Sodium Ethyl Xanthate, Sodium Ethyl Dithiocarbonate, Sodium Ethyl Xanthogenate, Sodium Ethyl Trithiocarbonate, SEX, NaEX, 140-90-9
SODIUM ETHYL XANTHATE (SEX)
Product Name: Sodium Ethyl Xanthate
Other Names: Sodium Ethyl Dithiocarbonate, Sodium Ethyl Xanthogenate, Sodium Ethyl Trithiocarbonate, Sodium O-Ethyl Dithiocarbonate, NaEX, SEX
CAS Number: 140-90-9
EC Number (EINECS): 205-433-4
Chemical Formula: C₃H₅NaOS₂
Molecular Weight: ~144.18 g/mol
Chemical Class: Xanthate (Dithiocarbonate) – Flotation Reagent
Origin: Synthetic, flotation reagent
SECTION 1: PRODUCT IDENTIFICATION AND DEFINITION
| Parameter |
Information |
| Product Name |
Sodium Ethyl Xanthate |
| Other Names |
Sodium Ethyl Dithiocarbonate, Sodium Ethyl Xanthogenate, Sodium Ethyl Trithiocarbonate, Sodium O-Ethyl Dithiocarbonate, NaEX, SEX, Sodium Ethylxanthate |
| CAS Number |
140-90-9 |
| EC Number (EINECS) |
205-433-4 |
| Chemical Formula |
C₃H₅NaOS₂ |
| Molecular Weight |
~144.18 g/mol |
| Chemical Class |
Xanthate (Dithiocarbonate) – Flotation Reagent |
| Origin |
Synthetic, flotation reagent |
| Appearance |
Yellowish to pale yellow powder or pellets |
| Odor |
Characteristic pungent, sharp odor |
| Solubility |
Readily soluble in water; forms alkaline solutions |
| Physical Form |
Powder or pellets depending on production method |
SECTION 2: PHYSICAL AND CHEMICAL PROPERTIES
| Property |
Value |
| Appearance |
Yellowish to pale yellow powder or pellets |
| Odor |
Characteristic pungent, sharp odor |
| Molecular Weight |
~144.18 g/mol |
| Chemical Formula |
C₃H₅NaOS₂ |
| pH (1% solution) |
8 – 11 |
| Density |
~1.1 – 1.3 g/cm³ |
| Solubility |
Readily soluble in water |
| Stability |
Stable under recommended storage conditions |
| Hygroscopicity |
Hygroscopic (absorbs moisture from air) |
| Decomposition Temperature |
> 200 °C |
| Bulk Density |
~0.6 – 0.9 g/cm³ |
| Melting Point |
Decomposes before melting |
SECTION 3: CHEMICAL STRUCTURE AND PROPERTIES
3.1. Chemical Structure
| Parameter |
Information |
| Chemical Name |
Sodium O-Ethyl Dithiocarbonate |
| IUPAC Name |
Sodium ethoxymethanedithioate |
| SMILES |
CCOC(=S)[S-].[Na+] |
| InChI Key |
RMLCSTHGMRGXGZ-UHFFFAOYSA-M |
| Alkyl Group |
Ethyl – C₂ (2-carbon chain) |
| Functional Group |
Dithiocarbonate (xanthate) – OCSS⁻ |
| Chain Type |
Linear |
3.2. Chemical Properties
| Property |
Description |
| pH Stability |
Stable in alkaline conditions; decomposes rapidly in acidic environments (pH < 7) |
| Reaction with Metal Ions |
Forms insoluble complexes with heavy metal ions (Cu²⁺, Pb²⁺, Zn²⁺) |
| Hydrolysis |
Hydrolyzes to produce xanthic acid and ethanol |
| Oxidation |
Oxidizes to dixanthogen in the presence of oxygen |
| Incompatible Materials |
Strong acids, strong bases, strong oxidizing agents, water |
| Hazardous Decomposition Products |
Carbon oxides, sulfur oxides, sodium oxides (under fire conditions) |
SECTION 4: MECHANISM OF ACTION IN FLOTATION
4.1. Collector Mechanism
| Mechanism |
Description |
| Adsorption |
SEX adsorbs onto the surface of sulfide minerals through chemisorption, forming metal-xanthate complexes |
| Hydrophobicity |
The adsorbed SEX layer makes the mineral surface hydrophobic, allowing attachment to air bubbles |
| Short Ethyl Chain |
The 2-carbon ethyl chain provides high selectivity, targeting specific minerals without collecting unwanted ones |
| Fast Action |
Quickly adsorbs onto mineral surfaces |
| Flotation |
Hydrophobic mineral particles attach to air bubbles and rise to the surface for collection |
4.2. Collecting Power Comparison (Xanthate Series)
| Xanthate Type |
Alkyl Chain |
