Method for preparing gypsum whisker by using phosphate tailings and raffinate phosphoric acid

Abstract

The invention discloses a method for preparing gypsum whisker by using phosphate tailings and raffinate phosphoric acid. A technical scheme adopted in the invention is characterized in that the method comprises the following steps: taking a certain amount tailing powder with a certain particle size, adding a certain amount of distilled water to prepare a tailing slurry with a certain solid content, gradually adding raffinate phosphoric acid, reacting under certain conditions, filtering after the reaction, gradually adding a certain concentration of sulfuric acid into the obtained filtrate, reacting for a certain time, filtering, washing the obtained filter cake, and drying the washed filter cake in a drying box to obtain the gypsum whisker. The gypsum whisker is prepared through a two-step technology by using the raffinate phosphoric acid, the phosphate tailings and other phosphorus chemical industry enterprise waste resources as raw materials, and the growth form of the crystals of the gypsum whisker is controlled in the formation process of the phosphate crystals, so compared with traditional gypsum whisker preparation technologies, the method has the advantages of production cost reduction, solving of the environmental protection problem of the phosphorous chemical enterprises to a certain extent, and full use of magnesium resources in the raffinate phosphoric acid and the tailings.

Description

technical field

[0001] The invention belongs to the field of phosphorus chemical manufacturing, and in particular relates to a preparation process of calcium sulfate whiskers. technical background

[0002] CaSO 4 Whiskers, also known as gypsum whiskers, are CaSO 4 Fibrous single crystal, like gypsum, has anhydrous, semi-hydrated and dihydrated points. Gypsum whiskers can enhance polymer mechanical properties, heat resistance and many other properties, and are widely used in aviation, aerospace and many civil industries. Moreover, the use of gypsum whiskers as a reinforcing material has the advantages of stable size, high strength, good toughness, high temperature resistance, chemical corrosion resistance, easy surface treatment, and strong affinity for polymers such as rubber and plastics. Medium-strength reinforcing agents can be used. Added to plastic rubber, it can improve the tensile strength, bending strength, elastic modulus and thermal deformation temperature of th...