Sheet‑type flame retardants are core fire‑prevention and control materials used in underground coal mines. They inhibit the oxidative spontaneous combustion of coal through a triple mechanism—oxygen barrier film formation, endothermic cooling, and chemical inertization—and comply with the MT/T 700‑2019 industry standard.

Flaky Inhibitor

Product Overview

The sheet‑type inhibitor is a chemical agent specially designed for fire prevention and suppression in underground coal mines, serving as a core protective material to ensure safe mine operations. It can be sprayed or injected onto the coal surface, forming an oxygen‑blocking inhibitory film while absorbing heat generated by coal oxidation. Simultaneously, through its chemical inerting effect, it effectively prevents coal from oxidizing and spontaneously combusting. This product comes in solid sheet form with neat edges and uniform thickness, resistant to caking, making it easy to store and transport. During dissolution, it gradually releases active ingredients, suitable for batch liquid preparation on site. When stored under sealed, moisture‑proof conditions, it remains stable for up to two years, fully meeting the practical operational needs of coal mines.

Technical Principle

The mechanism of action of the sheet‑type inhibitor enables effective control of spontaneous coal combustion across three key levels: First, oxygen isolation via film formation—after dissolving in water, the inhibitor is sprayed or injected into coal pores and fractures, penetrating the coal’s bedding planes and microcracks. Its strong hygroscopic properties allow it to form a stable, anti‑oxidation liquid inhibitory film on the coal surface, directly preventing contact between coal and oxygen, thus providing fundamental oxygen‑blocking inhibition. Second, heat absorption and cooling—the evaporating inhibitor solution absorbs the heat released during coal oxidation, preventing heat accumulation and making it difficult for the coal to reach its autoignition temperature, a critical step in suppressing spontaneous combustion. Finally, chemical inerting—its molecules bond with coal molecules to form relatively stable compounds, reducing the coal’s oxygen‑absorbing capacity and decreasing free radicals involved in coal‑oxygen reactions, thereby prolonging the low‑temperature oxidation process and offering deep‑seated protection against self‑ignition.

Performance Parameters

1. Product Form: Solid sheets with neat edges and uniform thickness, resistant to caking, facilitating handling and storage.
2. Packaging Specifications: Typically available in 25 kg or 50 kg plastic woven bags.
3. Shelf Life: Two years when stored under sealed, moisture‑proof conditions.
4. Inhibition Efficiency: According to MT/T 700-2019 standards, the inhibition rate for lignite and bituminous coal is no less than 40%; magnesium chloride inhibitors achieve an average inhibition efficiency of 63.6% for gas coal, while calcium chloride delivers an average efficiency of 47.6% for long‑flame bituminous coal.
5. Usage Concentration: Requires dilution into a 15%–35% solution before application.
6. Application Dosage: Apply 0.5–1.5 liters per square meter of coal surface (adjusted according to coal moisture); spray working faces every 3–5 days and coal piles every 7–10 days.
7. Compliance Standards: Meets the industry standard MT/T 700-2019 “General Technical Requirements for Fire‑Prevention Inhibitors in Coal Mines.”

Core Advantages

1. Outstanding Sheet Form: Compared to powdered products, the sheet‑type inhibitor features neat edges, uniform thickness, and resistance to caking, making it easier to handle and store long term. Under sealed, moisture‑proof, and waterproof conditions, it remains stable for two years, perfectly aligning with the practical needs of coal mines for phased procurement and use, significantly reducing storage and transportation challenges.
2. High Inhibition Efficiency and Remarkable Fire‑Prevention Performance: It effectively penetrates coal bedding planes and fine cracks, forming a stable anti‑oxidation liquid film on the coal surface that fully encapsulates coal particles and isolates oxygen. Key active ingredients such as magnesium chloride and calcium chloride demonstrate excellent inhibition effects on lignite, long‑flame coal, and gas coal, effectively curbing spontaneous oxidation and combustion.
3. Versatile Application Methods: Can be diluted into a 15%–35% solution for spraying, mixed into yellow mud slurry for injection into underground workings, or injected via drilling. Suitable for various scenarios including mining faces, old goafs, floating coal, mined-out areas, high‑temperature zones, and fire‑prone regions, addressing diverse fire‑prevention needs.
4. Solid Technical Credentials: Manufactured by Weifang Jiangchang Chemical Supply Co., Ltd., established on January 9, 2015. With many years of experience in the chemical industry, the company boasts a registered capital of RMB 16.5 million, occupies over 8,000 square meters, employs more than 120 staff, maintains ample inventory, and ensures consistent, reliable supply. The company holds multiple utility model patents, including anti‑clogging granulation machines and easy‑to‑clean dryers, and has been recognized as a national-level technology‑based SME (2025). Its product quality is dependable, backed by robust technical capabilities.

