Dear Sir: We are Boya (Tianjin) International Ltd, which is mainly dealing in the impport and export of chemical series, including : Sodium Sulphide Calcium Carbide Ammonium Chloride Humic Acid Barium chloride Dicyandiamide Barium Sulfate Oxalic Acid Sodium Hydroxide Sodium Hydrosulfide Chromium Sulphate Sodium metabisulfite Sodium thiosulfate We have our own manufacture base, and only co-operate with state-owned enterprises and famous fact... ...[More..]