打鐵花 (da2tie3hua1; struck iron fireworks) is a traditional folk firework that began in Henan and Shanxi, first arising in Queshan county, Henan and later circulating through the whole country. It had first appeared during the Northern Song dynasty, and was most popular during the Ming and Qing dynasties.
For Queshan struck iron fireworks, a two-layer pergola is built and covered with willow branches for performances, under which the molten iron is struck up with two willow sticks to create a rain of fire.
[eng by me + edited an ad out]
(On top of the information in the video, I have some more about its recent history under the cut.)
*Also, a note about one of the subtitles: I realized later that "going into battle without a shield" actually just meant going shirtless. I was only confused about this phrasing while translating because she didn't go shirtless, although that is for obvious reasons
Queshan struck iron fireworks had almost been lost before Yang Jianjun unearthed it again in 1988. It had almost died out in the early years of the Republic of China being established, after which there had only been three performances until 1988: 1952, 1956, 1962. Yang Jianjun had seen the 1956 performance as a 7-8 year old and later on as the director of a cultural centre, began digging up the skill and its history. In the process, he became an apprentice to Li Wanfa, who had been the last head of the Queshan Struck Iron Fireworks Society. He practised with sand and water, learning of its historical origin, its ancestral inheritors, craftsmanship and performance arts, but didn't touch the real thing until 1988. Through Yang Jianjun's efforts and investment, the first struck iron fireworks performance in more than 25 years took place in Nanshan Square (then a deserted area) in Queshan county.
Queshan struck iron fireworks are different from other struck iron fireworks in that it requires a wide area to perform, whereas others only needed a wall or could be hit straight up into the air, and it costs much more money to set up.
The names of inheritors are difficult to trace, and can only be traced back to the Qing dynasty during the Qianlong period, making Yang Jianjun a sixth-generation inheritor, and Jiang Xunqian (OP) the first woman and a seventh-generation inheritor.
A Queshan struck iron firework (打铁花; da2tie3hua1) performance to welcome the Year of the Dragon. Queshan struck iron fireworks differ from other iron fireworks due to the two-layered pergola and space required. This particular performance also features dragon dancing.
Please see my post here (my pinned post) for the full journey of how OP learned to strike iron fireworks as well as some other information and details about the art. (This is the video OP is referring to at the beginning of the video.)
*Before the countdown, OP is quoting the poem 青玉案·元夕 by 辛弃疾.
With [确山]打铁花 (da2tie3hua1; [Queshan] struck iron fireworks), a rain of fire is created by striking molten iron into a willow branch pergola using two willow sticks (See my post about this here).
Sparks are created with 火壶 (huo3hu2) by placing burning charcoal into wire mesh onto the two sides of a bar and shaking it.