Sodium Ethyl Xanthate Storage & Tank Compatibility

Storing Sodium Ethyl Xanthate? Start Here

Sodium ethyl xanthate (C₃H₅NaOS₂, CAS 140-90-9) is the sodium salt of O-ethyl dithiocarbonic acid and one of the most widely used short-chain xanthate collectors in sulfide-mineral froth flotation. The pale-yellow solid is shipped as powder, flake, or pellets and dissolves freely in water - roughly 450 grams per liter near 50 F - to give the alkaline dosing solutions fed into copper, nickel, gold, and silver recovery circuits. In the cell, the xanthate group adsorbs onto mineral surfaces and renders them hydrophobic so target particles attach to air bubbles and float. Handling centers on two realities: the dry product is a flammable solid that liberates toxic carbon disulfide when heated or wetted with acid, and the working solution is an alkaline salt water. Both behaviors point operators toward polyethylene tankage for safe, corrosion-free storage and metered delivery of the dissolved reagent.

Polyethylene (HDPE / XLPE) Compatibility With Sodium Ethyl Xanthate Solutions

Sodium ethyl xanthate is, chemically, a water-soluble salt, and salts and their aqueous solutions sit squarely in the range polyethylene handles well. For the solution and slurry duty that defines tank service - dissolving the powder, holding the make-down batch, and dosing it into the flotation feed - both high-density polyethylene (HDPE) and cross-linked polyethylene (XLPE) earn an S (Satisfactory) rating against published plastic chemical-resistance charts for aqueous dithiocarbonate and alkaline salt solutions. Polyethylene does not react with the xanthate anion, tolerates the mildly alkaline pH of the solution, and avoids the metal-attack problems that rule out copper, brass, and aluminum. A few honest caveats keep the verdict accurate. Polyethylene is a thermoplastic, so keep solution temperature moderate. Polyethylene is combustible, so the surrounding storage area must respect the flammable-solid and carbon-disulfide hazards of the raw reagent - vented, cool, dry, and away from acids and ignition sources. And the dry powder should be charged and dissolved per the supplier's procedure rather than stored long-term wet. Within those limits, an HDPE or XLPE tank with EPDM or compatible seals is a sound, corrosion-free choice for sodium ethyl xanthate solution storage and dosing.

Material compatibility at a glance

Sodium ethyl xanthate is supplied as a dry, flammable solid and put to work as an aqueous solution or slurry in mineral flotation circuits. For the wetted service that matters to tank buyers - mixing, storage, and metered dosing of the dissolved reagent - cross-linked and high-density polyethylene (XLPE / HDPE) are the workhorse materials and carry an S rating. Polypropylene, PVC, CPVC, and EPDM seals also serve well in dilute solution. Copper, brass, and aluminum are unsuitable because xanthates and their sulfur decomposition products attack them. The dry powder itself must be kept cool, dry, and away from acids and ignition sources, since heat or moisture drives off flammable, toxic carbon disulfide.

Ratings: S suitable · C conditional / limited · U unsuitable. Verify against the cited resistance charts and your concentration/temperature before specifying.

The safety that actually matters

• Treat the dry product as a flammable solid (H228): store cool and dry, away from heat, sparks, open flame, and oxidizers; autoignition is reported near 482 F (250 C).
• Keep acids and excess moisture away from the powder - both drive decomposition that releases flammable, toxic carbon disulfide and hydrogen sulfide; provide ventilation in storage and make-down areas.
• It causes severe skin burns and serious eye damage (H314 / H318): wear chemical-splash goggles, face shield, chemical-resistant gloves, and protective clothing when charging powder or handling solution.
• Avoid creating airborne dust - xanthate dusts can form explosive clouds and may cause respiratory irritation (H335) and skin sensitization (H317); use local exhaust and dust controls.
• It is very toxic to aquatic life (H400 / H412): bund storage and dosing tanks, prevent any solution from reaching drains or surface water, and capture spills.
• Use compatible materials - polyethylene, polypropylene, or PVC for solution; keep copper, brass, and aluminum out of the wetted path - and follow the current supplier Safety Data Sheet for first aid, spill response, and disposal.

Common questions

Can I store sodium ethyl xanthate solution in a polyethylene tank?

Yes. Sodium ethyl xanthate is a water-soluble salt, and its aqueous dosing solutions are well suited to HDPE and XLPE polyethylene, which carry an S (Satisfactory) rating for this service. Polyethylene resists the alkaline salt water without the metal-attack problems of copper or aluminum. Keep the tank in a cool, dry, ventilated, bunded area and respect the flammable-solid hazard of the raw powder.

Why is the dry powder flammable and what gas does it give off?

Sodium ethyl xanthate is classified as a flammable solid (H228) with autoignition reported near 482 F (250 C). When heated, wetted with acid, or stored damp, it decomposes and releases carbon disulfide - a highly flammable and toxic gas - along with hydrogen sulfide and related sulfur compounds. That is why it must be kept cool, dry, and away from acids and ignition sources.

Which metals should I keep away from xanthate solutions?

Copper, brass and other copper alloys, and aluminum are unsuitable: xanthates react readily with copper, and the alkaline salt plus its sulfur decomposition products attack aluminum. Stainless steel and carbon steel can be used with care, but polyethylene, polypropylene, and PVC are the cleaner, corrosion-free choices for the wetted solution path.

Is sodium ethyl xanthate dangerous to aquatic life?

Yes. It is classified very toxic to aquatic life (H400) and harmful with long-lasting effects (H412). Storage and dosing tanks should be bunded and located so that no solution can reach drains, soil, or surface water, and spills should be contained and cleaned up promptly per the supplier Safety Data Sheet.