Collecting Power |
Selectivity |
Typical Application |
| Sodium Ethyl Xanthate (SEX) |
Ethyl (C₂) |
Weakest |
Highest |
Selective flotation |
| Potassium Ethyl Xanthate (KEX) |
Ethyl (C₂) |
Weak |
High |
Selective flotation |
| Sodium Isopropyl Xanthate (SIPX) |
Isopropyl (C₃) |
Moderate-Strong |
Moderate-High |
Gold, copper sulfides |
| Sodium Isobutyl Xanthate (SIBX) |
Isobutyl (C₄) |
Strong |
Moderate |
Lead, zinc sulfides |
| Potassium Amyl Xanthate (PAX) |
Amyl (C₅) |
Strongest |
Lowest |
Difficult ores |
| Sodium Hexyl Xanthate (SHX) |
Hexyl (C₆) |
Very Strong |
Very Low |
Refractory ores |
SECTION 5: DETAILED COMPARISON WITH OTHER XANTHATES
| Parameter |
SEX (140-90-9) |
KEX (140-89-6) |
SIPX (140-93-2) |
SIBX (25306-75-6) |
PAX (2720-73-2) |
SHX (35042-31-6) |
| Alkyl Chain |
Ethyl (C₂) |
Ethyl (C₂) |
Isopropyl (C₃) |
Isobutyl (C₄) |
Amyl (C₅) |
Hexyl (C₆) |
| Collecting Power |
Weakest |
Weak |
Moderate-Strong |
Strong |
Strongest |
Very Strong |
| Selectivity |
Highest |
High |
Moderate-High |
Moderate |
Lowest |
Very Low |
| Primary Application |
Cu, Pb, Zn sulfides |
Cu, Zn ores |
Au, Cu sulfides |
Pb, Zn sulfides |
Au, Cu, Ni, pyrite |
Refractory ores |
| Chain Type |
Linear |
Linear |
Branched |
Branched |
Linear |
Linear |
| Suitable Ores |
Selective flotation |
Selective flotation |
Wide range |
Balanced |
Difficult ores |
Very difficult ores |
SECTION 6: APPLICATION AREAS
6.1. Mineral Processing (Flotation)
| Application |
Description |
| Copper Ores |
Flotation of chalcopyrite (CuFeS₂) and other copper sulfide minerals |
| Lead Ores |
Flotation of galena (PbS) |
| Zinc Ores |
Flotation of sphalerite (ZnS), often with activators like copper sulfate |
| Mixed Sulfide Ores |
Used when selectivity is important |
| Selective Flotation |
SEX is preferred when maximum selectivity is the primary requirement |
6.2. Other Industrial Applications
| Application |
Description |
| Hydrometallurgy |
Used as a precipitant in metal recovery processes |
| Rubber Industry |
Used as a vulcanization accelerator |
| Analytical Chemistry |
Reagent for metal ion detection and precipitation |
SECTION 7: ADVANTAGES AND DISADVANTAGES
7.1. Advantages
| Advantage |
Description |
| High Selectivity |
Reduces contamination from unwanted minerals; targets specific minerals without collecting unwanted ones |
| Fast Action |
Quickly adsorbs onto mineral surfaces |
| Cost-Effective |
Widely available and economical |
| Widely Used |
One of the most commonly used xanthates in the mining industry |
7.2. Disadvantages
| Disadvantage |
Description |
| Lower Collecting Strength |
Less effective compared to longer-chain xanthates (like PAX, SIBX) |
| Not Suitable for Refractory Ores |
Not ideal for difficult ores where stronger collectors are needed |
| Environmental Concerns |
Degradation can release carbon disulfide (CS₂), which is toxic |
| Hazardous Substance |
Requires careful storage; classified as hazardous: irritant, flammable, and toxic if ingested |
SECTION 8: TYPICAL DOSAGE AND APPLICATION
8.1. Recommended Dosage
| Parameter |
Value |
| Typical Dosage Range |
20 – 200 g/t of ore (depending on ore type and conditions) |
| Optimal Dosage |
Determined by flotation test work |
| Addition Point |
Added to the grinding circuit or conditioning tank |
| Solution Strength |
Typically 5-10% aqueous solution |
8.2. Application Instructions
| Step |
Description |
| 1 |
Prepare SEX solution by dissolving in water (typically 5-10% solution) |
| 2 |
Add to the flotation circuit at the designated addition point |
| 3 |
Conduct flotation at the optimal pH to ensure the xanthate remains stable |
