Part 1: Product Overview

Calcium Bentonite is a natural layered clay mineral mainly composed of montmorillonite (content 85–90%), with the general chemical formula: Naₓ(H₂O)₄(Al₂₋ₓMg₀.₈₃)Si₄O₁₀(OH)₂. The exchangeable cations between layers are dominated by Ca²⁺. It is named for its characteristics of swelling upon water contact, high adsorption capacity, and strong bonding performance.

China's proven bentonite reserves reach 2.33 billion tons, of which calcium-based bentonite accounts for more than 80%, mainly distributed in Xiuning (Anhui), Lingshou (Hebei), Xinjiang and other regions. Our calcium bentonite is produced from selected high-quality ore through crushing, drying, grinding, and sieving. It appears as a white or off-white powder, featuring fine particle size, high purity, high swelling capacity, and strong bonding strength. It is widely used in foundry, drilling, metallurgical pelletizing, building waterproofing, agriculture, environmental protection, and many other fields.

Part 2: Core Advantages and Characteristics

Swelling upon Water Absorption

Calcium bentonite exhibits significant water-swelling behavior. Its volume can increase by 20–30 times after absorbing water, forming a gel-like substance that effectively fills gaps.

Strong Adsorption Capacity

With a large effective pore volume, it has high adsorption capacity and adsorption loading. After activation, its decolorization power is ≥150, allowing it to be processed into high-efficiency activated clay.

Excellent Bonding Performance

It has good bonding and plasticity. When used in foundry molding sand, it significantly improves green compressive strength, hot-humid tensile strength, and shatter index.

Strong Cation Exchange Capacity

It has a high cation exchange capacity (CEC) and can adsorb heavy metal ions and organic pollutants in water, making it important in water treatment applications.

Good Thermal Stability

It has excellent high-temperature resistance and maintains structural stability under high-temperature environments in metallurgical pelletizing and foundry applications.

Non-toxic and Eco-friendly

As a natural mineral raw material, it is non-toxic, odorless, non-radioactive, safe, and environmentally friendly, suitable for use in food, pharmaceutical, cosmetic, and other industries.

Abundant Resources & High Cost Performance

China has abundant reserves of calcium bentonite, with a mining recovery rate up to 95%, stable pricing, and outstanding cost-effectiveness.

Core Indicators of Calcium Bentonite

Item	Unit	Index Range
Montmorillonite Content	%	85–90
Swelling Ratio	times	20–30
Colloid Index	ml/15g	45–90
Swelling Volume	ml/g	15–20
Moisture Content	%	≤2
Particle Size	mesh	325–600
pH Value	-	8–10

Chemical Composition

Component	SiO₂	Al₂O₃	CaO	Fe₂O₃	MgO
Content %	50.95–61.74	16.08–16.54	2.26–5.01	2–5	2–4

Note: Actual indicators shall be subject to the product test report of your company.

Part 3: Main Application Fields

With excellent adsorption, bonding, and swelling properties, calcium bentonite is widely used in many industries from traditional industries to emerging fields.

1. Foundry Industry

Calcium bentonite is an ideal binder for foundry molding sand and plays an irreplaceable role in mechanical foundry sand binders.

Improve Casting Quality

Good air permeability overcomes the poor permeability of ordinary clays, avoiding defects such as blowholes, sand inclusion, and peeling, greatly reducing the rejection rate of castings.

High Temperature Resistance & Easy Sand Removal

Excellent high-temperature resistance; easy sand cleaning after pouring, improving casting precision and surface finish.

Performance Indicators

Green compressive strength of foundry molding sand ≥90 kPa, with significantly improved hot-humid tensile strength.

Specific Effects

Reduce molding sand moisture and decrease casting defects caused by excessive moisture.

Improve permeability of green sand with low gas evolution, preventing blowholes.

Good toughness, plasticity, and wettability on sand surfaces, resulting in dense and smooth casting surfaces.

Enhance flowability of molding sand, shorten sand mixing time, and improve equipment utilization.

