Montan wax

Lignite wax is a scarce mineral extracted from lignite, hence it is also known internationally as Montan Wax. It is a mineral wax containing wax, resin, and bitumen.

Also referred to as Montan Wax. It is a mixture of wax, resin, and bitumen obtained by solvent extraction (using benzene, gasoline, etc.) from waxy coal (primarily lignite or certain peats). The properties of lignite wax largely depend on the raw materials, the solvents used, and the extraction conditions. Its color ranges from brown to black as the bitumen content increases. Melting point is 75–86°C, density (20°C) is 0.98–1.03 g/cm³. The main components of the wax are: wax esters composed of C16–C34 acids and C24, C26, C30 alcohols; long-chain fatty acids (C16–C35); fatty alcohols (C20–C34); and alkanes (C23–C33). The resin consists of resin acids, small amounts of sterols, and terpenes. The bitumen is primarily polymerized, esterified oxygen-containing resin acids. Crude wax can be refined through processes like oxidative bleaching.

The main indicators for evaluating the quality of lignite wax include melting point, density, viscosity, acid value, saponification value, resin content, bitumen content, benzene-insoluble matter, ash content, and heating loss. China has established national standard testing methods for these parameters.

Lignite wax has a relatively hard texture, high melting point, acid resistance, good chemical stability, gloss, and electrical insulation. It is easily soluble in organic solvents, can be mixed with petroleum wax and stearic acid, and is non-carcinogenic. It is widely used as a substitute and supplement for expensive natural animal and plant waxes, such as in the production of carbon paper, shoe polish, floor wax, polishing wax, and metal polishes. It is also used in medium-temperature mold materials for investment casting, leather finishing, electrical insulation, and more.

Physicochemical properties: High melting point (83°C–86°C), strong chemical stability, low electrical conductivity, acid resistance, high strength, high surface smoothness, and non-carcinogenic.

Application areas:

1. Daily chemical industry: Refined wax, a deep-processed product of lignite wax, is used in high-performance cosmetics such as lipstick, creams, and hairspray, with substantial application volumes.

2. Precision casting industry: Used as medium-to-high-temperature wax patterns to improve the precision and smoothness of castings.

3. Rubber, plastic, and textile industries: Used as a lubricant, especially in PVC engineering plastics for molding and anti-adhesion lubrication.

4. Paper industry: Used as a sizing agent.

5. Electrical industry: Used as an insulating material for wires and cables to provide waterproofing, corrosion resistance, anti-adhesion, and anti-aging properties.

6. Printing industry: Used as a coating for high-speed printing inks, carbon paper, and typewriter stencil paper, preventing drying cracks and ensuring clear, non-smudging text.

7. Packaging industry, hot melt adhesive industry, and candle industry.

8. Applied in drilling, road surface maintenance, reservoir leak sealing, and mine dust control.

9. Used as a high-quality polishing wax for automobiles, furniture, floors, bicycles, precision instruments, etc., with significant usage volumes.

10. Shoe polish industry: Used as a brightener in leather and shoe polish.