Method for combined processing of phosphogypsum and phosphate reverse flotation tailings

Abstract

The invention discloses a method for combined processing of phosphogypsum and phosphate rock reverse flotation tailings. It first thermally decomposes the phosphate rock reverse flotation tailings to collect carbon dioxide in the gas phase, then hydrates the obtained powder, and then After hydration, the slurry is graded. The material with a large specific gravity is phosphorus mineral raw material, and the material with a small specific gravity is carbonized with carbon dioxide, then clarified and separated from solid and liquid. The solid material is calcium carbonate, and the liquid material is heavy magnesium water. After the gypsum is pretreated, it is added to the heavy magnesium water for double decomposition reaction, and the resulting carbon dioxide tower is returned to the carbonization tower, and the solid-liquid mixture is separated from the solid-liquid. The solid material is calcium carbonate, and the liquid material is magnesium sulfate solution. The resulting magnesium sulfate solution is recycled into the The carbonization tower is cyclically carbonized until the magnesium sulfate solution is saturated, and then crystallized to obtain magnesium sulfate heptahydrate crystals. The invention effectively connects the resources of two kinds of industrial wastes together, fully utilizes the high value-added elements in tailings and phosphogypsum, and realizes the autonomous recycling of resources.

Description

technical field [0001] The invention relates to flotation, in particular to a combined processing method for reverse flotation tailings of phosphogypsum and phosphate rock. Background technique [0002] Phosphogypsum is a kind of solid waste produced in the production process of wet-process phosphoric acid. At present, the annual discharge of phosphogypsum in the world is more than 150 million tons, and the domestic annual discharge of phosphogypsum is close to 50 million tons. The stockpiling of phosphogypsum not only occupies a large amount of land, but also pollutes the surface (underground) water body, soil, vegetation, and atmospheric environment. With the increase in the output of high-concentration phosphorus compound fertilizers, the discharge of phosphogypsum in my country has increased significantly, and the pressure on environmental protection has increased. For this reason, domestic and foreign research institutes and phosphate compound fertilizer enterprises h...

AI Technical Summary

Problems solved by technology

At present, there are many plans for the utilization of phosphate rock reverse flotation tailings, such as road cushion, road subbase and drainage pipe trench backfill, production of glass-ceramics, cement production, production of phosphorus and magnesium fertilizers and magnesium salts, etc. Among them, the reverse flotation tailings of phosphate rock to produce magnesium salt is a relatively promising method, but there are certain economic problems at present, which limit the promotion of the project

[0005] Although there are many applications and researches on phosphogypsum and phosphate rock reverse flotation tailings in phosphate rock enterprises, the technical scheme of combining the two solid wastes for processing has not been reported yet

Images