Powdered inhibitor is a specialized white powdered agent used for fire prevention and extinguishment in underground coal mines. It inhibits the oxidative spontaneous combustion of coal through a triple mechanism—oxygen barrier film formation, heat absorption and temperature reduction, and chemical inertization—and complies with the MT/T 700-2019 standard. It requires a small dosage and delivers high efficiency.

Powdered Inhibitor

Product Overview

The powdered inhibitor is a white, powder‑form chemical agent specially designed for fire prevention and suppression in underground coal mines. It serves as a core preventive material ensuring safe mine operations. By spraying or injecting it onto the coal surface, it forms an oxygen‑blocking inhibitory film while absorbing heat generated by coal oxidation, effectively preventing coal from self‑igniting through multiple mechanisms. This product meets environmental and compliance requirements for safe coal production and is suitable for all fire‑prevention scenarios—both underground and aboveground—in coal storage and transportation.

Technical Principle

The mechanism of action of the powdered inhibitor can be divided into three key aspects: First, oxygen isolation and film formation—when dissolved in water and sprayed or injected into coal pores and fractures, the inhibitor penetrates coal layers and microcracks. Its strong hygroscopic properties enable it to form a stable, liquid antioxidant film on the coal surface, directly blocking contact between coal and oxygen and eliminating the essential conditions for oxidation. Second, heat absorption and cooling—the inhibitor solution absorbs heat released during coal oxidation as it evaporates, preventing heat buildup and making it difficult for the coal to reach its autoignition temperature. Additionally, its inorganic salt components exhibit strong hydrophilicity, maintaining prolonged moisture on the coal surface after application, further reducing the likelihood of spontaneous combustion. Finally, chemical inertization—its molecules bond with coal molecules to form relatively stable compounds, decreasing free radicals involved in coal–oxygen reactions, extending the low‑temperature oxidation process, and enhancing the coal’s chemical inertia at lower temperatures, thereby suppressing oxidation at the molecular level.

Compared to sheet‑ or granule‑type products, the powdered inhibitor boasts a larger specific surface area and faster dissolution. During underground mixing operations, it dissolves more thoroughly and disperses more evenly, making it particularly well suited for applications such as injection mixed with yellow mud slurry or pressure injection into boreholes, thus improving operational efficiency and uniformity of inhibition.

Performance Parameters

1. Product Form: White powder, non‑toxic, odorless, and non‑polluting; minimally corrosive to equipment and compliant with coal mine safety standards.
2. Inhibition Efficiency: Meets MT/T 700-2019 “General Technical Requirements for Fire‑Preventive Inhibitors in Coal Mines,” achieving an inhibition rate of no less than 40% for lignite and bituminous coal. The composite long‑acting inhibitor delivers an average inhibition rate of up to 52.78% throughout the entire process, raising the critical CO onset temperature of inhibited coal samples by 10°C compared to raw coal.
3. Usage Concentration: Requires dilution into a 15%–35% solution; diluting 40–100 times with water ensures optimal inhibition performance.
4. Spraying Frequency: Spray the working face every 3–5 days and coal piles every 7–10 days.
5. Scope of Application: Suitable for fire prevention in underground coal seams and aboveground stored coal, except for high‑sulfur coal.

Core Advantages

1. High Inhibition Efficiency and Remarkable Fire‑Prevention Effect: The powdered inhibitor effectively penetrates coal layers and fine cracks, forming a stable, liquid antioxidant film on the coal surface that fully encapsulates coal particles and isolates oxygen. The overall average inhibition rate exceeds 52%, and the critical CO onset temperature of inhibited coal samples rises by 10°C. Specifically, magnesium chloride inhibitors achieve an average inhibition efficiency of 63.6% for gas coal, while calcium chloride reaches 47.6% for long‑flame bituminous coal, delivering excellent results across different coal types.
2. Outstanding Powder Form Advantages: With a large specific surface area and rapid dissolution, the powdered product dissolves more completely and disperses more uniformly during underground mixing, enhancing both mixing efficiency and uniformity of inhibition. Moreover, being a white powder, it is non‑toxic, odorless, non‑polluting, and minimally corrosive to equipment, fully meeting environmental requirements for safe coal production.
3. Low Dosage, Great Results: Diluting the powdered inhibitor 40–100 times with water provides effective inhibition, significantly reducing material usage compared to previous colloidal inhibitors. Underground fire‑suppression material transport volume decreases by over tenfold, substantially easing labor burdens on miners while cutting material and logistics costs.
4. Solid Technical Credentials: Manufacturer Weifang Jiangchang Chemical was established on January 9, 2015, deeply rooted in the chemical industry for many years. With a registered capital of RMB 16.5 million, occupying over 8,000 square meters, employing more than 120 staff, and maintaining ample inventory, the company ensures a steady and reliable supply. It holds several utility model patents, including anti‑clogging granulation machines and easy‑to‑clean dryers, and has been recognized as a national-level science‑and‑technology‑based SME (2025). Product quality is dependable, backed by robust technical capabilities.

