Final answer:
The Mongols, led by Kublai Khan, became key consumers of Chinese goods after conquering the Song dynasty and establishing the Yuan Dynasty, which subsequently revitalized the Silk Road.
Step-by-step explanation:
The invaders during the Song dynasty who became key consumers of Chinese goods were the Mongols under the leadership of Kublai Khan. After the Mongols conquered the Song capital in 1279, establishing the Yuan Dynasty, they became greatly involved in the economic activities with the Chinese, utilizing the well-established Chinese trade networks. The Mongol conquest led to the re-establishment of the Silk Road, enhancing trade connectivity between China and Europe, and making the Mongols significant consumers of Chinese silk, porcelain, and spices.