CAS number: 7681-57-4

Water Solubility: 540 g/L(20 °C)

PH value: 3.5-5 (50g/l, H20, 20°℃)

Odor: Sulphorous

Specific Gravity: 1.48

Melting Point: >300°C(572 ℉)

Density: 1.48g/cm3

Storage Conditions: Store at +5'℃ to +30°C

Solubility: 540 g/L(20°C)

Morphology: Crystal powder or small crystals

Color: White to slightly yellow

Applications 

Sodium Metabisulfite has various uses and applications across different industries.

Food: It is commonly used as a food preservative, antioxidant, and flavor enhancer. In the food industry, it acts as a preservative to prevent the growth of bacteria and fungi, extending the shelf life of food products. It is also used in the production of wines and beers to inhibit the growth of unwanted microorganisms and to control oxidation.

Textile: Sodium Metabisulfite is utilized in the textile industry for dyeing and printing processes, as well as in water treatment to remove excess chlorine.

Metal beneficiation: Sodium metabisulfite is widely used in metal beneficiation, especially in the flotation process of copper, lead and zinc. As a flotation agent, it is able to react with organic matter and iron impurities in ore, thereby improving the flotation effect of metal minerals.

Tin removal process: sodium metabisulfite is also widely used in the beneficiation process of tin ore. In tin flotation, sodium metabisulfite is used as a reducing agent to reduce iron, iron-tin and other metal salts in cassiterite to reduce the interference of tin flotation process.

Reduce the oxidation of ore: sodium metabisulfite can also be used to reduce the oxidation degree of ore. In some beneficiation processes, sodium metabisulfite can react with oxides in oxidizing minerals to reduce them to substances in a lower oxidizing state, thereby improving the efficiency and yield of the beneficiation process.

Inhibition of polar minerals: Sodium metabisulfite can be used to inhibit flotation of polar minerals. It can bind to the active center in polar minerals and reduce its adsorption to flotation agents, thereby reducing the interference of mixing polar minerals and non-polar minerals in the beneficiation process.

It is also employed in the production of pharmaceuticals, cosmetics, and as a reducing agent in chemical processes.

Production Method

The crushed sulfur is sent to the combustion furnace, and the compressed air of about 2 times the theoretical amount is artificially generated, and spontaneously ignited at 600~800°C. After cooling, dust removal and water washing, it is sent to a multi-stage  reactor for  reverse absorption with sodium carbonate solution; The temperature of the absorption liquid is controlled at about 45°C, and the crystal slurry flowing out of the multi-stage reaction is separated by centrifugal, and dried below 160°C is a finished product.

The absorption method uses soda ash solution to absorb sulfur dioxide, and after separation and drying, sodium metabisulfite is prepared.

S+O2→SO2

Na2CO3+2SO2+H2O→2NaHSO3+CO2

2NaHSO3→Na2S2O5+H2O

Sodium Metabisulfite Global Market Forcast

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Regarding to the forecast of the global market for sodium metabisulfite, the well-known market research company Industry Arc has given a forecast of the global market size of US$700 million in 2025, while another famous business research company Future Market Insights has given a forecast of US$266.5 million in 2028. The forecasted compound annual growth rates of the two professional survey institutions are 5.3% and 6.0% respectively. Although the numbers are somewhat different, it also predicts the vigorous development of the global market for sodium metabisulfite.

Sodium metabisulfite is divided into industrial grade food grade and pharmaceutical grade according to grade. According to the purpose, it can be used as food additive, water treatment, bleaching agent, dyeing agent and disinfectant, dechlorination agent, reducing agent and so on. According to the use, it can be used for food and beverage water and wastewater treatment, textile paper and pulp, leather, pharmaceutical, mining, glass manufacturing and so on. Sodium metabisulfite has a wide range of applications.

In the global paper industry, sodium metabisulfite is used as a bleaching and antichlor agent, which can be used to prevent yellowing of pulp. And increase pulp brightness. According to the market forecast of professional institutions, the demand for paper and pulp is growing steadily every year, and will exceed the annual output of 400 million tons in 2018. The global demand for paper and pulp, such as disposable paper napkins, diapers, etc., has boosted the market demand for sodium metabisulfite

The water treatment sector accounts for approximately 25% of the global market for sodium metabisulfite, which can be used to remove free chlorine and as a biostatic in water treatment plants. Surging demand for fresh water in emerging countries such as Africa is providing strong support to the market for sodium metabisulfite. According to the Organization for Economic Co-operation and Development, the global demand for fresh water will increase by 55% between 20 and 2050, which may stimulate a huge demand for collagen sodium sulfate

Food and beverages account for approximately 30% of the sodium metabisulfite market. Sodium metabisulfite is used as a preservative in dried foods and canned juices, and as an antioxidant in wine. According to the survey report of the Association for Packaging and Processing Technologies (PMMI, Association for Packaging and Processing Technologies), the beverage industry in North America is expected to grow by 4.5% between 2018 and 2028, of which non-alcoholic beverages are expected to grow by about 40%, and commercial wine in plastic containers is expected to grow by 100%, which will greatly stimulate the use of sodium metabisulfite.

Asia Pacific dominated the sodium metabisulfite market in 2019 with a global share of over 40%, followed by North America and Europe. Population growth coupled with rapid industrialization and rising incomes are driving the growth in demand for sodium metabisulfite in Asia Pacific. Sodium pyrosulfite is used as a bleaching agent and cleaning agent in the textile industry. With the increasing demand for clothing, it also stimulates the demand for sodium pyrosulfite in the textile and leather industries. Sodium metabisulfite is also used as a bleaching agent in the paper and pulp industry. With the growth of various industries, the use of sodium metabisulfite will increase.

In the mining sector, sodium metabisulfite is widely used in gold mining as a reducing agent that helps remove cyanide and extract pure gold. Other mining industries such as copper mines also need sodium metabisulfite as a beneficiation agent and flotation agent, and the growth of the global mining industry has promoted the demand for sodium metabisulfite. In addition, sodium metabisulfite, as an anti-chlorine agent in water treatment, needs to remove chlorine and heavy metals in water before the water is discharged into nature. With the stricter regulations on sewage treatment by governments of various countries, the market demand for sodium metabisulfite has also been increased.