In a typical Chinese rare earth processing plant, 200 workers move through a maze of massive chemical tanks, risking life and limb to produce the materials that power everything from fighter jets and missile components to cellphones. Hundreds of these facilities operate across China, and they give Beijing overwhelming control over the single most critical choke point in the modern industrial economy. But now, in Saskatchewan, Canada, a hi-tech plant of engineers and chemists is beginning to break that monopoly. The facility is built around an AI…