https://andrey-zakharov.github.io/factorio-recipes/
This is tool for great video game "Factorio". It visualize proportions of products flow for recipes, so you could easily notes where mass flow is expected.
Open . Choose recipe, inspect. Tooltips shows items per seconds to make 1 item.
To authors of d3, d3-sankey, reddit/r/factorio and https://github.com/kevinta893/factorio-recipes-json