VATROLITE

Vatrolite is a rare, naturally occurring vitreous (glassy) mineral that is primarily composed of hydrated aluminum phosphate.
Due to its rarity, vatrolite is not commonly encountered in mineral collections, and it has limited practical applications beyond its significance as a mineralogical curiosity.
Vatrolite is widely used in industry due to its reducing properties and ability to react with oxygen, making it valuable in the textile, pulp and paper, water treatment, and chemical processing industries.

CAS Number: 7775-14-6
EC Number: 231-890-0
Chemical Formula: Na2S2O4
Molar Mass: 174.11 g/mol

Synonyms: Sodium dithionite, SODIUM HYDROSULFITE, 7775-14-6, Sodium hydrosulphite, Dithionous acid, disodium salt, Sodium sulfoxylate, Disodium dithionite, Sodium hypodisulfite, Vatrolite, 2K5B8F6ES1, CHEBI:66870, Blankit, Burmol, Hydros, sodiumdithionite, Blankit IN, Hydrosulfite R Conc, V-Brite B, Disodium hydrosulfite, Caswell No. 774, CCRIS 1428, HSDB 746, Sodium hydrosulfite (Na2S2O4), Sodium dithionite (Na2(S2O4)), EINECS 231-890-0, UN1384, EPA Pesticide Chemical Code 078202, UNII-2K5B8F6ES1, sodium dithionit, sodiumhydrosulfite, Sodiumhydrosulphite, sodium hydro sulfite, MFCD00011640, sodium sodium hydrosulfite, Dithionous aciddisodiuMsalt, Na2S2O4, EC 231-890-0, Sodium dithionite (Na2S2O4), SODIUM DITHIONITE [II], SODIUM DITHIONITE [MI], CHEMBL3410462, DTXSID9029697, Na2 (S2 O4), SODIUM DITHIONITE [MART.], SODIUM HYDROSULFITE [HSDB], SODIUM HYDROSULFITE [INCI], Dithionous acid, sodium salt (1:2), AKOS015904498, Sodium dithionite or sodium hydrosulfite, BP-13393, FT-0695294, S0562, Q414560, Sodium dithionite or sodium hydrosulfite [UN1384] [Spontaneously combustible], Sodium dithionite [Wiki], 14844-07-6 [RN], 231-890-0 [EINECS], 2K5B8F6ES1, 7775-14-6 [RN], Dinatriumdithionit [German] [ACD/IUPAC Name], Disodium dithionite [ACD/IUPAC Name], Dithionite [ACD/IUPAC Name], Dithionite de disodium [French] [ACD/IUPAC Name], Dithionous acid, disodium salt, MFCD00011640 [MDL number], Sodium hydrosulfite, Sodium hydrosulphite, Sodium hypodisulfite, 1340-77-8 [RN], Blankit, Burmol, Disodium hydrosulfite, disodium sulfinatosulfinate, Dithionous aciddisodiumsalt, EINECS 231-890-0, SODIUM DITHIONATE, Sodium dithionite (Na2S2O4), Sodium Hydrosulfite, 85per cent, Sodium hydrosulfite, Sodium hypodisulfite, Sodium hyposulfite, Sodium sulfoxylate, sodiumdithionite, UNII:2K5B8F6ES1, UNII-2K5B8F6ES1, Vatrolite, V-Brite B

Vatrolite is a rare, naturally occurring vitreous (glassy) mineral that is primarily composed of hydrated aluminum phosphate.
Vatrolite is typically found in phosphate-rich environments, often associated with minerals like variscite, wavellite, and crandallite.

Vatrolite is known for its translucent to opaque appearance, usually exhibiting colors ranging from pale gray, white, or yellowish hues.
Vatrolite forms as a result of the alteration of aluminum phosphate minerals under specific geological conditions, such as in phosphate deposits or pegmatitic environments.

Due to its rarity, vatrolite is not commonly encountered in mineral collections, and it has limited practical applications beyond its significance as a mineralogical curiosity.
Vatrolite's glassy texture and chemical composition distinguish it from other phosphate minerals, making it an intriguing subject for mineralogists and collectors alike.