| 4 |
Adjust dosage based on ore characteristics and flotation response |
| 5 |
Monitor concentration carefully; excessive amounts can lead to flotation of undesirable minerals |
8.3. Xanthate Selection Guide by Application
| Application |
Recommended Xanthate |
Reason |
| Selective Flotation |
SEX, KEX |
Highest selectivity required |
| Copper Sulfides |
SEX, KEX, SIPX |
SEX is effective for chalcopyrite |
| Lead Ores (Galena) |
SEX, SIBX |
SEX provides high selectivity |
| Zinc Ores (Sphalerite) |
SEX, KEX |
SEX with activators |
| Gold Ores |
SIPX, PAX |
Stronger collectors recommended |
| Mixed Sulfide Ores |
SIPX, SIBX |
Moderate strength needed |
| Refractory Ores |
PAX, SHX |
Maximum collecting power required |
SECTION 9: QUALITY SPECIFICATIONS
| Parameter |
Specification |
| Appearance |
Yellowish to pale yellow powder or pellets |
| Purity (Active Content) |
≥ 90.0% – 95.0% |
| Free Alkali (as NaOH) |
≤ 0.5% |
| Moisture |
≤ 4.0% |
| Insoluble Matter |
≤ 0.5% |
| pH (1% solution) |
8 – 11 |
| Sulfide Content |
< 0.5% |
| Heavy Metals (as Pb) |
< 10 ppm |
| HS Code |
2930902000 |
SECTION 10: PACKAGING OPTIONS
| Packaging Type |
Quantity |
Material |
| Plastic Drum |
100 – 200 kg |
HDPE |
| Fiber Drum |
100 – 150 kg |
HDPE + PE liner |
| Multi-layer Bag |
25 kg |
PE-lined kraft paper |
| Big-Bag |
500 – 1000 kg |
Polypropylene (with PE liner) |
SECTION 11: STORAGE AND SHELF LIFE
| Parameter |
Information |
| Storage Conditions |
Cool (<15-25°C), dry, well-ventilated area; away from direct sunlight; away from acids and oxidizers |
| Container Requirements |
Tightly closed, original packaging |
| Protect From |
Heat, moisture, direct sunlight, acidic conditions, oxidizing agents |
| Shelf Life |
6-12 months (unopened original packaging) |
| Stability Note |
Decomposes in acidic conditions; sensitive to heat and moisture; decomposes to carbon disulfide (CS₂) |
SECTION 12: SAFETY AND HEALTH INFORMATION
12.1. Classification
| Parameter |
Information |
| GHS Classification |
Flammable solid, Acute Toxicity (Category 4), Skin Irritation (Category 2), Eye Irritation (Category 2A) |
| Signal Word |
WARNING |
| UN Number |
3342 |
| Hazard Class |
4.2 (Substances liable to spontaneous combustion) |
12.2. Hazard Statements
| Code |
Statement |
| H228 |
Flammable solid |
| H302 |
Harmful if swallowed |
| H315 |
Causes skin irritation |
| H319 |
Causes serious eye irritation |
| H335 |
May cause respiratory irritation |
12.3. Precautionary Statements
| Code |
Statement |
| P210 |
Keep away from heat, sparks, open flames, hot surfaces – No smoking |
| P261 |
Avoid breathing dust |
| P280 |
Wear protective gloves, protective clothing, eye/face protection |
| P305+P351+P338 |
IF IN EYES: Rinse cautiously with water for several minutes; remove contact lenses; continue rinsing |
| P301+P312+P330 |
IF SWALLOWED: Call a POISON CENTER/doctor if you feel unwell; rinse mouth |
| P405 |
Store locked up |
12.4. Toxicological Information
| Parameter |
Value |
| Oral LD50 (Rat) |
~1,500 – 2,000 mg/kg (Acute Oral Toxicity – Category 4) |
| Skin Irritation |
Category 2 (Causes skin irritation) |
| Eye Irritation |
Category 2A (Causes serious eye irritation) |
| Inhalation |
May cause respiratory irritation |
SECTION 13: ENVIRONMENTAL INFORMATION
| Parameter |
Information |
| Decomposition |
Decomposes to carbon disulfide (CS₂), which is toxic and environmentally hazardous |
| Aquatic Toxicity |
Toxic to aquatic life if discharged untreated into water bodies |
| Persistence |
Degrades in the environment; may persist under certain conditions |
