40results about How to "Alkaline concentration decreased" patented technology

The invention relates to a method for decomposing chromite by low-temperature atmospheric-pressure fluidization, which comprises the following steps: adding potassium hydroxide and an optionally added mixed water solution of potassium carbonate and / or potassium metaaluminate into a reactor, preheating, adding chromite and / or pretreated chromite, and introducing oxidizing gas to perform oxidizing reaction while heating; diluting the reaction slurry with a diluter to obtain a solution containing potassium chromate, potassium hydroxide, potassium carbonate, potassium metaaluminate and other water-soluble impurity components and an iron-rich tailing solid-liquid mixed slurry; and carrying out solid-liquid separation on the mixed slurry at 80-130 DEG C to obtain the iron-rich tailings and chromium-containing alkali liquor. The reaction temperature of the method is below the boiling point of the solution, and the process is performed under atmospheric pressure; and thus, the method has the advantages of low equipment cost, high safety and high chromium extraction yield (up to 95% above), and is easy to operate, and the operating temperature is much lower than the temperature of the traditional chromium extraction technique.

This method for producing a potassium perfluoroalkanesulfonate includes an electrochemical fluorination step in which an alkanesulfonyl halide compound is subjected to electrochemical fluorination in anhydrous hydrogen fluoride, thereby to generate a production gas containing perfluoroalkanesulfonyl fluoride as the main component. In addition, for example, the methods may include a gas absorption step in which the production gas is reacted with an aqueous solution of potassium hydroxide, thereby to generate a gas absorbed solution containing potassium perfluoroalkanesulfonate, a purification step in which impurities such as potassium fluoride, potassium hydroxide, and potassium sulfate, are removed, and a concentration and collection step in which the aqueous solution from which the impurities are removed is concentrated and dried. In the electrochemical fluorination, for example, it is possible that the proton concentration in the reaction solution is maintained in the range of 150 to 1,500 ppm to suppress the formation of byproducts.

The invention provides an electrochemical treatment method for arsenic-containing anode mud. The electrochemical treatment method comprises: (1) mixing an alkali and a solvent or mixing an alkali solution and arsenic-containing anode mud to obtain a mixture; (2) placing the mixture as an electrolyte in an electrochemical reaction device, carrying out an electrochemical reaction, and introducing anoxidizing gas into the electrolyte during the electrochemical reaction; and (3) carrying out solid-liquid separation on the reaction product obtained in the step (2) to obtain the arsenic-containingsolution. According to the present invention, the method has advantages of high extraction rate of arsenic, cleaning property, no pollution, mild process condition, low cost and low requirements on equipment; the impurity is not introduced so as to conveniently perform the subsequent separation; the concentration of the used alkali is low so as to reduce the alkali consumption; and the automationdegree is high so as to reduce the manpower input, the good economic and social benefits can be provided, and the good application prospect can be provided.

The invention provides a method for promoting poplar ethanol production by pretreatment of hydrothermal combined with NaOH aqueous solution. In the present invention, the poplar is first crushed, reacted with water at 180-200 DEG C for 5-30 minutes, the separated filter residue is mixed with NaOH aqueous solution, reacted at 80-120 DEG C for 30-120 minutes, and the pretreatment residue is obtained by separation, Then add cellulase, yeast activation solution and nutrient solution for saccharification and fermentation. The method adopts the combination of two stages of pretreatment of hydrothermal and NaOH aqueous solution to reduce the influence of lignin on the enzymatic hydrolysis and fermentation process, and under the premise of reducing the alkali concentration, it can also effectively promote the production of ethanol from poplar, and the ethanol yield is as high as 50.91%.