Carbohydrate oxidation starch, glucose, dextrin and molasses with nitric acid at 73 ~ 80 ℃ oxidation in oxalic acid. Starch, for example, a purity of 85% (by mass) of the starch is dispersed in an aqueous solution containing oxalic acid 10% (by mass) of the mother liquor or other intermediate products, heating acid reflux 6h, oxalic acid manufacturers offer to obtain an intermediate product glucose, and then added at 63 ℃ in nitrate and iron - vanadium catalyst, further hydrolyzed, after completion of the reaction that was refined oxalic acid, a yield of about 63% to 65%. This method is currently only United Chemical Company is still in use. Oxidation of ethylene glycol 70s Mitsubishi Gas Chemical Company developed. Oxidized starch oxidation process is very similar, first concentrated glycol solution is heated to 60 ℃, then added with vigorous stirring in nitric acid (or a mixture of nitric acid and sulfuric acid), oxalic acid manufacturers in the 57 ~ 60 ℃, atmospheric pressure or under pressure to react. When the conversion to 80% to 85%, then warming to 77 ℃ to oxidation, each batch of a total reaction time of about 10 ~ 12h. Product by cooling and crystallization, filtration to obtain 99.9% of the oxalic acid, the yield of over 90%. 1kg glycol consumption of nitric acid (100% count) 2.6kg. Oxalic acid factory outlets | Jie Yu Chemical (Online) | oxalic acid factory by Guangzhou-yu Chemical Co. Jie Yu Guangzhou Chemical Co., Ltd. (shop1370240243690.1688.com) is Guangzhou, chemical products leader, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. In Jie Yu Chemical leadership with the staff warmly welcome all inquiries negotiations to create Jie Yu Chemical better future.