Core Functions

1. Oxygen‑Blocking Inhibition: Forms a stable hydrated film and antioxidant protective layer on the coal surface, directly isolating coal from oxygen and halting the spontaneous oxidation and combustion process at its source.
2. Heat‑Absorption Cooling: Absorbs heat generated during coal oxidation as the inhibitor solution evaporates, preventing heat buildup and ensuring the coal never reaches its autoignition temperature, thereby breaking the essential condition for spontaneous combustion.
3. Chemical Inerting: The inhibitor molecules bond with coal molecules to form relatively stable compounds, enhancing the coal’s chemical inertia at low temperatures, reducing free radicals involved in coal‑oxygen reactions, and extending the natural ignition delay period.
4. Fracture‑Filling Capability: Can fill internal fractures within coal pillars, increasing the coal’s water‑holding capacity and prolonging the duration of inhibitory effects, providing long‑term fire‑prevention support throughout the mining cycle.

Core Value

1. Compliance‑Driven Quality Assurance: The product meets the MT/T 700-2019 “General Technical Requirements for Fire‑Prevention Inhibitors in Coal Mines,” a standard overseen by the National Mine Safety Administration and managed by the Coal Industry Coal Mine Safety Standardization Technical Committee. Applicable to underground coal seams and aboveground coal stockpiles—except for high‑sulfur coal—it provides customers with clear selection criteria and ensures compliance with regulatory requirements.
2. Highly Effective Spontaneous Combustion Control: Achieves an inhibition rate of no less than 40% for lignite and bituminous coal; magnesium chloride delivers an average inhibition efficiency of 63.6% for gas coal, while calcium chloride offers 47.6% for long‑flame bituminous coal. Through a triple‑action mechanism, it significantly enhances mine fire‑prevention capabilities, reducing safety risks and resource losses caused by coal self‑ignition.
3. Reduced Operational Costs: The sheet form resists caking, simplifies handling and storage, and remains stable for two years under sealed, moisture‑proof conditions, substantially cutting down on underground warehousing and transportation expenses. Ideal for coal mines’ needs of phased procurement and use, minimizing material waste.
4. Stable Supply Support: Leveraging extensive production experience, ample inventory, and a robust patent portfolio, combined with Weifang Binhai Economic and Technological Development Zone’s abundant saline resources and convenient transportation links, Weifang Jiangchang Chemical ensures consistently high‑quality, reliably supplied products, supporting continuous fire‑prevention operations in coal mines.
5. Strong Credential Backing: The company has participated in 46 tender projects (winning 22), holds multiple utility model patents and two software copyrights, and was certified as a national‑level technology‑based SME (2025). These credentials provide solid assurance for the product’s batch stability and sustained supply capability.

Target Customer Groups

1. Coal Mining Enterprises: Including underground mine fire‑prevention management departments, which regularly conduct inhibitor‑spraying operations in mined‑out areas, upper and lower corners, behind supports where floating coal accumulates, along fractured coal pillars, near cut‑off eyes, and along stop‑mining lines. Also applicable to open‑pit coal mines and coal storage/transport enterprises managing aboveground coal stockpiles and preventing spontaneous combustion.
2. Coal Mine Safety Technology Service Providers: Companies offering design services for fire‑prevention solutions, inhibitor‑spraying construction, and maintenance of fire‑suppression systems.
3. Coal Equipment Integration Companies: Integrators supplying equipment such as inhibitor‑based fog fire‑suppression systems and pipe‑monitoring systems.

