How paraffin wax is made
Paraffin is the waxy sludge that clogs lubricating oil in the cold, filtered out and refined into candle wax.
- stations
- 6
- things upstream
- 4
- raw sources
- 3
- steps from the ground
- 2
The short version
Paraffin wax is a byproduct of making lubricating oil. A heavy cut from crude oil is chilled so that the waxy part crystallizes, and filters strain it out. The crude wax, called slack wax, is de-oiled and treated with hydrogen to remove color and odor, then cast into slabs or sold as liquid.
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Draw a heavy oil cut
Vacuum distillation of crude oil yields heavy lubricating oil fractions. These fractions are rich in long, straight hydrocarbons that turn solid in the cold.
Goes in -
Chill until wax crystallizes
The oil is mixed with a solvent and cooled until the wax forms crystals. The remaining oil stays liquid and flows freely.
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Filter out the wax
Rotating drum filters strain the crystals from the cold oil. What stays on the filter is slack wax, a greasy, oily solid.
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Sweat out the oil
Slack wax is warmed slowly or washed with solvent so the remaining oil drains away. This leaves a harder, drier wax with a higher melting point.
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Hydrotreat it clean
The wax is treated with hydrogen over a catalyst to remove color, smell and reactive compounds. The wax comes out white and nearly odorless.
Goes in -
Cast into slabs
Liquid wax is poured into molds or onto a cooling belt and cut into slabs. Candle, crayon and packaging makers buy it by the pallet.
Worth repeating
- Carl Reichenbach first made paraffin wax in Germany in 1830, and it burned more cleanly and reliably than tallow candles.
- Paraffin wax is a mix of hydrocarbons with 20 to 40 carbon atoms, and it begins to melt above approximately 37 °C.
- Paraffin phase-change cooling was used for the electronics of the Lunar Roving Vehicle in the early 1970s.
Back to the ground
Follow every input upstream and paraffin wax starts as these 3 raw sources.
Open the whole family tree
Where it goes next
Paraffin wax feeds 17 lines directly and reaches 148 things in total.
Further down the line
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Sources
Cite this page: "How paraffin wax is made." Assembly Line, 2026-11-03. https://assemblyline.org/make/paraffin-wax