Vatrolite is a white crystalline powder with a sulfurous odor. 
Although Vatrolite is stable in dry air, Vatrolite decomposes in hot water and in acid solutions.

Vatrolite is a whitish to light yellow crystalline solid having a sulfur dioxide-like odor. 
Vatrolite spontaneously heats on contact with air and moisture. 

This heat may be sufficient to ignite surrounding combustible materials. 
Under prolonged exposure to fire or intense heat containers of Vatrolite may violently rupture. 
Vatrolite is used in dyeing and to bleach paper pulp.

Vatrolite is a whitish to light yellow crystalline solid having a sulfur dioxide-like odor. 
Vatrolite spontaneously heats on contact with air and moisture. 

This heat may be sufficient to ignite surrounding combustible materials. 
Under prolonged exposure to fire or intense heat containers of this material may violently rupture. 
Vatrolite is used in dyeing and to bleach paper pulp.

Vatrolite is an inorganic sodium salt that is the disodium salt of dithionous acid. 
Vatrolite has a role as a reducing agent and a bleaching agent. 

Vatrolite contains a dithionite(2-).
Vatrolite is unstable under physiological conditions, Vatrolite degradation rate increases with increasing acidity.

After contact with moisture, Vatrolite is oxidized to hydrogen sulfide (hso3-), sulfite (so32-), and hydrogen sulfate (hso4-).
Vatrolite can release sulfur dioxide under strongly acidic conditions.

Under anaerobic conditions (as in the lower gastrointestinal tract), hydrogen sulfide (hso3-) and thiosulfate (s2o32-) can occur. 
Hydrogen sulfide (hso3-) can be absorbed after ingestion.
Vatrolite is metabolized efficiently and most of Vatrolite is rapidly excreted as sulfate in the urine.

Vatrolite is widely used in industry due to Vatrolite reducing properties and ability to react with oxygen.
Vatrolite is used as a reducing bleaching agent to make yellow discoloration of cellulose-based products in the textile industry, in the pulp and paper industry as a reducing bleach, as an oxygen scavenger in boilers, for preservation and water treatment to remove iron stains on cultural artifacts.

Iron flash control on white fabrics in bleaching environments.
Vatrolite is also used in photographic film, clay, wine, leather goods, food and beverages, polymers, cleaners, gas cleaning, environmental remediation, metal recovery and chemical processing.

Vatrolite is a powerful reducing agent. 
Vatrolite has therefore been suggested to be used as an additive in kraft pulping to improve the yield. 

However, Vatrolite easily decomposes and Vatrolite is thus important to determine the effect of different conditions. 
The stability of Vatrolite was found to decrease with increasing heating temperature, concentration of Vatrolite, heating time and pH. 

Vatrolite was found to be relatively stable at moderate alkaline pH: 11.5 and 12.5, while a rapid decrease in stability with time was noted at higher heating temperatures and concentrations of Vatrolite.
Based on this study on the thermal stability of Vatrolite, the following conditions are suggested as the most promising, when adding Vatrolite to the kraft cooking as an additive; pH 12.5, with 0.4 M concentration of the solution, at a heating temperature of 100 °C.

Vatrolite is a rare, naturally occurring vitreous (glassy) mineral composed primarily of hydrated aluminum phosphate.
Vatrolite is typically found in phosphate-rich environments, often occurring alongside minerals such as variscite, wavellite, and crandallite.

Vatrolite forms through the alteration of aluminum phosphate minerals under specific geological conditions, including low-temperature hydrothermal activity and the weathering of phosphate-bearing deposits.
Vatrolite is characterized by its glass-like luster and translucent to opaque appearance, with colors typically ranging from pale gray, white, and yellowish to light brown.

Vatrolite's structure is amorphous, meaning it lacks a well-defined crystalline form, which sets it apart from many other aluminum phosphates.
Due to its fragile and vitreous nature, vatrolite is not commonly used for industrial purposes but holds significance for mineralogists, geologists, and collectors.

Vatrolite is often found in nodular or irregular masses rather than well-formed crystals, adding to its uniqueness.
Although its rarity makes it a less prominent mineral, vatrolite contributes valuable insights into phosphate mineral formation and alteration processes in various geological settings.

