verify the supplier's ability to provide consistent quality across batches.
Related Manufacturers
- 主营：树脂合、木质素、分析纯、膨润土、化学试剂、涂覆金属、己二醇酯、油墨pu树脂、水性pu树脂、二乙二醇酯、二酸二甲酯、聚酯多元醇、树脂固化剂、水性聚氨酯、聚酰胺树脂、聚氨酯树脂、聚氨酯弹性体、水性喷墨打印、聚碳酸酯二醇、面料柔软整理、己二酸乙二醇、改性聚酰亚胺
- 主营：猫沙膨润土、硫酸钡
- 主营：润滑剂、石墨粉、超细石墨粉、钠基膨润土、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：氟金云母、云母片、云母粉、膨润土、高岭土、滑石粉、碳酸钙、石墨粉、电气石、岩片、陶土、海泡石、白炭黑、重晶石粉、沸石、石英砂、透明粉、粘土、蛭石、硅藻土、玻璃鳞片、果壳粉
- 主营：特种混凝土、铁砂混凝土、配重混凝土、膨润土、铁矿石混凝土、防辐射混凝土、重晶石混凝土、耐高温混凝土、钢砂混凝土、桥梁配重、钢箱梁配重、硫酸钡混凝土、铁屑混凝土、铁屑砂浆、防辐射砂浆、耐高温砂浆、不发火混凝土、配重材料、含硼混凝土、钢珠混凝土、钢渣混凝土、钢箱梁铁砂混凝土、配重铁砂混凝土、铁砂压重混凝土、压重铁砂混凝土、桥梁铁砂混凝土
- 主营：粘结剂、免烘干、粘合剂、膨润土、肥料造粒、变性淀粉、糊化淀粉、阿尔法淀粉、玉米预糊化、预糊化淀粉、免烘干粘合剂、型煤粘合剂、除尘灰粘合剂、焦粉粘合剂、肥料造粒剂、型煤胶粉、铁粉粘合剂、氧化铁皮粘结剂、氧化铁粉、除尘灰脱锌粘合剂、焦炭块、焦末、焦沫、新型焦炭、石墨增碳剂、增碳剂造粒
- 主营：油漆陶瓷原料、添加用硅酸铝粉、煅烧高岭土、膨润土、水洗高岭土、滑石粉、黄陶土、红陶土、轻质碳酸钙、重质碳酸钙、铝矾土、重晶石粉、石英砂、沸石粉、海泡石
- 主营：石墨、膨胀石墨、导电石墨粉、膨润土、钙基膨润土、纳基膨润土、防静电墨粉、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
- 主营：高岭土、重质碳酸钙、碳酸钙、膨润土、滑石粉、海泡石、石灰石、硅藻土、一级矿粉、萤石矿石、活性钙、沉淀硫酸钡、氢氧化钙、氧化钙、透明粉、硅酸铝粉、贝壳粉、彩砂、轻钙、萤石粉、水镁石、矿粉、铸石粉、浴沙、金玉明砂
- 主营：煅烧高岭土、轻质碳酸钙粉、硅藻土、膨润土、重质碳酸钙粉、硅灰粉、白云石粉、矿粉、火山石粉、滑石粉、粉煤灰、陶土粉、珍珠岩粉、石英粉、玻璃粉、重晶石粉、夜光石粉、变压器鹅卵石、水洗石、夜光石、火山石切片、彩色石子、石英砂、黑色金刚砂、鹅卵石切片
- 主营：重钙粉、轻钙粉、重质碳酸钙、钙基膨润土、钠基膨润土、轻质碳酸钙、碳酸钙、超细氢氧化钙、生石灰粉、猫砂矿砂、报纸纤维、脱硫石灰石粉、石英砂、白沙子、天然水洗石、卵石砾石、水磨石、白色黑色鹅卵石、天然鹅卵石、天然彩砂、染色彩砂、高岭土、五彩石、贝壳颗粒、圆粒砂海沙
- 主营：水晶盐、水草沙、草坪沙、饲料级膨润土颗粒、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
- 主营：超细硅酸铝粉、硅藻土、高岭土、膨润土、滑石粉、彩砂、透明粉、白炭黑、金刚砂、石墨、海泡石、木粉、轻钙、重钙、玻璃粉、贝壳粉、凹凸棒土、玻璃鳞片、陶土、铝矾土、火山岩、电气石粉、合成云母、赤铁粉
- 主营：真石漆、沙子全、腻子粉、膨润土、粘土球、白沙子、烘干沙、40目河沙、烘干河沙、水族婚庆、抗裂砂浆、钙粉工业、塑料橡胶、喷砂除锈、环氧草坪、人造沙滩、石粉填充、砂浆抹面、钻井泥浆、公园造景、石粉砂浆、石粉沙子、白色沙子、pvc填充料、河沙园艺
- 主营：轻质碳酸钙、4A沸石粉、重晶石粉、膨润土、配重铁粉 铁砂、氢氧化钙、红陶土 黄陶土、木粉、麦饭石粉、沸石粉、煅烧高岭土、水洗高岭土、滑石粉、负离子粉、硅藻土、白云石粉、玻璃鳞片、高铝耐火粉、蓝晶石粉
- 主营：氧化铁颜料、石墨粉、硅藻土、饲料级膨润土、二氧化硅、电气石、滑石粉、硅酸铝粉、硅灰石粉