≥98% Sodium thiosulfate is a commonly used chemical material, as the fixing agent in photography, film and printing plate-making industry, as a reducing agent used in tanning. It is used as a bleaching agent for removing residual and a mordant in the paper and textile industries, as antidotes of cyanide poisoning in medicine, as dechlorination agent and fungicides of drinking water and wastewater in water treatment, as a copper corrosion inhibitor of circulating cooling water and a deoxidizer of boiler water systems. It is also used for Cyanide wastewater treatment. Soda ash and sulfur are generally used as raw materials in industry, soda ash reacts with sulfur dioxide produced by the combustion of sulfur to produce sodium sulfite, then add sulfur for boiling reactions, and then filter, bleach, concentrate and crystallize, etc, can obtain sodium thiosulfate pentahydrate. Other production waste containing sodium sulfide, sodium sulfite, sulfur and sodium hydroxide can also be used, after appropriate treatment to get the product.