| Environmental Precautions |
Prevent entry into drains, soil, and surface waters; modern flotation plants implement advanced wastewater treatment technologies |
SECTION 14: TRANSPORT INFORMATION
| Parameter |
Information |
| UN Number |
3342 |
| UN Proper Shipping Name |
XANTHATES (Sodium Ethyl Xanthate) |
| Hazard Class |
4.2 (Substances liable to spontaneous combustion) |
| Packing Group |
II or III (depending on formulation) |
| ADR/RID |
Regulated |
| IMDG Code |
Regulated |
| IATA (Air) |
Regulated |
SECTION 15: REGULATORY STATUS
| Parameter |
Information |
| TSCA (USA) |
Yes |
| EINECS |
205-433-4 |
| RTECS Number |
KI1750000 |
| HS Code |
2930902000 |
SECTION 16: SUMMARY AND CRITICAL NOTES
Product Summary
| Parameter |
Value |
| Product |
Sodium Ethyl Xanthate (SEX) |
| CAS Number |
140-90-9 |
| Chemical Formula |
C₃H₅NaOS₂ |
| Appearance |
Yellowish to pale yellow powder or pellets |
| Primary Function |
Collector for sulfide minerals in froth flotation |
| Key Feature |
Highest selectivity among common xanthates |
| Typical Purity |
≥ 90.0% – 95.0% |
Critical Notes
-
Highest Selectivity: SEX has the shortest alkyl chain (C₂) among common xanthates, providing the highest selectivity. It is used when precision separation is required over maximum recovery.
-
Fast Action: SEX quickly adsorbs onto mineral surfaces, making it effective in fast flotation circuits.
-
Primary Applications: Copper ores (chalcopyrite), lead ores (galena), zinc ores (sphalerite with activators), and selective flotation of sulfide minerals.
-
Mechanism: SEX adsorbs onto sulfide mineral surfaces through chemisorption, forming metal-xanthate complexes; its short chain provides high selectivity.
-
Selectivity vs. Strength: As alkyl chain length increases, collecting power increases but selectivity decreases. SEX (C₂) is at the selectivity end of the spectrum; PAX (C₅) is at the strength end.
-
Decomposition: Decomposes in acidic conditions (pH < 7) to carbon disulfide (CS₂); must be stored in alkaline conditions.
-
Safety: Flammable solid; harmful if swallowed; causes skin and eye irritation; requires careful handling and storage.
-
Environmental: Decomposition products (CS₂) are toxic to the environment; SEX can be toxic to aquatic life if released untreated.
-
Storage: Store in a cool, dry place away from acids and oxidizers; protect from heat and moisture.
-
Dosage Control: Concentration must be carefully monitored; excessive amounts can lead to flotation of undesirable minerals.
-
pH Dependence: Conducting flotation at the optimal pH ensures the xanthate remains stable and effectively collects target minerals.
-
Incompatible Materials: Strong acids, strong bases, strong oxidizing agents.
-
Alternative Names: Also known as Sodium Ethyl Dithiocarbonate, Sodium Ethyl Xanthogenate, and NaEX.
-
Industry Standard: SEX is one of the most widely used xanthates globally, particularly in selective flotation circuits for copper, lead, and zinc ores.
-
Environmental Management: Modern flotation plants implement advanced wastewater treatment technologies to mitigate potential environmental risks associated with xanthate use.
IMPORTANT DECLARATION: This Technical Data Sheet (TDS) is for informational purposes only and has been prepared based on available technical data. The user is responsible for determining the product's suitability for their specific application and for complying with all local, national, and international regulations. For complete safety, storage, use, transport, waste, and regulatory compliance information, refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier.
