6 results about "Iron cyanide" patented technology

The invention provides a process for removing cyanide from a cyanide-bearing aqueous fluid, the process comprising: (i) adding a solid composition comprising a first mixed-metal cyanide complex comprising copper and iron to a cyanide-bearing aqueous fluid comprising free cyanide and metal-complexed cyanide, wherein at least a portion of the first mixed-metal cyanide complex dissolves, with complexation of the copper by the free cyanide, to produce an aqueous solution comprising cyanometallates, the cyanometallates comprising copper cyanide and iron cyanide complexes derived from the first mixed-metal cyanide complex; (ii) contacting the aqueous solution with an anion-exchange absorbent to absorb the cyanometallates, thereby producing a cyanide-lean aqueous fluid; (iii) extracting the anion-exchange absorbent comprising the absorbed cyanometallates with at least one non-acidic aqueous extractant to produce an aqueous extract comprising the copper cyanide and iron cyanide complexes; and (iv) acidifying the aqueous extract to produce a precipitate comprising a second mixed-metal cyanide complex comprising copper and iron.

The invention belongs to the technical field of medicine synthesis, and discloses a preparation method of a sodium nitroprusside raw material medicine. According to the method, weak acid is adopted for catalysis, the effect of remarkably reducing generation of toxic substances such as cyanide and nitrogen dioxide is achieved by controlling the material dripping speed and the dripping pH, the reaction is mild, the technological operation is safe and controllable, and industrial production of the sodium nitroprusside raw material medicine is facilitated. According to the preparation method of some examples, silica gel filtration is used for post-treatment, the residual risk of impurities such as sodium ferricyanide, ferric ferrocyanide and ferric ferricyanide is reduced, and the purity of the raw material medicine is larger than or equal to 99.9% and is far superior to the requirements of pharmacopoeia of various countries.

This application provides a method for the electrocatalytic oxidation removal of medium-to-high concentration iron cyanide complexes, belonging to the field of ferric cyanide wastewater treatment. This application involves adding a chlorine-containing electrolysis promoter to wastewater containing medium-to-high concentrations of iron cyanide complexes to obtain a solution to be electrolyzed; using a platinum-titanium electrode or a ruthenium-iridium-titanium electrode as the anode and a foamed copper electrode as the cathode, the solution to be electrolyzed is subjected to electrocatalytic oxidation treatment; during the electrocatalytic oxidation process, a pH adjuster is used to maintain the pH of the liquid phase >10; after the electrocatalytic oxidation treatment is completed, solid-liquid separation is performed to obtain filter residue and filtrate. By selecting specific types of anodes and cathodes and adding a chlorine-containing electrolysis promoter, this application can promote the decomposition and transformation of iron cyanide complexes, ultimately converting cyanide into carbonate ions and nitrogen gas, achieving efficient removal of medium-to-high concentrations of iron cyanide complexes safely and environmentally.

This invention belongs to the field of pharmaceutical synthesis technology and discloses a method for preparing sodium nitroprusside raw material. The method employs weak acid catalysis and significantly reduces the generation of toxic substances such as cyanide and nitrogen dioxide by controlling the material dropping rate and pH. The reaction is mild, the process is safe and controllable, and it facilitates the industrial production of sodium nitroprusside raw material. In some examples of the preparation method, silica gel filtration is used in the post-processing to reduce the residual risk of impurities such as sodium ferrocyanide, ferrous ferrocyanide, and ferric ferric ferrocyanide. The purity of the raw material is ≥99.9%, far exceeding the requirements of pharmacopoeias of various countries.

This invention discloses a method for suppressing water migration in a zinc-iron flow battery by adjusting the volume ratio of the positive and negative electrolytes, belonging to the field of flow battery technology. The positive electrolyte of the zinc-iron flow battery is an alkaline solution of iron cyanide complex ions, and the negative electrolyte is an alkaline solution of zincate ions. The volume ratio of the positive to negative electrolyte is 0.5-5:1; preferably 1-4:1; more preferably 2-4:1. The alkalinity of both the positive and negative electrolytes is 0.05-5 mol / L. This invention can effectively suppress water migration during the operation of the zinc-iron flow battery, improve its lifespan, and reduce maintenance costs during battery operation.