SODIUM HYDROSULPHITEBy:Imran Anwar

06-NTU-112

Imrananwar_112ntu@yahoo.com

NATIONAL TEXTILE UNIVERSITY

FAISALABAD

PAKISTAN

Sodium Hydrosulfite

Sodium hydrosulfite is a very effective reducing agent,comes in solid white crystalline powder form.Designed for flexible volume usage, solid sodium hydrosulfite can be transported easily and stored for an extended period of time. It has wide applications in various industries, including textile, pulp and paper, Kaolin clay, and water treatment. These are known for accurate compositions, eco friendliness and safe to use features.[1]

Manufacturing process From Zinc ,Sulphur Dioxide and Soda Ash Sodium hydrosulphite is manufactured by

reacting zinc dust with sulphur dioxide and treting the resultant zinc hydrosulphite with soda ash to convert it into sodium hydrosulphite.[2]

Raw material requirement Basis 1 ton sodium hydrosulphite

Zinc dust 425 kg

Soda ash 725 kg

Sulphur dioxide 770 kg

Sodium chloride 1050 kg

Manufacturing process Process is divided in two steps :manufacture of zinc hydrosulphite

and conversion into sodium hydrosulite.Charge high purity zinc dust into a lead lined vessel provided with

stirring and cooling arrangement. Add water to make suspension of zinc in water.bubble sulphur dioxide through the bottom of the vessel initially at rapid rate and slowly the rate near saturation at 25 to 30 c.

In Japan it is manufactured from sodium sulphate.In this process the manufacture of sodium hydrosulphite is carried out by the reaction of sulphur dioxide with alkialine sodium formate under controlled conditions.

 Reaction :Zn +so2 +h2o =zns2o4Zns2o4+na2co3=znco3+na2s2o4

Flexible yet safe

Sodium hydrosulfite is highly stable if stored and kept carefully. Our solid hydrosulfite has a shelf life of over 12 months. We provide a wide variety of packaging, 50KG drums, 100KG, 200KG to 1,800MT Intermediate Bulk Containers (IBC). We give you the option to choose the most appropriate packaging to minimize package handling and air exposure. All our solid hydrosulfite comes with inner liners as an extra precaution against moisture and water

Innovative bulk packagingDesigned for volume usersSafety - Unique inner liners prevent moisture

and waterConvenience - Designed for easy mechanical

operation by forkliftDust free and odorless - The liners trap all

powder and odor when the bag is emptiedNo packaging material handling - All packaging

materials, include drums and liners, can be returned to us.

 

Specifications and propertiesChemical formula: Na2S2O4

Appearance:  white granular powder

Bulk density:  0.9 to 1.1

Melting point: decomposed at 52 c

Solubility: decompose in water (hot) slightly soluble in cold water insoluble in acids.

 Common ApplicationsSodium hydrosulfite is commonly used in the

pulp and paper industry for bleaching brightening and de-colorization of virgin and recycled fiber. It is also applied extensively to brighten Kaolin clay. In textiles, the primary usage is in processing vat dyes and indigo dyes. Other applications include water treatment, leather processing and food bleaching (sugar, honey and gelatin). As a reducing agent ,it is used in organic synthesizing . 

HazardsSolid sodium hydrosulfite is highly stable when

stored in dry closed containers. However, solid sodium hydrosulfite is a very reactive chemical which can decompose when exposed to air and moisture or in contact with small amount of water. Decomposition will result in spontaneous ignition and liberation of toxic SO2. The chemical reacts violently with oxidants and will explode or combust.

Potential Health EffectsInhalation:

Inhalation can cause severe irritation of mucous membranes and upper respiratory tract. Symptoms may include burning sensation, coughing, wheezing, laryngitis, shortness of breath, headache, nausea and vomiting. High concentrations may cause lung damage. Higher exposures can cause a build-up of fluid in the lungs (pulmonary edema), a medical emergency.

Ingestion:May cause abdominal pain, nausea, vomiting, colic and diarrhea, circulatory disturbances, central nervous system depression, irritability, restlessness, convulsions, cyanosis, respiratory and cardiovascular collapse, and death. Estimated lethal dose 30 grams.

Potential Health EffectsSkin Contact:

Can irritate the skin causing a rash or burning feeling on contact. High concentrations could cause burns.

Eye Contact:Causes irritation, redness, and pain. May cause burns and possible damage to vision.

Chronic Exposure:Exposure may induce allergic reaction.

Aggravation of Pre-existing Conditions:Persons allergic to "sulfiting" agents, used to preserve some foods, may be more susceptible to the effects of this substance.

First Aid MeasuresInhalation:

Remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention.

Ingestion:Induce vomiting immediately as directed by medical personnel. Never give anything by mouth to an unconscious person. Get medical attention.

Skin Contact:Wipe off excess material from skin then immediately flush skin with plenty of water for at least 15 minutes. Remove contaminated clothing and shoes. Get medical attention. Wash clothing before reuse. Thoroughly clean shoes before reuse.

Eye Contact:Immediately flush eyes with plenty of water for at least 15 minutes, lifting lower and upper eyelids occasionally. Get medical attention immediately.

Accidental Release MeasuresRemove all sources of ignition. Ventilate area of leak or spill. Wear appropriate personal protective equipment as specified in Section 8. Spills: Clean up spills in a manner that does not disperse dust into the air. Use non-sparking tools and equipment. Reduce airborne dust and prevent scattering by moistening with water. Pick up spill for recovery or disposal and place in a closed container.

Stability and ReactivityStability:

Stable when stored in closed containers at room temperature. Heats spontaneously in contact with moisture and air. Loses all of its water of crystallization at 110C. Decomposes in hot water and acid.

Hazardous Decomposition Products:Burning may produce sulfur oxides.

Hazardous Polymerization:Will not occur.

Stability and ReactivityIncompatibilities:Water, combustible materials, strong oxidizing agents, strong acids and sodium chlorite. An explosion occurred after mixing sodium hydrosulfite, aluminum powder, potassium carbonate and benzaldehyde.

Conditions to Avoid:Moisture, humidity, heat, flame, ignition sources and incompatibles. 

Storage and handlingSodium hydrosulphite must be always handled and stored in sealed clean iron drums or bulk containers. Avoid contacts with moisture, acids, oxidizing chemicals and combustible organic substances. Protect it from heat, direct sunlight, sparks and naked flames. Avoid damaging the packaging.In the event of fire, use large quantities of water to extinguish the product. Other extinguishing media may not stop decomposition thoroughly

Stability and ReactivityDisposal ConsiderationsWhatever cannot be saved for recovery or recycling should be handled as hazardous waste and sent to a RCRA approved waste facility. Processing, use or contamination of this product may change the waste management options. State and local disposal regulations may differ from federal disposal regulations. Dispose of container and unused contents in accordance with federal, state and local requirements.

SpillageSweep up immediately all spillage of sodium hydrosulfite around the application and storage areas.Deposit it in a dry and clean container where it can be dissolved in water.Wash the area invovlved with water .If the product is suspected to already absorbed moisture.use it as soon as possible (if it is impossible to use it immediately,you need to dispose it.)  　

 

Thanks to Almighty ALLAH