U.S. imports of dolomite, not calcined or sintered (HS 251810) totaled $3.8M in August 2026, imported from 8 countries.
Importers of Dolomite, Not Calcined or Sintered paid $44K in duties in August 2026, an effective tariff rate of 1.17% of the $3.8M imported — duty actually collected as a share of that value, not the published tariff schedule. Dolomite, Not Calcined or Sintered imports of $3.8M in August 2026 ran 14% above the year-to-date monthly average of $3.3M.
Last updated: August 2026 dataRaw, uncalcined dolomite — a calcium magnesium carbonate mineral — is used as a flux in steelmaking, a filler in glass and ceramics, and a soil conditioner in agriculture, all before any heat treatment alters its chemistry. US imports enter under tariff line 2518100000, with Canada the dominant supplier by virtue of geographic proximity and large carbonate rock deposits. Italy, Mexico, Spain, and Germany round out the principal sources, reflecting Europe's significant dolomite quarrying sector. Purity levels (MgO and CaO content) are the primary commercial grade specifications that determine suitability for metallurgical versus agricultural applications.
AI-written summary of the official U.S. Census Bureau trade figures on this page — verify before relying on it.
132 shipments/mo
The distinction is purely thermal processing: dolomite that has not been subjected to calcination (high-temperature firing to drive off CO₂) or sintering remains under 2518100000. Once heat-treated to produce reactive magnesia and lime, the product shifts to 2518200000. Importers should obtain mill certificates confirming whether any thermal processing occurred at origin.
Steel producers use raw dolomite as a basic flux and refractory lining material. Glass manufacturers use it as a source of magnesium oxide. Agricultural suppliers use finely ground dolomite as a liming agent to neutralize acidic soils. Each end use has distinct purity and particle-size requirements.
HSChapter 25
Trade Directory
List your company under HS 251810 — Dolomite, Not Calcined or Sintered, so the companies trading it can find you. Be the first supplier listed.
Subheading 1 of 2 in heading 2518
Subheading 251810 · $3.8M of $4.4M
HS10 import codes under this HS6 parent, each with its own page. Source: U.S. Harmonized Tariff Schedule.
| Code | Description | Import Value | Effective Tariff % | Dutiable Share | Duty Collected |
|---|---|---|---|---|---|
| 2518100000 | Dolomite not Calcined or Sintered | $3.8M | 1.17% | 10.46% | $44K |
HS10 export codes under this HS6 parent, each with its own page. Source: U.S. Schedule B export classification.
| Code | Description | Export Value |
|---|---|---|
| 2518100000 | Dolomite not Calcined or Sintered | $64K |
Import lines come from the U.S. Harmonized Tariff Schedule and export lines from Schedule B. The two are numbered by different agencies, so the same 10-digit code can appear in both tables describing a different product.
ImportsExports
Imports
$3.8MYoY · free account
Exports
$64KYoY · free account
12-mo low · imports
YoY · free accountOver the twelve months to August 2026, the U.S. imported $35.9M of Dolomite, Not Calcined or Sintered.
Through August 2026. Source: U.S. Census Bureau.
Imports · August 2026
origin
Canada and Italy together supply 97% of it. China pays 37.5% duty; Canada 0.0%.
customs district
destination
entry
rate provision · imports
89.5% enters free of duty; duty collected equals 1.17% of total import value.