A practical minimum is usually driven by logistics and utilization. For regional road contractors, plants often make sense starting around several tons per hour capacity, enough to supply multiple projects and keep production running consistently. Too small a plant increases unit cost due to labor, QC, and downtime per batch. Too large raises capex and storage requirements. The optimal baseline is the smallest capacity that can meet peak seasonal demand without running extreme shifts, while keeping tank turnover fast enough to avoid long storage.