Overview[1]
Potassium tetrahydroxalate, whose chemical name is also called potassium trihydrogen oxalate, potassium trihydrogen oxalate, and potassium tetrahydroxalate; its English name is potassiumtrihydrogendioxalatedehydrate or potassiumtetraoxalate; its molecular formula is KH3(C2O4)2·2H2O or C4H3KO8· 2H2O. The pure product is colorless crystal or white powder. When heated to 100°C, it loses water and becomes anhydrous. At higher temperatures, it decomposes into potassium carbonate and carbon monoxide. It is soluble in water and slightly soluble in alcohol. The current market price of domestic analytically pure potassium tetraoxalate is 120 to 150 yuan/Kg. The market price of imported high-grade pure potassium tetraoxalate is 1568-1850 yuan/Kg.
The current preparation of potassium tetraoxalate is produced by chemical reaction of excess oxalic acid with potassium salts such as potassium carbonate or potassium chloride. The chemical reaction produces potassium tetraoxalate, and its by-products hydrochloric acid and oxalic acid bring pollution to the environment; excessive oxalic acid increases environmental hazards; using potassium carbonate and potassium chloride as reaction substrates, while producing potassium carbonate and potassium chloride, it also pollutes the environment. It causes secondary pollution and makes the production cost of potassium tetraoxalate high. However, the use of microorganisms to produce potassium tetraoxalate has not yet been reported.
Apply[1]
Potassium tetraoxalate has a wide range of uses in industry. It is a tanning, fabric finishing agent, mordant, metal polishing, anti-rust treatment agent, organic chemical raw material, catalyst, benchmark substance and analytical reagent for chemical analysis, and is also used for the preparation of photosensitive materials.
For example, high-temperature sensitization is used to prepare emulsion explosives. The method includes the following steps: water phase preparation, oil phase preparation, emulsification, sensitization, charging and cooling. The raw materials used are as follows: ammonium nitrate, sodium nitrate, urea, water , composite oil phase, emulsifier, foaming agent and accelerator; the accelerator is potassium hydrogen phthalate buffer solution with pH value 5.5 or potassium dihydrogen phosphate buffer solution with pH value 4.5 or potassium tartrate buffer solution with pH value 3.5 solution or potassium tetraoxalate buffer solution with a pH value of 1.0, etc.; sensitization operation: mix the accelerator and foaming agent evenly and add them to the latex matrix with a temperature of 85°C to 110°C, mix evenly, and sensitize for 0.5 to 10 minutes . The invention has the advantages of wide sources of accelerator raw materials, low cost and non-toxicity, can improve the pH value of explosives and improve the performance of explosives; the sensitization method is simple, fast and has no after-effects, simplifies the production process, saves costs and reduces energy consumption.
Preparation[2]
A method for fermenting Aspergillus niger to produce potassium tetraoxalate, which method includes the following steps:
a. Isolation and purification of Aspergillus niger: Select the stem segments of Huperzia frugata plants and rinse them with running water for 2-3 hours → Disinfect with 75% alcohol for 1-2 min → 0.01mol/L hydrochloric acid, 5% sodium hypochlorite, 2.4mmol/ Rinse once with L citric acid → Disinfect with 5% sodium hypochlorite for 10 to 12 minutes → Rinse with sterile water 3-5 times → Disinfect with 10% hydrogen peroxide for 8-12 min → Rinse with sterile water 4 to 5 times → Drain surface water on sterile absorbent paper →Inoculate on PDA plate →Isolate and purify Aspergillus niger.
b. Liquid fermentation culture of Aspergillus niger: Add 5 to 25g of sucrose to each liter of PDA liquid culture medium, adjust the pH value to 4.7 to 6.4, and inoculate Aspergillus niger spores under aseptic conditions. The amount of Aspergillus niger spores added is 1 Add 1% (volume) Aspergillus niger spores to 1 liter of PDA culture medium. The spore concentration is 1×104~106cfu/mL. The culture temperature is 30~40°C. The rotation speed is 120~150 rpm. The air ventilation volume is the total volume of the culture medium. That is, 30% of the total inoculum amount of PDA culture medium, sucrose and Aspergillus niger spores, fermented at a constant temperature for 72-100 hours, filtered mycelium, concentrated the fermentation liquid to 1/20 to 1/15 of the total volume of the culture medium, and precipitated crystals. Wash with ultrapure water 4 to 5 times and dry at 40 to 50°C to obtain potassium tetraoxalate product.
Main reference materials
[1] Dictionary of Chemical Substances
[2] CN200810030776.2 Method for producing potassium tetraoxalate by Aspergillus niger fermentation
[3] CN201410557053.3 Method for preparing emulsion explosives by high temperature sensitization
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