Application Scenarios

1. Prevention of Spontaneous Combustion in Mined‑Out Areas: Mined‑out areas are hotspots for residual coal self‑ignition. By injecting sheet‑type inhibitor solution via buried pipes or drilling, it can effectively penetrate residual coal pores and fractures, forming an inhibitory film while absorbing oxidation heat, thereby suppressing spontaneous combustion.
2. Spraying in Upper and Lower Corners and Behind Supports: The upper and lower corners of fully mechanized mining faces, as well as the floating coal areas behind supports, are prime locations for potential self‑ignition hazards. Manual or mechanical spraying of sheet‑type inhibitor solution creates an oxygen‑blocking layer on the floating coal surface, effectively curbing oxidation.
3. Protection of Fractured Coal Pillars Along the Face and Near Cut‑Off Eyes: Coal fractures along the face and around cut‑off eyes are prone to oxidation and spontaneous combustion. Regular injection or spraying of sheet‑type inhibitor fills these fractures and forms an inhibitory film, providing preventive treatment.
4. Surface Treatment of Stop‑Mining Lines: During workface stoppage, coal exposed along stop‑mining lines remains vulnerable to prolonged oxygen exposure. Spraying sheet‑type inhibitor creates an oxygen‑blocking protective layer, preventing long‑term oxidation and self‑ignition.
5. Prevention of Spontaneous Combustion in Aboveground Coal Stockpiles: Open‑air coal storage yards and transit stations face risks of self‑ignition during summer heat or extended storage periods. Spraying sheet‑type inhibitor solution forms an inhibitory film on the coal surface, absorbing oxidation heat and preventing spontaneous combustion.

Solving Core Pain Points

1. Coal Self‑Ignition Threatens Mine Safety: Coal self‑ignition is one of the major disasters in mines, directly endangering miners’ lives, causing resource loss, and damaging equipment. The sheet‑type inhibitor employs a triple‑action mechanism—oxygen‑blocking film formation, heat‑absorption cooling, and chemical inerting—to effectively suppress coal self‑ignition, slow down oxidation at low temperatures, extend the natural ignition delay period, and fundamentally reduce the risk of spontaneous combustion.
2. Traditional Fire‑Prevention Measures Lack Lasting Effect: Single nitrogen injection or leak‑sealing approaches often prove short‑lived and insufficient to meet the long‑term fire‑prevention needs of mining cycles. In contrast, after spraying, the sheet‑type inhibitor maintains a moist, oxygen‑isolated surface for an extended period, effectively prolonging the protective window.
3. Storage and Transportation Challenges of Powdered Inhibitors: Powdered inhibitors easily absorb moisture and cake together in humid underground environments, complicating storage and transport. The sheet‑type inhibitor, with its neat edges, uniform thickness, and resistance to caking, remains stable for two years under sealed, moisture‑proof conditions, dramatically reducing storage and transportation costs and difficulties.
4. Lack of Standardized Selection Criteria: While MT/T 700-2019 clearly defines indicators such as inhibition rate and service life, the sheet‑type inhibitor complies with these standards and further specifies that magnesium chloride and calcium chloride deliver superior inhibition effects on lignite, long‑flame coal, and gas coal, providing customers with clear guidance to avoid hasty choices.

Common Questions FAQ

Q1: What advantages does the sheet‑type inhibitor have over powdered inhibitors?
A: The sheet‑type inhibitor features neat edges, uniform thickness, and resistance to caking, making it easier to handle and store long term. Under sealed, moisture‑proof conditions, it remains stable for two years, ideal for coal mines’ needs of phased procurement and use. Moreover, it gradually releases active ingredients upon dissolution, adapting well to batch liquid preparation on site.
Q2: What standards govern the inhibition efficiency of the sheet‑type inhibitor?
A: The product complies with MT/T 700-2019 “General Technical Requirements for Fire‑Prevention Inhibitors in Coal Mines,” setting minimum inhibition rates of 40% for lignite and bituminous coal. Magnesium chloride inhibitors achieve an average inhibition efficiency of 63.6% for gas coal, while calcium chloride delivers 47.6% for long‑flame bituminous coal.
Q3: What are the application methods for the sheet‑type inhibitor?
A: The inhibitor must be diluted into a 15%–35% solution before use. It can be directly sprayed on mining faces, old goafs, floating coal areas, or mixed into yellow mud slurry for injection into underground workings or drilled into fractures. Suitable for a wide range of fire‑prevention scenarios.
Q4: How long is the shelf life of the sheet‑type inhibitor?
A: Stored under sealed, moisture‑proof conditions, the inhibitor remains stable for two years, fully satisfying coal mines’ reserve needs.
Q5: Which types of coal are suitable for the sheet‑type inhibitor?
A: Compliant with MT/T 700-2019, the product applies to underground coal seams and aboveground coal stockpiles—except for high‑sulfur coal. Key ingredients like magnesium chloride and calcium chloride exhibit excellent inhibition effects on lignite, long‑flame coal, and gas coal.