Part 1: Product Overview

Microcrystalline graphite, also known as cryptocrystalline graphite or earthy graphite, is an important form of natural graphite. Its crystal diameter is usually less than 1 micrometer, and the crystal shape can only be observed under an electron microscope. It features an earthy or massive structure, hence the common name "earthy graphite". As one of the crystalline carbon minerals, it is grayish-black or steel-gray with metallic luster, soft in texture (Mohs hardness 1–2), greasy to the touch, and easily stains hands.

China has the world's largest reserves of microcrystalline graphite, with a predicted resource volume of approximately 1 billion tons and an annual output accounting for more than 80% of the global total. It is mainly distributed in Lutang (Chenzhou, Hunan), Panshi (Jilin), Inner Mongolia, and other regions. Among them, the Lutang mining area in Chenzhou, Hunan Province, accounts for over 70% of the national total reserves and is known as "gold sand".

Our microcrystalline graphite products are selected from high-quality ore sources in Chenzhou, Hunan, with a fixed carbon content of up to 60%–88% (some exceeding 90%) and extremely low contents of sulfur, iron, and other impurities. The products are divided into two categories:

WT Series: With strict iron control, suitable for high-end fields such as batteries.
W Series: Without iron restrictions, suitable for traditional fields such as foundry.

The particle size fully covers from 45 mesh to 12,000 mesh. They are widely used in more than 20 fields, including foundry release agents, refractory materials, battery electrodes, pencil and welding rods, carburants, and anti-corrosion coatings.

Core Value of Microcrystalline Graphite

As the most abundant and cost-effective type of natural graphite, microcrystalline graphite plays an irreplaceable role in both traditional industries and new energy sectors due to its unique microcrystalline structure, high grade, and low impurity characteristics.

Part 2: Core Advantages and Properties

Fine Crystals & Strong Plasticity

Crystal diameter < 1 μm, specific surface area 1–5 m²/g. It has excellent plasticity and adhesion, forming a dense and smooth coating in foundry applications to prevent sand adhesion.

Excellent Chemical Stability

Chemically stable, unaffected by strong acids and alkalis, with outstanding high-temperature resistance: melting point ≈ 3800–3900°C (4073–4173 K), boiling point 4250°C.

High Fixed Carbon & Superior Grade

Raw ore fixed carbon is generally 60%–85%, and high-quality ore can exceed 90%. After purification, it can meet high-end application requirements, with high-purity products reaching above 99.99% fixed carbon.

Low Harmful Impurities

Extremely low contents of sulfur, iron, phosphorus, nitrogen, molybdenum, hydrogen, etc. The WT Series has strict limits on acid-soluble iron; the top-grade WT99.99 Series controls acid-soluble iron ≤ 0.005% (50 ppm), satisfying requirements for batteries and special carbon materials.

Good Electrical & Thermal Conductivity

Excellent electrical and thermal conductivity, suitable for battery electrodes and conductive materials.

Good Lubricity

Natural self-lubricating property with low friction coefficient, usable as a solid lubricant.

National Standard Grading & Complete Specifications

WT Series (iron-controlled)	Fixed carbon 75%–99.99%, strict acid-soluble iron control, for batteries and special carbon materials.
W Series (non-iron-controlled)	Fixed carbon 50%–90%, for foundry, refractories, dyes, etc.

Key Indicators of Microcrystalline Graphite (reference GB/T 3519-2008/2023)

Item	Unit	Range
Fixed Carbon Content	%	50–99.99 (adjustable)
Volatile Matter	%	0.8–4.5
Moisture	%	0.2–3.0
Acid-Soluble Fe (WT)	%	0.005–1.0
Particle Size	mesh	45–12000
Melting Point	°C	3850±50
Density	g/cm³	2.09–2.23
Specific Surface Area	m²/g	1–5

Note: Actual indicators are subject to the product test report.

Part 3: Microcrystalline Graphite vs. Flake Graphite

Item	Microcrystalline Graphite	Flake Graphite
Crystal Diameter	< 1 μm (visible under electron microscope)	0.05–1.5 mm (visible to naked eye)
Crystal Structure	Cryptocrystalline aggregate, microcrystalline	Hexagonal layered, well-crystallized
Raw Ore Grade	60%–85%, few over 90%	2%–25%
Specific Surface Area	1–5 m²/g	Smaller
Washability	Poor (impurities closely associated)	Excellent (good floatability)
Lubricity	Good	Best
Plasticity	Excellent, strong adhesion	Excellent
Luster	Steel-gray, metallic luster	Strong metallic luster
Main Applications	Foundry coatings, battery electrodes, carburants	Refractories, anode materials, expanded graphite
Price	Lower (cost-effective)	Higher
China Reserves	World's richest	Abundant

Part 4: Main Application Fields

Microcrystalline graphite is widely used in traditional and new energy industries due to its high grade, low impurities, microcrystalline structure, and excellent plasticity.

