How to Buy SEX: Specs, Activity and Packing

Sodium ethyl xanthate (SEX, CAS 140-90-9) is the cheapest xanthate and the most selective. Buying it well means confirming activity, protecting it from moisture, and using it where its selectivity – not its price – earns its place. This guide covers what to check.

1. The specification to confirm

Property	What to check
Appearance	Pale-yellow to yellow solid / granules
Activity (assay)	The active content you pay for (commonly 90% min; confirm your limit)
Free alkali	Affects pH and handling; keep it low
Form	Granules (low dust) or powder

Compare quotes on cost per unit of active – a lower-activity material needs a higher dose for the same result.

2. Buying it for the right reason

SEX is the least expensive xanthate, but it is also the weakest collector. Buy it to buy selectivity, not to save money per tonne: if your problem is recovery, a stronger collector (SIBX/PAX) will need less total reagent to do the job. Use SEX in cleaner and selective stages, paired with a strong collector in the rougher.

3. Degradation: buy to consumption

Order against monthly usage – xanthates lose activity with moisture, heat and time.
Rotate stock (FIFO) and keep it sealed, cool and dry.
Prefer scheduled deliveries over one bulk shipment.
Make up solutions fresh each shift.

4. Packaging

Packaging	Notes
PP/PE woven bags with inner liner (e.g. 25 kg)	Common export pack; liner keeps moisture out
Drums	Sturdier and more moisture-proof
Jumbo bags	For bulk handling and high consumption

5. Documents and supplier checklist

Per-batch COA showing activity and free alkali.
SDS for handling, storage and transport.
Moisture-protected packaging and scheduled delivery.
FOB or CIF quote to your port with lead time.
Ability to supply SEX alongside SIBX/SIPX/PAX for staged circuits.

Frequently Asked Questions

What activity does SEX come in?

Commonly 90% min; grades vary, so confirm the activity and free-alkali limits you need and check them on the batch COA.

Is SEX the cheapest xanthate?

Generally yes – it is made from ethanol, the lowest-cost alcohol. But it is also the weakest, so buy it for selectivity rather than for price alone.

How should SEX be stored?

Sealed, cool and dry, and used within its shelf life – xanthates degrade with moisture and heat.

How is SEX packed?

Moisture-barrier PP/PE bags with an inner liner, drums, or jumbo bags.