Core Functions

1. Oxygen Isolation and Inhibition: The powdered inhibitor creates a stable hydrated film and antioxidant protective layer on the coal surface, directly preventing contact between coal and oxygen and halting the coal oxidation–self‑ignition process at its source.
2. Heat Absorption and Cooling: As the inhibitor solution evaporates, it absorbs heat generated by coal oxidation, preventing heat accumulation and making it difficult for the coal to reach its autoignition temperature, thereby interrupting the heat‑accumulation phase of self‑ignition.
3. Chemical Inertization: The inhibitor molecules bond with coal molecules to form relatively stable compounds, increasing the coal’s chemical inertia at low temperatures, reducing free radicals involved in coal–oxygen reactions, prolonging the low‑temperature oxidation process, and suppressing oxidation at the molecular level.
4. Fracture Filling: The powdered inhibitor can fill internal fractures within coal pillars, enhancing the coal’s water‑retention capacity, extending the duration of inhibition, and improving the long‑term effectiveness of fire prevention.

Core Value

1. Data‑Driven Safety and Efficiency: The product meets MT/T 700-2019 requirements, with an inhibition rate of no less than 40%; the composite long‑acting inhibitor achieves an average inhibition rate of 52.78% throughout the process, raising the critical CO onset temperature of inhibited coal samples by 10°C compared to raw coal. Zinc‑magnesium‑aluminum hydrotalcite powder composites can elevate the exothermic peak temperature from 135°C to 560°C, significantly reducing peak area and providing multi‑stage heat absorption to suppress coal oxidation, with clear data supporting its fire‑prevention efficacy.
2. Qualification and Authority‑Backed Quality: Compliant with MT/T 700-2019 “General Technical Requirements for Fire‑Preventive Inhibitors in Coal Mines,” overseen by the National Mine Safety Administration and managed by the Coal Industry Coal Mine Safety Standardization Technical Committee, ensuring authoritative compliance. Manufacturer Weifang Jiangchang Chemical has earned national-level recognition as a science‑and‑technology‑based SME, holding numerous utility model patents and software copyrights, with strong production technology guaranteeing batch stability and continuous supply.
3. Cost‑Effective and Reliable Supply: Diluting the powdered inhibitor 40–100 times with water suffices for effective inhibition, reducing underground fire‑suppression material transport volume by over tenfold, significantly lowering material and labor costs for mine fire prevention. Located in the Weifang Binhai Economic and Technological Development Zone, rich in saline natural resources and benefiting from convenient transportation, the company enjoys distinct advantages in raw material procurement and logistics distribution, ensuring timely product delivery.

Target Customer Groups

1. Coal Mining Enterprises: Mine fire‑prevention management departments responsible for regularly spraying powdered inhibitors in areas such as goafs, upper and lower corners, floating coal behind supports, broken coal pillars along roadways, cut‑off eyes, and stop‑mining lines.
2. Coal Mine Safety Technology Service Providers: Companies offering design services for fire‑prevention solutions, powdered inhibitor spraying construction, and maintenance of fire‑prevention systems.
3. Coal Equipment Supporting Enterprises: Integrators supplying fire‑prevention mist systems, pipe‑monitoring systems, and other related equipment to coal mines.
4. Open‑Pit Coal Mines and Coal Storage/Transportation Enterprises: Operators managing self‑ignition prevention for aboveground stored coal and coal stockpiles, requiring daily fire‑prevention treatment using powdered inhibitors.