Vatrolite's association with other phosphate minerals suggests it forms in specific geochemical conditions, such as those found in sedimentary phosphate deposits, pegmatites, or areas undergoing supergene alteration.
Despite its limited practical applications, vatrolite remains an intriguing subject of study for those interested in mineralogy and the complex interactions of phosphate minerals in nature.

Uses of Vatrolite:
Vatrolite has limited practical applications due to its rarity and amorphous nature, but it holds significance in mineralogical and geological studies.
As a phosphate mineral, Vatrolite contributes to the understanding of phosphate deposits and alteration processes in various geological environments.

Researchers study vatrolite to gain insights into the formation and transformation of aluminum phosphates, which can be relevant in fields such as geochemistry and mineral exploration.
Although Vatrolite does not have industrial uses like some other phosphate minerals, its association with variscite and wavellite makes it valuable for collectors and museums.
Vatrolite specimens, when found, are often preserved for their scientific and educational value, helping geologists understand the conditions under which such rare vitreous minerals form.

Vatrolite is used to dye fibers and textiles, to strip dyes from fabrics, and to bleach sugar, soap, oils and wood pulp.
Vatrolite is used as a chemical reagent and an oxygen scavenger in the production of synthetic rubber.

All uses of Vatrolite are based on Vatrolite reducing properties. 
In the textile industry, Vatrolite is primarily used as reducing agent for vat dyes and sulfur containing dyes, and for the removal of pigments on textiles. 
Vatrolite is also used as a bleaching agent in reductive bleaching processes, for instance, in the bleaching of mechanical paper pulp, and the bleaching of cotton and wool, as well as sugar.

Industry Uses:
Bleaching agent
Bleaching agents
Cleaning agent
Dye
Not Known or Reasonably Ascertainable
Other (specify)
Oxidizing/reducing agents
Reducing agent
Solvents (which become part of product formulation or mixture)

Consumer Uses:
Not Known or Reasonably Ascertainable
Reducing agent

Usage Areas of Vatrolite:
In the textile sector, Vatrolite provides a reductive reaction with the dye remaining on the fiber after dyeing, allowing excess dye to be removed from the fiber.
Vatrolite is used in the paper industry for bleaching pulp.

Vatrolite is used in the food industry to bleach sherbet and maltose.
Sulfonation in water treatment, bleaching of minerals by removing iron ions, production of chemicals

Industrial Processes with risk of exposure:
Pulp and Paper Processing
Textiles (Printing, Dyeing, or Finishing)
Toxic Gas from Spilling Chemical in Water

Applications of Vatrolite:

Industry:
Being water-soluble, Vatrolite is used as a reducing agent in some industrial dyeing processes. 
In the case of sulfur dyes and vat dyes, an otherwise water-insoluble dye can be reduced into a water-soluble alkali metal salt (e.g. indigo dye).

Vatrolite can also be used for water treatment, aquarium water conditioners, gas purification, cleaning, and stripping. 
Vatrolite has also been applied as a sulfonating agent. 

In addition to the textile industry, this compound is used in industries concerned with leather, foods, polymers, photography, and many others, often as a decolourising agent. 
Vatrolite is even used domestically as a decoloring agent for white laundry, when Vatrolite has been accidentally stained by way of a dyed item slipping into the high temperature washing cycle. 
Vatrolite is usually available in 5 gram sachets termed hydrosulfite after the antiquated name of the salt.

Vatrolite is the an active ingredient in "Iron Out Rust Stain Remover", a commercial rust product.

Laboratory:
Vatrolite is often used in physiology experiments as a means of lowering solutions' redox potential (Eo' -0.66 V vs SHE at pH 7).
Potassium ferricyanide is usually used as an oxidizing chemical in such experiments (Eo' ~ .436 V at pH 7). 

In addition, Vatrolite is often used in soil chemistry experiments to determine the amount of iron that is not incorporated in primary silicate minerals. 
Hence, iron extracted by Vatrolite is also referred to as "free iron." 
The strong affinity of the dithionite ion for bi- and trivalent metal cations (M2+, M3+) allows Vatrolite to enhance the solubility of iron, and therefore dithionite is a useful chelating agent.