Good collapsibility for easy sand removal, shorten shot blasting time, and improve efficiency.

2. Metallurgical Pelletizing

In the metallurgical industry, calcium bentonite acts as a binder for iron ore concentrate pellets, improving pellet strength via its bonding properties.

Dosage Standard

20–25 kg of calcium bentonite per ton of iron ore concentrate pellets.

Mechanism

With high bonding and thermal stability, it maintains pellet integrity during high-temperature roasting and improves yield.

3. Drilling Mud

Calcium bentonite is used to prepare mud suspensions in oil and gas drilling engineering, reducing drilling accident rates.

Mud Performance

Provides good suspension, thixotropy, and filtration control when used as drilling mud flushing fluid.

Engineering Value

Helps remove cuttings, reduce fluid loss, enhance wellbore integrity, and has good compatibility with various additives.

Application Scope

Widely used in onshore and offshore drilling operations.

4. Construction & Civil Engineering

Calcium bentonite is widely used in construction due to its sealing and water-retention properties.

Waterproof & Anti-seepage Materials

Used in waterproof membranes and sealing layers for tunnel linings, foundations, landfills, dams, etc. It forms a low-permeability barrier after hydration to prevent water leakage.

Engineering Application

Used as a basic anti-seepage material in the South-to-Northorth Water Diversion Project.

Green Building

Its natural, non-toxic composition supports green building practices.

5. Environmental Protection & Water Treatment

Wastewater Treatment

Used as an adsorbent to remove heavy metal ions and organic pollutants.

Radioactive Waste Absorption

Used as an absorbent for radioactive waste.

Waste Gas Treatment

Used to remove SO₂ from sulfur-containing flue gas.

6. Agriculture & Soil Improvement

ISoil Conditioner

Improves soil structure, enhances water and nutrient retention, and increases nutrient utilization efficiency.

Fertilizer Carrier

Used as a carrier, diluent, or insecticide in pesticides; as a binder, granulating agent, slow-release agent, and coating agent in fertilizers.

Feed Additive

Used as a binder, adsorbent, desiccant, and nutrient additive in animal feed, with ammonia adsorption ≥150 mg/100g.

7. Coatings & Chemical Industry

Coating Thickening

Used as a thickener, suspending agent, and rheology modifier in coatings to improve viscosity, stability, and durability.

Filler

Used as a filler, thickener, and suspending agent in chemical products.

Decolorizer

After activation, used for refining and decolorizing animal and vegetable oils, and for decolorization and purification in the petroleum industry.

8. Personal Care & Cosmetics

Rising consumer awareness of natural ingredients and mineral skincare products drives market demand for calcium bentonite.

Detox & Skincare

Provides detoxification and exfoliation effects, used in masks, cleansers, scrubs, etc.

Clean Beauty

Aligns with the "clean beauty" trend, promoted by product innovation and marketing.

Part 5: Product Specifications and Technical Parameters

Product Series

Product Type	Specification (Mesh)	Montmorillonite Content	Swelling Ratio	Main Application
Foundry Grade	200, 270, 325	≥85%	≥15	Foundry sand binder, mold forming
Metallurgical Grade	200, 325	≥85%	≥15	Iron ore pellet binder
Drilling Grade	200, 325	≥80%	≥20	Drilling mud suspending agent
Building Material Grade	100, 200, 325	≥80%	≥15	Waterproof materials, anti-seepage projects
Chemical Grade	325, 400	≥85%	≥15	Coating thickener, catalyst carrier
Activated Clay Raw Material	200	≥85%	≥15	For decolorization and refining after activation
Feed Grade	200, 325	≥80%	-	Feed additive, carrier

Technical Indicators

Item	Index
Montmorillonite Content	≥85%
Swelling Volume	≥15 ml/g
Colloid Index	≥45 ml/15g
Water Absorption	≥150%
Moisture	≤12%
Particle Size (200/325 mesh)	≥95% pass
pH Value	8–10
Green Compressive Strength	≥90 kPa