1. Foundry Industry (Traditional Core Application)

Indispensable release agent and coating raw material for foundry.

Functions:

Release agent / mold coating: Forms a smooth film to prevent sand adhesion and improve surface finish.

Lubrication: Improves flowability and mold release performance.

Anti-permeability: Blocks surface pores to prevent molten iron penetration.

Typical Uses:

Manual molding of thin-walled small castings

Mold coatings for smoothness, reduced cracks and porosity

Foundry release agents, graphite sand, graphite balls

Recommended Grade: W Series, fixed carbon 65%–85%, particle size 100–325 mesh.

2. Battery & Electro-carbon Products (High-Growth Sector)

Especially WT Series with strict iron control.

Applications:

Battery carbon rods for dry and alkaline batteries

Cathode conductive additives

Lithium-ion battery anode materials: high graphitization, stable voltage platform, low cost, high lithium intercalation capacity; usable after coating, purification, and modification

Electrode compounds

Recommended Grade: WT Series, fixed carbon 99.9%–99.99%, strict acid-soluble iron control, particle size -45 μm or -75 μm.

3. Refractory & Metallurgical Industry

Refractory ingredients: refractory bricks, castables

Steelmaking carburant: increases carbon content in steel

Ingot casting mold powder: prevents oxidation

Electrode paste raw material

4. Pencil & Welding Electrode Industry

Pencil leads

Welding electrode coatings

Graphite emulsion for wire drawing and forging release

Recommended Grade: WT/W Series, fixed carbon 94%–99%, particle size -45 μm or -75 μm.

5. Lubrication & Friction Materials

Solid lubricants for machinery

Lubricating oil additives

Graphite bearings

6. Anti-Corrosion Coatings & Functional Coatings (Emerging)

Waterborne anti-corrosion coatings: "tortuous effect" blocks corrosive media

Conductive coatings

Road anti-skid coatings

7. New Energy & Advanced Technology

Lithium-ion battery anodes (modified porous microcrystalline graphite)

Supercapacitors

Graphene raw material

Wave-absorbing materials

Isotropic graphite for high-end applications

8. Other Applications

Flue gas desulfurization

Industrial anti-corrosion

Black pigments and dyes

Oilfield drilling fluid additives

Rubber & plastic functional fillers

Part 5: Product Specifications & Technical Parameters

Classified according to GB/T 3519-2008/2023.

Product Series Overview

Series	Code	Fixed Carbon	Iron Requirement	Main Applications
WT (Iron-controlled)	WT99.99–WT75	75–99.99%	Strict acid-soluble Fe control	Batteries, special carbon, pencils
W (General)	W90–W50	50–90%	No iron restriction	Foundry, refractories, dyes

WT Series (Iron-Controlled)

Grade	Fixed Carbon ≥	Volatile Matter ≤	Moisture ≤	Acid-Soluble Fe ≤	Main Applications
WT99.99-45/-75	99.99	–	0.2	0.005	Batteries, special carbon
WT99.9-45/-75	99.9	0.8	1.0	0.15	Pencils, batteries, welding rods
WT99-45/-75	99	0.8	1.0	0.15	Pencils, batteries, welding rods
WT98-45/-75	98	1.0	1.5	0.4	Pencils, batteries, welding rods
WT95-45/-75	95	–	1.5	0.4	Pencils, batteries, welding rods
WT90-45/-75	90	2.0	–	–	Release agents, bearings
WT80-45/-75	80	–	–	–	Release agents, bearings

W Series (Non-Iron-Controlled)

Grade	Fixed Carbon ≥	Volatile Matter ≤	Moisture ≤	Main Applications
W90-45/-75	90	3.0	–	Foundry, refractories, dyes
W85-45/-75	85	3.4	–	Foundry, refractories, dyes
W80-45/-75/-150	80	3.6	–	Foundry, refractories, dyes
W75-45/-75/-150	75	4.0	3.0	Foundry, refractories, dyes
W70-45/-75/-150	70	4.2	–	Foundry, refractories, dyes
W65-45/-75/-150	65	4.2	–	Foundry, refractories, dyes
W60-45/-75/-150	60	4.5	–	Foundry, refractories, dyes
W50-45/-75/-150	50	4.5	–	Foundry, refractories, dyes

Particle Size Specifications

Model	Size	Typical Applications
-45	≤45 μm (~325 mesh)	Battery materials, high-end coatings
-75	≤75 μm (~200 mesh)	General use, pencils, welding rods
-150	≤150 μm (~100 mesh)	Foundry, refractories
100–325 mesh	Standard industrial	Foundry release, bearings
800–12000 mesh	Ultra-fine powder	Anti-corrosion coatings, oil additives