Aqueous solutions of Vatrolite were once used to produce 'Fieser's solution' for the removal of oxygen from a gas stream.
Pyrithione can be prepared in a two-step synthesis from 2-bromopyridine by oxidation to the N-oxide with a suitable peracid followed by substitution using Vatrolite to introduce the thiol functional group.

Photography:
Vatrolite is used in Kodak fogging developer, FD-70. 
This is used in the second step in processing black and white positive images, for making slides. 
Vatrolite is part of the Kodak Direct Positive Film Developing Outfit.

Preparation of Vatrolite:
Vatrolite is produced industrially by reduction of sulfur dioxide. 
Approximately 300,000 tons were produced in 1990.

The route using zinc powder is a two-step process:
2 SO2 + Zn → ZnS2O4
ZnS2O4 + 2 NaOH → Na2S2O4 + Zn(OH)2

The sodium borohydride method obeys the following stoichiometry:
NaBH4 + 8 NaOH + 8 SO2 → 4 Na2S2O4 + NaBO2 + 6 H2O

Each equivalent of H− reduces two equivalents of sulfur dioxide. 
Formate has also been used as the reductant.

Structure of Vatrolite:
The structure has been examined by Raman spectroscopy and single-crystal X-ray diffraction. 
The dithionite dianion has C2 symmetry, with almost eclipsed with a 16° O-S-S-O torsional angle. 
In the dihydrated form (Na2S2O4·2H2O), the dithionite anion has gauche 56° O-S-S-O torsional angle.

A weak S-S bond is indicated by the S-S distance of 239 pm, which is elongated by ca. 30 pm relative to a typical S-S bond.
Because this bond is fragile, the dithionite anion dissociates in solution into the [SO2]− radicals, as has been confirmed by EPR spectroscopy. 
Vatrolite is also observed that 35S undergoes rapid exchange between S2O42− and SO2 in neutral or acidic solution, consistent with the weak S-S bond in the anion.

Properties and Reactions of Vatrolite:

Hydrolysis:
Vatrolite is stable when dry, but aqueous solutions deteriorate due to the following reaction:
2 S2O42− + H2O → S2O32− + 2 HSO3−

This behavior is consistent with the instability of dithionous acid. 
Thus, solutions of Vatrolite cannot be stored for a long period of time.

Anhydrous Vatrolite decomposes to sodium sulfate and sulfur dioxide above 90 °C in the air. 
In absence of air, Vatrolite decomposes quickly above 150 °C to sodium sulfite, sodium thiosulfate, sulfur dioxide and trace amount of sulfur.

Redox reactions of Vatrolite:
Vatrolite is a reducing agent. 
At pH 7, the potential is -0.66 V compared to the normal hydrogen electrode. 

Redox occurs with formation of bisulfite:
S2O42- + 2 H2O → 2 HSO3− + 2 e− + 2 H+

Vatrolite reacts with oxygen:
Na2S2O4 + O2 + H2O → NaHSO4 + NaHSO3

These reactions exhibit complex pH-dependent equilibria involving bisulfite, thiosulfate, and sulfur dioxide.

With organic carbonyls:
In the presence of aldehydes, Vatrolite reacts either to form α-hydroxy-sulfinates at room temperature or to reduce the aldehyde to the corresponding alcohol above a temperature of 85 °C.
Some ketones are also reduced under similar conditions.

Manufacturing Methods of Vatrolite:

Zinc dust process:
An aqueous slurry of zinc dust is treated in a stirred reactor with cooling at ca. 40 °C with liquid or gaseous sulfur dioxide to give zinc dithionite. 
After completion of the reaction the solution is passed through a filter press to remove unreacted zinc dust and impurities from the zinc. 

The zinc is then precipitated from the zinc dithionite by adding sodium carbonate or sodium hydroxide in stirred vessels. 
The zinc carbonate or hydroxide is removed in filter presses. 

Anhydrous Vatrolite is precipitated from the clarified Vatrolite solution by concentration under vacuum and addition of sodium chloride at > 60 °C. 
Vatrolite is filtered, washed with methanol, and dried at 90 - 100 °C. 

