Method for preparing calcium sulfate whisker through recrystallization

Abstract

The invention discloses a method for preparing a calcium sulfate whisker through recrystallization. The method is characterized in that the method comprises the steps of (1), conducting program control on heating and dissolution courses: putting a raw material with a main ingredient of calcium sulfate into a sulphuric acid solution for stirring, heating simultaneously, heating a mixture to 60-95 DEG C at a certain rate with the adoption of the program control, dissolving for 20min-1h, (2), conducting the program control on cooling and recrystallization courses: using the program control to cool a suspension obtained by dissolution to 10-30 DEG C, ageing for 20min-2h, (3), conducting separating and washing courses: conducting solid-liquid separation on the suspension, washing a separated solid-phase product, and (4), conducting a drying course: drying the washed solid-phase product at a certain temperature, and obtaining the calcium sulphate dihydrate whisker. The calcium sulfate whisker is prepared by utilizing a recrystallization principle under an ordinary-pressure mild condition, and a relatively economical technological approach can be provided for the resource utilization of industrial by-products such as desulfurization gypsum and phosphogypsum.

Description

technical field [0001] The invention belongs to the technical field of preparation of calcium sulfate inorganic mineral whiskers, and specifically relates to the preparation of calcium sulfate whiskers by using the principle of recrystallization under normal pressure and mild conditions, which can be used for resource utilization of industrial by-products such as desulfurized gypsum and phosphogypsum Provide a more economical technical approach. Background technique [0002] Calcium sulfate whisker refers to a whisker-like single crystal that grows in the form of a single crystal under certain conditions and is similar to a short fiber (diameter is generally between 0.01~10μm, and the aspect ratio is 5~1000). It is an environmentally friendly inorganic material. It has important uses in the fields of construction, medicine, plastics, rubber and environmental protection, and is currently used as a reinforcing component of composite materials. The disclosed main methods for p...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to provide a simple and efficient method for preparing recrystallized calcium sulfate whiskers, aiming at the problems of high temperature and high pressure conditions in the existing calcium sulfate whisker preparation technology, high cost, and complicated regulation and control that lead to industrial application difficulties. Introduce as few interfering substances and simplify the control factors as possible in the system, and use the principle of dissolution-recrystallization to prepare calcium sulfate whiskers. Under normal pressure, choose sulfuric acid solution commonly used in industry as the reaction medium. The concentration of sulfuric acid solution changes with temperature, and the temperature change and regulation are used to realize the dissolution-recrystallization process, and grow into whisker-like calcium sulfate dihydrate whiskers, which can be further processed into hemihydrate and anhydrous calcium sulfate whiskers.

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