Application Scenarios

1. Self‑Ignition Prevention in Goafs: Coal goafs are hotspots for residual coal self‑ignition. Injecting powdered inhibitor solution via buried pipes or drill holes effectively suppresses oxidation and self‑ignition. After in‑situ inhibition, monitoring via pipe‑systems reveals a significant drop in CO concentration, demonstrating remarkable fire‑prevention effects.
2. Spraying in Upper and Lower Corners and Floating Coal Behind Supports: These areas on fully mechanized mining faces are prime locations for self‑ignition hazards. Manual or mechanical spraying of powdered inhibitor solution effectively curbs oxidation of floating coal, reducing self‑ignition risks.
3. Protection of Broken Coal Pillars Along Roadways and Cut‑Off Eyes: Coal fractures along roadways and near cut‑off eyes are prone to oxidation and self‑ignition. Regular pressure injection or spraying of powdered inhibitor provides preventive care, filling gaps and forming inhibitory films.
4. Surface Treatment of Stop‑Mining Lines: During stop‑mining periods, coal surfaces exposed for extended durations benefit from powdered inhibitor spraying, creating an oxygen‑blocking protective layer to prevent oxidation‑induced self‑ignition.
5. Preventing Self‑Ignition in Aboveground Coal Stockpiles: Open‑air coal storage yards and transit stations face self‑ignition risks under summer heat or prolonged stacking conditions. Spraying powdered inhibitor solution offers preventive measures, suitable for both high‑concentration surface coverage and low‑concentration internal injection.

Solving Core Pain Points

1. Coal Self‑Ignition Threatens Mine Safety: Coal self‑ignition ranks among major mine disasters, endangering miners’ lives, causing resource loss, and damaging equipment. The powdered inhibitor employs a triple mechanism—oxygen isolation via film formation, heat absorption and cooling, and chemical inertization—to effectively curb coal self‑ignition, slow down oxidation at low temperatures, extend the natural ignition period of coal, and fundamentally reduce self‑ignition risks.
2. Traditional Fire‑Prevention Measures Lack Lasting Effect: Single nitrogen injection or leak‑sealing approaches often prove short‑lived, failing to meet the long‑term fire‑prevention needs of coal mining cycles. In contrast, powdered inhibitor spraying maintains prolonged moisture and oxygen isolation on coal surfaces, with composite long‑acting inhibitors achieving an average inhibition rate of 52.78% throughout the process, ensuring lasting and stable fire‑prevention effects.
3. High Material Usage and Logistics Costs: Conventional inhibitors require large quantities, imposing heavy underground transport burdens and high labor intensity. By diluting the powdered inhibitor 40–100 times with water, underground fire‑suppression material transport volume drops by over tenfold, dramatically reducing labor intensity and logistics expenses.
4. Lack of Standardized Selection Criteria: MT/T 700-2019 clearly defines indicators such as inhibition rate and lifespan, providing customers with clear guidelines for selection. Meanwhile, magnesium chloride and calcium chloride inhibitors demonstrate superior performance against lignite, long‑flame coal, and gas coal, allowing precise product selection based on coal type.

Frequently Asked Questions (FAQ)

Q1: Which coal types are suitable for the powdered inhibitor?
A: Compliant with MT/T 700-2019, this product applies to most coal types except high‑sulfur coal, including lignite, bituminous coal, long‑flame coal, and gas coal. Magnesium chloride inhibitors excel with gas coal, while calcium chloride shows outstanding performance against long‑flame bituminous coal.
Q2: What is the recommended usage cycle for the powdered inhibitor?
A: For coal mine working faces, spray every 3–5 days; for aboveground coal piles, spray every 7–10 days. If applying pressure injection to high‑temperature zones, adjust frequency according to monitoring data.
Q3: How does the powdered inhibitor compare to traditional inhibitors?
A: The powdered inhibitor features a larger specific surface area and faster dissolution, resulting in more uniform mixing. Diluting 40–100 times with water allows use with only about one‑tenth the material required by conventional colloidal inhibitors, reducing underground transport volume by over tenfold and significantly lowering labor intensity and costs. It also incorporates a triple inhibition mechanism, delivering longer‑lasting fire‑prevention effects.
Q4: Does the product comply with coal mine safety standards?
A: Strictly adhering to MT/T 700-2019 “General Technical Requirements for Fire‑Preventive Inhibitors in Coal Mines,” the product is non‑toxic, odorless, non‑polluting, minimally corrosive to equipment, and fully meets all compliance requirements for safe coal production.