With K2, engine units require silicone whose production chain includes a filtration plant which requires engine units

[stevecheckoway]

After fixing #21 locally, I realized that it's still not possible to progress with K2 and bzsilicon. Specifically, there's the following chain of dependencies:

• Engine units require silicone,
• Silicone requires silicon,
• Silicon requires Silica,
• Silica requires Quartz,
• Quartz is made in a filtration plant, and
• Filtration plants require engine units.

Before filing this issue, I searched the Mod forum and saw someone posted about the same issue earlier today.

[stevecheckoway]

I added

  (util.k2() and util.me.more_intermediates()) and {
    type = "recipe",
    name = "basic-silica",
    localised_name = {"item-name.silica"},
    icon = "__bzsilicon__/graphics/icons/silica.png",
    category = "crafting-with-fluid",
    enabled = false,
    energy_required = 30,
    allow_productivity = true,
    ingredients = {
      {type = "item", name = "kr-sand", amount = 100},
      {type = "fluid", name = "water", amount = 100}
    },
    results = {util.item("silica", 10)},
  } or nil,

and

if util.k2() and util.me.more_intermediates() then
  util.add_unlock("silica-processing", "basic-silica")
end

in prototypes/silica-recipe.lua.

The idea is there's a slow and extremely inefficient method of getting silica from sand and water. You can use this to make engine units and then make filtration plants and from there, get quartz which can be crushed into silica.