Sodium hydrosulphide flakes 70%

When sourcing Sodium Hydrosulphide, the purity level (70% min) is the primary benchmark. You must verify the Iron (Fe) content, which should ideally be below 10-30ppm for high-end applications like tanning or paper pulping to prevent staining. Additionally, check the Sodium Sulphide (Na2S) impurity levels and the Sodium Carbonate (Na2CO3) content, as these affect the chemical reactivity and stability of the flakes.

Sodium Hydrosulphide 70% is widely used in mineral flotation (specifically as a depressant in copper and molybdenum mining), the leather industry for dehairing hides, and the paper and pulp industry for the Kraft process. It also serves as a heavy metal precipitant in wastewater treatment. Ensure the grade you purchase matches the specific sensitivity of your application, especially regarding color and clarity when dissolved.

As a hazardous chemical, it must comply with UN Number 2949 (Class 8 Corrosive). Suppliers should provide a valid Material Safety Data Sheet (MSDS) and a Certificate of Analysis (COA) for every batch. For international trade, ensure the packaging meets IMDG (International Maritime Dangerous Goods) codes, typically involving UN-approved PP/PE bags (25kg or 900kg-1000kg jumbo bags) that are hermetically sealed to prevent moisture absorption and toxic gas release.

Request a pre-shipment sample to test for solubility and color; the solution should be clear or slightly yellow, not dark or turbid. For large-scale B2B orders, it is highly recommended to hire a third-party inspection agency like SGS or Intertek to perform a random sampling at the factory to verify the actual NaHS content and moisture levels before the balance payment is made.

The biggest risk is moisture absorption and oxidation, which can lead to the release of toxic Hydrogen Sulphide (H2S) gas. Ensure the supplier uses double-layered UV-resistant packaging and that the container is kept away from heat sources. Furthermore, because it is a Class 8 hazardous material, shipping costs are higher and require specialized dangerous goods (DG) containers and documentation.

Focus on volume-based pricing; for chemicals, a 20ft FCL (Full Container Load) is the standard unit for negotiation. Ask for tiered pricing (e.g., 20 tons vs. 100 tons). On Made-in-China.com, prioritize Audited Suppliers who have undergone on-site verification. Negotiate for a payment structure such as 30% deposit and 70% against the Bill of Lading (B/L) or via Letter of Credit (L/C) to mitigate financial risk.

You will need a Commercial Invoice, Packing List, Bill of Lading, and a COA. Crucially, for hazardous chemicals, you must have the Dangerous Goods Declaration and the Safety Data Sheet (SDS) in the language of the destination country. Ensure the HS Code (typically 283010) is correctly declared to avoid customs delays or heavy fines.

Always conduct transactions through secure channels and verify the supplier's business license and export permits for hazardous chemicals. Use the Star Rating and Audit Reports on Made-in-China.com to assess the supplier's reliability. Avoid making full payments upfront to unknown entities; instead, use escrow-type services or trade insurance if available to protect your capital.