Mines ore without mining it: place one 7x7 building on an ore field and it dissolves the patch where it lies, straight into Ore Liquefaction's dissolved-ore fluid. No drills, no belts, no inserters, Aqua Regia in one side, dissolved ore out the other.

Requires Ore Liquefaction, whose fluids it produces and whose ore support it follows.

Core Mechanic

The Ore Leaching Plant must be placed on ore, and the resource under its centre tile decides what it leaches. It surveys the connected field, claims it, and then consumes it farthest tile first, the patch visibly shrinks inward as it works, and one building mines out a field you would otherwise carpet with drills. Aqua Regia is charged at exactly the ratio a chemical plant would charge to dissolve the same ore, so the output feeds straight into your existing reconstitution setup.

By default the centre tile is never used up: once the rest of the field is gone, the plant switches to a slower recipe and keeps running on that one tile forever.

Key Features

• 9 ore per craft at 1 second per craft, 9 ore/s from a single building, 36 ore/s fully researched
• Costs 10 MW while crafting and 1 MW idle. Space is the other price: 7x7, and it wants a field to itself
• Claims can never overlap, so plants share out a field rather than fighting over it. A patch too large for one plant to survey can be worked by several, each taking the part the others left, but they cannot be crammed, because a plant may not be built on ground another already holds
• A circuit connector reports how much is left in the field, as the signal of whatever the ground yields
• Ores needing a mining fluid (uranium's sulfuric acid) need it here too, through a third fluid connection
• Craft time follows the field's own mining time, Space Age tungsten leaches slower than iron, Scrap faster
• Mining productivity research removes less ore from the field per craft instead of adding output, so a field yields the same total it would to researched drills. Productivity modules are not allowed
• Never a way around a drill requirement: a field only some mining drills can work (Space Age tungsten needs the big mining drill) can only be leached once your force has unlocked such a drill
• Ore support is automatic and follows Ore Liquefaction's, including ores with no resource patch of their own that can only be salvaged by recycling something else. Space Age's Holmium Ore is leached from a Scrap field, keeping that recycling chance intact
• New technology "Ore Leaching"; "Advanced Ore Leaching 1-3" speeds up every plant you already own
• Placing a plant draws its field on the ground as it surveys it, and opening one shows what is left

Customization

• Ore per craft, craft times, Aqua Regia cost multiplier, power draw, module slots
• Turn infinite leaching off to make fields finite, the centre tile is mined out like any other and the plant stops
• Toggle the mining-fluid requirement and mining-time scaling
• Field drain per ore leached, and whether mining productivity stretches the field
• Field scan budget, gap tolerance (how far apart fragments still count as one field), and how long the field highlight lasts

Attribution:

The art for the leaching plant is AI generated and serves more as a placeholder until I get something better, I tried my best to touch it up to make it as fitting and believable as possible.