186results about How to "Improve elution" patented technology

Disclosed herein are drug delivery devices and methods for the treatment of ocular disorders requiring targeted and controlled administration of a drug to an interior portion of the eye for reduction or prevention of symptoms of the disorder. The devices are capable of controlled release of one or more drugs and may also include structures which allows for treatment of increased intraocular pressure by permitting aqueous humor to flow out of the anterior chamber of the eye through the device.

The invention relates to an activation extraction separation method for fluorine and chloride ions in a zinc sulfate solution, which comprises the following steps: acid adjustment activation: adding concentrated sulfuric acid into the zinc sulfate solution to adjust the pH value and temperature, and mixing and blending the solution with an activating agent to damage the fluorine-containing metal complexes in the solution and decompose the fluorine-containing metal complexes into free-state fluorine ions and convert into HF molecules; extraction separation: separating the fluorine and chloride ions in the activated zinc sulfate solution by use of an extraction agent to obtain an organic phase loaded with fluorine and chloride and a raffinate with low content of fluorine and chloride; raffinate purification: removing most of the extraction organic phase through multi-segment standing clarification and ultrasonic air flotation; performing deep adsorption by use of powdery active carbon to remove residual organic phase in the raffinate to obtain adsorption residue and qualified raffinate; and impurity washing and back extraction of the loaded organic phase. According to the method provided by the invention, the key reason hindering the extraction fluorine removal effect in the zinc sulfate solution as well as the crystallization and scaling in the back extraction process is found so that the different problems are simple and easy to impellent. The fluorine removal rate exceeds 60%, and the chlorine removal rate reaches about 90%. The liquid after impurity washing and the liquid after back extraction directly return to an alkali washing process of a zinc hydrometallurgy system to be comprehensively utilized.