Tungsten Oxide National Standard

1. Range

This standard stipulates the types, technical requirement, test method, test rules of tungsten oxide. It is suitable for tungsten trioxide and blue tungsten oxide which is used to producing tungsten powder.

Product specification

3. Technical requirement

3.1 Yellow tungsten oxide is light yellow crystalline powder , blue tungsten oxide is dark blue or black blue crystalline powder. The color is uniform.

3.2 There is no visible inclusion or crumb.

3.3 Tungsten oxide of all grades should go through 250um (60 mesh) sieve pore.

3.4 In the phase composition of blue tungsten oxide, W20O58 should be less than 70%.

3.5 Apparent density and average particle size should be negotiated by supplier and demander.

3.6 Tungsten oxide chemical content should meet the below stipulation:

4.Test method

4.1 Appearance quality is tested by visual contact.

4.2 Test of grain size is processed under provision GB/T 3249.

4.3 Test of apparent density is processed under provision GB/T 1479.

4.4 Test of product chemical composition is processed under provision GB/T 4324.

5. Test rule

5.1 Product is checked by supplier to ensure the product is up to the standard, the product quality certificate is required.

5.2 After received the product, demander check the product according to the national standard. If the test result is not match to the stipulation, demander should inform the supplier within 3 monthes from the date of receive.

5.3 Product should be tested in batch, every batch should be consisted of the same blender.

5.4 Sample test of product is processed under provision GB/T 5314.

5.5 When the testing result is unqualified, then check this item repeated, if the repeated trials is still unqualified, then the product is below the standard.

6. Sign, packing, transportation, storage

6.1 Product is packed by barrel with polyethylene plastic bag inside, if there is special requirement for packing and the weight for per package, it should be negotiated by both demander and supplier.

6.2 Transportation and storage. During the transportation process, the product should be away from moisture, and avoid violent collision. Product should be installed under dry, ventilated, no acid-based atmosphere.

6.3 Quality certificate should be included in every batch of product.

1) Supplier name, address, postcode;
2) Product name, grade;
3) Batch number;
4) Weight (net weight and gross weight);
5) Standard number GB/T 26033-2010;
6) Test result and seal of quality inspection department;
7) Inspector ID;
8) Inspecting date.