Besides the evaporation process the salting out process, which was more widely used previously, is still known. 
In this process the dithionite is obtained from the solution by the addition of sodium chloride and methanol.

Amalgam Process:
In the amalgam process, sodium hydrogensulfite is reduced to Vatrolite in aqueous solution in a cooled, stirred vessel using the sodium amalgam of a chloralkali electrolysis cell. 
The sodium-free mercury is returned to the electrolysis cell where Vatrolite is recharged with sodium. 

During reaction of the amalgam with the hydrogensulfite solution a pH of 5 - 6 must be maintained. 
Vatrolite is obtained by precipitation with salts or methanol or both.

Formate Process: 
Sodium formate, dissolved in 80% aqueous methanol, is charged to a stirred vessel. 
At a pressure of 2 - 3 bar sulfur dioxide and sodium hydroxide are introduced into this solution such that a pH of 4 - 5 is maintained.

Sodium Borohydride Process Sodium borohydride is stable in strong aqueous alkali and can be used in this form for the production of Vatrolite by adding SO2 and sodium hydroxide.

Handling and Storage of Vatrolite:
Vatrolite should be handled with care to avoid damage, as it is a fragile mineral with a vitreous texture.
When storing, keep specimens in a dry, stable environment, preferably in a padded container to prevent chipping or breakage.

Avoid exposure to excessive moisture, extreme temperatures, or direct sunlight, as these conditions could potentially alter Vatrolite's physical properties over time.
Store away from acids or reactive chemicals to prevent any unwanted interactions.

Stability and Reactivity of Vatrolite:
Vatrolite is generally stable under normal environmental conditions and does not readily decompose or react with most substances.
However, Vatrolite may be susceptible to slow alteration when exposed to highly acidic or strongly alkaline environments.
Vatrolite does not pose a significant reactivity hazard but should be kept away from aggressive chemical agents that could cause degradation.

First Aid Measures of Vatrolite:

Inhalation:
If vatrolite dust is inhaled due to grinding or cutting, move the person to fresh air.
Seek medical attention if breathing difficulties persist.

Skin Contact:
Wash hands with soap and water after handling to remove any fine dust.
No known skin irritation risks.

Eye Contact:
If dust or small particles enter the eyes, rinse immediately with plenty of water for several minutes.
Seek medical attention if irritation persists.

Ingestion:
Although non-toxic, ingestion of small particles should be avoided.
If swallowed, rinse the mouth with water and seek medical advice if discomfort occurs.

Firefighting Measures of Vatrolite:
Vatrolite itself is non-combustible and does not contribute to fire hazards.
However, if stored with combustible materials, standard fire extinguishing methods such as water, foam, dry chemical, or CO₂ may be used.
Firefighters should wear protective gear and respiratory protection if mineral dust is present in the air.

Accidental Release Measures of Vatrolite:
If vatrolite specimens or dust are accidentally released, use protective gloves to collect larger fragments carefully and place them in a secure container.
For small particles or dust, use a damp cloth or vacuum with a HEPA filter to prevent airborne dispersion.

Avoid sweeping dry dust to minimize inhalation risk.
Dispose of collected material in accordance with local waste disposal regulations.

Exposure Controls/Personal Protection of Vatrolite:

Engineering Controls:
If working with vatrolite in powdered or fragmented form, use adequate ventilation to minimize dust exposure.

Personal Protective Equipment (PPE):

Respiratory Protection:
If dust is generated, use an N95 or equivalent dust mask.

Eye Protection:
Safety glasses or goggles should be worn when handling fine particles.

Skin Protection:
Gloves should be worn if prolonged handling is required, though no known skin hazards exist.

Hygiene Measures: 
Wash hands thoroughly after handling, especially before eating or drinking.
Avoid inhaling dust or ingesting particles.

