💾 Data Updated: Latest version • Last updated: December 09, 2025

2521.00.00.00 - Limestone flux; limestone and other calcareous stone, of a kind used for the manufacture of lime or cement 🖩

Details

FieldValue
Unit of Quantityt
General Rate of Duty (Column 1 - General)Free
Special Rate of Duty (Column 1 - Special)N/A
Column 2 Rate of DutyFree
Quota QuantityN/A
Additional DutiesN/A
About Duty Rates: Rates are divided into Column 1 and Column 2. Column 1 is subdivided into General (normal trade relations rates for all countries not eligible for special programs) and Special (preferential rates for countries with free trade agreements or preference programs). Column 2 rates apply to products from Cuba, North Korea, Belarus, and Russia. When no special rate exists for a classification, General rates apply.

Overview

This HTS classification, 2521.00.00.00, specifically addresses limestone and other calcareous stone that are intended for use in the production of lime or cement. This includes materials primarily composed of calcium carbonate (CaCO3) which undergo calcination or other processes to yield essential industrial products. The key determining factor for classification here is the material's intended industrial application, rather than its finished form or potential for other uses.

In contrast to other mineral products within Chapter 25, such as common salt (Chapter 2501) or sulfur (Chapter 2503), this category is focused solely on raw, calcareous stone for specific manufacturing purposes. It also differs from finished lime or cement products, which would fall under different chapters depending on their specific composition and form. While other types of stone might be found in Chapter 25, the defining characteristic of this entry is its chemical composition and designated use in lime and cement production.

As this is a leaf node within the HTS structure, there are no further subdivisions under 2521.00.00.00. Classification under this heading is based on the physical characteristics of the stone – its calcareous nature – and documentary evidence or clear intent regarding its primary use as a fluxing agent or raw material for the manufacture of lime or cement. Importers should be prepared to provide documentation that substantiates this intended use to customs authorities.

Frequently Asked Questions

›What is HTS code 2521.00.00.00?
HTS code 2521.00.00.00 covers Limestone flux; limestone and other calcareous stone, of a kind used for the manufacture of lime or cement under the US Harmonized Tariff Schedule. It falls under Chapter 25: Salt; sulfur; earths and stone; plastering materials, lime and cement.
›What products are classified under 2521.00.00.00?
This classification covers Limestone flux; limestone and other calcareous stone, of a kind used for the manufacture of lime or cement. It falls under Chapter 25: Salt; sulfur; earths and stone; plastering materials, lime and cement.
›What is the import duty rate for 2521.00.00.00?
The general rate of duty for HTS 2521.00.00.00 is Free. The Column 2 rate is Free.
›What unit of quantity is used for 2521.00.00.00?
Imports under HTS 2521.00.00.00 are measured in t.

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