Selenium

Selenium is a chemical element; it has the symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elemental state or as pure ore compounds in Earth’s crust. The consumption in 2010 was divided as follows: metallurgy – 30%, glass manufacturing – 30%, agriculture – 10%, chemicals and pigments – 10%, and electronics – 10%. China is the dominant consumer of selenium at 1,500–2,000 tonnes/year.

Description

Contract Specifications Abstract

1. Platform: Unilink China

2. Basic Requirements

Product Name	Selenium powder
Packing Requirements	Original packaging, with clear labels or markings on the iron drum, indicating the manufacturer’s name, product name, grade, batch number, net weight, gross weight, and hazardous materials symbol. Selenium powder should be sealed in polyethylene composite film bags and then placed in iron drums. Each drum should have a net weight of 25 kg or 20 kg. The iron drum must be placed on a pallet or the iron drum must be placed in a wooden box.
Delivery Location	Refer to Party A’s website for more details
Other Delivery Requirements	1. Measurement method: Copying of labels (based on the label net weight of the original packaging.) 2. Weighing Difference: Not more than ±0.1%.
Trading Unit	1 Kg	Delivery Units	100 Kg

3. Quality Standards

Standard Product:

(1) Selenium powder, black or dark gray powder, with uniform color and no visible differences upon visual inspection, and free from foreign inclusions. The chemical composition of the standard product should meet the following specifications:

Chemical Composition (Mass Fraction) / %*
Main Content, No less than;	Impurities, No greater than
Se	Cu	Hg	As	Sb	Te	Ni	Total % of impurities
99.5	0.01	0.003	0.005	0.003	0.2	0.003	0.5

Substitute Product:

(1) Selenium powder, black or dark gray powder, with uniform color and no visible differences upon visual inspection, and free from foreign inclusions. The chemical composition of the substitute product should meet the following specifications, with a premium of 12 RMB per kilogram:

Chemical Composition (Mass Fraction) / %*
Main Content, No less than	Impurities, No greater than
Se	Cu	Hg	As	Sb	Te	Fe	Pb	Ni	Total % of impurities
99.9	0.01	0.001	0.003	0.001	0.01	0.01	0.002	0.002	0.1

(2) Granularity: The passing rate through a standard 200‑mesh sieve must be greater than or equal to 99.8%.

Quality Certificate: A quality certificate must be provided for each batch of products.
Inspection: Each batch of products must be inspected and approved by the designated inspection agency of Unilink before participating in trading activities.
Testing Method: The testing method should refer to the YS/T1354‑2020 (Selenium Powder) standard.

For detailed information about the contract specifications, please refer to the specific Trading Agreement.