Identifiers of Vatrolite:
CAS Number: 7775-14-6
ChEBI: CHEBI:66870
ChemSpider: 22897
ECHA InfoCard: 100.028.991
EC Number: 231-890-0
PubChem CID: 24489
RTECS number: JP2100000
UNII: 2K5B8F6ES1
UN number: 1384
CompTox Dashboard (EPA): DTXSID9029697
InChI: InChI=1S/2Na.H2O4S2/c;;1-5(2)6(3)4/h;;(H,1,2)(H,3,4)/q2*+1;/p-2
Key: JVBXVOWTABLYPX-UHFFFAOYSA-L
SMILES: [O-]S(=O)S(=O)[O-].[Na+].[Na+]

Linear Formula: Na2S2O4
MDL Number: MFCD00011640
EC No.: 231-890-0
Beilstein/Reaxys No.: N/A
Pubchem CID: 24489
IUPAC Name: N/A
SMILES: [O-]S(=O)S(=O)[O-].[Na+].[Na+]
InchI Identifier: InChI=1S/2Na.H2O4S2/c;;1-5(2)6(3)4/h;;(H,1,2)(H,3,4)/q2*+1;/p-2
InchI Key: JVBXVOWTABLYPX-UHFFFAOYSA-L

CAS number: 7775-14-6
EC index number: 016-028-00-1
EC number: 231-890-0
Hill Formula: Na₂O₄S₂
Chemical formula: Na₂S₂O₄
Molar Mass: 174.11 g/mol
HS Code: 2831 10 00
Quality Level: MQ200

CAS: 7775-14-6
Molecular Formula: Na2O4S2
Molecular Weight (g/mol): 174.096
MDL Number: 11640
InChI Key: JVBXVOWTABLYPX-UHFFFAOYSA-L
PubChem CID: 24489
ChEBI: CHEBI:66870
SMILES: [O-]S(=O)S(=O)[O-].[Na+].[Na+]

Properties of Vatrolite:
Chemical formula: Na2S2O4
Molar mass: 174.107 g/mol (anhydrous)
210.146 g/mol (dihydrate)
Appearance: white to grayish crystalline powder
light-lemon colored flakes
Odor: faint sulfur odor
Density: 2.38 g/cm3 (anhydrous)
1.58 g/cm3 (dihydrate)
Melting point: 52 °C (126 °F; 325 K)
Boiling point: Decomposes
Solubility in water: 18.2 g/100 mL (anhydrous, 20 °C)
21.9 g/100 mL (Dihydrate, 20 °C)
Solubility: slightly soluble in alcohol

Density: 2.5 g/cm3 (20 °C)
Flash point: >100 °C
Ignition temperature: >200 °C
Melting Point: 100 °C (decomposition)
pH value: 5.5 - 8.5 (50 g/l, H₂O, 20 °C)
Bulk density: 1250 kg/m3
Solubility: 250 g/l (slow decomposition)

Compound Formula: Na2O4S2
Molecular Weight: 174.107
Appearance: White crystalline powder
Melting Point: 52 °C
Boiling Point: Decomposes
Density: 2.8 g/cm3
Solubility in H2O: 18.2 g/100 mL (20 °C)
Exact Mass: 173.903339
Monoisotopic Mass: 173.903339

Molecular Weight: 174.11 g/mol
Hydrogen Bond Donor Count: 0
Hydrogen Bond Acceptor Count: 6
Rotatable Bond Count: 0
Exact Mass: 173.90333939 g/mol
Monoisotopic Mass: 173.90333939 g/mol
Topological Polar Surface Area: 119Ų
Heavy Atom Count: 8
Complexity: 60.5
Isotope Atom Count: 0
Defined Atom Stereocenter Count: 0
Undefined Atom Stereocenter Count: 0
Defined Bond Stereocenter Count: 0
Undefined Bond Stereocenter Count: 0
Covalently-Bonded Unit Count: 3
Compound Is Canonicalized: Yes

Specifications of Vatrolite:
Assay (iodometric): ≥ 85.0 %
Identity: passes test
Chloride (Cl): ≤ 0.05 %
Fe (Iron): ≤ 0.005 %

Melting Point: 300°C
Color: White
pH: 8 to 9.5
Physical Form: Powder/Solid
Quantity: 500 g
Formula Weight: 174.1g/mol
Packaging: Plastic powder jar

Related compounds of Vatrolite:
Sodium thiosulfate
Sodium bisulfite
Sodium metabisulfite
Sodium bisulfate

Other anions:
Sodium sulfite
Sodium sulfate